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Sample records for central mexico metallogenic

  1. Epigenetic Mineralisation in Central Namibia: a metallogenic study

    International Nuclear Information System (INIS)

    Epigenetic gold, rare earth, tungsten and tin mineralisation has been investigated as part of a regional metallogenic study in the Omaruru -Usakos area, Central Namibia. The study has focused on the Nosib and Swakop Group metasediments, Damaran intrusions and associated alteration and mineralisation in the Northern Central Zone of the Damara Orogen. 1 fig., 1 ref

  2. Transitional adakite-like to calc-alkaline magmas in a continental extensional setting at La Paz Au-Cu skarn deposits, Mesa Central, Mexico: metallogenic implications

    OpenAIRE

    Porfirio J. Pinto Linares; Gilles Levresse; Jordi Tritlla; Víctor A. Valencia; José M. Torres Aguilera; Manuel González; David Estrada

    2008-01-01

    The granodiorite intrusions with associated Cu-Au skarn mineralization of La Paz district are located in the east part of the Mesa Central of Mexico. The skarn developed at the contact between a middle Cretaceous calc-argillaceous sedimentary sequence and the magmatic intrusions. A Ag-Pb-Zn vein system postdates the intrusive-skarn assemblage. Two well defined fault systems (N-S and E-W) divide the La Paz district. The N-S Dolores fault, with a normal vertical displacement estimated between 5...

  3. ALPINE MAGMATIC-METALLOGENIC FORMATIONS OF THE NORTHWESTERN AND CENTRAL DINARIDES

    Directory of Open Access Journals (Sweden)

    Jakob Pamić

    1997-12-01

    Full Text Available In the paper are presented basic geological, petrologieca1, geochemi-cal and mineral deposit data for five main magmatic-metallogenic formations of the northwestern and central Dinarides: (lThe Permo Triassic rifting related andesite-diorite formations; (2 The Jurassic-Lower Cretaceous accretionary (ophiolite formations; (3 The Upper Cretaceous-Paleogene subduction related basalt-rhyohite formations; (4 The Paleogene collisional granite formations, and (5 The Oligo-cene-Neogene postsubduction andesite formations. All these magmatic-metallogenic formations originated in different geotectonic settings during the Alpine evolution of the Dinaridic parts of thc Tethys and the postorogenic evolution of the Paratethys and the Pannonian Basin, respectively.

  4. Urban Governance and Participation in Central Mexico

    OpenAIRE

    Valeria Guarneros-Meza

    2007-01-01

    Valeria Guarneros-Meza looks at national aspects that characterize Mexico's democratization and decentralization processes, and their impact upon the central region of Mexico. Based on the region's social characteristics, she discusses the concept of ‘urban governance’ in terms of its ambiguity, which promotes municipal systems of participation at the same time as it fragments their internal organization. Development (2007) 50, 104–109. doi:10.1057/palgrave.development.1100340

  5. An air quality model for Central Mexico

    International Nuclear Information System (INIS)

    A computational air quality model for Central Mexico that includes the Basin of the Valley of Mexico, the Valleys of Toluca, Puebla and Cuernavaca already in experimental operation, is presented. The meteorology of the region is obtained combining two non-hydrostatic models: a model designed for synoptic scales called MM5 provides initial and boundary data to a model specially designed for urban environments and scales called MEMO. The transport model used numerical techniques developed by the authors that eliminate numerical diffusion and dispersion. For the photochemical model several ODE's integrators were tested. The emissions model developed uses the latest inventory data gathered in the region. (Author)

  6. Metallogenic regularities and models of Longshoushan uranium metallogenic belt

    International Nuclear Information System (INIS)

    In Longshoushan metallogenic zone two important uranium metallogenic series have been identified: the metallogenic series of multistage, multi source and poly genesis related with the migmatization and magmatism in Zhongtiao period; and the metallogenic series related with the evolution of the granite magma in late Caledonian period. During the former period uranium deposits of the pegmatoidal alas kite type occurred. During the latter one uranium deposits of the sodium metasomatic type and silicic vein type occurred. These deposits are originated from the special stage of development and evolution of the Earth crust in this area. Uranium metallogenesis is closely related with the evolution of granite magma, hydrothermal solution and the condition of the wall rocks, uranium mineralization in space are controlled by the structures of different orders

  7. Classic to postclassic in highland central Mexico.

    Science.gov (United States)

    Dumond, D E; Muller, F

    1972-03-17

    The data and argument we have presented converge on three points. 1) With the decline and abandonment of Teotihuacan by the end of the Metepec phase (Teotihuacan IV), the valleys of Mexico and of Puebla-Tlax-cala witnessed the development of a ceramic culture that was represented, on the one hand, by obvious Teotihuacan derivations in presumably ritual ware and possible Teotihuacan derivations in simpler pottery of red-on-buff, and, on the other hand, by elements that seem to represent a resurgence of Preclassic characteristics. Whether the development is explained through a measure of outside influence or as a local phenomenon, the direct derivation of a substantial portion of the complex from Classic Teotihuacan is unmistakable. This transitional horizon predated the arrival of plumbate tradeware in highland central Mexico. 2) The transitional horizon coincided with (and no doubt was an integral part of) an alteration of Classic settlement patterns so drastic that it must bespeak political disruption. Nevertheless, there is no evidence that the Postclassic center of Tula represented a significant force in the highlands at that time. There is no evidence that the center of Cholula, which may even have been substantially abandoned during the previous period, was able to exert any force at this juncture; it appears more likely that Cholula was largely reoccupied after the abandonment of Teotihuacan. There is no direct evidence of domination by Xochicalco or any other known major foreign center, although some ceramic traits suggest that relatively minor influences may have emanated from Xochicalco; unfortunately, the state of research at that center does not permit a determination at this time. Thus the most reasonable view on the basis of present evidence is that the abandonment of Teotihuacan was not the direct result of the strength of another centralized power, although some outside populations may have been involved in a minor way. Whatever the proximate cause

  8. Gray fox (Urocyon cinereoargenteus) parasite diversity in central Mexico

    OpenAIRE

    Norma Hernández-Camacho; Raúl Francisco Pineda-López; María de Jesús Guerrero-Carrillo; Germinal Jorge Cantó-Alarcón; Robert Wallace Jones; Marco Antonio Moreno-Pérez; Juan Joel Mosqueda-Gualito; Salvador Zamora-Ledesma; Brenda Camacho-Macías

    2016-01-01

    Mexico has a long history of parasitological studies in communities of vertebrates. However, the mega diversity of the country makes fauna inventories an ongoing priority. Presently, there is little published on the parasite fauna of gray foxes (Urocyon cinereoargenteus Schereber, 1775) and this study provides new records of parasites for gray foxes in central Mexico. It is a continuation of a series of previous parasitological studies conducted with this carnivore in Mexico from 2003 to the ...

  9. 1996 Central New Mexico Section [American Chemical Society] annual report

    Energy Technology Data Exchange (ETDEWEB)

    Cournoyer, M.E. [Los Alamos National Lab., NM (United States). Chemistry Science and Technology Div.

    1997-02-07

    The main goal of the Central New Mexico Section this year was to increase attendance at the local meetings. Throughout the course of the year attendance at the meeting more than doubled. This was brought on by several factors: having the meeting spread throughout the section (Albuquerque, Santa Fe, Las Vegas, Socorro, Los Alamos); supplementing the ACS National Tour speakers with interesting local sections speakers; and making full use of the newly formed Public Relations Committee. Activities during 1996 are summarized.

  10. Gray fox (Urocyon cinereoargenteus) parasite diversity in central Mexico.

    Science.gov (United States)

    Hernández-Camacho, Norma; Pineda-López, Raúl Francisco; de Jesús Guerrero-Carrillo, María; Cantó-Alarcón, Germinal Jorge; Jones, Robert Wallace; Moreno-Pérez, Marco Antonio; Mosqueda-Gualito, Juan Joel; Zamora-Ledesma, Salvador; Camacho-Macías, Brenda

    2016-08-01

    Mexico has a long history of parasitological studies in communities of vertebrates. However, the mega diversity of the country makes fauna inventories an ongoing priority. Presently, there is little published on the parasite fauna of gray foxes (Urocyon cinereoargenteus Schereber, 1775) and this study provides new records of parasites for gray foxes in central Mexico. It is a continuation of a series of previous parasitological studies conducted with this carnivore in Mexico from 2003 to the present. A total of 24 foxes in the Parque Nacional El Cimatario (PANEC) were trapped, anaesthetized, and parasites recovered. The species found were Dirofilaria immitis, Ctenocephalides canis, C. felis, Euhoplopsillus glacialis affinis (first report for gray foxes in Mexico) Pulex simulants, and Ixodes sp. Three additional gray fox carcasses were necropsied and the parasites collected were adult nematodes Physaloptera praeputialis and Toxocara canis. The intensive study of the gray fox population selected for the 2013-2015 recent period allowed for a two-fold increase in the number of parasite species recorded for this carnivore since 2003 (nine to 18 parasite species), mainly recording parasitic arthropods, Dirofilaria immitis filariae and adult nematodes. The parasite species recorded are generalists that can survive in anthropic environments; which is characteristic of the present ecological scenario in central Mexico. The close proximity of the PANEC to the city of Santiago de Queretaro suggests possible parasite transmission between the foxes and domestic and feral dogs. Furthermore, packs of feral dogs in the PANEC might have altered habitat use by foxes, with possible impacts on transmission. PMID:27408801

  11. Geothermal energy from deep sedimentary basins: The Valley of Mexico (Central Mexico)

    Science.gov (United States)

    Lenhardt, Nils; Götz, Annette E.

    2015-04-01

    The geothermal potential of the Valley of Mexico has not been addressed in the past, although volcaniclastic settings in other parts of the world contain promising target reservoir formations. A first assessment of the geothermal potential of the Valley of Mexico is based on thermophysical data gained from outcrop analogues, covering all lithofacies types, and evaluation of groundwater temperature and heat flow values from literature. Furthermore, the volumetric approach of Muffler and Cataldi (1978) leads to a first estimation of ca. 4000 TWh (14.4 EJ) of power generation from Neogene volcanic rocks within the Valley of Mexico. Comparison with data from other sedimentary basins where deep geothermal reservoirs are identified shows the high potential of the Valley of Mexico for future geothermal reservoir utilization. The mainly low permeable lithotypes may be operated as stimulated systems, depending on the fracture porosity in the deeper subsurface. In some areas also auto-convective thermal water circulation might be expected and direct heat use without artificial stimulation becomes reasonable. Thermophysical properties of tuffs and siliciclastic rocks qualify them as promising target horizons (Lenhardt and Götz, 2015). The here presented data serve to identify exploration areas and are valuable attributes for reservoir modelling, contributing to (1) a reliable reservoir prognosis, (2) the decision of potential reservoir stimulation, and (3) the planning of long-term efficient reservoir utilization. References Lenhardt, N., Götz, A.E., 2015. Geothermal reservoir potential of volcaniclastic settings: The Valley of Mexico, Central Mexico. Renewable Energy. [in press] Muffler, P., Cataldi, R., 1978. Methods for regional assessment of geothermal resources. Geothermics, 7, 53-89.

  12. Barren Miocene granitoids in the Central Andean metallogenic belt, Chile: Geochemistry and Nd-Hf and U-Pb isotope systematics

    International Nuclear Information System (INIS)

    Four Middle-to-Late Miocene barren plutonic complexes that occur between the giant porphyry copper deposits of the central Chilean Andes were selected for U-Pb LA-ICPMS geochronology and Hf-isotope systematics on single zircon grains. Major and trace elements and Sr-Nd-Hf isotope whole rock geochemical studies were undertaken to compare with slightly younger or coeval barren and fertile intrusive rocks between 32o and 34oS. The studied granitoids yield resolvable crystallization ages of 11.3±0.1 Ma (Cerro Meson Alto massif), 10.3±0.2 Ma (La Gloria pluton), 14.9±0.2 Ma/14.9±0.1 Ma (Yerba Loca stock) and 11.2±0.1 Ma/14.7±0.1 Ma (San Francisco Batholith). Major and trace elements discard an adakitic signature as suggested for coeval porphyric intrusions at 32oS, slightly younger mineralized porphyries at Rio Blanco-Los Bronces deposit and other Cenozoic adakites. Volcanic host rocks are less fractionated than the intrusive rock units. The same observation can be made for the unmineralized northern plutons compared to the southern ones. Initial Sr-Nd isotope data show insignificant variation (0.703761-0.704118 and 0.512758- 0.512882), plotting in the mantle array. Trace element enrichment can be explained by addition of subducted-slab fluids and/or terrigenous sediments to the mantle wedge prior to and/or slight crustal input during magma ascent. Zircon grains separated from these barren intrusives share a similar initial εHf-data variation for the younger age group (10-12 Ma; 7.04-9.54) and show a more scattered range for the older one (14-15 Ma; 8.50-15.34); both sets plot between the DM and CHUR evolution lines. There is evidence that magma evolution was slightly distinct through time from older to younger barren magmatism, compared to a few fertile porphyritic rocks from Rio Blanco-Los Bronces porphyry copper deposit. It is suggested that chronological inconsistencies within these complexes might be related to differential shortening across the NE

  13. Seismic stratigraphic framework of deep central Gulf of Mexico basin

    Energy Technology Data Exchange (ETDEWEB)

    Shaub, F.J.; Buffler, R.T.; Parsons, J.G.

    1984-11-01

    The deep Gulf of Mexico basin is underlain by up to 10 km (33,000 ft) of Jurassic(.) to Holocene layered sedimentary rocks. The multichannel reflection seismic record from the deep Gulf of Mexico was divided into six seismic stratigraphic units for study of the geologic history of this accumulation. The basal Challenger unit (Jurassic (.) to middle Cretaceous) is considered coeval with early basin formation. We interpret it as a deep marine sequence overlying oceanic crust in the central basin and as continental and shallow through deep marine rocks, including thick evaporites, over adjacent transitional crust. The next three units, Campeche, Lower Mexican Ridges and Upper Mexican Ridges, indicate that from the Late Cretaceous through middle Miocene the basin filled progressively from the west and north, most probably with siliceous turbidites interlayered with pelagic deposits. By the late Tertiary, however, salt and shale deformation within thick sedimentary sections along the western and northern margins trapped much of the incoming sediment supply on the shelves and upper slopes. The late Miocene to Pliocene Cinco de Mayo unit, therefore, represents a relatively starved interval. In contrast, the uppermost, or Sigsbee unit, includes the Mississippi Fan, an accumulation up to 3 km (10,000 ft) thick of mainly mass-transported deposits that bypassed the shelf and slope and were deposited directly onto the abyssal plain. In the western and southwestern portions of the deep basin, beyond the fan pinchout, the Pleistocene section is largely a continuation of the Pliocene suspension deposits.

  14. The economic impact of Sandia National Laboratories on central New Mexico and the state of New Mexico fiscal year 1997

    International Nuclear Information System (INIS)

    Sandia National Laboratories (SNL) was established in 1949 to perform the engineering development and ordnance responsibilities associated with nuclear weapons. By the early 1960's the facility had evolved into an engineering research and development laboratory and became a multiprogram laboratory during the 1970s. Sandia is operated for the US Department of Energy by the Sandia Corporation, a wholly-owned subsidiary of Lockheed Martin, Incorporated. For several years, the US Department of Energy (DOE) Albuquerque Operations Office (AL) and New Mexico State University (NMSU) have maintained an inter-industry, input-output model with capabilities to assess the impacts of developments initiated outside the economy such as federal DOE monies that flow into the state, on an economy. This model will be used to assess economic, personal income and employment impacts of SNL on central New Mexico and the state of New Mexico. For this report, the reference period is FY 1997 (October 1, 1996, through September 30, 1997) and includes two major impact analyses: the impact of SNL activities on central New Mexico and the economic impacts of SNL on the state of New Mexico. For purposes of this report, the central New Mexico region includes Bernalillo, Sandoval, Valencia, and Torrance counties. Total impact represents both direct and indirect respending by business, including induced effects (respending by households). The standard multipliers used in determining impacts results from the inter-industry, input-output models developed for the four-county region and the state of New Mexico. 6 figs., 10 tabs

  15. The economic impact of Sandia National Laboratories on central New Mexico and the state of New Mexico fiscal year 1997

    Energy Technology Data Exchange (ETDEWEB)

    Lansford, R.R.; Nielsen, T.G.; Schultz, J. [New Mexico State Univ., Las Cruces, NM (United States); Adcock, L.D.; Gentry, L.M. [Dept. of Energy, Albuquerque, NM (United States). Albuquerque Operations Office; Ben-David, S. [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Economics; Temple, J. [Temple (John), Albuquerque, NM (United States)

    1998-05-29

    Sandia National Laboratories (SNL) was established in 1949 to perform the engineering development and ordnance responsibilities associated with nuclear weapons. By the early 1960`s the facility had evolved into an engineering research and development laboratory and became a multiprogram laboratory during the 1970s. Sandia is operated for the US Department of Energy by the Sandia Corporation, a wholly-owned subsidiary of Lockheed Martin, Incorporated. For several years, the US Department of Energy (DOE) Albuquerque Operations Office (AL) and New Mexico State University (NMSU) have maintained an inter-industry, input-output model with capabilities to assess the impacts of developments initiated outside the economy such as federal DOE monies that flow into the state, on an economy. This model will be used to assess economic, personal income and employment impacts of SNL on central New Mexico and the state of New Mexico. For this report, the reference period is FY 1997 (October 1, 1996, through September 30, 1997) and includes two major impact analyses: the impact of SNL activities on central New Mexico and the economic impacts of SNL on the state of New Mexico. For purposes of this report, the central New Mexico region includes Bernalillo, Sandoval, Valencia, and Torrance counties. Total impact represents both direct and indirect respending by business, including induced effects (respending by households). The standard multipliers used in determining impacts results from the inter-industry, input-output models developed for the four-county region and the state of New Mexico. 6 figs., 10 tabs.

  16. Miocene Slab Detachment in Central Mexico: Causes and Consequences

    Science.gov (United States)

    Ferrari, L.

    2002-12-01

    I propose that the lower part of the Farallon slab subducted beneath Mexico has detached twice during the Miocene. Initiation of slab detachment is a consequence of the incoming of increasingly buoyant oceanic crust at the paleotrench off Baja California and, eventually, the capture by the Pacific plate of the microplates left over by the Farallon plate that produced a retrograde motion of the shallow part of the slab. Our first integration of the geology of the whole central Mexico reveals a number of features that support the detachment model and allow inferring the location through time of these events. A main consequence of detachments is the influx of hotter and geochemically enriched sub-slab material into the slab-free area. The process is thus expected to generate a pulse of volcanism and a geochemically heterogeneous mantle wedge. A first detachment is inferred to have begun shortly before the contact between the Pacific and North America plate at 28.5 Ma. A tear in the slab propagated to the SSE, producing a transient thermal anomaly, ignimbrite flare up, and extension at ~24-20 Ma in the southern Sierra Madre Occidental. A second detachment event is inferred as a result of the end of subduction off the southern half of Baja California at 12.5 Ma. In this case the slab detached from the southern Gulf of California toward the ESE, paralleling the southern Mexico trench system. This event caused an eastward migrating mafic pulse of volcanism, presently observed in the northern part of the Trans-Mexican Volcanic Belt (TMVB), between 11 and 7 Ma. New geochronological and geochemical data suggest the continuation of the detachment to the SSE in Veracruz state (Sierra de Tantima, Alamo, Poza Rica, Palma Sola and Los Tuxtlas volcanic fields). The occurrence of OIB volcanism in the TMVB since the end of Miocene is explained by the influx of enriched asthenospheric material into the gap formed by the detachment, enhanced by the corner flow induced by the

  17. Evaporation rates of pasture-mesquite vegetation in central Mexico

    Science.gov (United States)

    Sosa, E. G.; Escobar, A. G.

    2004-12-01

    The semiarid highlands of Queretaro, in central Mexico, are characterized by booming urban and industrial developments with increasing demand for water. Agriculture takes place in the valleys and the surrounding hills have different types of xeric to subtropical rangeland. Hills are unfit for agriculture and usually are managed for cattle production and fuelwood. However, recent studies suggest that some hill areas are important for groundwater recharge and if they are not protected, important water shortages are envisioned. A critical question involves the effects of land management practices on rangeland hydrologic processes. Evaporation (E), which includes plant and soil evaporation is the largest water loss from rangelands and few data are available for central Mexico. The objective of this study was to estimate E from a mesquite (Prosopis sp.) dominated vegetation using the eddy correlation and the Pennman-Monteith models. Measurements were made during 24 summer days of 2004 at a piedmont site at Amascala, Queretaro (1919 m, 20° 41' N, 100° 16' W). Long term annual rainfall is 568 ± 137 mm. Shrub density was 770 plants per hectare and mean height was 1.8 m. The understory was composed by a mixture of annual and perennial grasses but their biomass was negligible. Agroforestry was the current land use of the site. Shrubs were pruned every 2 or 3 years to maintain its height and promote leafty regrowth. Goats usually browsed the mesquite canopy, but during the time of the study they were excluded from the area.The rainy season started on 15 May and measurements initiated on 1 June, five days after a severe hail storm. Although the mesquite canopy had a full developed canopy with leaf area index of 3.2 by this time, they lost approximately 70% of leaf area. May and June rainfall was 146 mm and 46 mm occurred during the measuring period. Throughout the measurement period E was coupled to global radiation and total evaporation was 73.8 mm. On cloudy days E ranged

  18. Ground-based Fourier transform infrared spectroscopy in central Mexico

    Science.gov (United States)

    Plaza, Eddy; Stremme, Wolfgang; Bezanilla, Alejandro; Baylon, Jorge; Grutter, Michel; Blumenstock, Thomas; Hase, Frank

    2014-05-01

    Altzomoni is a high altitude station in central Mexico (19.12 N, 98.65 W, 4000 m a.s.l.) for continuous measurements of various atmospheric parameters. It is located within the Izta-Popo National Park and is operated remotely from the UNAM campus. Since May 2012, high resolution solar absorption spectra have been recorded from this site using a FTIR from Bruker (HR120/5) equipped with MCT, InSb and InGaAs detectors and various optical filters. In this contribution we present a detailed description of the measurement site and the instrumental set-up including a record of the instrumental line-shapes (modulation efficiency and phase error) obtained from cell measurements and analyzed with the LINEFIT code. A preliminary analysis of almost two years of spectra recorded at the Altzomoni site resulting in profile retrievals of four NDACC gases O3, CO, HF and HCl is presented. The retrieval code PROFFIT is used and the Averaging Kernels and an error analysis are used to describe the quality of the measurements. The annual cycles in the time series of O3 and CO are presented and discussed, as well as some examples of anomalies due to volcanic gas emissions of HF and HCl are shown. The presented work is part of an effort to certify this station as part of the NDACC international network.

  19. BLM/OCS Ecological Investigations of Petroleum Production Platforms in the Central Gulf of Mexico

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ecological Investigations of Petroleum Production Platforms in the Central Gulf of Mexico Project was conducted by Texas A and M University under contract to...

  20. Paleoseismological History of the Acambay Graben (Central Mexico)

    Science.gov (United States)

    Lacan, P.; Zúñiga, R.; Ortuño, M.; Persaud, M.; Aguirre-Diaz, G. J.; Langridge, R. M.; Villamor, P.; Perea, H.; Štěpančíková, P.; Carreon, D.; Cerca, M.; Suñe Puchol, I.; Corominas Calvet, O.; Audin, L.; Baize, S.; Lawton, T. F.; Rendón, A.

    2013-12-01

    The Acambay graben is part of the Trans-Mexican Volcanic Belt (TMVB) which strikes ESE-WNW across central Mexico, where the major part of the Mexican population is concentrated. The TMVB is an active, calc-alkaline volcanic arc that is related to the subduction of the Rivera and Cocos plates underneath the North American plate. The TMVB contains a series of intra-arc basins that form the Chapala-Tula fault zone (450 km long, 50 km wide). One of these extensive basins, the Acambay graben, is 80 km long and 15 to 30 km wide. It is limited north by the E-W striking Epitacio-Huerta (EHF) and Acambay-Tixmadejé normal faults and south by the Venta de Bravo (VBF) and the Pastores faults (PF) in the south. Other minor active faults are located within the basin, along the axis of the Graben. In the area, the instrumental seismicity is low to moderate, although one major historical earthquake (Ms = 6.9 Acambay event) occurred on November 19, 1912, causing widespread damage. In the last decade, our group has focused on the neotectonic and paleoseismological study of the major faults of the Acambay graben. More than 30 trenches have been dug at 15 sites in order to interpret the paleoseismological history of 7 major faults of the graben. In addition to paleoseismological trench studies, tectonic geomorphology, subsurface geophysics and micro topographic surveys have been used to assess the rupture history. All of the studied faults have to be considered as active faults, with a minimum of 2 to 5 paleoseismic events on each fault during the last 20 ka. Each fault rupture corresponds to a vertical displacement ranging from 1 to 150 centimetres. Considering the size of the observed displacements and the length of active segments, we demonstrate that large earthquakes with magnitude higher than 7 have occurred along some of these faults. Based on paleoseismological results, we calculate a major earthquake recurrence interval ranging from 2,000 to 5,000 years over a time span (~20

  1. Seismic imaging of the Cocos plate subduction zone system in central Mexico

    OpenAIRE

    Kim, YoungHee; Miller, Meghan S.; Pearce, Frederick; Clayton, Robert W.

    2012-01-01

    Broadband data from the Meso-America Subduction Experiment (MASE) line in central Mexico were used to image the subducted Cocos plate and the overriding continental lithosphere beneath central Mexico using a generalized radon transform based migration. Our images provide insight into the process of subducting relatively young oceanic lithosphere and its complex geometry beneath continental North America. The converted and reverberated phase image shows complete horizontal tectonic underplatin...

  2. Patterns of illness in travelers visiting Mexico and Central America: the GeoSentinel experience

    OpenAIRE

    Flores-Figueroa, J; Okhuysen, P C; von Sonnenburg, F.; DuPont, H L; Libman, M D; Keystone, J S; Hale, D C; Burchard, G; Han, P V; Wilder-Smith, A.; Freedman, D O

    2011-01-01

    BACKGROUND: Mexico and Central America are important travel destinations for North American and European travelers. There is limited information on regional differences in travel related morbidity. METHODS: We describe the morbidity among 4779 ill travelers returned from Mexico and Central America who were evaluated at GeoSentinel network clinics during December 1996 to February 2010. RESULTS: The most frequent presenting syndromes included acute and chronic diarrhea, dermat...

  3. [Production systems of Spondias purpurea (Anacardiaceae) in Central West Mexico].

    Science.gov (United States)

    Ramírez Hernández, Blanca C; Barrios Eulogio, Pimienta; Castellanos Ramos, Javier Z; Muñoz Urias, Alejandro; Palomino Hasbach, Guadalupe; Pimienta Barrios, Enrique

    2008-06-01

    Morphological, physical and chemical traits related with fruit quality characteristics of Spondias purpurea L. agroecosystems were studied in Central-West Mexico for wild and cultivated populations. Spondias purpurea regularly thrive in shallow, rocky infertile soils unsuitable for conventional crops. The weight, axial and radial length, pH, total soluble solids (SST), reducing sugars, proteins and mineral content in fruits were recorded. The mean fresh fruit weight was superior in the cultivated varieties (20 g) than in the wild (16 g). Similarly the highest values of pH, SST, reducing sugars and protein content (3.3, 12.15 degrees Brix, 0.38 g/100 g and 1.18 g/100 g, respectively) were observed in the cultivated plantations compared with wild populations (3.0, 8.31 degrees Brix, 0.24 g/100 g and 0.14 g/100 g, respectively). In cultivated plantations, productivity ranged from 0.15 ton ha(-1) to 5.0 ton ha(-1), and must be considered satisfactory, considering the low inputs of fertilizers and pesticides applied to orchards. The fruits of S. purpurea are similar in nutrimental content to more important commercial fruit species; it produces fresh fruits during the dry months of spring, when few fresh fruits are available in the local markets. In addition, S. purpurea is a source of water and food for domestic animals and wild fauna. These traits emphasize their agronomical and ecological importance for tropical and subtropical environments, where it can also be used in reforestation programs because it can grow in infertile rocky soils, and in agroecosystems inhabited by low income farmers that practice subsistence agriculture. In fact, the cultivation of Spondias has helped convert marginal lands into productive lands. PMID:19256436

  4. The economic impact of Sandia National Laboratories on Central New Mexico and the State of New Mexico Fiscal Year 1998

    Energy Technology Data Exchange (ETDEWEB)

    Lansford, Robert R.; Adcock, Larry D.; Gentry, Lucille M.; Ben-David, Shaul; Temple, John

    1999-08-09

    Sandia National Laboratories (SNL) is a Department of Energy federally funded national security laboratory that uses engineering and science to ensure the security of the Nation. SNL provides scientific and engineering solutions to meet national needs in nuclear weapons and related defense systems, energy security, and environmental integrity. SNL works in partnerships with universities and industry to enhance their mission and transfer technology that will address emerging national challenges for both government and industry. For several years, the U.S. Department of Energy (DOE) Albuquerque Operations Office (AL) and New Mexico State University (NMSU) have maintained an inter-industry, input-output (I/O) model with capabilities to assess the impacts of developments initiated outside the economy such as federal DOE monies that flow into the state, on an economy. This model will be used to assess economic, personal income and employment impacts of SNL on Central New Mexico and the State of New Mexico. Caution should be exercised when comparing economic impacts between fiscal years prior to this report. The I/O model was rebased for FY 1998. The fringe benefits coefficients have been updated for the FY 1996 and FY 1997 economic impacts analysis. Prior to FY 1993 two different I/O base models were used to estimate the impacts. New technical information was released by the Bureau of Economic Analysis (BEA), U.S. Department of Commerce in 1991 and in 1994 and was incorporated in FY 1991, FY 1993, and FY 1994 I/O models. Also in 1993, the state and local tax coefficients and expenditure patterns were updated from a 1986 study for the FY 1992 report. Further details about the input-output model can be found in ''The Economic Impact of the Department of Energy on the State of New Mexico--FY 1998'' report by Lansford, et al. (1999). For this report, the reference period is FY 1998 (October 1, 1997, through September 30, 1998) and includes two major

  5. Cetaceans and gillnet fisheries in Mexico, Central America and the Wider Caribbean: a preliminary review

    OpenAIRE

    Vidal, O.; Van Waerebeek, K.; Findley, L.T.

    1994-01-01

    This paper reviews published and unpublished information on the mortality of cetaceans in gillnets in Mexico, Central America and the wider Caribbean. Data on this incidental mortality are provided from only nine of the 36 nations in the area (Colombia, the Dominican Republic. French Guiana, Honduras, Mexico. Panama, Surinam, Trinidad and Tobago, and Venezuela); the lack of mortality records from the other countries reflects poor or non-existent documentation. We surveyed those types of passi...

  6. Contribution to the knowledge of planktic cyanoprokaryotes from central Mexico

    Czech Academy of Sciences Publication Activity Database

    Komárek, Jiří; Komárková, Jaroslava

    2002-01-01

    Roč. 74, - (2002), s. 207-233. ISSN 0032-7786 R&D Projects: GA AV ČR KSK6005114; GA AV ČR IAA6005704 Institutional research plan: CEZ:AV0Z6005908 Keywords : plankton * cyanobacteria * cyanoprokaryotes * taxonomy * ecology * distribution * phenotypic variability * Mexico Subject RIV: DA - Hydrology ; Limnology

  7. Groundwater modeling of the Calera Aquifer region in Central Mexico

    Science.gov (United States)

    The Calera Aquifer is the main source of water for irrigated agriculture, industrial, and drinking water purposes in the Calera Aquifer Region (CAR) in the state of Zacatecas, Mexico. Irrigated agriculture accounts for 80% of the total groundwater extracted from the Calera Aquifer. In recent years, ...

  8. THE COMMUNITY OF FURCRAEA PARMENTIERI, A THREATENED SPECIE, CENTRAL MEXICO

    OpenAIRE

    Lucía Almeida-Leñero; Ana María Mondragón; Beatriz Ludlow-Wiechers; Verónica Aguilar-Zamora

    2014-01-01

    The fl ora and vegetation of Furcraea par- mentieri (Roezl ex Ortigies) Garcia-Mend. ( F. bedinghausii ) community was studied on the Pelado volcano, at the S area of Mexico City. Following Zurich-Montpellier criteria, 25 phytosociological plots were done, and the Jaccard index of similarity was calcula- ted. Furcraea parmentieri is associated with Muhlenbergia macroura to form an azonal community between 3 020 and 3 300 m, on rocky soils and gaps of Pinus - Alnus forest. Three subcommunities...

  9. 78 FR 52562 - Outer Continental Shelf (OCS), Gulf of Mexico (GOM), Oil and Gas Lease Sales, Central Planning...

    Science.gov (United States)

    2013-08-23

    ... Bureau of Ocean Energy Management Outer Continental Shelf (OCS), Gulf of Mexico (GOM), Oil and Gas Lease Sales, Central Planning Area (CPA) Lease Sales 235, 241, and 247 AGENCY: Bureau of Ocean Energy... EIS for proposed Central Planning Area (CPA) Lease Sales 235, 241 and 247 in the Gulf of Mexico...

  10. Rainwater chemical composition at two sites in Central Mexico

    Science.gov (United States)

    Báez, A. P.; Belmont, R. D.; García, R. M.; Torres, M. C. B.; Padilla, H. G.

    2006-04-01

    Chemical analyses were performed on rainwater samples collected at the National Autonomous University of Mexico (UNAM) in Mexico City and at a wooded site, Rancho Viejo (RV) in the State of Mexico, for the periods 1994-2000 and 1994-1999, respectively. At UNAM, rainwater was collected for the entire rainy season period each year, while at RV, technical considerations limited collection to weekends only. The results showed large variations in rainwater chemical composition in most years, mainly because of the variability of meteorological conditions and also because of changes in source emissions. Sulfates and NH 4+ showed higher annual volume-weighted mean concentrations (VWMC) in both sites. At UNAM, the maximum annual VWMC for SO 42- occurred in March and the minimum in July and August. Lower concentrations of almost all ions were found at RV; however, the H + concentration was higher at this site. The pH in Mexico City, calculated from the annual VWMC of H +, was 4.95, which is a little higher than pH values reported in some other countries. Despite the fact that sulfate and NO 3- concentrations were lower at RV, the pH was lower. Air-mass back trajectories were calculated for individual concentrations of SO 42-, H +, NH 4+, Ca 2+, and Mg 2+, observed at each sampling site for weekend data. At RV, sulfate concentrations were higher when air-mass back trajectories indicated a wind flow from Mexico City and Toluca at 1000 MAGL (meters above ground level) and 3000 MAGL. The hydrogen ion exhibited the same behavior. Calcium and Mg 2+ concentrations were also higher when the wind blew from urban areas at 1000 and 3000 MAGL. At UNAM, H + concentration was lower and Ca 2+ and Mg 2+ were higher when wind blew from the northern sector of the city at 1000 and 3000 MAGL. In UNAM, the NO 3-/SO 42- and NH 4+/SO 42- ratios were 0.5 and 1.09 in 1994 and 0.86 and 1.64 in 2000, respectively, indicating a decrease in SO 2 emissions resulting from the change of fuel oil to gas

  11. Metallogenic aspects of Itu intrusive suite

    International Nuclear Information System (INIS)

    The integrated use of geological, geochemical, geophysical and remote sensing data is providing interesting new information on the metallogenic characteristics of the Itu Intrusive Suite. During World War II, up to 1959, a wolframite deposit was mined near the border of the northernmost body (Itupeva Granite). This deposit is formed by greisen veins associated with cassiterite and topaz, clearly linked with later phases of magmatic differentiation. Generally those veins are related to hydrothermal alteration of the granites and the above mentioned shear zone. U, Th and K determinations by field and laboratory gammaspectrometry were used for regional distribution analysis of those elements and its ratios and calculation of radioactivity heat production. In this aspects, the Itupeva Granite is the hottest and presents several anomalies in the Th/U ratio, indicative of late or post magmatic oxidation processes. (author)

  12. Uranium metallogenic geological conditions and prediction vision in Linxi-Wulanhaote region

    International Nuclear Information System (INIS)

    Linxi-Wulanhaote region, where the Mesozoic marginal-Pacific metallogenic domain superimposed the Paleozoic Paleo-Asian metallogenic domain, is a significant polymetallic metallogenic province and a Uranium mineralization vision area with prospecting potential. According to the special region of metallogenic geological environment, the distribution of Uranium deposits (mineral occurrence) and uranium mineralization types, geophysical and geochemical prospecting anomalous features and ore-forming geological background was studied, and summarizes the uranium mineralization geological characteristics, mineralization and metallogenic regularity, preliminary several differentiate uranium metallogenic areas. According to forecasting criterion and the prediction model, screening prospecting prospect areas. (authors)

  13. Geothermal power plants of Mexico and Central America: a technical survey of existing and planned installations

    Energy Technology Data Exchange (ETDEWEB)

    DiPippo. R.

    1978-07-01

    In this report, the fifth in a series describing the geothermal power plants of the world, the countries of Mexico and of Central America are studied. The geothermal plants are located in areas of recent and active volcanism; the resources are of the liquid-dominated type. Details are given about the plants located at Cerro Prieto in Mexico and at Ahuachapan in El Salvador. In both cases, attention is paid to the geologic nature of the fields, the well programs, geofluid characteristics, energy conversion systems, materials of construction, effluent handling systems, economic factors and plant operating experience. Exploration and development activities are described for other promising geothermal areas in Mexico and El Salvador, along with those in the countries of Costa Rica, Nicaragua, Guatemala, Honduras, and Panama.

  14. A submarine fan in the Mesa Central, Mexico

    Science.gov (United States)

    Silva-Romo, G.; Arellano-Gil, J.; Mendoza-Rosales, C.; Nieto-Obregón, J.

    2000-10-01

    The contact between the Guerrero and Sierra Madre tectonostratigraphic terranes has been proposed to lie in the Mesa Central, east of the city of Zacatecas. Marine Triassic units have been assigned to the Guerrero Terrane. It is here proposed that this contact occurs to the west of the city of Zacatecas and the Triassic marine sequence assigned to the Sierra Madre Terrane. We analyzed the stratigraphic record and structural features of pre-Late Jurassic sequences at four localities in the Mesa Central. They contain a marine turbiditic Triassic unit, which includes La Bellena, Taray, and Zacatecas Formations, and a continental unit of probable Middle Jurassic age. Triassic sandstones were derived from a cratonic area, without the influence of arc volcanism. The sequences were affected by two phases of deformation. The Triassic formations are unconformably overlain by a continental volcano-sedimentary sequence that contains fragments of sandstones derived from the underlying unit. Sedimentologic characteristics of the Triassic unit fit a submarine fan model. The submarine fan developed at the continental margin of Pangaea during Triassic times. Turbidite associations in the San Rafael Area indicate a middle fan depositional environment, while in the Real de Catorce Area, they correspond to the distal part (basin plain facies). At La Ballena and Zacatecas the turbidite associations occur in the middle part and perhaps the external part of the fan.

  15. Water Quality of a Reservoir and Its Major Tributary Located in East-Central Mexico

    OpenAIRE

    Patricia Castilla-Hernández; María del Rocío Torres-Alvarado; José Antonio Herrera-San Luis; Norma Cruz-López

    2014-01-01

    A reservoir with ecological and economic importance and its major tributary, localized in east-central Mexico, were studied. The aim of this work was to know the physicochemical water characteristics of both water bodies and to contrast these by their different uses, and also estimate overall water quality using a Water Quality Index (WQI). Water samples from the reservoir and the tributary were obtained in different climatic seasons. In the tributary, anoxic and hypoxic conditions and high l...

  16. Long-term forest dynamics in high-altitude mountains of West-Central Mexico

    OpenAIRE

    Figueroa Rangel, Blanca.; Professor Katherine J. Willis

    2007-01-01

    This thesis presents the results of a study to examine long-term forest dynamics in the high-altitude mountains of West-Central Mexico. Vegetation dynamics on temporal scales ranging from 102 to 103 years were reconstructed in order to provide essential information on the temporal variability of ecological patterns and processes in these forests; information that is of direct relevance for their current and future conservation and management strategies. Vegetation and palae...

  17. Characterization, functioning and classification of two volcanic soil profiles under different land uses in Central Mexico

    OpenAIRE

    Prado, B.; Duwig, Céline; Hidalgo, C; Gomez, D.; Yee, H.; Prat, Christian; Esteves, Michel; Etchevers, J.D.

    2007-01-01

    Volcanic soils constitute an important resource for agriculture and forestry in Central Mexico, as well as in various world regions. They exhibit unique properties and high productive potential related to the amorphous materials they contain. The relationship between amorphous materials, soil characteristic and functioning, has not been well studied. The objectives of the present work were to assess the influence of land use (agricultural and forest), topography and other soil forming factors...

  18. Geometry and seismic properties of the subducting Cocos plate in central Mexico

    OpenAIRE

    Kim, Y.; Clayton, R. W.; Jackson, J. M.

    2010-01-01

    The geometry and properties of the interface of the Cocos plate beneath central Mexico are determined from the receiver functions (RFs) utilizing data from the Meso America Subduction Experiment (MASE). The RF image shows that the subducting oceanic crust is shallowly dipping to the north at 15° for 80 km from Acapulco and then horizontally underplates the continental crust for approximately 200 km to the Trans-Mexican Volcanic Belt (TMVB). The crustal image also shows that there is no contin...

  19. Seismic structure in central Mexico: Implications for fragmentation of the subducted Cocos plate

    OpenAIRE

    Dougherty, Sara L.; Clayton, Robert W.; Helmberger, Don V.

    2012-01-01

    The fine-scale seismic structure of the central Mexico subduction zone is studied using moderate-sized (M4-6) intraslab earthquakes. Regional waveforms from the Mapping the Rivera Subduction Zone (MARS) seismic array are complicated and contain detailed information about the subduction zone structure, including evidence of lateral heterogeneity. This waveform information is used to model the structure of the subducted plates, particularly along the transition from flat to normal subduction, w...

  20. Evidence from central Mexico supporting the Younger Dryas extraterrestrial impact hypothesis

    OpenAIRE

    Israde-Alcántara, Isabel; Bischoff, James L.; Domínguez-Vázquez, Gabriela; Li, Hong-Chun; DeCarli, Paul S.; Bunch, Ted E.; Wittke, James H.; Weaver, James C.; Firestone, Richard B.; West, Allen; Kennett, James P.; Mercer, Chris; Xie, Sujing; Richman, Eric K.; Kinzie, Charles R.

    2012-01-01

    We report the discovery in Lake Cuitzeo in central Mexico of a black, carbon-rich, lacustrine layer, containing nanodiamonds, microspherules, and other unusual materials that date to the early Younger Dryas and are interpreted to result from an extraterrestrial impact. These proxies were found in a 27-m-long core as part of an interdisciplinary effort to extract a paleoclimate record back through the previous interglacial. Our attention focused early on an anomalous, 10-cm-thick, carbon-rich ...

  1. Limitations and potentials of dual-purpose cow herds in Central Coastal Veracruz, Mexico

    OpenAIRE

    Absalón-Medina, Victor Antonio; Blake, Robert W.; Fox, Danny Gene; Juárez-Lagunes, Francisco I.; Charles F. Nicholson; Canudas-Lara, Eduardo G.; Rueda-Maldonado, Bertha L.

    2011-01-01

    Feed chemical and kinetic composition and animal performance information was used to evaluate productivity limitations and potentials of dual-purpose member herds of the Genesis farmer organization of central coastal Veracruz, Mexico. The Cornell Net Carbohydrate and Protein System model (Version 6.0) was systematically applied to specific groups of cows in structured simulations to establish probable input–output relationships for typical management, and to estimate probable outcomes from al...

  2. Some tentative idea about uranium metallogenic prognosis on the basis of application of GIS

    International Nuclear Information System (INIS)

    Geographic information system (GIS) is a new borderline subject. The principal components of MAPGIS are introduced, and the data needed, main procedures and outstanding advantages in uranium metallogenic prognosis applying MAPGIS are discussed. For uranium metallogenic areas with detailed research basis and abundant data, it is of great prospects to apply MAPGIS for metallogenic prognosis

  3. Assessment of tsunami hazards for the Central American Pacific coast from southern Mexico to northern Peru

    OpenAIRE

    B. Brizuela; Armigliato, A.; S. Tinti

    2014-01-01

    Central America (CA), from Guatemala to Panama, has been struck by at least 52 tsunamis between 1539 and 2013, and in the extended region from Mexico to northern Peru (denoted as ECA, Extended Central America in this paper) the number of recorded tsunamis in the same time span is more than 100, most of which were triggered by earthquakes located in the Middle American Trench that runs parallel to the Pacific coast. The most severe event in the catalogue is the tsunami that o...

  4. soil carbon pools within oak forest is endangered by global climate change in central mexico

    Science.gov (United States)

    García-Oliva, Felipe; Merino, Agustín; González-Rodriguez, Antonio; Chávez-Vergara, Bruno; Tapia-Torres, Yunuen; Oyama, Ken

    2016-04-01

    Forest soil represents the main C pool in terrestrial ecosystems. In particular, temperate forest ecosystems play an important role in the C budget among tropical countries, such as Mexico. For example, the temperate forest ecosystem contains higher C contents on average (295 Mg C ha-1) than the soil C associated with other ecosystems in Mexico (between 56 to 287 Mg C ha-1). At a regional scale, oak forest has the highest C content (460 Mg C ha-1) among the forest ecosystem in Michoacán State at Central Mexico. At the local scale, the soil C content is strongly affected by the composition of organic matter produced by the plant species. The oak species are very diverse in Mexico, distributed within two sections: Quercus sensu stricto and Lobatae. The oak species from Quercus s.s. section produced litterfall with lower concentrations of recalcitrant and thermostable compounds than oak species from Lobatae section, therefore the soil under the former species had higher microbial activity and nutrient availability than the soil under the later species. However, the forest fragment with higher amount of oak species from Quercus s.s. section increases the amount of soil C contents. Unfortunately, Quercus species distribution models for the central western region of Mexico predict a decrease of distribution area of the majority of oak species by the year 2080, as a consequence of higher temperatures and lower precipitation expected under climate change scenarios. Additionally to these scenarios, the remnant oak forest fragments suffer strong degradation due to uncontrolled wood extraction and deforestation. For this reason, the conservation of oak forest fragments is a priority to mitigate the greenhouse gases emission to the atmosphere. In order to enhance the protection of these forest fragments it is required that the society identify the ecosystem services that are provided by these forest fragments.

  5. Seismic attenuation structure in central Mexico: Image of a focused high-attenuation zone in the mantle wedge

    OpenAIRE

    Chen, Ting; Clayton, Robert W.

    2009-01-01

    Velocity spectra from moderate-sized earthquakes were used to investigate the P wave attenuation structure in central Mexico. In particular, we included regional events with magnitudes in the range of 4.5 to 6.1 recorded from 2005 to 2007 on the Middle American Subduction Experiment (MASE) array, which consists of 100 broadband sensors across central Mexico from Acapulco to Tempoal, near the Gulf of Mexico. By assuming a Brune-type source, a frequency-independent t* value was obtained for eac...

  6. A review of ozone-induced effects on the forests of central Mexico

    International Nuclear Information System (INIS)

    The first report on oxidant-induced plant damage in the Valley of Mexico was presented over 30 years ago. Ozone is known to occur in the Mexico City Metropolitan Area and elsewhere as the cause of chlorotic mottling on pine needles that are 2 years old or older as observed in 1976 on Pinus hartwegii and Pinus leiophylla. Visible evidences for the negative effects of ozone on the vegetation of central Mexico include foliar injury expressed as chlorotic mottling and premature defoliation on pines, a general decline of sacred fir, visible symptoms on native forest broadleaved species (e.g. Mexican black cherry). Recent investigations have also indicated that indirect effects are occurring such as limited root colonization by symbiotic fungi on ozone-damaged P. hartwegii trees and a negative influence of the pollutant on the natural regeneration of this species. The negative ozone-induced effects on the vegetation will most likely continue to increase. - Ozone induced symptoms, poor tree regeneration and limited root colonization by mycorrhiza fungi observed in the valley of Mexico

  7. Paleotectonic controls on deposition of upper Upper Jurassic La Casita Formation, east-central Chihuahua, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, D.C.

    1989-03-01

    Surface mapping of the basal Mesozoic La Casita Formation (upper Upper Jurassic) in east-central Chihuahua, Mexico, indicates initial Mesozoic sedimentation occurred in a segmented, interconnected subbasin of the Chihuahua trough. La Casite Formation (1200 m thick) is a tectonostratigraphic unit resting with angular unconformity on the Lower Permian Plomosas Formation. It consists primarily of siliciclastic material with sporadic interbedded limestones. The dominant lithofacies, approximately 1000 m thick, consists of turbiditic sandstone units (10-20 m) alternating with thicker, monotonous shale sequences. In the mapped area (approximately 30 km/sup 2/), flute cast measurements indicate flows from both the northeast (N20/degree/E) and southwest (S58/degree/W). Turbiditic sandstone units appear to pinch out and/or interfinger as they extend from the north and south into the central portion of the area. The initial opening of the Chihuahua trough is often associated with Late Jurassic block faulting, related to development of the ancestral Gulf of Mexico. Synrift depositional sequences of a similar age have been described in southern Coahuila, northern Zacatecas, and western Chiapas, Mexico. The subbasin (graben ) examined here may be ascribed a paleoposition near the western edge of the early Chihuahua trough. The western boundary of the early trough may have comprised a series of these subbasins, forming a cuspate or serrated coastline. Late Jurassic ammonites recovered from this and other localities along the length of the Chihuahua trough suggest that the subbasins were interconnected by means of an eastern continuous seaway.

  8. Oil and gas developments in South America, Central America, Caribbean area, and Mexico in 1987

    Energy Technology Data Exchange (ETDEWEB)

    Wiman, W.D.

    1988-10-01

    Exploration activity in South America, Central America, the Caribbean area, and Mexico in 1987 showed significant increases in seismic acquisition in Belize, Bolivia, Brazil, Costa Rica, Guatemala, Mexico, Paraguay, and Peru, and a decrease in Chile and Venezuela. Exploratory drilling increased in most major producing countries but was accompanied by a decline in development drilling. Most of the increase could be attributed to private companies fulfilling obligations under risk contracts; however, state oil companies in Bolivia, Chile, and Colombia showed significant increased activity, with only Mexico showing a decrease. Colombia again had a dramatic increase in production (29% from 1986). Noteworthy discoveries were made in Bolivia (Villamontes-1); Brazil, in the Solimoes basin (1-RUC-1-AM); Chile (Rio Honda-1); Colombia, in the Llanos basin (Austral-1, La Reforma-1, Libertad Norte-1, Cravo Este-1, and Cano Yarumal-1), in the Upper Magdalena basin (Toldado-1 and Los Mangos-1); Ecuador (Frontera-1, a joint-exploration venture with Colombia); Mexico, in the Chiapas-Tabasco region (Guacho-1 and Iridi-1), in the Frontera Norte area (Huatempo-1); Peru, in the Madre de Dios basin (Armihuari-4X); Trinidad (West East Queen's Beach-1); and Venezuela (Musipan-1X). Brazil's upper Amazon (Solimoes basin) discovery, Colombia's Upper Magdalena basin discoveries Toldado-1 and Los Mangos-1, Mexico's Chiapas-Tabasco discoveries, Peru's confirmation of the giant Cashiriari discovery of 1986, and Venezuela's success in Monagas state were the highlights of 1987. 5 figs., 8 tabs.

  9. Seismic stratigraphy of middle Cretaceous unconformity (MCU) in central Gulf of Mexico basin

    Energy Technology Data Exchange (ETDEWEB)

    Faust, M.J.

    1986-05-01

    A widespread high-amplitude reflector seen on seismic data throughout the Gulf of Mexico has been called the middle Cretaceous unconformity (MCU). This reflector seems to be a major stratigraphic boundary in the Gulf of Mexico basin. It is believed to correspond to Vail's type 1 unconformity of middle Cenomanian age (97 Ma), which records an eustatic drop in sea level of approximately 200 m. This study area includes the entire Gulf of Mexico, except areas of thick, highly deformed salt where following the MCU with any degree of confidence becomes impossible. The MCU is easy to follow in multichannel seismic reflection profiles collected by the Institute for Geophysics of the University of Texas at Austin in the Gulf of Mexico. In central, deeper part of the gulf, reflectors above and below the MCU are parallel. In the southern and eastern rims of the gulf, along the Campeche and Florida escarpments, reflectors are truncated below the MCU and show onlap relationships above it. Therefore, the MCU may be interpreted as representing an unconformity along the southern and eastern rims of the Gulf of Mexico basin. The unconformity appears to die out and grade into a conformable section toward the center of the basin, and channeling is common along the Campeche and Florida escarpments. These channels can be projected back into canyons in the escarpments, which were probably initiated by subaerial exposure of the top of the escarpments during the middle Cretaceous lowstand. The downslope channels, being sourced by the canyons, were cut in deep water.

  10. Subsidence and associated shallow faulting hazard assessment in central Mexico using InSAR and GPS

    Science.gov (United States)

    Cabral-Cano, E.; Solano Rojas, D. E.; Oliver-Cabrera, T.; Salazar-Tlaczani, L.; Wdowinski, S.; DeMets, C.; Pacheco, J.

    2014-12-01

    While subsidence has affected Mexico City for over a century, other cities in central Mexico have been subjected to subsidence since the '80, as a result of their large urban expansion, population increase and aggressive groundwater extraction rates. The continuous subsidence results in severe damage to urban infrastructure and civil structures. Unfortunately the damage cost assessment and vulnerability are difficult to evaluate, because of the variable geographic extent and the continuous nature of the process, which have different characteristics than localized, short duration hazards, as earthquakes or flood events.We have monitored land subsidence in 17 cities in central Mexico using both InSAR and GPS observations. InSAR provides an unsurpassed synoptic view of the earth's dynamic surface. However, different satellite sensors and sometimes widely spaced data availability make it difficult to derive long-term time series, rapid changes or nonlinear variations of subsidence velocities. To alleviate this situation, higher temporal resolution subsidence observations of associated fault motion has been pursued using continuously operating GPS stations. We have developed a GPS network that covers 6 urban centers to detect short duration variations using different processing schemes that include both real-time solutions using RTNet as well as daily solution using Gipsy-Oasis.Cartographic products based on these techniques have been merged with other population, hydrology and meteorology data sets. This approach allows a better hazard assessment and provides information for other purposes, such as vulnerability for shallow faulting, land use zonations, and other decision elements for water resource management agencies. We will provide examples of these hazard assessments for several cities, including Mexico City, Aguascalientes, Morelia, Irapuato and Celaya and the challenges encountered to integrate these results with other data sets from federal and state

  11. The Central Gulf of Mexico Ocean Observing System (CenGOOS)

    Science.gov (United States)

    Howden, S. D.; Asper, V.; Lohrenz, S.; Roman, D.

    2005-05-01

    The University of Southern Mississippi has established a coastal ocean observing system in the north-central Gulf of Mexico, where there is a dearth of real-time oceanographic observations on the continental shelf. The development of the Central Gulf of Mexico Ocean Observing System (CenGOOS) follows overall guidelines for the Integrated Ocean Observing System as articulated by Ocean.US, and draft regional guidelines set forth by the Gulf of Mexico Coastal Ocean Observing System Regional Association (GCOOS-RA). The present system consists of a 3-m discus buoy measuring both meteorological and oceanographic parameters that are telemetered to the USM Department of Marine Science every three hours via Globalstar satellite communications. Data are served via a web site (www.cengoos.org). The near-term development of the system will include: Further integration with the coastal and near coastal observatories in the region Deployment of a two station, long range, high frequency radar system for mapping surface currents in the Mississippi Bight Deployment of additional instrumented moorings in the Mississippi Bight Development of a data assimilative nowcast/forecast numerical model of the region Regional database of high resolution multibeam and side-scan sonar data The initial plan for development of CenGOOS was formulated based on input solicited from identified stakeholders, regional priorities identified through opinion surveys conducted by the GCOOS-RA, and guidance from both Ocean.US and GCOOS-RA. An overview of our accomplishments, and vision for the future will be presented. This will include the hardware infrastructure, data management and communications plans and implementation, and other activities to integrate CenGOOS with the other observing systems in the Gulf of Mexico.

  12. Mexico

    Science.gov (United States)

    2002-01-01

    This true-color image of Mexico was acquired by the Moderate-resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra spacecraft. In areal extent, Mexico is the third largest country on the continent of North America (not counting Greenland, which is a province of Denmark), comprised of almost 2 million square kilometers (756,000 square miles) of land. Home to roughly 100 million people, Mexico is second only to the United States in population, making it the world's largest Spanish-speaking nation. To the north, Mexico shares its border with the United States-a line that runs some 3,100 kilometers (1,900 miles) east to west. About half of this border is defined by the Rio Grande River, which runs southeast to the Gulf of Mexico (partially obscured by clouds in this image) and marks the dividing line between Texas and Mexico. Toward the upper left (northwest) corner of this image is the Baja California peninsula, which provides the western land boundary for the Gulf of California. Toward the northwestern side of the Mexican mainland, you can see the Sierra Madre Occidental Mountains (brownish pixels) running southeast toward Lake Chapala and the city of Guadalajara. About 400 km (250 miles) east and slightly south of Lake Chapala is the capital, Mexico City. Extending northward from Mexico City is the Sierra Madre Oriental Mountains, the irregular line of brownish pixels that seem to frame the western edges of the bright white cumulus clouds in this image. Between these two large mountain ranges is a large, relatively dry highland region. To the south, Mexico shares borders with Guatemala and Belize, both of which are located south of Mexico's Yucatan Peninsula. Image courtesy Reto Stockli, Brian Montgomery, and Robert Simmon, based on data from the MODIS Science Team

  13. Neotropical River Otter Micro-Habitat Preference In West-Central Chihuahua, Mexico

    Directory of Open Access Journals (Sweden)

    Carrillo-Rubio E.

    2004-07-01

    Full Text Available We characterised habitat selected by the Neotropical otter (Lontra longicaudis in the Río San Pedro, located in the central portion of the State of Chihuahua in Northern Mexico. We monitored a 30 km stretch of the river for over two years and compared micro-site habitat characteristics at 21 used and 25 random sites. Characteristics of habitat preferred by the otter included pools that averaged >0.8 m deep, >14.6 m wide, >64% under-story vegetation cover, and rock talus/vegetation cover within 4.8 m.

  14. Fluoride in ash leachates: environmental implications at Popocatépetl volcano, central Mexico

    Directory of Open Access Journals (Sweden)

    M. A. Armienta

    2011-07-01

    Full Text Available Ash emitted by volcanic eruptions, even of moderate magnitude, may affect the environment and the health of humans and animals through different mechanisms at distances significantly larger than those indicated in the volcanic hazard maps. One such mechanism is the high capacity of ash to transport toxic volatiles like fluoride, as soluble condensates on the particles' surface. The mobilization and hazards related to volcanic fluoride are discussed based on the data obtained during the recent activity of Popocatépetl volcano in Central Mexico.

  15. CO2 Total Column Variability From Ground-Based FTIR Measurements Over Central Mexico

    Science.gov (United States)

    Baylon, J. L.; Stremme, W.; Plaza, E.; Bezanilla, A.; Grutter, M.; Hase, F.; Blumenstock, T.

    2014-12-01

    There are now several space missions dedicated to measure greenhouse gases in order to improve the understanding of the carbon cycle. Ground based measurement sites are of great value in the validation process, however there are only a few stations in tropical latitudes. We present measurements of solar-absorption infrared spectra recorded on two locations over Central Mexico: the High-Altitude Station Altzomoni (19.12 N, 98.65 W), located in the Izta-Popo National Park outside of Mexico City; and the UNAM's Atmospheric Observatory (19.32 N, 99.17 W) in Mexico City. These measurements were performed using a high resolution Fourier transform infrared spectrometer FTIR (Bruker, HR 120/5) at Altzomoni and a moderate resolution FTIR (Bruker, Vertex 80) within the city. In this work, we present the first results for total vertical columns of CO2 derived from near-infrared spectra recorded at both locations using the retrieval code PROFFIT. We present the seasonal cycle and variability from the measurements, as well as the full diagnostics of the retrieval in order assess its quality and discuss the differences of both instruments and locations (altitudes, urban vs remote). This work aims to contribute to generate high quality datasets for satellite validation.

  16. Stratigraphy, geochronology, geochemistry and tectonic setting of the Mesozoic Nazas Formation, north-central Mexico

    Science.gov (United States)

    Bartolini, Claudio

    Late Triassic to Middle Jurassic volcanic-sedimentary sequences that were part of the Mesozoic continental-margin of western North America are exposed in northern and central Mexico. These sequences have been grouped into the Nazas Formation and crop out in the states of Durango, Coahuila, Zacatecas, and San Luis Potosi. The Nazas Formation consists of 2,500 m or more of volcanic and pyroclastic rocks and interbedded clastic sedimentary rocks that were deposited in alluvial fan and fluvial depositional systems that developed in intra-arc basins, mainly fault-bound grabens and topographic depressions within an extending Mesozoic volcanic arc. Major and trace element geochemistry of volcanic rocks suggests that the volcanic suite is calc-alkaline and includes rhyolite, dacite, rhyodacite, andesite, trachyandesite and rare basalt. Pyroclastic rocks are basically air-fall tuffs and volcanic breccias. The sedimentary strata include conglomerate, sandstone, shale, and siltstone, locally red in color. Geochronology (Ar-Ar, K-Ar and Rb-Sr) and field evidence indicate that the age of the Nazas Formation ranges from Late Triassic to Middle Jurassic, but the peak of arc volcanism appears to be Early and Middle Jurassic. The Mesozoic magmatic arc in Mexico has a northwest trend and extends from Sonora to Chiapas. The arc structure is more than 2,000 km long, and possibly up to 150 km wide. The width of the arc is uncertain due to the limited number of surface outcrops, however, it did not extend east into the Gulf of Mexico. Arc-related magmatism began in latest Triassic time, but the peak of arc evolution occurred during the Early and Middle Jurassic. By Oxfordian time, the arc was deeply dissected and eroded, and magmatic activity had ceased. A marine transgression from the Gulf of Mexico covered most of the Nazas arc, depositing the initial sediments of the Oxfordian Zuloaga Limestone in the Mexican Geosyncline. Jurassic crustal extension in the Gulf of Mexico was

  17. Mexico.

    Science.gov (United States)

    1988-02-01

    Focus in this discussion of Mexico is on the following: geography; the people; history; political conditions; the economy; foreign relations; and relations between the US and Mexico. As of July 1987, the population of Mexico numbered 81.9 million with an estimated annual growth rate of 2.09%. 60% of the population is Indian-Spanish (mestizo), 30% American Indian, 9% white, and 1% other. Mexico is the most populous Spanish-speaking country in the world and the 2nd most populous country in Latin America. Education is decentralized and expanded. Mexico's topography ranges from low desert plains and jungle-like coastal strips to high plateaus and rugged mountains. Hernan Cortes conquered Mexico in 1919-21 and founded a Spanish colony that lasted for almost 300 years. Independence from Spain was proclaimed by Father Miguel Hidalgo on September 16, 1810; the republic was established on December 6, 1822. Mexico's constitution of 1917 provides for a federal republic with a separation of powers into independent executive, legislative, and judicial branches of government. Significant political themes of the administration of President Miguel de la Madrid Hurtado, who began his 6-year term in 1982, have been restructuring the economy, liberalizing trade practices, decentralizing government services, and eliminating corruption among public servants. In 1987, estimates put the real growth of the Mexican economy at 1.5%; the gross domestic product (GDP) had shrunk by 3.5% in 1986. Yet, on the positive side, Mexico's international reserves increased to record levels in 1987 (to about $15 billion), and its current account surplus reached more than $3 billion. Mexico has made considerable progress in moving to restructure its economy. It has substantially reduced impediments to international trade and has moved to reduce the number of parastatal firms. 1987 was the 2nd consecutive year in which Mexico recorded triple-digit inflation; inflation reached 158.8%. Other problems include

  18. Microsystems technologist workforce development capacity and challenges in Central New Mexico.

    Energy Technology Data Exchange (ETDEWEB)

    Osborn, Thor D.

    2008-04-01

    Sandia National Laboratories has made major investments in microsystems-related infrastructure and research staff development over the past two decades, culminating most recently in the MESA project. These investment decisions have been made based in part upon the necessity for highly reliable, secure, and for some purposes, radiation-hardened devices and subsystems for safety and sustainability of the United States nuclear arsenal and other national security applications. SNL's microsystems development and fabrication capabilities are located almost entirely within its New Mexico site, rendering their effectiveness somewhat dependent on the depth and breadth of the local microsystems workforce. Consequently, the status and development capacity of this workforce has been seen as a key personnel readiness issue in relation to the maintenance of SNL's microsystems capabilities. For this reason SNL has supported the instantiation and development of the Southwest Center for Microsystems Education, an Advanced Technology Education center funded primarily by the National Science Foundation, in order to foster the development of local training capacity for microsystems technologists. Although the SCME and the associated Manufacturing Technology program at Central New Mexico Community College have developed an effective curriculum and graduated several highly capable microsystems technologists, the future of both the center and the degree program remain uncertain due to insufficient student enrollment. The central region of New Mexico has become home to many microsystems-oriented commercial firms. As the demands of those firms for technologists evolve, SNL may face staffing problems in the future, especially if local training capacity is lost.

  19. Teacher perceptions of the Centers for Ocean Sciences Education Excellence: Central Gulf of Mexico program

    Science.gov (United States)

    Sempier, Tracie Tingle

    The 12 Centers for Ocean Sciences Education Excellence (COSEE) are funded by the National Science Foundation and are designed to promote creative ways of disseminating marine science research and its importance to the public. The focus of this study is the COSEE Central Gulf of Mexico program which encourages active partnerships between research scientists and teachers. In these collaborative partnerships, teachers and scientists work together to create educational products and disseminate best practices in ocean sciences education. The purpose of this study was to determine whether the lesson plans and curricula created through the Centers for Ocean Sciences Education Excellence: Central Gulf of Mexico program (COSEE:CGOM), which are the products of this collaboration, were being used effectively in the classroom. The study addressed issues such as teacher perceptions of collaboration with scientists, effectiveness of COSEE:CGOM curriculum implementation in producing more ocean literate students, and teachers' varying views concerning how to successfully implement new COSEE:CGOM knowledge and concepts into their classrooms in order to improve student scientific understanding. In addition, the study examined frequency of use of COSEE:CGOM lesson plans and identified predictor variables that can produce a model for understanding factors hindering or enhancing lesson plan use. Further, participant perceptions of using peer-teaching as a method for disseminating COSEE:CGOM information in their districts were addressed.

  20. Neospora caninum infection in beef cattle reared under grazing conditions in north-central Mexico

    Directory of Open Access Journals (Sweden)

    Karina Mondragón-Zavala

    2011-05-01

    Full Text Available Objetive. To determine the seroprevalence of N. caninum antibodies and prevalence of parasite DNA in blood, and estimate the association between seroprevalence and the potential risk of some factors in beef cattle under grazing conditions in north-central Mexico. Materials and methods. Blood samples from 139 cows and only 10 bulls belonging to 13 farms were collected and evaluated by ELISA test to detect antibodies against N. caninum. Furthermore, to determine the presence of parasite DNA, nested PCR probe was performed on blood samples. Association between potential risk factors and seroprevalence was estimated. Results. Overall seroprevalence was 23% (35/149 samples, while the prevalence of parasite DNA in blood was 28% (42/149 samples. Of the 149 animals examined 28 (19% were positive to both tests (25 cows and 3 bulls. Concordance between tests was k = 0.63. All herds had seropositive animals with positive parasite DNA detection in blood. The only risk factor identified was the presence of dogs (OR= 2.65. Conclusions. This study showed that bovine neospososis should be considered as an important infectious disease in north-central Mexico herds. Therefore, an epidemiological control should be taken into consideration to avoid the negative effect of this disease on mexican beef industry.

  1. Seismic structure along transitions from flat to normal subduction: central Mexico, southern Peru, and southwest Japan

    Science.gov (United States)

    Dougherty, Sara L.

    The fine-scale seismic structure of the central Mexico, southern Peru, and southwest Japan subduction zones is studied using intraslab earthquakes recorded by temporary and permanent regional seismic arrays. The morphology of the transition from flat to normal subduction is explored in central Mexico and southern Peru, while in southwest Japan the spatial coincidence of a thin ultra-slow velocity layer (USL) atop the flat slab with locations of slow slip events (SSEs) is explored. This USL is also observed in central Mexico and southern Peru, where its lateral extent is used as one constraint on the nature of the flat-to-normal transitions. In western central Mexico, I find an edge to this USL which is coincident with the western boundary of the projected Orozco Fracture Zone (OFZ) region. Forward modeling of the 2D structure of the subducted Cocos plate using a finite-difference algorithm provides constraints on the velocity and geometry of the slab's seismic structure in this region and confirms the location of the USL edge. I propose that the Cocos slab is currently fragmenting into a North Cocos plate and a South Cocos plate along the projection of the OFZ, by a process analogous to that which occurred when the Rivera plate separated from the proto-Cocos plate 10 Ma. In eastern central Mexico, observations of a sharp transition in slab dip near the abrupt end of the Trans Mexican Volcanic Belt (TMVB) suggest a possible slab tear located within the subducted South Cocos plate. The eastern lateral extent of the USL is found to be coincident with these features and with the western boundary of a zone of decreased seismicity, indicating a change in structure which I interpret as evidence of a possible tear. Analysis of intraslab seismicity patterns and focal mechanism orientations and faulting types provides further support for a possible tear in the South Cocos slab. This potential tear, together with the tear along the projection of the OFZ to the northwest

  2. Mexico.

    Science.gov (United States)

    1984-09-01

    Although Mexico has serious economic and population growth problems, the country is making progress toward solving both of these problems. Mexico has a population of 77.7 million and a population density of 102 persons/square mile. The country has a birth rate of 32/1000, a death rate of 6/1000, and an annual growth rate of 2.6%. The estimated infant mortality rate is 55/1000. The median age of the population is 17.4. Mexico City, with a population of 15 million, is the 3rd largest city in the world, and by 1995, it is expected to be the largest city in the world, with a projected population of 25.2 million. The government vigorously promotes family planning, and the annual population growth rate slowed down from a high of 3.2% in 1970-75 to the current rate of 2.6%. Mexico hopes to achieve replacement level fertility by the year 2000. Other government policies promote income equality, agricultural development, and regional equalization of population growth. In 1982 Mexico's per capita income was US$2270, exports totaled US$21 billion, and imports totaled US$15 billion. By 1976, Mexico's international debt was US$30.2 billion, and inflation was rampant. Recently, the newly elected president, Miguel de la Madrid of the Partido Revolucionario Institutional, obtained a grant of US$39 million from the International Monetary Fund and removed price controls. These efforts should help stabilize Mexico's economy. The country will also need to expand its exports and increase its cultivatable acreage. PMID:12339665

  3. The economic impact of Sandia National Laboratories on Central New Mexico and the State of New Mexico Fiscal Year 1998; ANNUAL

    International Nuclear Information System (INIS)

    Sandia National Laboratories (SNL) is a Department of Energy federally funded national security laboratory that uses engineering and science to ensure the security of the Nation. SNL provides scientific and engineering solutions to meet national needs in nuclear weapons and related defense systems, energy security, and environmental integrity. SNL works in partnerships with universities and industry to enhance their mission and transfer technology that will address emerging national challenges for both government and industry. For several years, the U.S. Department of Energy (DOE) Albuquerque Operations Office (AL) and New Mexico State University (NMSU) have maintained an inter-industry, input-output (I/O) model with capabilities to assess the impacts of developments initiated outside the economy such as federal DOE monies that flow into the state, on an economy. This model will be used to assess economic, personal income and employment impacts of SNL on Central New Mexico and the State of New Mexico. Caution should be exercised when comparing economic impacts between fiscal years prior to this report. The I/O model was rebased for FY 1998. The fringe benefits coefficients have been updated for the FY 1996 and FY 1997 economic impacts analysis. Prior to FY 1993 two different I/O base models were used to estimate the impacts. New technical information was released by the Bureau of Economic Analysis (BEA), U.S. Department of Commerce in 1991 and in 1994 and was incorporated in FY 1991, FY 1993, and FY 1994 I/O models. Also in 1993, the state and local tax coefficients and expenditure patterns were updated from a 1986 study for the FY 1992 report. Further details about the input-output model can be found in ''The Economic Impact of the Department of Energy on the State of New Mexico-FY 1998'' report by Lansford, et al. (1999). For this report, the reference period is FY 1998 (October 1, 1997, through September 30, 1998) and includes two major impact analyses: The

  4. Seismic hazard maps of Mexico, the Caribbean, and Central and South America

    Science.gov (United States)

    Tanner, James G.; Shedlock, Kaye M.

    2004-10-01

    The growth of megacities in seismically active regions around the world often includes the construction of seismically unsafe buildings and infrastructures due to an insufficient knowledge of existing seismic hazard and/or economic constraints. Minimization of the loss of life, property damage, and social and economic disruption due to earthquakes depends on reliable estimates of seismic hazard. We have produced a suite of seismic hazard estimates for Mexico, the Caribbean, and Central and South America. One of the preliminary maps in this suite served as the basis for the Caribbean and Central and South America portion of the Global Seismic Hazard Map (GSHM) published in 1999, which depicted peak ground acceleration (pga) with a 10% chance of exceedance in 50 years for rock sites. Herein we present maps depicting pga and 0.2 and 1.0 s spectral accelerations (SA) with 50%, 10%, and 2% chances of exceedance in 50 years for rock sites. The seismicity catalog used in the generation of these maps adds 3 more years of data to those used to calculate the GSH Map. Different attenuation functions (consistent with those used to calculate the U.S. and Canadian maps) were used as well. These nine maps are designed to assist in global risk mitigation by providing a general seismic hazard framework and serving as a resource for any national or regional agency to help focus further detailed studies required for regional/local needs. The largest seismic hazard values in Mexico, the Caribbean, and Central and South America generally occur in areas that have been, or are likely to be, the sites of the largest plate boundary earthquakes. High hazard values occur in areas where shallow-to-intermediate seismicity occurs frequently.

  5. Seismic hazard maps of Mexico, the Caribbean, and Central and South America

    Science.gov (United States)

    Tanner, J.G.; Shedlock, K.M.

    2004-01-01

    The growth of megacities in seismically active regions around the world often includes the construction of seismically unsafe buildings and infrastructures due to an insufficient knowledge of existing seismic hazard and/or economic constraints. Minimization of the loss of life, property damage, and social and economic disruption due to earthquakes depends on reliable estimates of seismic hazard. We have produced a suite of seismic hazard estimates for Mexico, the Caribbean, and Central and South America. One of the preliminary maps in this suite served as the basis for the Caribbean and Central and South America portion of the Global Seismic Hazard Map (GSHM) published in 1999, which depicted peak ground acceleration (pga) with a 10% chance of exceedance in 50 years for rock sites. Herein we present maps depicting pga and 0.2 and 1.0 s spectral accelerations (SA) with 50%, 10%, and 2% chances of exceedance in 50 years for rock sites. The seismicity catalog used in the generation of these maps adds 3 more years of data to those used to calculate the GSH Map. Different attenuation functions (consistent with those used to calculate the U.S. and Canadian maps) were used as well. These nine maps are designed to assist in global risk mitigation by providing a general seismic hazard framework and serving as a resource for any national or regional agency to help focus further detailed studies required for regional/local needs. The largest seismic hazard values in Mexico, the Caribbean, and Central and South America generally occur in areas that have been, or are likely to be, the sites of the largest plate boundary earthquakes. High hazard values occur in areas where shallow-to-intermediate seismicity occurs frequently. ?? 2004 Elsevier B.V. All rights reserved.

  6. Emerging deforestation trends in tropical dry forests ecoregions of Mexico and Central America

    Science.gov (United States)

    Portillo, C. A.; Cao, G.; Smith, V.

    2015-12-01

    Neotropical dry forests (TDF) have experienced an unprecedented deforestation that is leading to the loss of tropical biodiversity at a rapid pace, but information on deforestation dynamics in TDF is scarce. In this study, we present a sub-continental and national level assessment of TDF loss patterns in Mexico and Central America at high spatial and temporal resolution using remote sensing and GIS technologies. We used the Global Forest Change (GFC) dataset published by Hansen et al. (2013) which shows results from time-series analysis of Landsat images in characterizing global forest extent and change from 2000 through 2013. We analyzed forest loss within and around mapped TDF cover mapped by Portillo-Quintero et al. 2010. In order to minimize errors in source data, we overlaid a 25 x 25 km grid on top of the regional dataset and conducted a cell by cell and country by country inspection at multiple scales using high resolution ancillary data. We identified trends in the clustering of space-time TDF deforestation data using ArcGIS, categorizing trends in: new, consecutive, intensifying, persistent, diminishing, sporadic, oscillating and historical hotspots (high frequency of deforestation events) and cold spots (low frequency of deforestation). In general, the region is experiencing less frequent deforestation events with a higher number of intensifying and new cold spots across TDF landscapes. However, an important number of intensifying and persistent hotspots exist so no general trend in forest loss was detected for the period 2001-2013, except for El Salvador which shows a significant decreasing trend in forest loss. Mexico, Nicaragua, Honduras and Guatemala are the major sources of intensifying, persistent and new deforestation hot spots. These were identified in the southern pacific coast and the Yucatan Peninsula in Mexico, northwestern Guatemala, both western and eastern Honduras and around Lake Nicaragua in Nicaragua.

  7. Cooperation and tensions in multiethnic corporate societies using Teotihuacan, Central Mexico, as a case study.

    Science.gov (United States)

    Manzanilla, Linda R

    2015-07-28

    In this paper, I address the case of a corporate society in Central Mexico. After volcanic eruptions triggered population displacements in the southern Basin of Mexico during the first and fourth centuries A.D., Teotihuacan became a multiethnic settlement. Groups from different backgrounds settled primarily on the periphery of the metropolis; nevertheless, around the core, intermediate elites actively fostered the movement of sumptuary goods and the arrival of workers from diverse homelands for a range of specialized tasks. Some of these skilled craftsmen acquired status and perhaps economic power as a result of the dynamic competition among neighborhoods to display the most lavish sumptuary goods, as well as to manufacture specific symbols of identity that distinguished one neighborhood from another, such as elaborate garments and headdresses. Cotton attire worn by the Teotihuacan elite may have been one of the goods that granted economic importance to neighborhood centers such as Teopancazco, a compound that displayed strong ties to the Gulf Coast where cotton cloth was made. The ruling elite controlled raw materials that came from afar whereas the intermediate elite may have been more active in providing other sumptuary goods: pigments, cosmetics, slate, greenstone, travertine, and foreign pottery. The contrast between the corporate organization at the base and top of Teotihuacan society and the exclusionary organization of the neighborhoods headed by the highly competitive intermediate elite introduced tensions that set the stage for Teotihuacan's collapse. PMID:25775567

  8. Groundwater flow functioning in arid zones with thick volcanic aquifer units: North-Central Mexico

    International Nuclear Information System (INIS)

    Population increase in arid zones of Mexico has created the presence of 450% new cities with more that 50,000 inhabitants, as related to the 1950s. Due to the arid nature of the environment, the once sufficient spring and shallow water are becoming inadequate for the supply of those cities. An answer to this problem lies with the sustainable development of deep groundwater. The geological features of the country include fractured volcanic aquifer units that are more than 1,500 m thick, and are regionally continuous over of several hundred thousands of square kilometres. Groundwater development decisions need to consider, in the long span, inter-basin groundwater flow and the need to prevent environmental impacts in distant sites hydraulically connected with extraction centres. Radiocarbon is an excellent tool that initially has been applied to characterize groundwater in thick aquifer units in central Mexico to provide evidence on the hierarchy of flow (local/regional) and water age from where the distance of regional recharge was inferred. Radiocarbon also helps constrain flow path length which can then be used to characterize inter-basin groundwater communication. Radiocarbon has a large potential for future expansion of research and water management application. (author)

  9. Tectonic setting of blueschist and island-arc terranes of west-central Baja California, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Sedlock, R.L.

    1988-07-01

    Diverse oceanic rocks exposed in west-central Baja California (Mexico) are assigned to three shallowly dipping tectonic units. The lower plate is a subduction complex consisting of regionally metamorphosed blueschists and divided into structurally and petrologically distinct subterranes. The upper plate consists of Triassic-Lower Cretaceous arc rocks and overlapping mid-Cretaceous turbidites. A fault-bounded serpentinite-matrix melange between lower and upper plate rocks contains blueschist, eclogite, amphibolite, and variably serpentinized mafic and ultramafic blocks. Lower plate blueschists were metamorphosed in the late Early Cretaceous and uplifted along shallowly dipping normal faults during conditions of steady-state subduction. Exotic blocks of blueschist, eclogite, and amphibolite are derived from a cryptic terrane or terranes, record varied P-T-t histories, and were uplifted via tectonic emplacement or diapiric rise of serpentinite along the normal faults.

  10. The ectomycorrhizas of Lactarius cuspidoaurantiacus and Lactarius herrerae associated with Alnus acuminata in Central Mexico.

    Science.gov (United States)

    Montoya, Leticia; Bandala, Victor M; Garay-Serrano, Edith

    2015-08-01

    Two pure Alnus acuminata stands established in a montane forest in central Mexico (Puebla State) were monitored between 2010 and 2013 to confirm and recognize the ectomycorrhizal (EcM) systems of A. acuminata with Lactarius cuspidoaurantiacus and Lactarius herrerae, two recently described species. Through comparison of internal transcribed spacer (ITS) of nuclear ribosomal DNA sequences from basidiomes and ectomycorrhizas sampled in the forest stands, we confirmed their ectomycorrhizal association. The phytobiont was corroborated by comparing ITS sequences obtained from EcM root tips and leaves collected in the study site and from other sequences of A. acuminata available in Genbank. Detailed morphological and anatomical descriptions of the ectomycorrhizal systems are presented and complemented with photographs. PMID:25619188

  11. A detailed rock-magnetic and archeomagnetic study of lime-plasters from central Mexico

    Science.gov (United States)

    Soler-Arechalde, A. M.; Rodriguez, M.; Ramirez, O.; Gogichaishvili, A.; Caballero-Miranda, C.; Hueda-Tanabe, Y.; Urrutia-Fucugauchi, J.

    2003-04-01

    We carried out a reconnaissance rock-magnetic and archeomagnetic investigations of lime-plasters at some most important pre-Hispanic sites in Central Mexico. Both burned and unburned lime plasters (in total 30 samples) were analyzed from Teotihuacan, Tlatelolco, Santa Cruz Atizapan and Pañhu. The characteristic directions determined in this study are considered to be of primary origin. Thermomagnetic investigation show that the remanence is carried in most cases by magnetite or Ti-poor titanomagnetite. Unblocking temperature spectra and relatively high coercivity point to 'small' pseudo-single domain magnetic structure grains as responsible for remanent magnetization. Single-component, linear demagnetization plots were observed in most of cases. The mean site directions are consistent with the available reference master curve for Mesoamerica.

  12. Strategic integration of public transport networks with airport infrastructure in the megalopolis of Central Mexico: Evolution and challenges

    NARCIS (Netherlands)

    Salinas, C.R.; Garcia Cejudo, D.; Van Timmeren, A.

    2014-01-01

    Airports represent the contemporary global gateways of metropolitan areas worldwide. In the case of the megalopolis of Central Mexico, air transport was traditionally used only by upper social segments of the population, however, during the last years, the introduction of low-cost airlines in the co

  13. Mexico Geoid Heights (MEXICO97)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This 2' geoid height grid for Mexico, and North-Central America, is the MEXICO97 geoid model. The computation used about one million terrestrial and marine gravity...

  14. Mexico.

    Science.gov (United States)

    1993-01-01

    The background notes on Mexico provide text and recent statistical information on the geography, population, government, economy, and foreign relations, specifically the North American Free Trade Agreement with US. The 1992 population is estimated at 89 million of which 60% are mestizo (Indian-Spanish), 30% are American Indian, 9% are Caucasian, and 1% are other. 90% are Roman Catholic. There are 8 years of compulsory education. Infant mortality is 30/1000 live births. Life expectancy for males is 68 years and 76 years for females. The labor force is comprised of 30% in services, 24% in agriculture and fishing, 19% in manufacturing, 13% in commerce, 7% in construction, 4% in transportation and communication, and .4% in mining. There are 31 states and a federal district. Gross domestic product (GDP) per capita was $3200 in 1991. Military expenditures were .5% of GDP in 1991. The average inflation rate is 19%. Mexico City with 20 million is the largest urban center in the world. In recent years, the economy has been restructured with market oriented reforms; the result has been a growth of GDP of 3.6% in 1991 from 2% in 1987. Dependence on oil exports has decreased. There has been privatization and deregulation of state-owned companies. Subsidies to inefficient companies have been stopped. Tariff rates were reduced. The financial debt has been reduced and turned into a surplus of .8% in 1992. Mexico's foreign debt has been reduced from its high in 1987 of $107 billion. Agricultural reforms have been ongoing for 50 years. Land was redistributed, but standards of living and productivity have improved only slightly. Rural land tenure regulations have been changed, and other economic reforms are expected. Mexico engages in ad hoc international groups and is selective about membership in international organizations. PMID:12178052

  15. The economic impact of Los Alamos National Laboratory on north-central New Mexico and the state of New Mexico fiscal year 1997

    International Nuclear Information System (INIS)

    Los Alamos National Laboratory (LANL) is a multidisciplinary, multiprogram laboratory with a mission to enhance national military and economic security through science and technology. Its mission is to reduce the nuclear danger through stewardship of the nation's nuclear stockpile and through its nonproliferation and verification activities. An important secondary mission is to promote US industrial competitiveness by working with US companies in technology transfer and technology development partnerships. Los Alamos is involved in partnerships and collaborations with other federal agencies, with industry (including New Mexico businesses), and with universities worldwide. For this report, the reference period is FY 1997 (October 1, 1996, through September 30, 1997) and includes two major impact analysis: the impact of LANL activities on north-central New Mexico and the economic impacts of LANL on the state of New Mexico. Total impact represents both direct and indirect respending by business, including induced effects (respending by households). The standard multipliers used in determining impacts result from the inter-industry, input-output models developed for the three-county region and the state of New Mexico. 5 figs., 12 tabs

  16. The economic impact of Los Alamos National Laboratory on north-central New Mexico and the state of New Mexico fiscal year 1998

    Energy Technology Data Exchange (ETDEWEB)

    Lansford, R.R. [New Mexico State Univ., Las Cruces, NM (US); Adcock, L.D.; Gentry, L.M. [Albuquerque Operations Office, Dept. of Energy, Albuquerque, NM (US); Ben-David, S. [Univ. of New Mexico, Albuquerque, NM (US). Dept. of Economics; Temple, J. [Temple (John), Albuquerque, NM (US)

    1999-08-05

    Los Alamos National Laboratory (LANL) is a multidisciplinary, multiprogram laboratory with a mission to enhance national military and economic security through science and technology. Its mission is to reduce the nuclear danger through stewardship of the nation`s nuclear stockpile and through its nonproliferation and verification activities. An important secondary mission is to promote US industrial competitiveness by working with US companies in technology transfer and technology development partnerships. Los Alamos is involved in partnerships and collaborations with other federal agencies, with industry (including New Mexico businesses), and with universities worldwide. For this report, the reference period is FY 1998 (October 1, 1997, through September 30, 1998). It includes two major impact analysis: the impact of LANL activities on north-central New Mexico and the economic impacts of LANL on the state of New Mexico. Total impact represents both direct and indirect responding by business, including induced effects (responding by households). The standard multipliers used in determining impacts result from the inter-industry, input-output models developed for the three-county region and the state of New Mexico.

  17. The economic impact of Los Alamos National Laboratory on north-central New Mexico and the state of New Mexico fiscal year 1997

    Energy Technology Data Exchange (ETDEWEB)

    Lansford, R.R.; Nielsen, T.G.; Schultz, J. [New Mexico State Univ., Las Cruces, NM (United States); Adcock, L.D.; Gentry, L.M. [Dept. of Energy, Albuquerque, NM (United States). Albuquerque Operations Office; Ben-David, S. [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Economics; Temple, J. [Temple (John), Albuquerque, NM (United States)

    1998-05-29

    Los Alamos National Laboratory (LANL) is a multidisciplinary, multiprogram laboratory with a mission to enhance national military and economic security through science and technology. Its mission is to reduce the nuclear danger through stewardship of the nation`s nuclear stockpile and through its nonproliferation and verification activities. An important secondary mission is to promote US industrial competitiveness by working with US companies in technology transfer and technology development partnerships. Los Alamos is involved in partnerships and collaborations with other federal agencies, with industry (including New Mexico businesses), and with universities worldwide. For this report, the reference period is FY 1997 (October 1, 1996, through September 30, 1997) and includes two major impact analysis: the impact of LANL activities on north-central New Mexico and the economic impacts of LANL on the state of New Mexico. Total impact represents both direct and indirect respending by business, including induced effects (respending by households). The standard multipliers used in determining impacts result from the inter-industry, input-output models developed for the three-county region and the state of New Mexico. 5 figs., 12 tabs.

  18. Cenozoic evolution of tectono-fluid and metallogenic process in Lanping Basin,western Yunnan Province, Southwest China: Constraints from apatite fission track data

    Institute of Scientific and Technical Information of China (English)

    LI Xiaoming; SONG Yougui

    2006-01-01

    Since the Mesozoic, abundant metal and salt deposits have been formed in the Lanping Basin, western Yunnan Province, Southwest China, constituting a well-known hydrothermal ore belt in China. Most of the deposits are meso-epithermal hydrothermal deposits. This paper preliminarily deals with the mineralization ages of hydrothermal deposits in the Lanping Basin by using the apatite fission track method, and integrates the spatial distribution of the deposits and their regional geological backgrounds, to give the preliminary viewpoints as follows: (1) the apatite fission track ages acquired range from 19.9 Ma to 52.8 Ma, much younger than those of their host strata, so they may be considered to be mineralization ages, which represent the late mineralization period; (2) the apatite fission track ages tend to become younger from the west to the middle of the basin, indicating that the latest evolution of tectono-fluid and/or metallogenic processes of the middle basin ended later than that in the west; (3) in the Paleogene, most of the Cu deposits were formed in the western part of the basin; (4) the major metallogenic processes occur between the Paleogene and the Neogene, because the eastern and western edges of the basin were subducted into and collided with its bilateral continental blocks, respectively, and the central fault was strongly activated, which led to the processes of large-scale ore-forming fluids, and their differentiation and transport because of the variation of their physical and chemical properties. Having been squeezed and uplifted, the Lanping Basin became an intermontane basin that contains many kinds of fluid traps resulting in the formation of different types of ore deposits (for example, Pb-Zn, Cu, Ag) of different scales in the middle of the basin. Simultaneously, the fluids with volatile elements such as Hg, Sb and As were transported upwards along the central fault system and diffused into its subordinate fractures, thus leading to the

  19. Environmental interpretation of lithofacies and biofacies, lower Sierra Madre Limestone, west central Chiapas, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, D.K.T.

    1989-03-01

    The Jiquipilas section of the Cretaceous Sierra Madre Limestone, which encompasses the lower part of the formation, was measured northwest of the town of Ocozocuautla in west-central Chiapas, Mexico. The section is 2140 m thick and is characterized by six lithofacies interpreted to represent supratidal, intertidal platform, restricted inner shelf, open inner shelf, shoal, and open-marine middle shelf environments. Overall, the sequence is submergent, with minor emergent episodes. Based upon cluster analysis, three biofacies associations were established: offshore middle shelf, nearshore middle shelf, and inner shelf. The lower 2045 m of the section are dominated by the inner shelf association, while the upper 95 m are dominated by the offshore association. The nearshore middle-shelf association is a minor component throughout the section. Correlation with a measure section from a previous study resulted in a composite thickness for the Sierra Madre Limestone in west-central Chiapas of 3355 m. This figure is considerably greater than previously reported thicknesses for the formation. It indicates that sedimentation on the Yucatan carbonate platform during the middle Cretaceous may have approached sediment accumulation rates in modern sedimentary basins.

  20. Assessment of tsunami hazards for the Central American Pacific coast from southern Mexico to northern Peru

    Science.gov (United States)

    Brizuela, B.; Armigliato, A.; Tinti, S.

    2014-07-01

    Central America (CA), from Guatemala to Panama, has been struck by at least 52 tsunamis between 1539 and 2013, and in the extended region from Mexico to northern Peru (denoted as ECA, Extended Central America in this paper) the number of recorded tsunamis in the same time span is more than 100, most of which were triggered by earthquakes located in the Middle American Trench that runs parallel to the Pacific coast. The most severe event in the catalogue is the tsunami that occurred on 2 September 1992 off Nicaragua, with run-up measured in the range of 5-10 m in several places along the Nicaraguan coast. The aim of this paper is to assess the tsunami hazard on the Pacific coast of this extended region, and to this purpose a hybrid probabilistic-deterministic analysis is performed, that is adequate for tsunamis generated by earthquakes. More specifically, the probabilistic approach is used to compute the Gutenberg-Richter coefficients of the main seismic tsunamigenic zones of the area and to estimate the annual rate of occurrence of tsunamigenic earthquakes and their corresponding return period. The output of the probabilistic part of the method is taken as input by the deterministic part, which is applied to calculate the tsunami run-up distribution along the coast.

  1. Magnitude and extent of land subsidence in central Mexico revealed by regional InSAR ALOS time-series survey

    Science.gov (United States)

    Chaussard, E.; Wdowinski, S.; Amelung, F.; Cabral-Cano, E.

    2013-05-01

    Massive groundwater extraction is very common in Mexico and is well known to result in land subsidence. However, most surveys dedicated to land subsidence focus on one single city, mainly Mexico City, and thus fail to provide a comprehensive picture of the problem. Here we use a space-based radar remote sensing technique, known as Interferometric Synthetic Aperture Radar (InSAR) to detect land subsidence in the entire central Mexico area. We used data from the Japanese satellite ALOS, processed over 600 SAR images acquired between 2007-2011 and produced over 3000 interferograms to cover and area of 200,000 km2 in central Mexico. We identify land subsidence in twenty-one areas, including seventeen cities, namely from east to west, Puebla, Mexico city, Toluca de Lerdo, Queretaro, San Luis de la Paz, south of San Luis de la Paz, Celaya, south of Villa de Reyes, San Luis Potosi, west of Villa de Arista, Morelia, Salamanca, Irapuato, Silao, Leon, Aguascalientes, north of Aguascalientes, Zamora de Hidalgo, Guadalajara, Ahuacatlan, and Tepic. Subsidence rates of 30 cm/yr are observed in Mexico City, while in the other locations typical rates of 5-10 cm/yr are noticed. Regional surveys of this type are necessary for the development of hazard mitigation plans and efficient use of ground-based monitoring. We additionally correlate subsidence with land use, surface geology, and faults distribution and suggest that groundwater extraction for agricultural, urban, and industrial uses are the main causes of land subsidence. We also reveal that the limits of the subsiding areas often correlate with existing faults, motion on these faults being driven by water extraction rather than by tectonic activity. In all the subsiding locations we observe high ground velocity gradients emphasizing the significant risks associated with land subsidence in central Mexico. Averaged 2007-2011 ground velocity map from ALOS InSAR time-series in central Mexico, revealing land subsidence in 21

  2. Geochemical and faunal investigation of shelf/slope environment of north-central Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Healy-Williams, N.; Trainor, D.M.; Williams, D.F.; Jenkins, P. (Univ. of South Carolina, Columbia (United States)); Gary, A. (Unocal, Brea, CA (United States))

    1991-03-01

    The shelf/slope environment of the northern Gulf of Mexico offers a complex pattern of marine and terrestrial derived sediments. The authors have performed geochemical and faunal investigations on approximately 80 box cores from 30 to 1,300 m water depth from the north-central Gulf of Mexico. The geochemical results relate the modern and late Holocene distribution of marine and terrestrial organic carbon to the present day depositional systems of this actively prograding system. Total organic carbon (%TOC) analyses of the surface sediment are used to characterize the distribution of TOC on the Louisiana shelf and slope as a function of distance from the Mississippi delta. Stable carbon isotopic analyses ({sup 13}C/{sup 12}C) of the TOC are used to distinguish marine from terrestrial organic carbon. Higher amounts of terrestrial organic carbon are associated with the western edge of the Mississippi delta. Marine organic carbon increases seaward of the deltaic system. The percentage of fine-grained (< 63 microns) calcium carbonate also increases seaward of the Mississippi delta as well as with lateral distance along the shelf-slope. Percent CaCO{sub 3} and {delta}{sup 13}C of the fine-grained carbonate determinations have been performed in Plio-Pleistocene cores and exploration wells from this region. The authors use this data to examine how the modern/late Holocene patterns of these variables have changed as a function of continental margin evolution. They have also analyzed the benthic foraminiferal distributions in terms of the sedimentary nature of the box cores. They note increased abundances in certain species in relation to deltaic vs nondeltaic environments along with some species altering their depth ranges between the two environments.

  3. Climate change in Central America and Mexico: regional climate model validation and climate change projections

    Energy Technology Data Exchange (ETDEWEB)

    Karmalkar, Ambarish V. [University of Oxford, School of Geography and the Environment, Oxford (United Kingdom); Bradley, Raymond S. [University of Massachusetts, Department of Geosciences, Amherst, MA (United States); Diaz, Henry F. [NOAA/ESRL/CIRES, Boulder, CO (United States)

    2011-08-15

    Central America has high biodiversity, it harbors high-value ecosystems and it's important to provide regional climate change information to assist in adaptation and mitigation work in the region. Here we study climate change projections for Central America and Mexico using a regional climate model. The model evaluation shows its success in simulating spatial and temporal variability of temperature and precipitation and also in capturing regional climate features such as the bimodal annual cycle of precipitation and the Caribbean low-level jet. A variety of climate regimes within the model domain are also better identified in the regional model simulation due to improved resolution of topographic features. Although, the model suffers from large precipitation biases, it shows improvements over the coarse-resolution driving model in simulating precipitation amounts. The model shows a dry bias in the wet season and a wet bias in the dry season suggesting that it's unable to capture the full range of precipitation variability. Projected warming under the A2 scenario is higher in the wet season than that in the dry season with the Yucatan Peninsula experiencing highest warming. A large reduction in precipitation in the wet season is projected for the region, whereas parts of Central America that receive a considerable amount of moisture in the form of orographic precipitation show significant decreases in precipitation in the dry season. Projected climatic changes can have detrimental impacts on biodiversity as they are spatially similar, but far greater in magnitude, than those observed during the El Nino events in recent decades that adversely affected species in the region. (orig.)

  4. Geology and Geochronology of the Central Part of Chiapanecan Volcanic Arc, Mexico.

    Science.gov (United States)

    Layer, P. W.

    2006-12-01

    The Chiapanecan Volcanic Arc (CVA) is a 150 km stretch of volcanoes irregularly aligned in a northwest direction, including El Chichón volcano located in the central portion of the State of Chiapas, southern Mexico. It lies between two great volcanic features: the Trans-Mexican Volcanic Arc to the northwest, and the Central American Volcanic Arc to the southeast, in a complex zone of the interaction of the North American, Caribbean and Cocos Plates. The central part of the CVA is composed of an irregular northwest alignment of at least 12 volcanic structures located 80 km to the southeast of El Chichón (the only currently active volcano in the CVA). These structures include one explosion crater (Navenchauc), one collapse structure (Apas), one dome complex (Tzontehuitz) and nine volcanic domes (Navenchauc, Huitepec, Amahuitz, La Iglesia, Mispía, La Lanza, Venustiano Carranza, Miguel Hidalgo and Santotón) with associated pyroclastic flow deposits. The juvenile lithics from these deposits have a porphyritic texture with phenocrysts of plagioclase (±), amphibole (±), clinopyroxene (±), orthopyroxene (±) and Fe-Ti oxides surrounded by a matrix composed by microlites of plagioclase and glass. The chemical results obtained from representative samples from the deposits and structures indicate that these belong to the series of subalkaline rocks, and fall into the calcalkaline field with medium to high contents of potassium. They vary in their composition from andesite to dacite with an interval of silica between a 56 to a 66% (wt.). The ages reported in the literature and obtained in this study by means of the K-Ar and the 40Ar/39Ar methods, respectively, indicated that volcanism was episodic and spanned a time from 2100 ky ago (Tzontehuitz) to 225 ky ago (Venustiano Carranza).

  5. Water balances of old-growth and regenerating montane cloud forests in central Veracruz, Mexico

    Science.gov (United States)

    Muñoz-Villers, L. E.; Holwerda, F.; Gómez-Cárdenas, M.; Equihua, M.; Asbjornsen, H.; Bruijnzeel, L. A.; Marín-Castro, B. E.; Tobón, C.

    2012-09-01

    SummaryThis paper compares the water budgets of two adjacent micro-catchments covered by mature (MAT) and 20-year-old secondary (SEC) lower montane cloud forests, respectively, in central Veracruz, Mexico over a 2-year period. Rainfall (P) and streamflow (Q) were measured continuously, whereas dry canopy evaporation (transpiration Et), wet canopy evaporation (rainfall interception I), and cloud water interception (CWI) were quantified using a combination of field measurements and modeling. Mean annual P was 3467 mm, of which typically 80% fell during the wet season (May-October). Fog interception occurred exclusively during the dry season (November-April), and was ⩽2% of annual P for both forests. Rainfall interception loss was dominated by post-event evaporation of intercepted water rather than by within-event evaporation. Therefore, the higher overall I (i.e. including CWI) by the MAT (16% of P vs. 8% for the SEC) reflects a higher canopy storage capacity, related in turn to higher leaf area index and greater epiphyte biomass. Annual Et totals derived from sapflow measurements were nearly equal for the MAT and SEC (˜790 mm each). Total annual water yield calculated as P minus (Et + I) was somewhat higher for the SEC (2441 mm) than for the MAT (2077 mm), and mainly reflects the difference in I. Mean annual Q was also higher for the SEC (1527 mm) than for the MAT (1338 mm), and consisted mostly of baseflow (˜90%). Baseflow recession rates were nearly equal between the two forests, as were stormflow coefficients (4% and 5% for MAT and SEC, respectively). The very low runoff response to rainfall is attributed to the high infiltration and water retention capacities of the volcanic soils throughout the ˜2 m deep profile. The water budget results indicate that ˜875 and 700 mm year-1 leave the SEC and MAT as deep groundwater leakage, which is considered plausible given the fractured geology in the study area. It is concluded that 20 years of natural regeneration

  6. Monstera florescanoana (Araceae, a new species from central Veracruz, Mexico Monstera florescanoana (Araceae, una especie nueva de la región central de Veracruz, México

    Directory of Open Access Journals (Sweden)

    Thomas B. Croat

    2010-08-01

    Full Text Available Monstera florescanoana (Araceae, a new species in section Monstera, endemic to central Veracruz, Mexico, is described and illustrated. This species appears to be most closely related to Monstera siltepecana Matuda and Monstera dubia (Kunth Engl. et K. Krause.Se describe e ilustra Monstera florescanoana (Araceae, una nueva especie de la sección Monstera, endémica de la región central del estado de Veracruz, México. Esta especie parece estar más cercanamente relacionada a los taxones Monstera siltepecana Matuda y Monstera dubia (Kunth Engl. et K. Krause.

  7. Monstera florescanoana (Araceae), a new species from central Veracruz, Mexico Monstera florescanoana (Araceae), una especie nueva de la región central de Veracruz, México

    OpenAIRE

    Croat, Thomas B.; Thorsten Krömer; Amparo Acebey

    2010-01-01

    Monstera florescanoana (Araceae), a new species in section Monstera, endemic to central Veracruz, Mexico, is described and illustrated. This species appears to be most closely related to Monstera siltepecana Matuda and Monstera dubia (Kunth) Engl. et K. Krause.Se describe e ilustra Monstera florescanoana (Araceae), una nueva especie de la sección Monstera, endémica de la región central del estado de Veracruz, México. Esta especie parece estar más cercanamente relacionada a los taxones Monster...

  8. Mexico

    International Nuclear Information System (INIS)

    This document summarizes the key energy data for Mexico: 1 - energy organizations and policy: Ministry of energy (SENER), Comision Reguladora de Energia (CRE), Ministry of Finances, Ministry of trade and industrial development (SECOFI), national commission for energy savings (CONAE); 2 - companies: federal commission of electricity (CFE), Minera Carbonifera Rio Escondido (MICARE - coal), Pemex (petroleum); 3 - energy production: resources, electric power, petroleum, natural gas; 4 - energy consumption; 5 - stakes and perspectives. Some economic and energy indicators are summarized in a series of tables: general indicators, supply indicators (reserves, refining and electric capacity, energy production, foreign trade), demand indicators (consumption trends, end use, energy independence, energy efficiency, CO2 emissions), energy status per year and per energy source. (J.S.)

  9. [Nesting habitat characterization for Amazona oratrix (Psittaciformes: Psittacidae) in the Central Pacific, Mexico].

    Science.gov (United States)

    Monterrubio-Rico, Tiberio C; Álvarez-Jara, Margarito; Tellez-Garcia, Loreno; Tena-Morelos, Carlos

    2014-09-01

    The nesting requirements of the Yellow-headed Parrot (Amazona oratrix) are poorly understood, despite their broad historical distribution, high demand for pet trade and current endangered status. Information concerning their nesting requirements is required in order to design specific restoration and conser- vation actions. To assess this, we studied their nesting ecology in the Central Pacific, Michoacan, Mexico during a ten year period. The analyzed variables ranged from local scale nest site characteristics such as nesting tree species, dimensions, geographic positions, diet and nesting forest patches structure, to large scale features such as vegetation use and climatic variables associated to the nesting tree distributions by an ecological niche model using Maxent. We also evaluated the parrot tolerance to land management regimes, and compared the Pacific nest trees with 18 nest trees recorded in an intensively managed private ranch in Tamaulipas, Gulf of Mexico. Parrots nested in tall trees with canopy level cavities in 92 nest-trees recorded from 11 tree species. The 72.8% of nesting occurred in trees of Astronium graveolens, and Enterolobium cyclocarpum which qualified as key- stone trees. The forests where the parrots nested, presented a maximum of 54 tree species, 50% of which were identified as food source; besides, these areas also had a high abundance of trees used as food supply. The lowest number of tree species and trees to forage occurred in an active cattle ranch, whereas the highest species rich- ness was observed in areas with natural recovery. The nesting cavity entrance height from above ground of the Pacific nesting trees resulted higher than those found in the Gulf of Mexico. We hypothesize that the differences may be attributed to Parrot behavioral differences adapting to differential poaching pressure and cavity avail- ability. Nesting trees were found in six vegetation types; however the parrots preferred conserved and riparian semi

  10. Trichospermum lessertianum comb. nov., the correct name for the Cuban species of Trichospermum (Malvaceae: Grewioideae also found in Mexico and Central America

    Directory of Open Access Journals (Sweden)

    Laurence J. Dorr

    2011-02-01

    Full Text Available The correct name for the Cuban species of Trichospermum Bl. (Malvaceae: Grewioideae also found in Mexico and Central America is T. lessertianum (Hochr. Dorr, comb. n. The name T. mexicanum (DC. Baill., incorrectly applied to this Cuban species, should be restricted to a species endemic to western and southern Mexico.

  11. Trichospermum lessertianum comb. n., the correct name for the Cuban species of Trichospermum (Malvaceae, Grewioideae) also found in Mexico and Central America

    OpenAIRE

    Dorr, Laurence J.

    2011-01-01

    Abstract The correct name for the Cuban species of Trichospermum Bl. (Malvaceae: Grewioideae) also found in Mexico and Central America is Trichospermum lessertianum (Hochr.) Dorr, comb. n. The name Trichospermum mexicanum (DC.) Baill., incorrectly applied to this Cuban species, should be restricted to a species endemic to western and southern Mexico.

  12. On the age of human footprints in Central Mexico: paleomagnetic constraints

    Science.gov (United States)

    Rocha Fernandez, J.; Gogichaishvili, A.; Martin Del Pozo, A.; Urrutia Fucugauchi, J.

    2007-05-01

    Until recently, we thought we knew where ancestral Native Americans came from (central Siberia, then across Beringia), and when they arrived (about 13 000 cal BP, after a trek between the recently separated Canadian ice sheets after Fiedel, 2006). Recent theories of American origins postulate multiple pre-Clovis migrations including Transpacific or coastal voyages by Australians, Melanesians, or Ainu, and even a Transatlantic migrations by Caucasoid Solutreans from Iberia. Thus, timing, route and origin of the first colonization to the Americas remains one of the most important topics in human evolution. Human and animal footprints have been found within the upper bedding surfaces of the Xalnene volcanic ash layer that outcrops in the Valsequillo Basin, south of Puebla, Mexico (Gonzalez et al., 2005). The ash has been dated to at least 40 ka BP. Paleomagnetic investigation yielded an intermediate magnetic polarity for Xalnene ash deposits while nearby Toluquilla volcano is reversely magnetized. Moreover, the absolute geomagnetic paleointensity derived from the volcanic lava flow is significantly reduced with respect to the present day geomagnetic field strength. It is quite possible that the ash as well as volcanic lava flow formed during worldwide observed Laschamp geomagnetic event.

  13. Medicinal Plants from Mexico, Central America, and the Caribbean Used as Immunostimulants

    Science.gov (United States)

    Juárez-Vázquez, María del Carmen; Campos-Xolalpa, Nimsi

    2016-01-01

    A literature review was undertaken by analyzing distinguished books, undergraduate and postgraduate theses, and peer-reviewed scientific articles and by consulting worldwide accepted scientific databases, such as SCOPUS, Web of Science, SCIELO, Medline, and Google Scholar. Medicinal plants used as immunostimulants were classified into two categories: (1) plants with pharmacological studies and (2) plants without pharmacological research. Medicinal plants with pharmacological studies of their immunostimulatory properties were subclassified into four groups as follows: (a) plant extracts evaluated for in vitro effects, (b) plant extracts with documented in vivo effects, (c) active compounds tested on in vitro studies, and (d) active compounds assayed in animal models. Pharmacological studies have been conducted on 29 of the plants, including extracts and compounds, whereas 75 plants lack pharmacological studies regarding their immunostimulatory activity. Medicinal plants were experimentally studied in vitro (19 plants) and in vivo (8 plants). A total of 12 compounds isolated from medicinal plants used as immunostimulants have been tested using in vitro (11 compounds) and in vivo (2 compounds) assays. This review clearly indicates the need to perform scientific studies with medicinal flora from Mexico, Central America, and the Caribbean, to obtain new immunostimulatory agents. PMID:27042188

  14. Extinction Risk of Pseudotsuga Menziesii Populations in the Central Region of Mexico: An AHP Analysis

    Directory of Open Access Journals (Sweden)

    Javier López-Upton

    2015-05-01

    Full Text Available Within the Analytic Hierarchy Process (AHP framework, a hierarchical model was created considering anthropogenic, genetic and ecological criteria and sub-criteria that directly affect Douglas-fir (Pseudotsuga menziesii (Mirb. risk of extinction in central Mexico. The sub-criteria values were standardized, weighted, and ordered by importance in a pairwise comparison matrix; the model was mathematically integrated to quantify the degree of extinction risk for each of the 29 populations present in the study area. The results indicate diverse levels of risk for the populations, ranging from very low to very high. Estanzuela, Presa Jaramillo, Peñas Cargadas and Plan del Baile populations have very low risk, with values less than 0.25. On the other hand, Vicente Guerrero, Morán, Minatitlán, La Garita and Tonalapa populations have very high risk (>0.35 because they are heavily influenced by anthropogenic (close to roads and towns, ecological (presence of exotic species and little or no natural regeneration and genetic (presence of mature to overmature trees and geographic isolation factors. In situ conservation activities, prioritizing their implementation in populations at most risk is highly recommended; in addition, germplasm collection for use of assisted gene flow and migration approaches, including artificial reforestation, should be considered in these locations.

  15. Medicinal Plants from Mexico, Central America, and the Caribbean Used as Immunostimulants.

    Science.gov (United States)

    Alonso-Castro, Angel Josabad; Juárez-Vázquez, María Del Carmen; Campos-Xolalpa, Nimsi

    2016-01-01

    A literature review was undertaken by analyzing distinguished books, undergraduate and postgraduate theses, and peer-reviewed scientific articles and by consulting worldwide accepted scientific databases, such as SCOPUS, Web of Science, SCIELO, Medline, and Google Scholar. Medicinal plants used as immunostimulants were classified into two categories: (1) plants with pharmacological studies and (2) plants without pharmacological research. Medicinal plants with pharmacological studies of their immunostimulatory properties were subclassified into four groups as follows: (a) plant extracts evaluated for in vitro effects, (b) plant extracts with documented in vivo effects, (c) active compounds tested on in vitro studies, and (d) active compounds assayed in animal models. Pharmacological studies have been conducted on 29 of the plants, including extracts and compounds, whereas 75 plants lack pharmacological studies regarding their immunostimulatory activity. Medicinal plants were experimentally studied in vitro (19 plants) and in vivo (8 plants). A total of 12 compounds isolated from medicinal plants used as immunostimulants have been tested using in vitro (11 compounds) and in vivo (2 compounds) assays. This review clearly indicates the need to perform scientific studies with medicinal flora from Mexico, Central America, and the Caribbean, to obtain new immunostimulatory agents. PMID:27042188

  16. The influence of mistletoes on birds in an agricultural landscape of central Mexico

    Science.gov (United States)

    Zuria, Iriana; Castellanos, Ignacio; Gates, J. Edward

    2014-11-01

    Mistletoes are hemiparasitic flowering plants that function as keystone resources in forests and woodlands of temperate regions, where a positive relationship between mistletoe density and avian species richness has been observed. Mistletoes have been less studied in tropical regions and the relationship between birds and mistletoes has seldom been explored in tropical agricultural systems. Therefore, we studied the presence of infected trees and infection prevalence (i.e., number of parasitized trees/total number of trees) by Psittacanthus (Loranthaceae) mistletoes in 23 hedgerows located in an agricultural landscape of central Mexico during the dry and rainy seasons, and investigated the relationship between bird species richness and abundance and the abundance of mistletoes. We found a mean of 74 mistletoe plants per 100-m transect of only one species, Psittacanthus calyculatus. Thirty-one percent of the trees surveyed were infected and tree species differed in infection prevalence, mesquite (Prosopis laevigata) being the most infected species with 86% of the surveyed trees infected. For both seasons, we found a positive and significant association between bird species richness and number of mistletoe plants. The same pattern was observed for total bird abundance. Many resident and Neotropical migratory birds were observed foraging on mistletoes. Our results show that mistletoes are important in promoting a higher bird species richness and abundance in tropical agricultural landscapes.

  17. Archaeomagnetic Study of Limeplasters from Pre-hispanic Sites from Central Mexico

    Science.gov (United States)

    Hueda, Y. T.; Soler, A. M.; Urrutia-Fucugauchi, J. H.; Rebolledo, M.; Goguitchaichvili, A.; Caballero, C. I.; Tarling, D. H.

    2001-05-01

    In this work, we report the new archeomagnetic data from limeplasters of the archeological sites Teopancazco, Teotihuacan, Xochicalco and Templo Mayor, which correspond to Classical, Epi-Classical and Post-Classical periods of Mesoamerica, respectively. The results obtained allowed us to improve the existing paleosecular variation reference curve for Mesoamerica. The previously reported results, we used for our database belongs to Latham et al., 1986, (stalagmite with a time span from 750 A.D. to 1941 A.D.), and from Urrutia-Fucugauchi, 1996, (historic eruptions). We also incorporated some declination data from explorers and mexican scientists during 1587 to 1869. The observatory data used in this study come from the Teoloyucan magnetic observatory, run by UNAM in central Mexico since 1923. Results of unburned limeplasters permit date the time of elaboration of the limeplasters. Moreover, we were able to discriminate between different construction steps for studied archaeological sites. From the study of burned samples it is possible to date the re-occupation of Teotihuacan culture by the Aztecs.

  18. Modeling susceptibility to deforestation of remaining ecosystems in North Central Mexico with logistic regression

    Institute of Scientific and Technical Information of China (English)

    L. Miranda-Aragón; E.J. Trevi(n)o-Garza; J. Jiménez-Pérez; O.A. Aguirre-Calderón; M.A. González-Tagle; M. Pompa-García; C.A. Aguirre-Salado

    2012-01-01

    Determining underlying factors that foster deforestation and delineating forest areas by levels of susceptibility are of the main challenges when defining policies for forest management and planning at regional scale.The susceptibility to deforestation of remaining forest ecosystems (shrubland,temperate forest and rainforest) was conducted in the state of San Luis Potosi,located in north central Mexico.Spatial analysis techniques were used to detect the deforested areas in the study area during 1993-2007.Logistic regression was used to relate explanatory variables (such as social,investment,forest production,biophysical and proximity factors) with susceptibility to deforestation to construct predictive models with two focuses:general and by biogeographical zone.In all models,deforestation has positive correlation with distance to rainfed agriculture,and negative correlation with slope,distance to roads and distance to towns.Other variables were significant in some cases,but in others they had dual relationships,which varied in each biogeographical zone.The results show that the remaining rainforest of Huasteca region is highly susceptible to deforestation.Both approaches show that more than 70% of the current rainforest area has high and very high levels of susceptibility to deforestation.The values represent a serious concern with global warming whether tree carbon is released to atmosphere.However,after some considerations,encouraging forest environmental services appears to be the best alternative to achieve sustainabie forest management.

  19. A new species of Cletocamptus Schmankewitsch, 1875 (Crustacea, Copepoda, Harpacticoida) from a high altitude saline lake in Central Mexico

    OpenAIRE

    Eduardo Suarez Morales; Omar Barrera-Moreno; Jorge Ciros-Pérez

    2013-01-01

    During the analysis of littoral samples collected from a high-altitude saline crater lake in Central Mexico, several female and male specimens of harpacticoid copepods were recovered and taxonomically examined. They were found to represent an undescribed species of the canthocamptid genus Cletocamptus Schmankewitsch, 1875. The new species, C. gomezi n. sp. is described herein based on specimens of both sexes. It resembles C. stimpsoni Gómez, Fleeger, Rocha-Olivares and Foltz, 2004 from Louisi...

  20. Students and Teachers’ Reasons for Using the First Language Within the Foreign Language Classroom (French and English) in Central Mexico

    OpenAIRE

    Mora Pablo Irasema; Lengeling M. Martha; Rubio Zenil Buenaventura; Crawford Troy; Goodwin Douglas

    2011-01-01

    The present study explores the use of the first language in a context of foreign language teaching. This qualitative research presents the classroom practice and points of view of French and English teachers and students within a public educational institute in central Mexico using the techniques of questionnaires and semi-structured interviews. The results show that teachers and the majority of students perceive the use of the first language as positive and part of the teaching and ...

  1. Initial Time Of Two High Altitude Crater Lakes (Nevado De Toluca, Central Mexico) Recorded In Subfossil Cladocera

    OpenAIRE

    Szeroczyńska Krystyna; Zawisza Edyta; Wojewódka Marta

    2015-01-01

    The objective of this study was the recognition and reconstruction of the origin of two high altitude lakes and the ecological conditions of their early existence based on subfossil Cladocera and chemical analyses. The study focused on the oldest lacustrine sediments from Lake Sol and Lake Luna, located in the crater of Volcano Nevado de Toluca (Central Mexico). The Nevado de Toluca crater developed approximately 12 ka yr BP. According to the literature, the volcano was last active approximat...

  2. Trace gas and particle emissions from domestic and industrial biofuel use and garbage burning in central Mexico

    OpenAIRE

    Christian, T. J; R. J. Yokelson; B. Cárdenas; Molina, L. T.; G. Engling; Hsu, S.-C.

    2009-01-01

    In central Mexico during the spring of 2007 we measured the initial emissions of 12 gases and the aerosol speciation for elemental and organic carbon (EC, OC), anhydrosugars, Cl, NO3, and 20 metals from 10 cooking fires, four garbage fires, three brick making kilns, three charcoal making kilns, and two crop residue fires. Global biofuel use has been estimated at over 2600 Tg/y. With several simple case ...

  3. [Distribution patterns of wild felids (Carnivora: Felidae) in the dry tropics of Central-Western Mexico].

    Science.gov (United States)

    Charre-Medellín, Juan Felipe; Monterrubio-Rico, Tiberio Cesar; Guido-Lemus, Daniel; Mendoza, Eduardo

    2015-09-01

    The Michoacán state is characterized by the existence of important environmental heterogeneity in terms of climate, topography and types of vegetation, which includes the worldwide endangered tropical dry forest. Some reports indicating the presence of the six species of felids occurring in Mexico in this region have been made; however, evidence to support these reports is scant, and filling this lack of information is particularly critical in the case of threatened species or habitats. The aim of this study was to systematize and analyze data distribution patterns of felids in the state of Michoacán, in the Central-Western Mexico. We conducted a review of literature and databases to compile species presence records in the study region. Moreover, we analyzed data obtained from ten years of field work conducted in the region, in which complementary methods (detection of direct and indirect evidence of species occurrence along transects, camera-trapping and interviews to local people) were applied to detect the presence of felid species. We compiled a total of 29 presence records of felids in the region from our review. Additionally, field work, which accumulated 1,107.5 km of walked transects, and 8 699 camera-trap days, produced 672 records of species presence. Lynx rufus was the species with the lowest number of records and the most restricted distribution. In contrast, the species with the greatest number of records was Leoparduspardalis (n = 343). In general, 89% of felids records occurred below 1,000 masl. Overall mean annual temperature of presence records was 24 °C and mean annual precipitation was 1,040 mm. The species whose presence records showed the most distinctive pattern, in terms of temperature and precipitation associated, was L. rufus (15.8 ± 1.3°C and 941 ± 171 mm). Results of a cluster analysis showed that areas supporting different combinations of eco-regions and types of vegetation could be grouped in five clusters having different

  4. Metallogenic characteristics of volcanic hydrothermal type U-Au-polymetallic deposits in Yanshan-Liaoning region

    International Nuclear Information System (INIS)

    Yanshan-Liaoning area is located in the east part of the northern margin of North-China platform. It is a famous metallogenic region of Mesozoic volcanic hydrothermal type U-Au-polymetallic deposits in the country. The metallogenesis is controlled by a united Late Mesozoic continental taphrogenic volcano-magmatic activity. The metallogenic epochs are concentrated in Late Jurassic-Early Cretaceous periods. The metallogenic media are moderate and moderate-low temperature volcanic hydrothermal solutions originated from the mixing of volcano-magmatic water, metamorphic water and atmospheric water. The ore-forming materials are mainly derived from enrichment type upper mantle and lower crust. (8 refs., 5 figs.)

  5. The Large-Scale Oscillations Influence Over the Interdecadal Climate Variability in Mexico's Central Region

    Science.gov (United States)

    Jofre, R.; Brito-Castillo, L.; Tereshchenko, I.; Atmospheric Sciences Climatology Climate Variability

    2013-05-01

    Climate in the highlands of Mexico displays high variability due to its complex terrain and elevation. The knowledge to elucidate the principal forcings of these variations can be useful for forecasting annual and seasonal temperature and precipitation over this area. Due to its complexity a small area in the highlands was delimited with defined physical boundaries, encompassing several states of Mexico. The study area was defined as Mexico's Central Region (MCR), which is located between 19.5 ° - 22.5 ° N and 98.5 ° - 104 ° W. Most of this area overlies the plateau of Anahuac, whose physical boundaries extend to the north from the "Sierras Transversales" (composed by the "Sierra de Zacatecas", the "Sierra de la "Breña" and the "Sierra de San Luis") to the "Eje Neovolcánico" to the south; east and west boundaries are confined by the "Sierra Madre Oriental" and the "Sierra Madre Occidental", respectively. Daily data of maximum and minimum temperature and precipitation series from a total of 112 weather stations were obtained from CLICOM and ERICIII databases. Several climatic indices with average periods of phase oscillations greater than five years, such as the Pacific Decadal Oscillation (PDOI), the Atlantic Multidecadal Oscillation (AMOI), The Arctic Oscillation (AOI), the North Atlantic Oscillation (NAOI), and Aleutian Low Pressure (ALPI) on a monthly basis for all series, except the ALPI series which is on annual rate, were also used in this study. Indices data were obtained from the web site http://www.cicimar.ipn.mx/oacis/Indices_Climaticos.php/. The common period of all series was 1961-2000. We applied Principal Component Analysis to precipitation and temperature series to identify the principal modes of variation of the series. The first mode explained more than 68% of the variance in the original series and corresponds to annual variations. Contour maps were useful to elucidate that temperature variations are highly correlated with the terrain

  6. Agave salmiana Plant Communities in Central Mexico as Affected by Commercial Use

    Science.gov (United States)

    Martínez Salvador, Martin; Mata-González, Ricardo; Morales Nieto, Carlos; Valdez-Cepeda, Ricardo

    2012-01-01

    Agave salmiana is a native plant species harvested for the commercial production of mezcal ( Agave spirits) in the highlands of central Mexico. The objective of this study was to identify vegetation changes in natural communities where A. salmiana has been differentially harvested for commercial purposes. Three plant community categories were identified in the state of Zacatecas based on their history of A. salmiana utilization: short (less than 10 years of use), moderate (about 25 years), and long (60 or more years). Species cover, composition, and density were evaluated in field surveys by use category. A gradient of vegetation structure of the communities parallels the duration of A. salmiana use. A. salmiana density was greatest (3,125 plants ha-1) in the short-use areas and less (892 plants ha-1) in the moderate-use areas, associated with markedly greater density of shrubs (200%) and Opuntia spp. (50%) in moderate-use areas. The main shrubs were Larrea tridentata, Mimosa biuncifera, Jatropha dioica and Buddleia scordioides while the main Opuntia species were Opuntia leucotricha and Opuntia robusta. A. salmiana density was least (652 plants ha-1) in the long-use areas where shrubs were less abundant but Opuntia spp. density was 25% higher than in moderate-use areas. We suggest that shrubs may increase with moderate use creating an intermediate successional stage that facilitates the establishment of Opuntia spp. Long-term Agave use is generating new plant communities dominated by Opuntia spp. (nopaleras) as a replacement of the original communities dominated by A. salmiana (magueyeras).

  7. Late Pleistocene and Holocene environmental history of the Iguala Valley, Central Balsas Watershed of Mexico.

    Science.gov (United States)

    Piperno, D R; Moreno, J E; Iriarte, J; Holst, I; Lachniet, M; Jones, J G; Ranere, A J; Castanzo, R

    2007-07-17

    The origin of agriculture was a signal development in human affairs and as such has occupied the attention of scholars from the natural and social sciences for well over a century. Historical studies of climate and vegetation are closely associated with crop plant evolution because they can reveal the ecological contexts of plant domestication together with the antiquity and effects of agricultural practices on the environment. In this article, we present paleoecological evidence from three lakes and a swamp located in the Central Balsas watershed of tropical southwestern Mexico that date from 14,000 B.P. to the modern era. [Dates expressed in B.P. years are radiocarbon ages. Calibrated (calendar) ages, expressed as cal B.P., are provided for dates in the text.] Previous molecular studies suggest that maize (Zea mays L.) and other important crops such as squashes (Cucurbita spp.) were domesticated in the region. Our combined pollen, phytolith, charcoal, and sedimentary studies indicate that during the late glacial period (14,000-10,000 B.P.), lake beds were dry, the climate was cooler and drier, and open vegetational communities were more widespread than after the Pleistocene ended. Zea was a continuous part of the vegetation since at least the terminal Pleistocene. During the Holocene, lakes became important foci of human activity, and cultural interference with a species-diverse tropical forest is indicated. Maize and squash were grown at lake edges starting between 10,000 and 5,000 B.P., most likely sometime during the first half of that period. Significant episodes of climatic drying evidenced between 1,800 B.P. and 900 B.P. appear to be coeval with those documented in the Classic Maya region and elsewhere, showing widespread instability in the late Holocene climate. PMID:17537917

  8. Electromagnetic Induction Survey at an Archaeological Site in Chapingo (Central Mexico)

    Science.gov (United States)

    Salas, J. L.; Arango, C.; Cabral-Cano, E.; Arciniega-Ceballos, A.; Vergara, F.; Novo, X.

    2013-05-01

    The aim of this work is to locate buried remains of ancient civil constructions belonging to the Teotihuacan culture in Chapingo, Central Mexico. Several housing structures of this culture have been found during the excavation of a pipe trench within the University of Chapingo campus in the town of Chapingo. These units were found at 6 m deep covered by recent lacustrine sediments. In order to further explore the extension of this settlement that could guide further excavations and shed more light into these settlements, we have initiated a multi technique geophysical exploration. Here we present the initial results from this survey. An electromagnetic induction survey (EMI) was carried out to characterize the subsurface in an area of about 16,000 m2. We used a GF Instruments CMD-4 conductivity meter to map the horizontal distribution of the subsurface electrical conductivity. This instrument was operated in a continuous mode and linked to a single frequency GPS receiver attached to the probe to georeference the survey. The distance between the probe coils was 3.77 m and the investigation depth range was 4-6 m. The resulting electrical conductivity map shows two low conductivity zones with a NW-SE orientation. The inphase map also presented these characteristics. Since the electrical conductivity is associated with the material compaction, low conductivity values are expected for highly consolidated material; thus our results suggest that these low conductivity features could be related to areas that were the soil was compacted to serve as foundation of these ancient structures. The EMI survey present good initial results and will be expanded along with other techniques such as electrical tomography and ground penetrating radar in the near future in order to better map the extend of Teotihuacan culture in the region.

  9. Semiarid watershed response in central New Mexico and its sensitivity to climate variability and change

    Directory of Open Access Journals (Sweden)

    E. R. Vivoni

    2009-06-01

    Full Text Available Hydrologic processes in the semiarid regions of the Southwest United States are considered to be highly susceptible to variations in temperature and precipitation characteristics due to the effects of climate change. Relatively little is known about the potential impacts of climate change on the basin hydrologic response, namely streamflow, evapotranspiration and recharge, in the region. In this study, we present the development and application of a continuous, semi-distributed watershed model for climate change studies in semiarid basins of the Southwest US. Our objective is to capture hydrologic processes in large watersheds, while accounting for the spatial and temporal variations of climate forcing and basin properties in a simple fashion. We apply the model to the Río Salado basin in central New Mexico since it exhibits both a winter and summer precipitation regime and has a historical streamflow record for model testing purposes. Subsequently, we use a sequence of climate change scenarios that capture observed trends for winter and summer precipitation, as well as their interaction with higher temperatures, to perform long-term ensemble simulations of the basin response. Results of the modeling exercise indicate that precipitation uncertainty is amplified in the hydrologic response, in particular for processes that depend on a soil saturation threshold. We obtained substantially different hydrologic sensitivities for winter and summer precipitation ensembles, indicating a greater sensitivity to more intense summer storms as compared to more frequent winter events. In addition, the impact of changes in precipitation characteristics overwhelmed the effects of increased temperature in the study basin. Nevertheless, combined trends in precipitation and temperature yield a more sensitive hydrologic response throughout the year.

  10. Inversion polymorphism in some natural populations of Drosophila pseudoobscura from central Mexico

    Directory of Open Access Journals (Sweden)

    Salceda Víctor M.

    2007-01-01

    Full Text Available Samples of D. pseudoobscura were taken in seventeen localities in Central Mexico inside the parallels 18o - 20o N, with the purpose of determine the chromosomal polymorphism in the third of the different populations of this species. From each captured female a single larva of its offspring was taken, its salivary glands extracted and stained with a solution of aceto orcein to observe the polytene chromosomes. From these smears the corresponding karyotype of each larva was determined, keeping a record of them. With the information gathered the relative frequency of each one of the fourteen different inversions found was calculated. A grand total of 1894 third chromosomes were analyzed. The fourteen different inversions found are equivalent to a 34.1 % of the total chromosomal variation of the species. The most abundant inversions found were: TL 50.6 %, CU 27.2 5, SC 9.1 % and EP 5.5 %; the remaining ten inversions detected are in general grounds rare ones with variable relative frequencies depending on the locality. Analysis of the predominant inversions for each population was done. The presence of West-East gradients is reported, even if in cases not so well defined, since as one moves in a particular direction the ups and downs in relative frequency for the alternating pairs TL-CU; TL-SC in the western populations and TL-CU in the eastern ones were observed. The assignment of each population to a particular race was also done, and such a way we were able to recognize three different races coexisting in the area of study.

  11. Ecosystem service trade-offs, perceived drivers, and sustainability in contrasting agroecosystems in central Mexico

    Directory of Open Access Journals (Sweden)

    2015-03-01

    Full Text Available The ability of agroecosystems to provide food ultimately depends on the regulating and supporting ecosystem services that underpin their functioning, such as the regulation of soil quality, water quality, soil erosion, pests, and pollinators. However, there are trade-offs between provisioning and regulating or supporting services, whose nature at the farm and plot scales is poorly understood. We analyzed data at the farm level for two agroecosystems with contrasting objectives in central Mexico: one aimed at staple crop production for self-subsistence and local markets, the other directed to a cash crop for export markets. Bivariate and multivariate trade-offs were analyzed for different crop management strategies (conventional, organic, traditional, crop rotation and their underpinning socioeconomic drivers. There was a clear trade-off between crop yield and soil quality in self-subsistence systems. However, other expected trade-offs between yields and soil quality did not always occur, likely because of the overall good soils of the region and the low to medium input profile of most farms. Trade-offs were highly dependent on farm-specific agricultural practices; organic, traditional, and rotation management systems generally showed smaller trade-offs between yield and soil quality, pest control, and biodiversity than did conventional management systems. Perceived drivers reported by farmers included increasing prices for cash crops, rising costs of inputs, and extreme climatic events (e.g., drought, hail, frost. Farmers did not identify the regulation of soil quality, water quality, soil erosion, pests, or pollinators as important constraints. Although acceptable yields could be maintained irrespective of key regulating and supporting services according to these perceptions, current levels of soil erosion and nutrient runoff are likely to have important negative effects at the watershed scale. Sustainability in both agroecosystems could be

  12. Formation conditions of the Rudny Altai metallogenic province

    Science.gov (United States)

    Kozlov, M. S.

    2015-07-01

    The results of previous geological, petrochemical, and metallogenic surveys conducted from the 1960s to the 1990s provide the geological and tectonic basis of this study. The unique mineral deposits of the Rudny Altai metallogenic province were formed in the Middle Paleozoic (S2-C1) at the junction between different structures of the Altai-Mongolian terrane: the Alei-Charysh-Tigirek rift (in the north) with the Korgon-Markakol' island arc and Belaya Uba-Maimyr intra-arc trough (in the southwest). The Rudny Altai structural-formational zone that formed at the junction between these structures evolved as a magmatic arc and was characterized by the formation of granite-greenschist arches, volcanoplutonic magmatism and high heat and fluid flow (greenschist-facies metamorphism of Upper Silurian-Upper Devonian rocks and deposition of pyrite-bearing hydrothermal-sedimentary horizons, VMS and copper-VMS deposits and isolated base-metal ore bodies). The tectonomagmatic history of the Rudny Altai zone can be subdivided into several stages: Ludlow-Emsian, Late Emsian-Givetian, Frasnian-Early Famennian, Middle Famennian-Early Visean, and Late Visean-Serpukhovian. The island arc is represented by volcanic rocks of the andesite-dacite-rhyolite (early stage), basalt-rhyolite (Late Emsian-Eifelian), and basalt-andesite-rhyolite series (Late Visean). Volcanosedimentary strata (until the Givetian age) and turbidites up to 3-5 km thick were deposited in the interarc trough. Because of their metastable behavior, the volcanic rocks became actively involved in ion-exchange reactions with the formational waters, whereas the differences in hydraulic head between arches and troughs created favorable conditions for the transport of the metamorphic fluids, and the thermal gradient promoted thermodiffusion of divalent species of Mg, Pb, Zn, Cu, etc. toward the high-temperature zone and development of the high-Mg metamorphic-metasomatic alteration with a VMS-base-metal mineralization. As a

  13. Perchlorate in pleistocene and holocene groundwater in North-Central New Mexico

    Science.gov (United States)

    Plummer, L.N.; Böhlke, J.K.; Doughten, M.W.

    2006-01-01

    Groundwater from remote parts of the Middle Rio Grande Basin in north-central New Mexico has perchlorate (ClO4-) concentrations of 0.12-1.8 ??g/L Because the water samples are mostly preanthropogenic in age (0-28 000 years) and there are no industrial sources in the study area, a natural source of the ClO4- is likely. Most of the samples have Br-, Cl-, and SO42- concentrations that are similar to those of modern bulk atmospheric deposition with evapotranspiration (ET) factors of about 7-40. Most of the ET values for Pleistocene recharge were nearly twice that for Holocene recharge. The NO3-/Cl- and ClO4-/Cl- ratios are more variable than those of Br -/Cl- or SO42-/Cl-. Samples thought to have recharged under the most arid conditions in the Holocene have relatively high NO3-/Cl- ratios and low ??15N values (+1 per mil (???)) similar to those of modern bulk atmospheric N deposition. The ??18O values of the NO 3- (-4 to 0 ???) indicate that atmospheric N0 3- was not transmitted directly to the groundwater but may have been cycled in the soils before infiltrating. Samples with nearly atmospheric NO3-/Cl- ratios have relatively high ClO4- concentrations (1.0-1.8 ??g/L) with a nearly constant ClO4-/Cl- mole ratio of (1.4 ?? 0.1) ?? 10-4, which would be consistent with an average ClO 4- concentration of 0.093 ?? 0.005 ??g/L in bulk atmospheric deposition during the late Holocene in north-central NM. Samples thought to have recharged underwetter conditions have higher ??15N values (+3 to +8 ???), lower N03-/Cl- ratios, and lower ClO4-/Cl- ratios than the ones most likely to preserve an atmospheric signal. Processes in the soils that may have depleted atmospherically derived NO3- also may have depleted ClO4- to varying degrees prior to recharge. If these interpretations are correct, then ClO4- concentrations of atmospheric origin as high as 4 ??g/L are possible in preanthropogenic groundwater in parts of the Southwest where ET approaches a factor of 40. Higher ClO4

  14. Bathymetry Mapping of the West Florida Shelf (Central Region), Gulf of Mexico (NODC Accession 0001410)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — XYZ ASCII format data generated from the 2001 multibeam sonar survey of the West Florida Shelf, Gulf of Mexico. The data include high-resolution bathymetry and...

  15. Backscatter Mapping of the West Florida Shelf (Central Region), Gulf of Mexico (NODC Accession 0001410)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — XYZ ASCII format data generated from the 2001 multibeam sonar survey of the West Florida Shelf, Gulf of Mexico. The data include high-resolution bathymetry and...

  16. Soil Survey Geographic (SSURGO) database for Grant County, Central and Southern Parts, New Mexico

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This data set is a digital soil survey and generally is the most detailed level of soil geographic data developed by the National Cooperative Soil Survey. The...

  17. Analysis on metallogenic conditions of Xiangshan uranium ore-field

    International Nuclear Information System (INIS)

    Based on the research achievements the authors propose that: the formation of the ore-field not only results from a favourable regional tectonic background, i.e. a giant tectonic intersection of two deep-seated faults expressed as granite and volcanic belts, but also, the more important point is the favourable metallogenic environments, namely: the ore-field is located in a large superimposed collapse-type volcanic basin with simple binary structure; the space superimposition of U-rich basement metamorphic rocks intruded by granite, and extremely thick U-rich volcanic rocks preparing a uranium source 'bank' for the ore-formation; the combination of main faults cutting the basement, the fault structures in the cover and volcanic collapse structures create favourable space for the ore-formation (migration of ore-forming fluid and accumulation of ore-forming material); the geologic trap formed by compression-over thrust is the important ore-preserving condition

  18. Eolic central Guerrero Negro, BCS, Mexico, performance first year operation; Central eolica Guerrero Negro, BCS, Mexico, resultados del primer ano de operacion

    Energy Technology Data Exchange (ETDEWEB)

    Cadenas Tovar, Roberto; Sanchez Cornejo, Carlos; Lopez Rios, Serafin [Comision Federal de Electricidad, Morelia, Michoacan (Mexico); Ley Romero, Jose R [Comision Federal de Electricidad, Guerrero Negro, Baja California Sur (Mexico)

    2000-07-01

    Comision Federal de Electricidad installed a 600 kW wind turbine in the Guerrero Negro isolated electrical grid to evaluate, under actual operation conditions, the contribution of wind energy in the generation of electricity. This paper describes the performance of the wind turbine in terms of its availability, power curve and electricity produced. The results have been satisfactory, electricity was supplied with a lesser fuel consumption than before. [Spanish] La Comision Federal de Electricidad instalo en Guerrero Negro, Baja California Sur, Mexico un aerogenerador de 600 kW para evaluar en condiciones reales de operacion la integracion de la energia del viento a sistemas electricos aislados basados en diesel. En este trabajo se describen los resultados del primer ano de operacion del aerogenerador en terminos de su disponibilidad, curva de potencia y generacion obtenida. Los resultados han sido satisfactorios, registrandose una reduccion en el consumo de combustible fosil en el sistema.

  19. Trisection distribution pattern of volcanic type uranium deposits and metallogenic prognosis in northeast section of Qinhang metallogenic belt

    International Nuclear Information System (INIS)

    Uranium deposits of volcanic type are densely distributed along the two sides of Fuzhou-Shaoxing section of Qinhang Paleo-plate structure zone. They are the products of tectonic-volcanic magmatism at the same Mesozoic tectonic background and comprise the northeast section of Qinhang metallogenic belt. Structure was found the main ore-controlling factor of volcanic type uranium deposits in this area. Volcanic structures and faults jointly control the deposits, not only in the hierarchically controlling of different grade structures to mineralization units but also the even space distribution pattern of uranium deposit in the unit. According to the trisection distribution pattern in cluster area, some area is predicted for further research and exploration. (authors)

  20. Concentration and dry deposition of mercury species in arid south central New Mexico (2001-2002).

    Science.gov (United States)

    Caldwell, Colleen A; Swartzendruber, Philip; Prestbo, Eric

    2006-12-15

    This research was initiated to characterize atmospheric deposition of reactive gaseous mercury (RGM), particulate mercury (HgP; <2.5 microm), and gaseous elemental mercury (Hg0) in the arid lands of south central New Mexico. Two methods were field-tested to estimate dry deposition of three mercury species. A manual speciation sampling train consisting of a KCl-coated denuder, 2.5 microm quartz fiber filters, and gold-coated quartz traps and an ion-exchange membrane (as a passive surrogate surface) were deployed concurrently over 24-h intervals for an entire year. The mean 24-h atmospheric concentration for RGM was 6.8 pg m(-3) with an estimated deposition of 0.10 ng m(-2) h(-1). The estimated deposition of mercury to the passive surrogate surface was much greater (4.0 ng m(-2) h(-1)) but demonstrated a diurnal pattern with elevated deposition from late afternoon to late evening (1400-2200; 8.0 ng m(-2) h(-1)) and lowest deposition during the night just prior to sunrise (2200-0600; 1.7 ng m(-2) h(-1)). The mean 24-h atmospheric concentrations for HgP and Hg0 were 1.52 pg m(-3) and 1.59 ng m(-3), respectively. Diurnal patterns were observed for RGM with atmospheric levels lowest during the night prior to sunrise (3.8 pg m(-3)) and greater during the afternoon and early evening (8.9 pg m(-3)). Discernible diurnal patterns were not observed for either HgP or Hg0. The total dry deposition of Hg was 5.9 microg m-2 year-' with the contribution from the three species as follows: RGM (0.88 microg m(-2) year(-1)), HgP (0.025 microg m(-2) year(-1)), and Hg0 (5.0 microg m(-2) year(-1)). The annual wet deposition for total mercury throughout the same collection duration was 4.2 microg m(-2) year (-1), resulting in an estimated total deposition of 10.1 microg m(-2) year(-1) for Hg. On one sampling date, enhanced HgP (12 pg m(-3)) was observed due to emissions from a wildfire approximately 250 km to the east. PMID:17256491

  1. Implementation of MAR within the Rio Grande Basin of Central New Mexico, USA

    Science.gov (United States)

    Marley, Robert; Blandford, T. Neil; Ewing, Amy; Webb, Larry; Yuhas, Katherine

    2014-05-01

    The U.S. Bureau of Reclamation has identified the Rio Grande basin within Central New Mexico as one of several regions where water supplies are over-allocated and future conflicts over the inadequate resource are highly likely. Local water providers have consistently identified managed aquifer recharge (MAR) as an important tool to provide conjunctive management of surface-water, groundwater, and reclaimed water sources in order to extend the useful life of existing water sources. However, MAR projects have been slow to take root partly due to rigorous demonstration requirements, groundwater quality protection concerns, and ongoing water right uncertainties. At first glance the several thousand meters of unconsolidated basin-fill sediments hosting the regional aquifer appear to provide an ideal environment for the subsurface storage of surplus water. However, the basin has a complex structural and depositional history that impacts the siting and overall effectiveness of MAR systems. Several recharge projects are now in various stages of implementation and are overcoming site specific challenges including source water and ambient groundwater compatibility, low-permeability sediments and compartmentalization of the aquifer by extensive faulting, well clogging, and overall water quality management. This presentation will highlight ongoing efforts of these water providers to develop full-scale recharge facilities. The performance of natural in-channel infiltration, engineered infiltration galleries, and direct injection systems designed to introduce from 500 to 5,000 mega-liters per annum to target intervals present from 150 to 600 meters below ground surface will be described. Source waters for recharge operations include inter-basin transferred surface water and highly treated reclaimed water sources requiring from minor to extensive treatment pre-recharge and post-recovery. Operational complexities have raised concerns related to long-term operation and maintenance

  2. Soil-geomorphology and “wet” cycles in the Holocene record of North-Central Mexico

    Science.gov (United States)

    Butzer, Karl W.; Abbott, James T.; Frederick, Charles D.; Lehman, Paul H.; Cordova, Carlos E.; Oswald, John F.

    2008-10-01

    The distinction between the impact of climatic periodicities or land-use practices on soil erosion is an important issue for Pre-Hispanic and Colonial Mexico. That question can best be addressed by first documenting the dynamics of changing "wet" cycles during the Holocene in the central Mexican region between the northern limits of Pre-Hispanic agriculture and its southern margins in northwestern Chihuahua. Consequently the Laguna Project targeted a 125,000 km 2 sector of North-Central Mexico, 250 km from north to south and 500 km from east to west, from Saltillo to Durango. Some 40 sedimentary profiles with multiple cumulic soils were studied in the field and laboratory, supported by 163 conventional 14C and AMS dates on charcoal and soil humates. We distinguish: (1) wet floodplains (with humic paleosols, redox phenomena reflecting high water tables, channel-ponding sequences, and interbedded tufas) that imply aquifer recharge, sustained base flow, and mainly low-energy conditions; and (2) high-energy pulses of discharge that mobilized cobble gravels or forced channel entrenchment ("gullying") and were tied to episodic, excessive rains that promoted valley and slope instability. In between such "wet" cycles and recurrent disequilibrium events, climate was similar to today, probably less humid, with limited geomorphologic change or slow soil formation. "Wet" cycles were rare at the end of the Pleistocene, but prominent during the Holocene. Disequilibrium proxies became common and dramatic after 2500 BP. The drainages from the Eastern and Western Sierra Madres responded in phase, but varied in detail. Around AD 1050-1200 "natural" erosion led to loss of soil organic carbon, as alternating severe droughts and heavy rains destroyed the ground cover and led to ecological aridification, well before arrival of Spanish miners and settlers. The evidence that human activity triggered Pre-Hispanic or Colonial erosion in Central Mexico should therefore be re

  3. Description of piezometers installed in the middle Rio Grande basin area, 1997-99, central New Mexico

    Science.gov (United States)

    Bartolino, J.R.; Rankin, D.R.

    2000-01-01

    Since 1993, the Santa Fe Group aquifer system in the Middle Rio Grande Basin, and particularly in the Albuquerque area, has been the focus of studies to further define the extent of the most productive parts of the aquifer and to gain a better understanding of how ground- water levels are changing over time. The U.S. Geological Survey, in cooperation with the New Mexico Office of the State Engineer, installed nine piezometers during 1998-99 at five sites in and near the margin of the Middle Rio Grande Basin in central New Mexico. In addition, the New Mexico Office of the State Engineer installed another nine piezometers at three sites during 1997. These piezometers allow for collection of ground-water-level data in areas for which little information is available. Most of the piezometers were constructed of 2.5-inch-diameter flush-joint polyvinyl chloride (PVC) schedule 80 casing with 10-foot stainless steel screens; the shallow piezometer at the Tome site has a 40-foot screen, and the single piezometers at the Dome Road and Phoenix Road sites have steel casing with welded joints and a 10- and a 20-foot screen, respectively. Steel casing with a locking lid covers the uppermost 2 feet of the piezometer casing. Drillers' logs and petrophysical logs were collected from the deepest borehole at each site.

  4. Evolución tectónica, paleogeográfica y metalogénica durante el Cenozoico en los Andes de Chile norte y central e implicaciones para las regiones adyacentes de Bolivia y Argentina Tectonic, paleogeographic, and metallogenic evolution during the Cenozoic in the Andes of Central and Northern Chile and implication for the adjacent regions of Bolivia and Argentina

    OpenAIRE

    Reynaldo Charrier; Marcelo Farías; Víctor Maksaev

    2009-01-01

    La orogenia incaica dio origen a un importante relieve en el Eoceno Medio, el que se concentró en el ámbito del arco magmático precedente, la Cordillera Incaica. Este relieve positivo de orientación NNE se extendió desde el sur de Perú hasta la región central de Chile y separó dos dominios paleogeográficos que tuvieron evoluciones diferentes durante el resto del Cenozoico. El dominio occidental se caracterizó por el predominio de procesos de erosión y sedimentación. En el dominio oriental tam...

  5. Beyond the Policy of No Policy: Emigration from Mexico and Central America

    OpenAIRE

    Rosenblum, Marc

    2002-01-01

    Immediately following the 2000-1 inaugurations of Presidents Vicente Fox and George W. Bush, Mexico and the United States entered into intense negotiations aimed at a bilateral guestworker agreement on migration. Although the terror attacks of September, 2001 put these negotiations on hold, the progress which had been made—and the extent to which Mexico set the bilateral agenda—highlight the transnational character of U.S. immigration policy-making. But what do sending-states want when it com...

  6. Gulf of Mexico Sales 157 and 161: Central and western planning areas final environmental impact statement, Volume I: Sections I through IV.C

    International Nuclear Information System (INIS)

    This Final Environmental Impact Statement (EIS) covers the proposed 1996 Gulf of Mexico OCS oil and gas lease sales [Central Gulf of Mexico Sale 157 (March 1996) and Western Gulf of Mexico Sale 161 (August 1996)]. This document includes the purpose and background of the proposed actions, the alternatives, the descriptions of the affected environment, and the potential environmental impacts of the proposed actions and alternatives. Proposed mitigating measures and their potential effects are analyzed, in addition to potential cumulative impacts resulting from proposed activities

  7. Gulf of Mexico Sales 147 and 150: Central and Western planning areas. Final environmental impact statement, Volume 1: Sections 1 through 4.C

    Energy Technology Data Exchange (ETDEWEB)

    1993-11-01

    This Final Environmental Impact Statement (EIS) covers the proposed 1994 Gulf of Mexico OCS oil and gas lease sales [Central Gulf of Mexico Sale 147 (March 1994) and Western Gulf of Mexico Sale 150 (August 1994)]. This document includes the purpose and background of the proposed actions, the alternatives, the descriptions of the affected environment, and the potential environmental impacts of the proposed actions and alternatives. Proposed mitigating measures and their effects are analyzed, in addition to potential cumulative impacts resulting from proposed activities.

  8. Gulf of Mexico sales 147 and 150: Central and western planning areas. Draft environmental impact statement. Volume 1. Sections I through IV.C. Draft report

    International Nuclear Information System (INIS)

    The Draft Environmental Impact Statement (EIS) covers the proposed 1994 Gulf of Mexico OCS oil and gas lease sales (Central Gulf of Mexico Sale 147 (March 1994) and Western Gulf of Mexico Sale 150 (August 1994)). The document includes the purpose and background of the proposed actions, the alternatives, the description of the affected environment, and the potential environmental impacts of the proposed actions and alternatives. Proposed mitigating measures and their effects are analyzed, in addition to potential cumulative impacts resulting from proposed activities

  9. Land subsidence in major cities of Central Mexico: Interpreting InSAR-derived land subsidence mapping with hydrogeological data

    Science.gov (United States)

    Castellazzi, Pascal; Arroyo-Domínguez, Norma; Martel, Richard; Calderhead, Angus I.; Normand, Jonathan C. L.; Gárfias, Jaime; Rivera, Alfonso

    2016-05-01

    Significant structural damages to urban infrastructures caused by compaction of over-exploited aquifers are an important problem in Central Mexico. While the case of Mexico City has been well-documented, insight into land subsidence problems in other cities of Central Mexico is still limited. Among the cities concerned, we present and discuss the cases of five of them, located within the Trans-Mexican Volcanic Belt (TMVB): Toluca, Celaya, Aguascalientes, Morelia, and Queretaro. Applying the SBAS-InSAR method to C-Band RADARSAT-2 data, five high resolution ground motion time-series were produced to monitor the spatio-temporal variations of displacements and fracturing from 2012 to 2014. The study presents recent changes of land subsidence rates along with concordant geological and water data. It aims to provide suggestions to mitigate future damages to infrastructure and to assist in groundwater resources management. Aguascalientes, Celaya, Morelia and Queretaro (respectively in order of decreasing subsidence rates) are typical cases of fault-limited land subsidence of Central Mexico. It occurs as a result of groundwater over-exploitation in lacustrine and alluvial deposits covering highly variable bedrock topography, typical of horst-graben geological settings. Aguascalientes and Toluca show high rates of land subsidence (up to 10 cm/yr), while Celaya and Morelia show lower rates (from 2 to 5 cm/yr). Comparing these results with previous studies, it is inferred that the spatial patterns of land subsidence have changed in the city of Toluca. This change appears to be mainly controlled by the spatial heterogeneity of compressible sediments since no noticeable change occurred in groundwater extraction and related drawdown rates. While land subsidence of up to 8 cm/yr has been reported in the Queretaro Valley before 2011, rates inferior to 1 cm/yr are measured in 2013-2014. The subsidence has been almost entirely mitigated by major changes in the water management

  10. Chicxulub impact ejecta deposits in southern Quintana Roo, Mexico, and central Belize

    Czech Academy of Sciences Publication Activity Database

    Pope, K. O.; Ocampo, A.; Fischer, A. G.; Vega, F. J.; Ames, D. E.; King, D. T. Jr.; Fouke, B. W.; Wachtman, R. J.; Kletetschka, Günther

    Colo: Geological Society of America; Boulder, 2005 - (Kenkmann, T.; Horz, F.; Deutsch, A.), s. 171-190. (Special Paper - Geological Society of America. 384). ISBN 0-8137-2384-1 Institutional research plan: CEZ:AV0Z30130516 Keywords : Chicxulubu crater * impact ejecta * Mexico * Belize Subject RIV: BM - Solid Matter Physics ; Magnetism

  11. Modeling groundwater levels on the Calera Aquifer Region in Central Mexico using ModFLow.

    Science.gov (United States)

    A conceptual model for the Calera Aquifer has been created to represent the aquifer system beneath the Calera Aquifer Region (CAR) in the State of Zacatecas, Mexico. The CAR area was uniformly partitioned into a 500 X 500 m grid generating a high resolution model that represented the natural boundar...

  12. Structural Vulnerability among Migrating Women and Children Fleeing Central America and Mexico:The Public Health Impact of Humanitarian Parole

    Directory of Open Access Journals (Sweden)

    Elizabeth Salerno Valdez

    2015-06-01

    Full Text Available Since October 2013, US Customs and Border Patrol (USCBP has apprehended 15,979 families on the Southwest Border of the United States. Daily, migrating women and children from Mexico and Central America that qualify for humanitarian parole are released from immigration detention to a humanitarian aid organization in Southern Arizona. After several days in detention facilities, these families arrive tired, hungry, dehydrated, and with minimal direction regarding their final destination, and adherence to the parameters of their parole. Project Helping Hands (PHH utilizes a network of volunteers to provide the women and children with food, water, clothing, hygiene products, hospitality, and legal orientation. The aim of this assessment was to document the experiences of families granted humanitarian parole through the lens of structural vulnerability. Here we apply qualitative methods to elicit PHH lead volunteer perspectives regarding the migration experience of migrating families. Using inductive analysis, we found six major themes emerged from the qualitative data: reasons for leaving, experience on the journey, dehumanization in detention, family separation, vulnerability, and resiliency.These findings elucidate the different physical and psychological distresses that migrating families from Mexico and Central America experience before, during and after their arrival at the US-Mexico border. We posit that these distresses are a result of, or exacerbated by, structural vulnerability. Structural vulnerability has life-long health implications for a sub-population of young mothers and their children. The number of migrating families who have experienced traumatic events before, and during their migration experience continues to expand and thus warrants consideration of mental health surveillance and intervention efforts for these families. More public health research is needed to better understand and combat the health challenges of this growing

  13. Optimal management of on-farm resources in small-scale dairy systems of Central Mexico: model development and evaluation.

    Science.gov (United States)

    Castelán-Ortega, Octavio Alonso; Martínez-García, Carlos Galdino; Mould, Fergus L; Dorward, Peter; Rehman, Tahir; Rayas-Amor, Adolfo Armando

    2016-06-01

    This study evaluates the available on-farm resources of five case studies typified as small-scale dairy systems in central Mexico. A comprehensive mixed-integer linear programming model was developed and applied to two case studies. The optimal plan suggested the following: (1) instruction and utilization of maize silage, (2) alfalfa hay making that added US$140/ha/cut to the total net income, (3) allocation of land to cultivated pastures in a ratio of 27:41(cultivated pastures/maize crop) rather than at the current 14:69, and dairy cattle should graze 12 h/day, (4) to avoid grazing of communal pastures because this activity represented an opportunity cost of family labor that reduced the farm net income, and (5) that the highest farm net income was obtained when liquid milk and yogurt sales were included in the optimal plan. In the context of small-scale dairy systems of central Mexico, the optimal plan would need to be implemented gradually to enable farmers to develop required skills and to change management strategies from reliance on forage and purchased concentrate to pasture-based and conserved forage systems. PMID:26992734

  14. Assessment of the sustainability of dual-purpose farms by the IDEA method in the subtropical area of central Mexico.

    Science.gov (United States)

    Salas-Reyes, Isela Guadalupe; Arriaga-Jordán, Carlos Manuel; Rebollar-Rebollar, Samuel; García-Martínez, Anastacio; Albarrán-Portillo, Benito

    2015-08-01

    The objective of this study was to assess the sustainability of 10 dual-purpose cattle farms in a subtropical area of central Mexico. The IDEA method (Indicateurs de Durabilité des Exploitations Agricoles) was applied, which includes the agroecological, socio-territorial and economic scales (scores from 0 to 100 points per scale). A sample of 47 farms from a total of 91 registered in the local livestock growers association was analysed with principal component analysis and cluster analysis. From results, 10 farms were selected for the in-depth study herein reported, being the selection criterion continuous milk production throughout the year. Farms had a score of 88 and 86 points for the agroecological scale in the rainy and dry seasons. In the socio-territorial scale, scores were 73 points for both seasons, being the component of employment and services the strongest. Scores for the economic scale were 64 and 56 points for the rainy and dry seasons, respectively, when no economic cost for family labour is charged, which decreases to 59 and 45 points when an opportunity cost for family labour is considered. Dual-purpose farms in the subtropical area of central Mexico have a medium sustainability, with the economic scale being the limiting factor, and an area of opportunity. PMID:25958175

  15. Helminth infracommunity structure of the sympatric garter snakes Thamnophis eques and Thamnophis melanogaster from the Mesa Central of Mexico.

    Science.gov (United States)

    Jiménez-Ruiz, F Agustin; García-Prieto, Luis; Pérez-Ponce de León, Gerardo

    2002-06-01

    Seventy-two Mexican garter snakes (Thamnophis eques) and 126 black-bellied garter snakes (T. melanogaster) were collected from 4 localities of the Mesa Central of Mexico between July 1996 and February 1998 and examined for helminths. Both species of garter snakes occurred sympatrically in every locality except in Lake Cuitzeo. Both species of snakes shared 9 helminth species, and in general, T. melanogaster hosted a larger number of species than T. eques. In each locality, a different helminth species showed the highest levels of prevalence and abundance (Spiroxys susanae in Ciénaga de Lerma, Telorchis corti in Lago de Pátzcuaro, Proteocephalus variabilis in Lago de Cuitzeo, and Contracaecum sp. in Lago de Chapala). Helminth communities in garter snakes of the Mesa Central are depauperate and dominated by a single parasite species. In those localities where the snakes occurred in sympatry, helminth communities were, in general, more diverse and species-rich in T. melanogaster. Differences in the ecology and physiology of these species of garter snakes may explain this pattern because black-bellied garter snakes (T. melanogaster) are more aquatic than Mexican garter snakes (T. eques) and primarily eat aquatic prey, potentially exposing themselves to a larger number of helminths transmitted by predator-prey infection. The helminth infracommunities of garter snakes in the Mesa Central of Mexico show a strong Nearctic influence because most of the species infecting these hosts have been recorded in other Nearctic colubrid snakes. However, the helminth infracommunities of these garter snakes are less species-rich and less diverse than those in colubrid snakes in more temperate latitudes. The widespread ecological perturbation of sampling sites in the Mesa Central because of human activity, and geographic differences in foraging ecology of the hosts and, thus, exposure to parasites transmitted by intermediate hosts may help to explain these patterns. PMID:12099411

  16. Evolución tectónica, paleogeográfica y metalogénica durante el Cenozoico en los Andes de Chile norte y central e implicaciones para las regiones adyacentes de Bolivia y Argentina Tectonic, paleogeographic, and metallogenic evolution during the Cenozoic in the Andes of Central and Northern Chile and implication for the adjacent regions of Bolivia and Argentina

    Directory of Open Access Journals (Sweden)

    Reynaldo Charrier

    2009-10-01

    Full Text Available La orogenia incaica dio origen a un importante relieve en el Eoceno Medio, el que se concentró en el ámbito del arco magmático precedente, la Cordillera Incaica. Este relieve positivo de orientación NNE se extendió desde el sur de Perú hasta la región central de Chile y separó dos dominios paleogeográficos que tuvieron evoluciones diferentes durante el resto del Cenozoico. El dominio occidental se caracterizó por el predominio de procesos de erosión y sedimentación. En el dominio oriental también existieron importantes episodios de erosión que originaron depósitos que se encuentran en la vertiente oriental de la cadena en la actualidad y presentan una cronología comparable con la de los depósitos del dominio occidental. Sin embargo, la evolución se caracterizó por presentar, a partir del Eoceno Tardío, diferencias al norte y sur de los ~27ºS. Al norte de esa latitud, en el ámbito del Altiplano-Puna, el arco magmático se mantuvo aproximadamente en la misma posición, coincidente con la del arco actual, y estuvo bordeado por una cuenca de antepaís de retroarco; mientras que, al sur de ~27ºS, se desarrollaron sucesivos arcos magmáticos con una marcada migración hacia el este. El arco magmático del Eoceno Tardío al Oligoceno Tardío - Mioceno Temprano se caracterizó por el desarrollo de una amplia cuenca extensional de intra-arco, la cuenca de Abanico. En esta cuenca se acumularon hasta 3.000 m de rocas volcánicas, volcaniclásticas y, subordinadamente, sedimentarias. A partir del límite oligoceno-mioceno, tuvo lugar un nuevo evento compresivo a lo largo de todo el orógeno que rejuveneció el núcleo de la Cordillera Incaica e invirtió la cuenca de Abanico permitiendo la generación de abundantes depósitos sintectónicos a ambos lados de los nuevos relieves. El inicio de este evento coincide con la orogenia pehuenche, los pulsos compresivos se mantuvieron hasta el Plioceno Temprano. En el Mioceno Temprano a Medio

  17. A possible metallogenic model and analysis of potential resources of Xiangshan uranium ore field

    International Nuclear Information System (INIS)

    Based on analysis of metallogenic dynamics process, geological characteristics and geochemistry of Xiangshan uranium ore field, uranium metallogenic model is discussed to guide uranium metallogenic prognosis and analysis of re- sources potential. REE geochemical characteristics, diagenetic and mineralization ages indicate that volcanic rock series in Xiangshan derived from melt of crust materials and are products of pulsating events of the same magma chamber. Di- agenesis of granitic porphyry and metallogenesis are consecutive geological events. On basis of research of fluids of wall rock alteration, REE geochemical feature and regional distribution characteristics of uranium abundance, regional uranium bearing strata are considered as the primary source for metallogenic substances, Xiangshan volcanic basin became uranium accumulative area with the help of volcanism and magmatism. Hydrothermal solution in post magmatism is rich in uranium. Interaction between fluid and rock promotes evolution of hydrothermal solution in post magmatism into metallogenic fluid, further produces process of uranium metallogenesis, eventually forms two-later spatial structure of 'volcanic lava and granitic porphyry' of uranium metallogenesis. There are greater exploration space and resources potential in the north and west parts of the ore field. Caldera, volcanic neck and volcanic pipe, and their peripheries are worth exploration. Total uranium resources of Xiangshan ore field are optimistically predicted to super-large size. (authors)

  18. Breed and environmental factors of sows and their repeatabilities in central Mexico

    OpenAIRE

    José C. Segura-Correa; José Herrera-Camacho; Rosa E. Pérez-Sánchez; Ernestina Gutiérrez-Vázquez

    2015-01-01

    Background: reproductive traits influence lifetime productivity of sows. Objective: to determine the effects of year and season of farrowing, parity number, and breed, on litter size at birth, weaning to service interval (WSI), farrowing to service interval (FSI), and to estimate their repeatabilities. Methods: data from years 1998 to 2008 from a farm in La Piedad, Michoacan, Mexico, were used. Sow breeds were Camborough 22 (PIC), Yorkshire (Y), F1 Landrace x Yorkshire (F1 LY), and ¼ Landrace...

  19. Canopy arthropods community within and among oak species in central Mexico

    OpenAIRE

    Efraín TOVAR-SANCHEZ

    2009-01-01

    Quercus rugosa and Q.laurina are species that presents a wide geographical distribution range in temperate forests of Mexico. Oak canopies contain a considerable portion of arthropod diversity and the arthropods fauna fulfill a wide variety of ecological roles. We examined the effect of oak species and seasonal changes on some community structure parameters (diversity, composition, similarity, biomass, rare species, and density of arthropod fauna) of canopy arthropods. In total, 40 oak ca...

  20. Coyotes, Concessions and Construction Companies: Illegal Water Markets and Legally Constructed Water Scarcity in Central Mexico

    OpenAIRE

    Nadine Reis

    2014-01-01

    Many regions of (semi)arid Mexico, such as the Valley of Toluca, face challenges due to rapid growth and the simultaneous overexploitation of groundwater. The water reform of the 1990s introduced individual water rights concessions granted through the National Water Commission (Comisión Nacional del Agua, or CONAGUA). Since then, acquiring new water rights in officially 'water-scarce' aquifers is only possible through official rights transmissions from users ceding their rights. With the law ...

  1. The ~ 2000 yr BP Jumento volcano, one of the youngest edifices of the Chichinautzin Volcanic Field, Central Mexico

    Science.gov (United States)

    Arce, J. L.; Muñoz-Salinas, E.; Castillo, M.; Salinas, I.

    2015-12-01

    The Chichinautzin Volcanic Field is situated at the southern limit of the Basin of Mexico and the Metropolitan area of Mexico City, the third most populated city around the world. The Chichinautzin Volcanic field holds more than 220 monogenetic volcanoes. Xitle is the youngest of these with an estimated age of 1.6 ky BP. Xitle's eruptive activity took place during the Mesoamerican Mexican Pre-classic period and is related to the destruction of Cuicuilco Archaeological Site, the oldest civilization known in Central Mexico. However, there are still several regional cones that have not been dated. Based on 14C ages, stratigraphic and geomorphologic criteria, we conclude that the Jumento volcano, located to the west of Xitle, is one of the youngest cones of the Chichinautzin Volcanic Field. The Jumento volcano has a basaltic andesite composition, and its eruptive activity was initially hydromagmatic, followed by Strombolian and finally effusive events occurred recorded through: (1) a sequence of hydromagmatic pyroclastic surges and ashfall layers emplaced at a radius of > 5 km from the crater with charcoal fragments at its base; this activity built the Jumento's cone with slopes of 32°; and (2) lava flows that breached the southern part of the cone and flowed for up to 2.5 km from the vent. The resulting 14C ages for this volcano yielded a maximum age of ~ 2 ky BP. Morphometric analysis indicates that the state of degradation of Jumento cone is similar to the Xitle, suggesting that the Jumento could be in the state of degradation of a volcanic structure of similar age or younger adding credence to the probable radiocarbon age of ~ 2 ky BP for the Jumento edifice.

  2. Study of Metallogenic Fluid Sources of Five Gold Deposits in Zhangjiakou,China

    Institute of Scientific and Technical Information of China (English)

    魏俊浩; 刘丛强; 等

    2001-01-01

    It is very important to define the type and composition of metallogenic fluid in terms of the hydrogen and oxygen isotope data in the study of ore-forming mechanism.In the long past,the method to discriminate metallogenic fluid sources by comparing the δD-δ18 O diagram with the standard values in not valid when the hydrogen and oxygen isotope values are plotted between the meteoric water line and the magmatic water area.Based on their hydrogen and oxygen isotope information of five gold deposits(Shuijingtun,Xiaoyingpan,Dongping, Zhongshangou and Jinjiazhuang)in the Zhangjiakou area,this paper details the metallogenic fluid sources and presents water/rock ratios in the vie gold deposits and the principle of water/rock exchange.

  3. Study of Metallogenic Fluid Sources of Five Gold Deposits in Zhangjiakou, China

    Institute of Scientific and Technical Information of China (English)

    魏俊浩; 刘丛强; 袁艳斌

    2001-01-01

    It is very important to define the type and composition of metallogenic fluid in terms of the hydrogen and oxygen isotope data in the study of ore-forming mechanism. In the long past, the method to discriminate metallogenic fluid sources by comparing the δD-δ18O diagram with the standard values is not valid when the hydrogen and oxygen isotope values are plotted between the meteoric water line and the magmatic water area. Based on their hydrogen and oxygen isotope information on five gold deposits (Shuijingtun, Xiaoyingpan, Dongping,Zhongshangou and Jinjiazhuang) in the Zhangjiakou area, this paper details the metallogenic fluid sources and presents water/rock ratios in the five gold deposits and the principle of water/rock exchange.

  4. 4200 years of pine-dominated upland forest dynamics in west-central Mexico: human or natural legacy?

    Science.gov (United States)

    Figueroa-Rangel, Blanca L; Willis, Katherine J; Olvera-Vargas, Miguel

    2008-07-01

    The pine-dominated forests of west-central Mexico are internationally recognized for their high biodiversity, and some areas are protected through various conservation measures including prohibition of human activity. In this region, however, there is evidence for human settlement dating back to ca. AD 1200. It is therefore unclear whether the present forest composition and structure are part of a successional stage following use by indigenous human populations during the past, or due to natural processes, such as climate. We present a study reconstructing the vegetation dynamics of pine-dominated forest over the past 4200 years using paleoecological techniques. Results from fossil pollen and charcoal indicate that, in this region, pine-dominated forests are the native vegetation type and not anthropogenically derived secondary succession. The predominant driving mechanism for the expansion of pine-dominated forest appears to be intervals of aridity and naturally induced burning. A close association is noted between pine abundance and longer-term climatic trends, including intervals of aridity between ca. 4200 and 2500, 1200 and 850, and 500 and 200 cal yr BP and shorter-term trends. Evident periodicity occurs in pine and Poaceae abundance every 80 years. These short-term quasi-periodic oscillations have been recorded in a number of lake and ocean sediments in Mexico and are thought to be linked to solar forcing resulting in drought cycles that occur at approximately the same time intervals. PMID:18705376

  5. The functional PTPN22 C1858T polymorphism confers risk for rheumatoid arthritis in patients from Central Mexico.

    Science.gov (United States)

    Rincón, J F Mendoza; Cano, D López; Morales, S Jiménez; Jiménez, M L Rivas; Cobos, R E Barbosa; Bello, J Ramírez

    2016-06-01

    Rheumatoid arthritis (RA) is a complex genetic disease. Human leukocyte antigen (HLA) and non-HLA genes are reportedly associated with an increased risk of RA. The protein tyrosine phosphatase non-receptor 22 gene (PTPN22), which encodes the lymphoid tyrosine phosphatase (LYP) protein, is one of the best examples of a non-HLA gene associated with a risk for RA in several populations. The functional PTPN22 C1858T (R620W) non-synonymous polymorphism is widely associated with an increased risk for RA in Europeans and non-Europeans. The aim of this study was to determine if the PTPN22 C1858T polymorphism confers susceptibility to RA in a sample of patients from Mexico. This study included 364 RA patients and 387 non-related controls from Central Mexico. Genotyping of the PTPN22 C1858T (rs2476601) polymorphism was performed using allelic discrimination assays with TaqMan probes. The functional PTPN22 C1858T polymorphism was associated with an increased risk for RA in our study population. The CC vs CT genotype in RA patients versus healthy controls had an odds ratio (OR) of 4.17 (95 % CI 1.79-9.74, p = 0.00036), while T allele had an OR of 4.06 (95 % CI 1.75-9.41, p = 0.00043). PTPN22 is a genetic risk factor for developing RA in the Mexican population. PMID:26951256

  6. A new species of Cletocamptus Schmankewitsch, 1875 (Crustacea, Copepoda, Harpacticoida from a high altitude saline lake in Central Mexico

    Directory of Open Access Journals (Sweden)

    Eduardo Suarez Morales

    2013-04-01

    Full Text Available During the analysis of littoral samples collected from a high-altitude saline crater lake in Central Mexico, several female and male specimens of harpacticoid copepods were recovered and taxonomically examined. They were found to represent an undescribed species of the canthocamptid genus Cletocamptus Schmankewitsch, 1875. The new species, C. gomezi n. sp. is described herein based on specimens of both sexes. It resembles C. stimpsoni Gómez, Fleeger, Rocha-Olivares and Foltz, 2004 from Louisiana but also C. trichotus Kiefer, 1929. The new species differs from C. stimpsoni and from other congeners by details of the maxillular armature, the setation of the endopodal segments of legs 2 and 3, and the armature of the third exopodal segment of legs 3 and 4. Also, the dorsal (VII and the outer (IV caudal setae are both relatively shorter than in C. stimpsoni. This is the second species of the genus known to be distributed in Mexico. The occurrence of the new species in a high-altitude saline lake, the isolation of the type locality, and its absence from adjacent freshwater lakes suggest that this species is endemic to this site.

  7. Hantavirus testing in rodents of north-central New Mexico 1993-1995

    Energy Technology Data Exchange (ETDEWEB)

    Biggs, J.; Bennett, K.; Salisbury, M. [and others

    1996-03-01

    In 1993, an outbreak of a new strain of hantavirus in the southwestern US indicated that deer mice (Peromyscus maniculatus) was the primary carrier of the virus. In 1993, 1994, and 1995 the Ecological Studies Team (EST) at Los Alamos National Laboratory surveyed small mammal populations using live capture-recapture methods in Los Alamos County, New Mexico, to determine seroprevalence of hantavirus in this region. EST used trapping grids in 1993 and 1994 and used trapping webs in 1995. Grids were 120 m x 120 m (400 ft x 400 ft) with 144 trap stations at each grid. Three webs consisting of 148 traps each were used in 1995. Trapping took place over 4 to 8 consecutive nights. Programs CAPTURE and Distance were used to determine density estimates for grids and webs, respectively. Blood samples were analyzed in 1993 by the Centers for Disease Control and the University of New Mexico, School of Medicine. The 1994 and 1995 samples were analyzed by the University of New Mexico, School of Medicine. The deer mouse (Peromyscus maniculatus) was the most commonly captured species at all locations except one site where voles (Microtus spp.) were the most commonly captured species. Other species sampled included: harvest mice (Reithrodontomys megalotis), woodrats (Neotoma spp.), shrews (Sorex spp.), white-footed mice (Peromyscus leucopus), pinyon mice (Peromyscus trueii), and brush mouse (Peromyscus boylii). Results of the 1993, 1994, and 1995 testing identified a total overall seroprevalence rate among deer mice of approximately 5.5%, 4.2%, and 0%, respectively. Several other species tested positive for the hantavirus but it is uncertain if it is Sin Nombre virus. Further studies will be necessary to quantify seroprevalence rates in those species. Higher seroprevalence rates were found in males than females. Seroprevalence rates for Los Alamos County were much lower than elsewhere in the region.

  8. Detection of ULF geomagnetic signals associated with seismic events in Central Mexico using Discrete Wavelet Transform

    OpenAIRE

    O. Chavez; J. R. Millan-Almaraz; R. Pérez-Enríquez; J. A. Arzate-Flores; Kotsarenko, A.; Cruz-Abeyro, J. A.; Rojas, E

    2010-01-01

    The geomagnetic observatory of Juriquilla Mexico, located at longitude –100.45° and latitude 20.70°, and 1946 m a.s.l., has been operational since June 2004 compiling geomagnetic field measurements with a three component fluxgate magnetometer. In this paper, the results of the analysis of these measurements in relation to important seismic activity in the period of 2007 to 2009 are presented. For this purpose, we used superposed epochs of Discrete Wavelet Transform of filtered signals for the...

  9. Occurrence of environmental mycobacteria in water from the central zone of the Chihuahua, Mexico

    International Nuclear Information System (INIS)

    Environmental mycobacteria are inhabitants of many reservoirs, including water, soil, plats, animals and humans, The aquatic environment is an important reservoir of environmental mycobacteria; where their presence is influenced by biotic and abiotic factors. The presence of environmental mycobacteria in water has been related with health problems in immunosuppressed patients. In Mexico, there are not reports of the ecology of mycobacteria; therefore, the aim of this work was to characterize reservoir sites, like creeks and drinking troughs, and to determine some biotic and abiotic environmental factors to understand the conditions leading to their environmental persistence. (Author)

  10. Permeability alteration in small-displacement faults in poorly lithified sediments: Rio Grande Rift, Central New Mexico

    Science.gov (United States)

    Sigda, John M.; Goodwin, Laurel B.; Mozley, Peter S.; Wilson, John L.

    Faults in clastic rocks influence fluid flow by juxtaposition of different lithologic units and by localized alteration of petrophysical properties through cataclasis, cementation, or other deformational and diagenetic processes. Extensional tectonic settings, such as the Basin and Range Province and the Rio Grande rift, are characterized by numerous faults in both sedimentary rocks and poorly lithified basin-fill sediments. Faults in poorly lithified sediments have received little attention; our study is the first to examine their permeability. We tested whether faulting of poorly lithified sediments significantly affects permeability by comparing two uncemented, small-displacement, normal faults in New Mexico's central Rio Grande rift: one with a clay-rich core (displacement > bed thickness) and one without a clay-rich core (displacement Southwest. Numerous in extensional basins but typically not included on most geologic maps, such faults could significantly influence flow through basin-fill sediments.

  11. Centrality of Event across Cultures. Emotionally Positive and Negative Events in Mexico, China, Greenland, and Denmark

    DEFF Research Database (Denmark)

    Zaragoza Scherman, Alejandra; Berntsen, Dorthe

    During their lifetime, people experience both emotionally positive and negative events. The Centrality of Event Scale (CES; Berntsen and Rubin, 2006; Berntsen, Rubin and Siegler, 2011) measures the extent to which an event is central to someone’s identity and life story. An event becomes central...... when it is an important part of our identity and life story, when it changes the way we view the world in everyday life, and when we use it as a turning point in our life story. CES research has produced important findings regarding how the emotionality of a life event influences the way we incorporate...... an emotional event into our life story and our identity. Key findings: 1) Positive events are rated as more central to identity than negative events; 2) The extent to which highly traumatic and negative events become central to a person’s life story and identity varies as a function of post-traumatic stress...

  12. Geological characteristics and metallogenic prognosis of main gold deposit in Altai gold ore belt, Xinjiang

    Institute of Scientific and Technical Information of China (English)

    SHEN Yuan-chao; SHEN Ping; ZHENG Qing-dong; LIU Tie-bing; LI Guang-ming

    2004-01-01

    Altai polymetallic mineralization belt is famous copper-polymetallic mineralization belt in the world. There are a lot of gold deposits in the Altai ore belt in Xinjiang, China. These gold deposits belong to two genetic types: volcanogene late-stage hydrothermal type and fractured altered rock type. The authors discuss mainly the geological and mineralized features of fractured altered rock type of gold deposits in Altai gold ore belt. Base on this study, the metallogenic law is summarized and the deep metallogenic prognosis has been done in Duolanasayi and Tuokuzibayi gold deposits, and some mineralized anomalys have been discovered.

  13. The metallogenic condition and prospecting direction of hydrothermal uranium deposit in Sanjiang area of eastern tibet

    International Nuclear Information System (INIS)

    This paper makes a systematic analysis of the metallogenic condition of hydrothermal type uranium deposit in Sanjiang area of Eastern Tibet in the following prospects: geotectonic background, basement maturity, uranium source conditions, strata and lithology, genetic types of magmatic rock, forming time and space configuration of magmatic rocks, volcanic rock characteristics, ore-controlling structure and the wall-rock alteration etc. We explicitly point out that Sanjiang area bears the basic geological condition to form hydrothermal type uranium deposits, but the metallogenic conditions are not superior on the whole. The main targets should be the granite type deposit in the internal and external contact zone between pluton and the strata. (authors)

  14. Discussion on metallogenic prospect of sandstone-type uranium deposit in Yabulai basin

    International Nuclear Information System (INIS)

    Based on characteristics of initial basin type and tectonic reworking process, this article analyses the distribution features of depositional system and subsequent alteration of the target horizon of sandstone-type uranium deposits in Yabulai basin. Guided by prognostic criteria of sandstone-type uranium deposits, authors suggest that the post-depositional tectonic reworking in the basin was quite intense, and uranium metallogenic prospects are unfavorable. However, the Lower Cretaceous in the paleo-slope at the middle of the basin does show certain metallogenic prospects for sandstone-type uranium deposits

  15. Structure of the Cocos subduction zone in central and southern Mexico from three-dimensional body-wave attenuation and travel time tomography

    Science.gov (United States)

    Chen, T.; Clayton, R. W.

    2011-12-01

    The 3D P- and S-wave attenuation and velocity structure of the Cocos subduction zone in Mexico is imaged using seismic events recorded by the MASE (100 seismometers running across central Mexico, 2005-2007) and VEOX (47 seismometers running across southern Mexico, 2007-2009) arrays, supplemented by stations from the National Seismic Network in Mexico (SSN). Using a spectral-decay method, we obtain a path attenuation operator t* for each seismogram in the frequency band 1 to 30 Hz, depending on the signal quality. These measurements are then inverted for 3D spatial variations in attenuation. Direct body-wave arrivals from local events are used for 3D velocity inversion. Deeper velocity structures along MASE and VEOX arrays are obtained by including teleseismic events. Inversion results show low attenuation associated with the Cocos slab, and show the slab dip angle increases from central to southern Mexico. High attenuation is imaged in the mantle wedge and the crust above. The highest attenuation is found in the crust near the active Los Tuxtlas volcanic field, probably related to the dehydration and melting process. Low velocity is observed in the mantle wedge and the crust above from velocity inversion. The Cocos slab is traced as high-velocity structure. The Cocos slab dips down to about 500 km in central Mexico along MASE array as shown by previous study (Perez-Campos, GRL, 2008). In southern Mexico along VEOX line, no clear continuous Cocos slab is observed deeper than about 150 km, which is also found by receiver function studies (Kim et al., in press; Perez-Campos et al., in press). There are some indications that the Cocos slab in southern Mexico near the Isthmus of Tehuantepec is truncated by some high-velocity structure dipping south from the Gulf of Mexico. This anomalous south-dipping structure is also seen in receiver function images, and may be related to the collision between the Yucatan Block and Mexico in the Miocene (Kim et al., in press).

  16. Assessment of DDT levels in selected environmental media and biological samples from Mexico and Central America.

    Science.gov (United States)

    Pérez-Maldonado, Iván N; Trejo, Antonio; Ruepert, Clemens; Jovel, Reyna del Carmen; Méndez, Mónica Patricia; Ferrari, Mirtha; Saballos-Sobalvarro, Emilio; Alexander, Carlos; Yáñez-Estrada, Leticia; Lopez, Dania; Henao, Samuel; Pinto, Emilio R; Díaz-Barriga, Fernando

    2010-03-01

    Taking into account the environmental persistence and the toxicity of DDT, the Pan American Health Organization (PAHO) organized a surveillance program in Mesoamerica which included the detection of residual DDT in environmental (soil) and biological samples (fish tissue and children's blood). This program was carried out in communities from Mexico, Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica and Panama. This paper presents the first report of that program. As expected, the results show that the levels for [summation operator] DDT in soil (outdoor or indoor) and fish samples in the majority of the locations studied are below guidelines. However, in some locations, we found children with high concentrations of DDT as in Mexico (mean level 50.2 ng/mL). Furthermore, in some communities and for some matrices, the DDT/DDE quotient is higher than one and this may reflect a recent DDT exposure. Therefore, more efforts are needed to avoid exposure and to prevent the reintroduction of DDT into the region. In this regard it is important to know that under the surveillance of PAHO and with the support of UNEP, a regional program in Mesoamerica for the collection and disposal of DDT and other POPs stockpiles is in progress. PMID:20092871

  17. Coyotes, Concessions and Construction Companies: Illegal Water Markets and Legally Constructed Water Scarcity in Central Mexico

    Directory of Open Access Journals (Sweden)

    Nadine Reis

    2014-10-01

    Full Text Available Many regions of (semiarid Mexico, such as the Valley of Toluca, face challenges due to rapid growth and the simultaneous overexploitation of groundwater. The water reform of the 1990s introduced individual water rights concessions granted through the National Water Commission (Comisión Nacional del Agua, or CONAGUA. Since then, acquiring new water rights in officially 'water-scarce' aquifers is only possible through official rights transmissions from users ceding their rights. With the law prohibiting the sale of water rights, a profitable illegal market for these rights has emerged. The key actor in the water rights allocation network is the coyote, functioning as a broker between a people wanting to cede water rights and those needing them, and b the formal and informal spheres of water rights allocation. Actors benefitting from water rights trading include the coyote and his 'working brigades', water users selling surplus rights, and (senior and lower-level staff in the water bureaucracy. The paper concludes that legally constructed water scarcity is key to the reproduction of illegal water rights trading. This has important implications regarding the current push for expanding regularisation of groundwater extraction in Mexico. Currently, regularisation does not counter overexploitation, while possibly leading to a de facto privatisation of groundwater.

  18. Geochemical proxies and millennial-scale climate variability during MIS 3 at Lake Chalco, central Mexico

    Science.gov (United States)

    Torres, E.; Lozano, S.; Roy, P.; Ortega, B.; Caballero, M.

    2013-05-01

    The Basin of Mexico (20N, 99W; 2240 m.a.s.l.) is present at the northern limit of the American tropics and is surrounded by up to 5400 m high mountains. The Lake Chalco is situated at the southern part of the basin and spreads over 120 km2. The precipitation in the modern era is influenced by the seasonal displacement of the Intertropical Convergence Zone and the high-pressure belt located at about 35 N. Five cores were drilled (up to 122.5 m depth) in order to document climate variability in paleohydrological conditions during the late Quaternary. The age model includes several 14C dates and tephra layers present in the upper 25 m of the core. We documented millennial-scale events during MIS 3 based on geochemical data (total organic carbon (TOC), total inorganic carbon (TIC), C/N ratio) and abundance of charcoal particles. By temporal correlation with GISP2 core we founded that Greenland interstadials match with TOC percentages suggesting wet conditions while stadials match with high TIC percentages and high charcoal concentrations suggesting dry conditions. We compared our data with speleothem records (δ18O) from Fort Station Cave (New Mexico) and Terciopelo Cave (Costa Rica), our preliminary results indicate that Chalco record has a similar climatic signal as Terciopelo Cave, both presented wet interstadials and dry stadials which appear to have been regulated by the seasonal migration of the ITCZ.

  19. A new species of Torrestrongylus (Trichostrongylidae, Anoplostrongylinae) from Macrotus waterhousii (Chiroptera: Phyllostomidae) in Central Mexico

    Science.gov (United States)

    Caspeta-Mandujano, Juan Manuel; Peralta-Rodríguez, Jorge Luis; Galindo-García, María Guadalupe; Jiménez, Francisco Agustín

    2015-01-01

    A new species of nematode, Torrestrongylus tetradorsalis n. sp., is described herein, based on specimens recovered from the small intestine of the leaf-nosed bat, Macrotus waterhousii, from the Biosphere Reserve “Sierra de Huautla” in the state of Morelos, Mexico. The new species is included in Torrestrongylus because it features a bursa of the type 3 – 2, a divided cephalic vesicle with an anterior half in the shape of an umbrella, and a posterior widened half. The new species can be distinguished from the only other congener T. torrei Pérez-Vigueras, 1935 by four key features: first, by the absence of cervical alae in both males and females; second, by the relatively longer second half of the cephalic cap; third, by the configuration of the dorsal ray, that does not have a medial terminal ray, and finally, by the structure of the spicules. This is the second species in the genus, previously known from bats of the families Phyllostomidae and Molossidae in Cuba, and now in Mexico. PMID:26514594

  20. Reinterpretation of the stratigraphy and structure of the Rancho Las Norias area, central Sonora, Mexico

    Science.gov (United States)

    Page, William R.; Harris, Anita G.; Poole, Forrest G.; Repetski, John E.

    2003-12-01

    New geologic mapping and fossil data in the vicinity of Rancho Las Norias, 30 km east of Hermosillo, Sonora, Mexico, show that rocks previously mapped as Precambrian instead are Paleozoic. Previous geologic maps of the Rancho Las Norias area show northeast-directed, southwest-dipping reverse or thrust faults deforming both Precambrian and Paleozoic rocks. The revised stratigraphy requires reinterpretation of some of these faults as high-angle normal or oblique-slip faults and the elimination of other faults. We agree with earlier geologic map interpretations that compressional structures have affected the Paleozoic rocks in the area, but our mapping suggests that the direction of compression is from southeast to northwest.

  1. Detection of ULF geomagnetic signals associated with seismic events in Central Mexico using Discrete Wavelet Transform

    Directory of Open Access Journals (Sweden)

    O. Chavez

    2010-12-01

    Full Text Available The geomagnetic observatory of Juriquilla Mexico, located at longitude –100.45° and latitude 20.70°, and 1946 m a.s.l., has been operational since June 2004 compiling geomagnetic field measurements with a three component fluxgate magnetometer. In this paper, the results of the analysis of these measurements in relation to important seismic activity in the period of 2007 to 2009 are presented. For this purpose, we used superposed epochs of Discrete Wavelet Transform of filtered signals for the three components of the geomagnetic field during relative seismic calm, and it was compared with seismic events of magnitudes greater than Ms > 5.5, which have occurred in Mexico. The analysed epochs consisted of 18 h of observations for a dataset corresponding to 18 different earthquakes (EQs. The time series were processed for a period of 9 h prior to and 9 h after each seismic event. This data processing was compared with the same number of observations during a seismic calm. The proposed methodology proved to be an efficient tool to detect signals associated with seismic activity, especially when the seismic events occur in a distance (D from the observatory to the EQ, such that the ratio D/ρ < 1.8 where ρ is the earthquake radius preparation zone. The methodology presented herein shows important anomalies in the Ultra Low Frequency Range (ULF; 0.005–1 Hz, primarily for 0.25 to 0.5 Hz. Furthermore, the time variance (σ2 increases prior to, during and after the seismic event in relation to the coefficient D1 obtained, principally in the Bx (N-S and By (E-W geomagnetic components. Therefore, this paper proposes and develops a new methodology to extract the abnormal signals of the geomagnetic anomalies related to different stages of the EQs.

  2. Metallogenic evolution of uranium deposits in the Middle East and North Africa deposits

    Science.gov (United States)

    Howari, Fares; Goodell, Philip; Salman, Abdulaty

    2016-02-01

    This paper is briefly involved in classification and distributions of the Middle East and North Africa (MENA) uranium deposits. The study of these mineral systems can significantly contribute to our further understanding of the metallogeny of known and poorly explored deposits. This provides contribution to, and further enhancement of, current classifications and metallogenic models of uranium systems, allowing researchers to emphasize on unknown or poorly studied mineral systems found in MENA. The present study identified eight metallogenic types of uranium associated with: 1) the Archean rocks and intra-cratonic basins, 2) the Pan-African granites and rhyolites which are characterized by igneous activity, 3) Phanerozoic (Paleozoic) clastics, these deposits are the sedimentological response to Pan African magmatism, 4) Mesozoic (basal) clastics type e.g. Nubia sandstones which are characterized by uranium minerals, 5) regional sedimentary phosphate deposits which are categorized as geosynclinal, or continental margin deposits, on the shelf of the Tethys Ocean, 6) Cenozoic Intracratonic Felsic Magmatism of the Tibesti and Hoggar, and the sandstone U deposits of adjoining Niger. These are similar to the Pan-African magmatism metallogenic, 7) Calcretes, and 8) Resistate minerals which are often enriched in rare earth elements, sometimes including uranium. They are thus sometimes considered as U resources but poorly explored in the MENA region. These metallogenic types are described and discussed in the current paper.

  3. Metallogenic systems related to Mesozoic and Cenozoic granitoids in South China

    Institute of Scientific and Technical Information of China (English)

    HUA; Renmin; (华仁民); CHEN; Peirong; (陈培荣); ZHANG; Wenlan; (张文兰); LIU; Xiaodong; (刘晓东); LU; Jianjun; (陆建军); LIN; Jinfu; (林锦富); YAO; Junming; (姚军明); QI; Huawen; (戚华文); ZHANG; Zhanshi; (张展适); GU; Shengyan; (顾晟彦)

    2003-01-01

    Large scale mineralizations of nonferrous, precious, and rare metals took place in South China in Mesozoic and Cenozoic Eras, which were mostly closely related with granitic magmatisms of different sources and features. Four metallogenic systems related to Mesozoic and Cenozoic granitoids are put forward in this paper. They are: (i) the porphyry-epithermal copper-gold system related to calc-alkaline volcanic-intrusive magmatism, (ii) rare metal (mainly W, Sn, Ta, Nb, etc) metallogenic system related with continental crust re-melting type granitoids, (iii) copper and polymetallic metallogenic system related with intra-plate high potassium calc-alkaline and shoshonitic magmatism, and (iv) Au-Cu and REE metallogenic system related to A-type granites. The main characteristics of these systems are briefly discussed. These Mesozoic and Cenozoic granitoids of different sources were the products of different periods of lithosphere evolution in that area under different tectonic-dynamic environments. Fundamentally speaking, however, the granitoids and related metallogeneses are the results of mantle-crust interactions under a tensile tectonic environment in South China.

  4. Trace gas and particle emissions from domestic and industrial biofuel use and garbage burning in central Mexico

    Science.gov (United States)

    Christian, T. J.; Yokelson, R. J.; Cárdenas, B.; Molina, L. T.; Engling, G.; Hsu, S.-C.

    2009-04-01

    In central Mexico during the spring of 2007 we measured the initial emissions of 12 gases and the aerosol speciation for elemental and organic carbon (EC, OC), anhydrosugars, Cl-, NO3-, and 20 metals from 10 cooking fires, four garbage fires, three brick making kilns, three charcoal making kilns, and two crop residue fires. Biofuel use has been estimated at over 2600 Tg/y. With several simple case studies we show that cooking fires can be a major, or the major, source of several gases and fine particles in developing countries. Insulated cook stoves with chimneys were earlier shown to reduce indoor air pollution and the fuel use per cooking task. We confirm that they also reduce the emissions of VOC pollutants per mass of fuel burned by about half. We did not detect HCN emissions from cooking fires in Mexico or Africa. Thus, if regional source attribution is based on HCN emissions typical for other types of biomass burning (BB), then biofuel use and total BB will be underestimated in much of the developing world. This is also significant because cooking fires are not detected from space. We estimate that 2000 Tg/y of garbage are generated and about half may be burned, making this a commonly overlooked major global source of emissions. We estimate a fine particle emission factor (EFPM2.5 for garbage burning of ~10±5 g/kg, which is in reasonable agreement with very limited previous work. We observe large HCl emission factors in the range 2-10 g/kg. Consideration of the Cl content of the global waste stream suggests that garbage burning may generate as much as 6-9 Tg/yr of HCl, which would make it a major source of this compound. HCl generated by garbage burning in dry environments may have a relatively greater atmospheric impact than HCl generated in humid areas. Garbage burning PM2.5 was found to contain levoglucosan and K in concentrations similar to those for biomass burning, so it could be a source of interference in some areas when using these tracers to

  5. Trace gas and particle emissions from domestic and industrial biofuel use and garbage burning in central Mexico

    Directory of Open Access Journals (Sweden)

    T. J. Christian

    2009-04-01

    Full Text Available In central Mexico during the spring of 2007 we measured the initial emissions of 12 gases and the aerosol speciation for elemental and organic carbon (EC, OC, anhydrosugars, Cl-, NO3-, and 20 metals from 10 cooking fires, four garbage fires, three brick making kilns, three charcoal making kilns, and two crop residue fires. Biofuel use has been estimated at over 2600 Tg/y. With several simple case studies we show that cooking fires can be a major, or the major, source of several gases and fine particles in developing countries. Insulated cook stoves with chimneys were earlier shown to reduce indoor air pollution and the fuel use per cooking task. We confirm that they also reduce the emissions of VOC pollutants per mass of fuel burned by about half. We did not detect HCN emissions from cooking fires in Mexico or Africa. Thus, if regional source attribution is based on HCN emissions typical for other types of biomass burning (BB, then biofuel use and total BB will be underestimated in much of the developing world. This is also significant because cooking fires are not detected from space. We estimate that 2000 Tg/y of garbage are generated and about half may be burned, making this a commonly overlooked major global source of emissions. We estimate a fine particle emission factor (EFPM2.5 for garbage burning of ~10±5 g/kg, which is in reasonable agreement with very limited previous work. We observe large HCl emission factors in the range 2–10 g/kg. Consideration of the Cl content of the global waste stream suggests that garbage burning may generate as much as 6–9 Tg/yr of HCl, which would make it a major source of this compound. HCl generated by garbage burning in dry environments may have a relatively greater atmospheric impact than HCl generated in humid areas. Garbage burning PM2.5 was found to contain levoglucosan and K in concentrations similar to those for biomass burning, so it could

  6. Trace gas and particle emissions from domestic and industrial biofuel use and garbage burning in central Mexico

    Science.gov (United States)

    Christian, T. J.; Yokelson, R. J.; Cárdenas, B.; Molina, L. T.; Engling, G.; Hsu, S.-C.

    2010-01-01

    In central Mexico during the spring of 2007 we measured the initial emissions of 12 gases and the aerosol speciation for elemental and organic carbon (EC, OC), anhydrosugars, Cl-, NO3-, and 20 metals from 10 cooking fires, four garbage fires, three brick making kilns, three charcoal making kilns, and two crop residue fires. Global biofuel use has been estimated at over 2600 Tg/y. With several simple case studies we show that cooking fires can be a major, or the major, source of several gases and fine particles in developing countries. Insulated cook stoves with chimneys were earlier shown to reduce indoor air pollution and the fuel use per cooking task. We confirm that they also reduce the emissions of VOC pollutants per mass of fuel burned by about half. We did not detect HCN emissions from cooking fires in Mexico or Africa. Thus, if regional source attribution is based on HCN emissions typical for other types of biomass burning (BB), then biofuel use and total BB will be underestimated in much of the developing world. This is also significant because cooking fires are not detected from space. We estimate that ~2000 Tg/y of garbage are generated globally and about half may be burned, making this a commonly overlooked major global source of emissions. We estimate a fine particle emission factor (EFPM2.5) for garbage burning of ~10.5±8.8 g/kg, which is in reasonable agreement with very limited previous work. We observe large HCl emission factors in the range 2-10 g/kg. Consideration of the Cl content of the global waste stream suggests that garbage burning may generate as much as 6-9 Tg/yr of HCl, which would make it a major source of this compound. HCl generated by garbage burning in dry environments may have a relatively greater atmospheric impact than HCl generated in humid areas. Garbage burning PM2.5 was found to contain levoglucosan and K in concentrations similar to those for biomass burning, so it could be a source of interference in some areas when using

  7. Trace gas and particle emissions from domestic and industrial biofuel use and garbage burning in central Mexico

    Directory of Open Access Journals (Sweden)

    T. J. Christian

    2010-01-01

    Full Text Available In central Mexico during the spring of 2007 we measured the initial emissions of 12 gases and the aerosol speciation for elemental and organic carbon (EC, OC, anhydrosugars, Cl, NO3, and 20 metals from 10 cooking fires, four garbage fires, three brick making kilns, three charcoal making kilns, and two crop residue fires. Global biofuel use has been estimated at over 2600 Tg/y. With several simple case studies we show that cooking fires can be a major, or the major, source of several gases and fine particles in developing countries. Insulated cook stoves with chimneys were earlier shown to reduce indoor air pollution and the fuel use per cooking task. We confirm that they also reduce the emissions of VOC pollutants per mass of fuel burned by about half. We did not detect HCN emissions from cooking fires in Mexico or Africa. Thus, if regional source attribution is based on HCN emissions typical for other types of biomass burning (BB, then biofuel use and total BB will be underestimated in much of the developing world. This is also significant because cooking fires are not detected from space. We estimate that ~2000 Tg/y of garbage are generated globally and about half may be burned, making this a commonly overlooked major global source of emissions. We estimate a fine particle emission factor (EFPM2.5 for garbage burning of ~10.5±8.8 g/kg, which is in reasonable agreement with very limited previous work. We observe large HCl emission factors in the range 2–10 g/kg. Consideration of the Cl content of the global waste stream suggests that garbage burning may generate as much as 6–9 Tg/yr of HCl, which would make it a major source of this compound. HCl generated by garbage burning in dry environments may have a relatively greater atmospheric impact than HCl generated in humid areas. Garbage burning PM2.5 was found to contain levoglucosan and K in concentrations similar to those for

  8. Lacustrine sedimentation and facies model for the last 45,000 yr in Chalco basin. Central Mexico

    Science.gov (United States)

    Ortega, B.; Lozano, S.; Caballero, M.; Herrera, D.

    2013-05-01

    Chalco basin in central Mexico (19° 15' N, 98° 58' W, 2200 m asl) is one of the most detailed lake sediment sequence analyzed in Mexico for paleoclimatic and paleoenvironmental studies. In this former lake, five drill cores up to 27 m depth were recovered in 1987-1989 by the UNAM team, and three cores covering most of the former sequence were obtained in 2008 and 2011. The upper 27 m of the Chalco lacustrine sequence contains the record of the last 45 kyr climate history in the northern American tropics. The active tectonic and volcanic setting of Chalco Lake in the Trans-Mexican Volcanic Belt, provides an opportunity to evaluate environmental (volcanic + tectonic vs. climatic) controls on lacustrine sedimentation. The establishment of a detailed time scale by 14C in pollen extracts provides an accurate chronological control. The stratigraphical and sedimentological analyses presented here provided the recognition of depositional environments and the architecture of the upper lacustrine succession. Sedimentary facies were defined on the basis of sedimentological descriptions, microscopic observation and compositional analyses. According to compositional criteria, facies were identified and groped into two main categories according to compositional criteria: 1) detrital and volcaniclastic, and 2) biogenic facies. The clastic facies includes massive to laminated, silty and clayey sediments composed of clay minerals, feldspars, amphiboles with minor amounts of quartz, opaque minerals and calcite. Diatoms are the most common biological remains in all the clastic facies. Most of the volcaniclastic deposits correspond to fall-out deposits, some of them of well documented eruptions of the nearby large stratovolcanoes Popocatepetl and Nevado de Toluca, which in turn serve as stratigraphical markers. The biogenic facies are massive to finely laminated diatom ooze and ostracod ooze layers. The sedimentary architecture of the lacustrine succession has been controlled by

  9. Detection of Phytoplasma on Indian Fig (Opuntia ficus-indica Mill in Mexico Central Region

    Directory of Open Access Journals (Sweden)

    Ricardo Gaspar

    2009-01-01

    Full Text Available Problem statement: The Indian fig (a species of prickly pear cactus, has been known as Nopal, comprises an approximate area of 100,000 ha, in plantations used for human consumption. “Pyramids” Indian fig area located in the northeastern State of Mexico has been an important Indian-fig area in the country, with 15810 ha, where a phytoplasma has been consistently present in symptomatic plant. Approach: An unknown symptomatology in the Indian fig (prickly pear cactus (Opuntia ficus-indica Mill was analyzed through grafting and a nested-PCR reaction and graft on healthy plants grown in a greenhouse. Results: The symptoms found, deforming, buds proliferation, thickening and heart-shaping in cladodes, with arrested plant growth and deep yellowing of cladodes, were all attributed to the presence of a phytoplasma given the amplification of a 1200 pb fragment of the 16S rRNA gene using primers R16 F2/R2 and R16F2n/R2 and 80% of phytoplasma transmission efficiency of successful grafts. Conclusion: Although the symptoms observed did not completely match those described for this organism in the region, a 1200 pb fragment was amplified and PCR products restriction analysis leading us to assume that the phytoplasma corresponds to subgroup 16Srll, previously reported for other crops in others world regions.

  10. Elevation Control on Vegetation Organization in a Semiarid Ecosystem in Central New Mexico

    Science.gov (United States)

    Nudurupati, S. S.; Istanbulluoglu, E.; Adams, J. M.; Hobley, D. E. J.; Gasparini, N. M.; Tucker, G. E.; Hutton, E. W. H.

    2015-12-01

    Many semiarid and desert ecosystems are characterized by patchy and dynamic vegetation. Topography plays a commanding role on vegetation patterns. It is observed that plant biomes and biodiversity vary systematically with slope and aspect, from shrublands in low desert elevations, to mixed grass/shrublands in mid elevations, and forests at high elevations. In this study, we investigate the role of elevation dependent climatology on vegetation organization in a semiarid New Mexico catchment where elevation and hillslope aspect play a defining role on plant types. An ecohydrologic cellular automaton model developed within Landlab (component based modeling framework) is used. The model couples local vegetation dynamics (that simulate biomass production based on local soil moisture and potential evapotranspiration) and plant establishment and mortality based on competition for resources and space. This model is driven by elevation dependent rainfall pulses and solar radiation. The domain is initialized with randomly assigned plant types and the model parameters that couple plant response with soil moisture are systematically changed. Climate perturbation experiments are conducted to examine spatial vegetation organization and associated timescales. Model results reproduce elevation and aspect controls on observed vegetation patterns indicating that this model captures necessary and sufficient conditions that explain these observed ecohydrological patterns.

  11. Canopy arthropods community within and among oak species in central Mexico

    Institute of Scientific and Technical Information of China (English)

    Efraín TOVAR-SANCHEZ

    2009-01-01

    Quercus rugosa and Q.laurina are species that presents a wide geographical distribution range in temperate forests of Mexico. Oak canopies contain a considerable portion of arthropod diversity and the arthropods fauna fulfill a wide variety of ecological roles. We examined the effect of oak species and seasonal changes on some community structure parameters (diversity, composition, similarity, biomass, rare species, and density of arthropod fauna) of canopy arthropods. In total, 40 oak canopies were fogged during rainy and dry season. A total of 614 identified arthropod morphospecies were recognized belonging to 22 orders associated with tree canopies. A separation of host tree species during both seasons, suggesting a different community structure on host plants species was demonstrated by the principal component analyses (PCA), therefore, differences between oak species results in phenotypes that structure the composition of the arthropod community. Q.laurina registered the highest densities, diversity index and number of rare species in comparison with Q.rugosa. While arthropod biomass showed an inverse pattern. Trees more close to one another (spatial distance) register a more similar canopy arthropod fauna. This study suggests that the trees of Q.laurina could act as a center of biodiversity by the accumulation of arthropod fauna with a considerable number of rare species, which presents wide ecological roles or is involved in critical processes that maintain forest ecosystems[Current Zoology 55(2):132-144,2009].

  12. Direct impacts of outer continental shelf activities on wetland loss in the central Gulf of Mexico

    International Nuclear Information System (INIS)

    The direct impacts of outer continental shelf (OCS) development on recent wetland loss in the northern Gulf of Mexico were quantified using aerial imagery, field surveys, and literature review. The total direct impacts accounted for an estimated 25.6 percent of total net wetland loss within the Louisiana portion of the study area from 1955/56 to 1978. Of the total direct impacts of 73,905 ha, OCS-related activities accounted for 11,589-13,631 ha of the wetland loss during the same time interval. Although this is a substantial areal loss, it represents only 4.0-4.7 percent of the total Louisiana wetland loss from 1955/56 to 1978, and 15.7-18.4 percent of direct impacts. Direct impacts from OCS pipelines averages 2.49 ha/km, lower than published guidelines, and totaled 12,012 ha. Lowest impacts are for backfilled pipelines in the Chenier Plain of western Louisiana and for small young pipeline canals does not appear to be an important factor for total new wetland loss in the coastal zone because few pipelines are open to navigation and, for the examples found, the impact width was not significantly different than for open pipelines closed to navigation. Navigation channels account for a minimum of 16,902 ha of habitat change. Direct impacts per unit length of navigation channel average 20 times greater than pipelines

  13. Air Pollutant Characterization in Tula Industrial Corridor, Central Mexico, during the MILAGRO Study

    Directory of Open Access Journals (Sweden)

    G. Sosa

    2013-01-01

    Full Text Available Pollutant emissions and their contribution to local and regional air quality at the industrial area of Tula were studied during a four-week period as part of the MILAGRO initiative. A recurrent shallow stable layer was observed in the morning favoring air pollutants accumulation in the lower 100 m atmospheric layer. In the afternoon the mixing layer height reached 3000 m, along with a featuring low level jet which was responsible of transporting air pollutants at regional scales. Average PM10 at Jasso (JAS and Tepeji (TEP was 75.1 and 36.8 μg/m3, respectively while average PM2.5 was 31.0 and 25.7 μg/m3. JAS was highly impacted by local limestone dust, while TEP was a receptor of major sources of combustion emissions with 70% of the PM10 constituted by PM2.5. Average hourly aerosol light absorption was 22 Mm−1, while aerosol scattering (76 Mm−1 was higher compared to a rural site but much lower than at Mexico City. δ13C values in the epiphyte Tillandsia recurvata show that the emission plume directly affects the SW sector of Mezquital Valley and is then constrained by a mountain range preventing its dispersion. Air pollutants may exacerbate acute and chronic adverse health effects in this region.

  14. Active mountain building and the distribution of core Maxillariinae species in tropical Mexico and Central America

    Science.gov (United States)

    Kirby, Stephen H.

    2011-01-01

    The observation that southeastern Central America is a hotspot for orchid diversity has long been known and confirmed by recent systematic studies and checklists. An analysis of the geographic and elevation distribution demonstrates that the most widespread species of “core” Maxillariinae are all adapted to life near sea level, whereas the most narrowly endemic species are largely distributed in wet highland environments. Drier, hotter lowland gaps exist between these cordilleras and evidently restrict the dispersal of the species adapted to wetter, cooler conditions. Among the recent generic realignments of “core” Maxillariinae based on molecular phylogenetics, the Camaridium clade is easily the most prominent genus in Central America and is largely restricted to the highlands of Costa Rica and Panama, indicating that this region is the ancestral home of this genus and that its dispersal limits are drier, lowland cordilleran gaps. The mountains of Costa Rica and Panama are among the geologically youngest topographic features in the Neotropics, reflecting the complex and dynamic interactions of numerous tectonic plates. From consideration of the available geological evidence, I conclude that the rapid growth of the mountain ranges in Costa Rica and Panama during the late Cenozoic times created, in turn, very rapid ranges in ecological life zones and geographic isolation in that part of the isthmus. Thus, I suggest that these recent geologic events were the primary drivers for accelerated orchid evolution in southeastern Central America.

  15. P wave velocity of the uppermost mantle of the Rio Grande rift region of North Central New Mexico

    International Nuclear Information System (INIS)

    A network of seismograph stations has operated in north-central New Mexico since 1975. The network is approximtely 200 by 300 km in size and encompasses the Rio Grande rift there. Several seismic refraction experiments have been reported in the literature for the region of the network and adjacent areas. Because all of the seismic refraction lines are unreversed, P/sub n/ velocities reported were mainly of the inverse travel time slope for the direction of the corresponding line. The values of the inverse slope for those studies range from 7.6 to 8.2 km/s. The purpose of our study is to estimate the P wave velocity of the uppermost mantle by using the time term method. First, we timed the P/sub n/ waves of strong signals from five explosions and eight shallow earthquakes recorded by the network. The main data set, which contains 87 time-distance pairs, was processed by using the time term method. The P/sub n/ velocity estimated by this method is 8.0 +- 0.1 km/s. To corroborate this estimate, we then processed 10 subsets of the main data set in the same way. Almost allof the solutions show velocities 7.9--8.1 km/s, in agreement with the velocity determined for the main data set. The station time terms of the main data set also are substantied, and they suggest that the base of the crust dips northward by a few degrees in the region of the survey. The smallest value reported by other investigators for the inverse slope (7.6 km/s) appears to be related to the dip. The normal P wave velocity of the uppermost mantle of north-central New Mexico places restrictions on thermal models of the rift. For instance, the results exlude the likelihood of a wide zone of asthenosphere at the base of the crust beneath the rift, but they do not exclude a narrow such zone

  16. Pedogenesis and paleoenvironmental records in the tephra-paleosol sequences of Central Mexico: micromorphometric indicators.

    Science.gov (United States)

    Diaz, Jaime; Solleiro, Elizabeth; Sedov, Sergey

    2014-05-01

    tepetates (hardened volcanic soils) in Mexico have been studied from an agronomic and mechanisms viewpoint, however due to their different origins have not been established mechanisms that link them to environmental studies. This paper uses morphometric tools to determine the origin of the Tepetates in Mexico, using them as indicators of environmental changes and periods of instability of the landscape. The Glacis de Buenavista is located mainly in the northwestern portion of the state of Morelos, between the parallels 18° 20'and 19° 08' north latitude and meridians 98° 37' and 99° 30' west, forming a piedmont relief caused by erosion-sedimentation phases of volcanic materials from the Sierra de Zempoala mainly, and that is a big fan of Pleistocene age. Covers an area of 202.7 km 2. The maximum altitude is in the north, 2600 m, and minimun in the south to the 970 m, with an average slope of 6 . The Glacis de Buenavista has soils cover which consists of Luvisols, Vertisols, and layers of Tepetates, Phaeozems and Luvisols, in particular, represent soils polycyclic polygenetic high degree of development that have been formed in the Holocene. The next question is what mechanisms control the presence of a floor or other unit that occurs in the area? Since the lateral boundaries between soil types are abrupt, which speaks of discontinuities in the processes that have given rise. The morphometric study was carried out in thins sections of the blocks of Tepetates undisturbed. The blocks were vacuum impregnated with polyester resin. The thins sections were scanned with an Epson scanner 7100 with high resolution 9600 dpi and 24 bit color depth and analyzed using Image Pro Plus 5.1 program. The stratigraphic control was performed by 14C dating of organic matter. The pedofeatures measured were roundness of soil fragments, matrix percentage, percentage of papules and porosity. Was also carried out a microscopic control using a microscope BX51 Olimpus pedofeatures observing

  17. Geology and geochemistry characteristics of the Chiapanecan Volcanic Arc (Central Area), Chiapas Mexico

    Science.gov (United States)

    Mora, J. C.; Jaimes-Viera, M. C.; Garduño-Monroy, V. H.; Layer, P. W.; Pompa-Mera, V.; Godinez, M. L.

    2007-04-01

    The Chiapanecan Volcanic Arc (CVA), located in the central portion of the State of Chiapas, is a 150 km stretch of volcanoes irregularly aligned in the northwest direction between two great volcanic features: the Trans-Mexican Volcanic Belt to the northwest and the Central American Volcanic Arc to the southeast. The CVA is located in a complex zone marking the interaction of the North American, Caribbean and Cocos plates, near the Motagua-Polochic fault system, the boundary between North American and Caribbean plates. The central part of the CVA is composed of an irregular northwest alignment of at least 10 volcanic structures generally lying along NNW-SSE-trending faults splayed from the Motagua-Polochic system. Among the structures there are seven volcanic domes (Huitepec, Amahuitz, La Iglesia, Mispía, La Lanza, Venustiano Carranza and Santotón), one explosion crater (Navenchauc), one collapse structure (Apas), and one dome complex (Tzontehuitz). In the majority of the structures there is a clear resurgence with the formation of several domes in the same structure, with the destruction of previous domes (Navenchauc) or with the formation of new explosion craters or collapse structures (Apas). The volcanic activity in the CVA was mainly effusive accompanied by explosive and phreatomagmatic events and is characterized by volcanic domes accompanied by block-and-ash-flows, ash flows with accretionary lapilli, falls, and pumice flows. The volcanic structures and deposits are calcalkaline in composition with a medium to high content of potassium. CVA volcanic rocks vary from andesite to dacite with SiO 2 between 57 and 66 wt.%, show low concentrations of Ti, P, Nb and Ta, are enriched in Light Rare Earths, depleted in Heavy Rare Earths, and show a small Eu anomaly; all indicative of arc-related volcanism associated with subduction of the Cocos plate under the North American plate, but complicated by the geometry of the plate boundary fault system.

  18. Herbivory of sympatric elk and cattle on Lincoln National Forest, south-central New Mexico

    Directory of Open Access Journals (Sweden)

    Heather H. Halbritter

    2015-09-01

    Full Text Available Background Wildlife and livestock grazing are important products of forest ecosystems, but can be controversial. Herbivory by North American elk and domestic cattle is a contentious management issue throughout western North America, often driving management proposals to decrease cattle and elk numbers based on perceived overutilization of forages. Such observations are often site level rather than landscape, and may confuse ecological sustainability with desired conditions. Methods We used line transects to document vegetation composition, structure, and grazing and browsing utilization for 4 key habitat types: mountain meadows, aspen, thinned conifer, and burned conifer on Lincoln National Forest, New Mexico, USA. We documented relative habitat use of these types by elk, mule deer, and cattle and modeled relative use on residual grass biomass of mountain meadows and browse utilization of forested types. We determined diets and diet quality of elk and cattle to assess degree of competition. Results Use of grasses in meadows was below management thresholds, and combined elk, cattle, and deer relative habitat use accounted for < 14 % of the variance in residual stubble height of Poa pratensis, the most abundant grass. Palatable browse was limited in habitat types (< 107 stems·ha -1 , use was generally high, and elk presence was correlated with the majority of browsing. Elk and cattle diets did not significantly overlap (Schoener’s index 0.54–0.57; elk fed primarily on deciduous shrubs (34 %–55 % of annual diets and cattle on grass (72 %–77 %. Digestibility and crude protein levels of cattle diets and body condition of elk indicated high quality diets for cattle and marginal–good quality diets for elk. Conclusions At observed stocking levels and densities, cattle and elk were not competing for forage based on diet similarity, nor were key habitat types being used beyond sustainable levels. Low browse availability indicates that

  19. Concentration and dry deposition of mercury species in Arid South Central New Mexico (2001-2002)

    Science.gov (United States)

    Caldwell, C.A.; Swartzendruber, P.; Prestbo, E.

    2006-01-01

    This research was initiated to characterize atmospheric deposition of reactive gaseous mercury (RGM), particulate mercury (HgP; Mexico. Two methods were field-tested to estimate dry deposition of three mercury species. A manual speciation sampling train consisting of a KCl-coated denuder, 2.5 ??m quartz fiber filters, and gold-coated quartz traps and an ion-exchange membrane (as a passive surrogate surface) were deployed concurrently over 24-h intervals for an entire year. The mean 24-h atmospheric concentration for RGM was 6.8 pg m-3 with an estimated deposition of 0.10 ng m-2 h-1. The estimated deposition of mercury to the passive surrogate surface was much greater (4.0 ng m-2 h -1) but demonstrated a diurnal pattern with elevated deposition from late afternoon to late evening (1400-2200; 8.0 ng m-2 h-1) and lowest deposition during the night just prior to sunrise (2200-0600; 1.7 ng m-2 h-1). The mean 24-h atmospheric concentrations for HgP and Hg0 were 1.52 pg m-3 and 1.59 ng m-3, respectively. Diurnal patterns were observed for RGM with atmospheric levels lowest during the night prior to sunrise (3.8 pg m-3) and greater during the afternoon and early evening (8.9 pg m-3). Discernible diurnal patterns were not observed for either HgP or Hg0. The total dry deposition of Hg was 5.9 ??g m-2 year-1 with the contribution from the three species as follows: RGM (0.88 ??g m-2 year-1), HgP (0.025 ??g m-2 year-1), and Hg0 (5.0 ??g m-2 year-1). The annual wet deposition for total mercury throughout the same collection duration was 4.2 ??g m-2 year-1, resulting in an estimated total deposition of 10.1 ??g m-2 year-1 for Hg. On one sampling date, enhanced HgP (12 pg m-3) was observed due to emissions from a wildfire approximately 250 km to the east. ?? 2006 American Chemical Society.

  20. Stratigraphy, sedimentology and paleontology of lower Eocene San Jose formation, central San Juan basin, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Lucas, S.G.; Smith, L.N. (New Mexico Museum of Natural History, Albuquerque (USA))

    1989-09-01

    The lower Eocene San Jose Formation in the central portion of the San Juan basin (Gobernador-Vigas Canyon area) consists of the Cuba Mesa, Regina, Llaves, and Tapicitos Members. Well log data indicate that, from its 100-m thickness, the Cuba Mesa Member thins toward the basin center and pinches out to the northeast by lat. 36{degree}40'N, long. 107{degree}19'W. The Regina Member has the most extensive outcrops in the central basin, and it decreases in sandstone/mud rock ratio to the north. The Llaves and Tapicitos Members occur only at the highest elevations, are thin due to erosion, and are not mappable as separate units. Well log data and 1,275 m of measured stratigraphic section in the Regina, Llaves, and Tapicitos Members indicate these strata are composed of approximately 35% medium to coarse-grained sandstone and 65% fine-grained sandstone and mud rock. Sedimentology and sediment-dispersal patterns indicate deposition by generally south-flowing streams that had sources to the northwest, northeast, and east. Low-sinuosity, sand-bedded, braided( ) streams shifted laterally across about 1 km-wide channel belts to produce sheet sandstones that are prominent throughout the San Jose Formation. Subtle levees separated channel environments from floodplain and local lacustrine areas. Avulsion relocated channels periodically to areas on the floodplain, resulting in the typically disconnected sheet sandstones within muddy overbank deposits of the Regina Member.

  1. Shoreline erosion rates along barrier islands of the north central gulf of Mexico

    Science.gov (United States)

    Shabica, Stephen V.; Dolan, Robert; May, Suzette; May, Paul

    1983-09-01

    Rates of shoreline change and overwash penetration distances were calculated for barrier islands along the Louisiana, Mississippi, and Alabama coasts with the orthogonal grid mapping system (OGMS). Average rates of shoreline change are exceptionally high in Louisiana, being of the order -4.7 to -7.4 m yr-1. Mississippi and Alabama recession rates are lower and range from -2.0 to -3.1 m yr-1 over the period of record. Erosion rates along the shorelines of these islands have remained relatively constant over the period of study with five exceptions in coastal Louisiana and the Chandeleur-Breton Islands Arc, and two exceptions along the Mississippi-Alabama barrier islands where they have accelerated. Mean overwash penetration is greatest along Dauphin Island, Alabama, and Cat Island, Mississippi: 207.6 and 197.9 m, respectively. The Chandeleur-Brenton Islands Arc range from 88.1 m at the central barrier to 180.4 along the flanks. The Mississippi islands range from 105.2 m on Ship Island to 200.5 m along central Horn Island. Mean overwash penetration along the Louisiana barriers is highly variable: 46.3 to 211.4 m.

  2. Farm and socio-economic characteristics of smallholder milk producers and their influence on technology adoption in Central Mexico.

    Science.gov (United States)

    García, Carlos Galdino Martínez; Dorward, Peter; Rehman, Tahir

    2012-08-01

    In order to identify the factors influencing adoption of technologies promoted by government to small-scale dairy farmers in the highlands of central Mexico, a field survey was conducted. A total of 115 farmers were grouped through cluster analysis (CA) and divided into three wealth status categories (high, medium and low) using wealth ranking. Chi-square analysis was used to examine the association of wealth status with technology adoption. Four groups of farms were differentiated in terms of farms' dimensions, farmers' education, sources of incomes, wealth status, management of herd, monetary support by government and technological availability. Statistical differences (p technology adoption. Although wealth status had a significant association (p < 0.05) with adoption, other factors including importance of the technology to farmers, usefulness and productive benefits of innovations together with farmers' knowledge of them, were important. It is concluded that the analysis of the information per group and wealth status was useful to identify suitable crop or forage related and animal husbandry technologies per group and wealth status of farmers. Therefore the characterizations of farmers could provide a useful starting point for the design and delivery of more appropriate and effective extension. PMID:22297420

  3. Computer-assisted cartography using topographic properties: precision and accuracy of local soil maps in central Mexico

    Directory of Open Access Journals (Sweden)

    Gustavo Cruz-Cárdenas

    2011-06-01

    Full Text Available Map units directly related to properties of soil-landscape are generated by local soil classes. Therefore to take into consideration the knowledge of farmers is essential to automate the procedure. The aim of this study was to map local soil classes by computer-assisted cartography (CAC, using several combinations of topographic properties produced by GIS (digital elevation model, aspect, slope, and profile curvature. A decision tree was used to find the number of topographic properties required for digital cartography of the local soil classes. The maps produced were evaluated based on the attributes of map quality defined as precision and accuracy of the CAC-based maps. The evaluation was carried out in Central Mexico using three maps of local soil classes with contrasting landscape and climatic conditions (desert, temperate, and tropical. In the three areas the precision (56 % of the CAC maps based on elevation as topographical feature was higher than when based on slope, aspect and profile curvature. The accuracy of the maps (boundary locations was however low (33 %, in other words, further research is required to improve this indicator.

  4. Reproductive cycles and reproductive strategies among populations of the Rose-bellied Lizard Sceloporus variabilis (Squamata: Phrynosomatidae) from central Mexico.

    Science.gov (United States)

    Cruz-Elizalde, Raciel; Ramírez-Bautista, Aurelio

    2016-03-01

    Species with wide distribution, generally show variations in life history characteristics, which can be attributed to environmental causes. In this study, we analyzed the reproductive cycle and reproductive characteristics from three populations (Atlapexco, San Pablo Tetlapayac, and Santa Catarina) of the lizard Sceloporus variabilis from central Mexico. The specific goal of this study was to evaluate life history characteristics such as reproductive period extent, SVL (snout-vent length) at sexual maturity, clutch size, egg mass and volume, and RCM (relative clutch mass). The San Pablo Tetlapayac population showed a larger clutch size, RCM, egg mass, and a smaller SVL, body mass and reproductive period (January-September), as well as egg volume than the Atlapexco and Santa Catarina populations. Reproductive cycle and reproductive characteristics were more similar between the Atlapexco and Santa Catarina populations. Differences found in the population of San Pablo Tetlapayac with respect to the Atlapexco and Santa Catarina populations could be attributed to environmental variations where lizard populations occur. Differences in the reproductive period and reproductive characteristics in each population could be the result of both historical (phylogenetic; e.g., reproductive mode) and nonhistorical (environmental; e.g., temperature, food availability) causes. This study showed that populations of the same species are under different selection pressures, and these affect the reproductive characteristics of populations. Our results also indicate that long-term and targeted studies on predation, use and selection of food, are needed to determine the causes of these variations in populations of S. variabilis. PMID:26929815

  5. Quaternary volcanism in the Acambay graben, Mexican Volcanic Belt: Re-evaluation for potential volcanic danger in central Mexico

    Science.gov (United States)

    Aguirre-Diaz, G. J.; Pedrazzi, D.; Lacan, P.; Roldan-Quintana, J.; Ortuňo, M.; Zuniga, R. R.; Laurence, A.

    2015-12-01

    The Mexican Volcanic Belt (MVB) is best known for the major active stratovolcanoes, such as Popocatépetl, Citlaltépetl and Colima. The most common stratovolcanoes in this province are modest-size cones with heights of 800 to 1000 m. Examples are Tequila, Sangangüey, Las Navajas, Culiacán, La Joya, El Zamorano, Temascalcingo and Altamirano; these last two were formed within the Acambay Graben in central MVB. The Acambay graben (20 x 70 km) is 100 km to the NW of Mexico City, with E-W trending seismically active normal faults; in particular the Acambay-Tixmadejé fault related to a mB =7 earthquake in 1912. Within the graben there are many volcanic structures, including calderas, domes, cinder cones and stratovolcanoes; Temascalcingo and Altamirano are the largest, with about 800 and 900 m heights, respectively. Temascalcingo is mostly composed of dacitic lavas and block and ash flow deposits. Includes a 3 x 2.5 km summit caldera and a magmatic sector collapse event with the associated debris avalanche deposit. 14C ages of 37-12 ka correspond to the volcano's latest phases that produced pyroclastic deposits. A major plinian eruption formed the San Mateo Pumice with an age of UNAM-PAPIIT IN-104615.

  6. Seismicity and structure in central Mexico: Evidence for a possible slab tear in the South Cocos plate

    Science.gov (United States)

    Dougherty, Sara L.; Clayton, Robert W.

    2014-04-01

    The morphology of the transition from flat to normal subduction in eastern central Mexico is explored using intraslab earthquakes recorded by temporary and permanent regional seismic arrays. Observations of a sharp transition in slab dip near the abrupt end of the Trans-Mexican Volcanic Belt (TMVB) suggest a possible slab tear located within the subducted South Cocos plate. The eastern lateral extent of a thin ultra-slow velocity layer (USL) imaged atop the Cocos slab in recent studies along the Meso America Subduction Experiment array is examined here using additional data. We find an end to this USL which is coincident with the western boundary of a zone of decreased seismicity and the end of the TMVB near the sharp transition in slab dip. Waveform modeling of the 2-D structure in this region using a finite difference algorithm provides constraints on the velocity and geometry of the slab's seismic structure and confirms the location of the USL. Analysis of intraslab seismicity patterns reveals clustering, sudden increase in depth, variable focal mechanism orientations and faulting types, and alignment of source mechanisms along the sharp transition in slab dip. The seismicity and structural evidence suggests a possible tear in the South Cocos slab. This potential tear, together with the tear along the Orozco Fracture Zone to the northwest, indicates a slab rollback mechanism in which separate slab segments move independently, allowing for mantle flow between the segments.

  7. Decadal to millennial-scale solar forcing of Last Glacial Maximum climate in the Estancia Basin of central New Mexico

    Science.gov (United States)

    Menking, Kirsten M.

    2015-05-01

    Lacustrine sediments from the Estancia Basin of central New Mexico reveal decadal to millennial oscillations in the volume of Lake Estancia during Last Glacial Maximum (LGM) time. LGM sediments consist of authigenic carbonates, detrital clastics delivered to the lake in stream flow pulses, and evaporites that precipitated in mudflats exposed during lake lowstands and were subsequently blown into the lake. Variations in sediment mineralogy thus reflect changes in hydrologic balance and were quantified using Rietveld analysis of X-ray diffraction traces. Radiocarbon dates on ostracode valve calcite allowed the construction of mineralogical time series for the interval ~ 23,600 to ~ 18,300 ka, which were subjected to spectral analysis using REDFIT (Schulz and Mudelsee, 2002). Dominant periods of ~ 900, ~ 375, and ~ 265 yr are similar to cycles in Holocene 14C production reported for a variety of tree ring records, suggesting that the Lake Estancia sediments record variations in solar activity during LGM time. A prominent spectral peak with a period of ~ 88 yr appears to reflect the solar Gleissberg cycle and may help, along with the ~ 265 yr cycle, to explain an ongoing mystery about how Lake Estancia was able to undergo abrupt expansions without overflowing its drainage basin.

  8. Buried palaeosols of the Nevado de Toluca: an alternative record of Late Quaternary environmental change in central Mexico

    Science.gov (United States)

    Sedov, Sergey; Solleiro-Rebolledo, Elizabeth; Gama-Castro, Jorge E.; Vallejo-Gómez, Ernestina; González-Velázquez, Arelia

    2001-05-01

    Buried palaeosols of central Mexico, not previously analysed from a palaeopedological standpoint, have helped to develop a reliable regional model of Late Quaternary climatic change. This paper focuses upon morphological and micromorphological properties, particle-size distribution, and extractable Fe, Al and Si of seven palaeosols (named PT1-PT7) in the vicinity of the Nevado de Toluca volcano. The characteristics of Andic Cambisol PT1, similar to those of modern soils in semi-arid environments, indicate a drier climate in the first half of the Holocene. Humic Andosols PT2-PT4 are analogous to modern volcanic soils of humid forest environments. They show evidence that a moist palaeoclimate prevailed during marine oxygen isotope stages (OIS) 2 and 3. Luvisols PT5 and PT6, which are assumed to have formed at the end of marine OIS 5 to marine OIS 4, also indicate humid conditions. We attribute the differences between Andosols PT2-PT4 and Luvisols PT5-PT7 to variations in the duration in the pedogenesis rather than to changes in palaeoclimate. Micromorphological features of Andosol to Luvisol transition confirm that these soils form an evolutionary sequence. Being for the most part consistent with lacustrine records, the palaeosol properties do not reflect the episodes of drier climate during the Last Glacial Maximum, however, as shown by diatom and palynological data from lake sediments. Mesoclimate variations and/or incompleteness of soil memory, reflecting mostly periods of humid pedogenesis, probably provide the reason for this disagreement.

  9. Generation of Talc from the Mantle Wedge and its Role on the Subduction Dynamics in Central Mexico

    Science.gov (United States)

    Kim, Y.; Clayton, R. W.; Asimow, P. D.; Jackson, J. M.

    2013-05-01

    Geophysical evidence shows the existence of low-seismic velocity material at the surface of subducting slabs in subduction zones although its termination point may vary depending on various parameters such as its thermal state and slab dip angle. In central Mexican subduction zone, modeling of the teleseismic converted amplitudes of the horizontal oceanic crust previously revealed a thin (~4 km) low-velocity zone at the upper oceanic crust between the Cocos plate and the continental crust that appears to absorb nearly all of the strain between two plates. Using Vp/Vs as a function of S wave velocity (Vs) in a range of likely pressures (P) and temperatures (T) for candidate mineral phases, this thin layer in the flat slab region is determined to be enriched with hydrous (low-strength) minerals such as talc over the normal oceanic crustal compositions such as MORB-like gabbro. Based on the P-T curves for equilibria involving talc derived from available thermodynamic data, the generation of talc from the basaltic lithology of the oceanic crust subducting at the trench side is nearly impossible. Also, there is no clear evidence to explain the origin of the flat subduction based on the offshore anomalies, which may lead to the current configuration. We therefore propose that the talc-rich layer on top of the subducting plate is generated from the mantle wedge side during the slab flattening process coupled with trench rollback. The evolution of this low-strength zone has important implications for the dynamics of the subduction system including the flattening process of the slab as well as the geochemistry of the mantle wedge and arc in central Mexico.

  10. Genetic diversity and conservation of Mammillaria huitzilopochtli and M. supertexta, two threatened species endemic of the semiarid region of central Mexico

    OpenAIRE

    Sofía Solórzano; Patricia Diana Cuevas-Alducin; Verónica García-Gómez; Patricia Dávila

    2014-01-01

    Nearly 168 species of Mammillaria are endangered at the global level; most of these cactus species exhibit a narrow distribution range and/or small population size. Recently, the first population genetics studies showed low to moderate levels of heterozygosity in this genus. This study examines Mammillaria huitzilopochtli and M. supertexta, 2 threatened species endemic to the central semiarid region of Mexico, to propose conservation actions, as well as to identify the underlying processes th...

  11. Tillandsia usneoides L, a biomonitor in the determination of Ce, La and Sm by neutron activation analysis in an industrial corridor in Central Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Isaac-Olive, K. [Facultad de Medicina. Universidad Autonoma del Estado de Mexico, Paseo Tollocan s/n, esq. Jesus Carranza, Toluca, 50120 Estado de Mexico (Mexico); Solis, C., E-mail: corina@fisica.unam.mx [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, 04510 Mexico DF (Mexico); Martinez-Carrillo, M.A; Andrade, E. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, 04510 Mexico DF (Mexico); Lopez, C.; Longoria, L.C. [Instituto Nacional de Investigaciones Nucleares (ININ), Salazar, 50045 Estado de Mexico (Mexico); Lucho-Constantino, C.A. [Universidad Politecnica de Pachuca, Carretera Pachuca-Cd. Sahagun, Km. 20., Hidalgo, Mexico (Mexico); Beltran-Hernandez, R.I. [Centro de Investigaciones Quimicas, Universidad Autonoma del Estado de Hidalgo. Carretera Pachuca-Tulancingo km. 4.5, 42184, Pachuca, Hidalgo (Mexico)

    2012-04-15

    The atmosphere of the Tula Industrial Corridor in Central Mexico is contaminated due to several industries including oil refining while station monitoring in this area are limited. Lanthanides are considered fingerprint of oil refinery activities, and La, Ce and Sm have been previously detected in this area using filters. The suitability of T. usneoides as a biomonitor assessing the La, Ce and Sm concentrations in Particulate Matter is evaluated by NAA. Results of both biomonitor and filters are highly correlated.

  12. Tillandsia usneoides L, a biomonitor in the determination of Ce, La and Sm by neutron activation analysis in an industrial corridor in Central Mexico

    International Nuclear Information System (INIS)

    The atmosphere of the Tula Industrial Corridor in Central Mexico is contaminated due to several industries including oil refining while station monitoring in this area are limited. Lanthanides are considered fingerprint of oil refinery activities, and La, Ce and Sm have been previously detected in this area using filters. The suitability of T. usneoides as a biomonitor assessing the La, Ce and Sm concentrations in Particulate Matter is evaluated by NAA. Results of both biomonitor and filters are highly correlated.

  13. Rock magnetic and geochemical proxies for iron mineral diagenesis in a tropical lake: Lago Verde, Los Tuxtlas, East Central Mexico

    Science.gov (United States)

    Ortega, Beatriz; Caballero, Margarita; Lozano, Socorro; Vilaclara, Gloria; Rodríguez, Alejandro

    2006-10-01

    inferred are in concordance with the glacial advances recorded in central Mexico. Higher erosion rates reflect destruction of the rainforest over the last 40 years.

  14. Microanalysis of the aerosol collected over south-central New Mexico during the alive field experiment, May-December 1989

    Science.gov (United States)

    Sheridan, Patrick J.; Schnell, Russel C.; Kahl, Jonathan D.; Boatman, Joe F.; Garvey, Dennis M.

    Thirty-eight size-segregated aerosol samples were collected in the lower troposphere over the high desert of south-central New Mexico, using cascade impactors mounted onboard two research aircraft. Four of these samples were collected in early May, sixteen in mid-July, and the remaining ones in December 1989, during three segments of the ALIVE field initiative. Analytical electron microscope analyses of aerosol deposits and individual particles from these samples were performed to physically and chemically characterize the major particulate species present in the aerosol. Air-mass trajectories arriving at the sampling area in the May program were quite different from those calculated for the July period. In general, the May trajectories showed strong westerly winds, while the July winds were weaker and southerly, consistently passing over or very near the border cities of El Paso, Texas, and Ciudad Juarez, Mexico. Aerosol samples collected during the May period were predominantly fine (0.1-0.5 μm dia.), liquid H 2SO 4 droplets. Samples from the July experiment were comprised mostly of fine, solid (NH 4) 2SO 4 or mostly neutralized sulfate particles. In both sampling periods, numerous other particle classes were observed, including many types with probable terrestrial or anthropogenic sources. The numbers of these particles, however, were small when compared with the sulfates. Composite particle types, including sulfate/crustal and sulfate/carbonaceous, were also found to be present. The major differences in aerosol composition between the May and July samples (i.e. the extensive neutralization of sulfates in the July samples) can be explained by considering the different aerosol transport pathways and the proximity of the July aerosol to the El Paso/Juarez urban plume. Winds during the December experiment were quite variable, and may have contributed to the widely varying aerosol compositions observed in these samples. When the aircraft sampled the El Paso

  15. On the behavior of site effects in Central Mexico (the Mexican Volcanic Belt – MVB), based on records of shallow earthquakes that occurred in the zone between 1998 and 2011

    OpenAIRE

    Clemente-Chavez, A.; Zúñiga, F. R.; Lermo, J.; A. Figueroa-Soto; Valdés, C.; M. Montiel; O. Chavez; Arroyo, M.

    2013-01-01

    The Mexican Volcanic Belt (MVB) is a seismogenic zone that transects the central part of Mexico with an east–west orientation. The risk and hazard seismic of this seismogenic zone has not been studied at detail due to the scarcity of instrumental data as well as because seismicity in the continental regimen of Central Mexico is not too frequent, however, it is known that there are precedents of large earthquakes (Mw > 6.0) that have taken place in this zone...

  16. GPR and Magnetic Modeling on an Archaeological Site in Central Mexico

    Science.gov (United States)

    Chavez, R. E.; Argote, D. L.; Camara, M. E.; Cifuentes, G.; Lopez, P.

    2007-05-01

    A geophysical study was carried out in an archaeological site called Los Teteles de Ocotitla, which means `bunch of rocks'. The area is located within the central portion of the Sierra de Ocotitla, towards the northeast of La Malinche volcano, in the municipality of Altzayanca, State of Tlaxcala. This site is conformed of several artificial terraces with evidence of human occupation, probably from the Teotihuacan or Tenanyecac phase. At first the presence of several hills, which are the remains of small pyramids can be seen. Also, some exposed walls and floors can be appreciated. The geophysical work included magnetic (vertical field) and GPR observations in five terraces. The magnetic data depicted a series of dipolar anomalies probably related to walls, and stairways. A report from a previous archaeological excavation carried out almost 30 years ago on an upper terrace, mentioned the discovery of an ancient burial. The tomb was a room (3x2x2 m3) to a depth of 1 m, where corpse remains were found, along other archaeological artifacts. Magnetic and GPR profiles were observed in this area to define geophysical signatures of the mentioned ancient structure, to later compare with anomalies obtained in other terraces. Two interesting anomalies were observed in two lower terraces that compared well with the signatures obtained. The magnetic anomalies were modeled employing a 3D inverse approach, assuming that the Earth is conformed of a series of magnetic dipoles. The final result produced a magnetic block of 5x3x3 m3 to a depth of 1.5 m, approximately. The GPR anomalies helped to constrain the initial geometry of the archaeological structure.

  17. Volcanic and granite type uranium metallogenesis of South China uranium metallogenic province

    International Nuclear Information System (INIS)

    Uranium deposits of both volcanic and granite type are studied as the systematic process of tectonic evolution-magmatism-metallogenic fluid action in South China. By summarizing the geological characteristics of hydrothermal uranium deposits, the spatial-temporal distribution of regional uranium mineralization and hydrogen and oxygen isotopic compositions of ore-forming fluid are used to study the origin of ore-forming matter and to elaborate its evolution and metallogenic process. It is considered that Early Cambrian uranium-rich strata are the most substantial uranium sources for hydrothermal uranium deposit in South China and the ore-forming fluid is the mixture of magmatic water and meteoric water. Uranium was accumulated by magmatism controlled by Yanshanian tectonic extension or transitional geodynamic background which facilitated the formation and evolution of ore-forming hydrothermal systems and metallogenesis. (authors)

  18. Brief analysis of uranium metallogenic features in Motianling area, northern Guangxi

    International Nuclear Information System (INIS)

    In Motianling area, uranium metallogenesis are intimately related to weathering and denudation of the granite, atmospheric precipitation, closing degree of the ore storing structure, and the specific reducing environment. The denuded substances of the granite surface and the metamorphic residue body provide the uranium sources for uranium ore-forming. As a result of surficial leaching, uranium is leached by meteoric water, and entered deep earth with precipitation along the fractures. Ore-forming fluids are heated and raised to the near surface for mineralization owing to siliceous hydrothermal activity. Uranium metallogenic features in Motianling area are briefly described in the aspects of uranium sources, water sources, heat sources, ore-storing structure and reducing environment etc., and uranium metallogenic model is established in the paper. (authors)

  19. Uranium deposits of Gabon and Oklo reactors. Metallogenic model for rich deposits of the lower proterozoic

    International Nuclear Information System (INIS)

    The geology of the Franceville basin (Gabon) is examined: stratigraphy, tectonics and geodynamics. The mobile zone of the Ogooue is specially studied: lithology, metamorphism and tectonics, isotopic geochronologic data are given. The different uranium deposits are described. A whole chapter is devoted to the study of Oklo natural nuclear reactor. A metallogenic model is proposed evidencing conditions required for deposit genesis. Tectonics, microstructures sedimentology, organic matter, diagenesis and uraniferous mineralizations are examined

  20. Tectonogeochemical features and metallogenic prognosis in the Xiaolongtan copper mining district, Binchuan, Yunnan Province, China

    Institute of Scientific and Technical Information of China (English)

    HE Mingqin; SONG Huanbin; SU Xunqing

    2007-01-01

    The Xiaolongtan copper mining district is an important area in Dali, West Yunnan, where porphyry copper deposits occur, and copper orebodies are controlled by fault or contact zone structures between porphyry massifs and country rocks. Based on detailed field investigation and deep-going analysis, the authors systematically studied the tectonogeochemical features of this mining district, proposed the principle and foundation of metallogenic prognosis, and delineated the most potential mineralization target area.

  1. Metallogenic aspects of the feldspars and micas geochemistry in pegmatite from Alto-Ligonha (Mocambique)

    International Nuclear Information System (INIS)

    This paper deals with metallogenic aspects concerning the huge Alto Ligonha pegmatite Province. The geological setting of the pegmatites is briefly reviewed and the metamorphic grade of the country rocks of the pegmatites, ranging from granulitic to greenschist facies, has been considered. The economically most interesting pegmatites are those emplaced within rocks with lighter metamorphism. The available geochronological data allow us to link, the most interesting pegmatites from Alto Ligonha, to the Pan-African granitoid magmatism, about 500 Ma ago. (author)

  2. TECTONIC SETTING AND METALLOGENESIS OF THE PRINCIPAL SECTORS OF THE TETHYAN EURASIAN METALLOGENIC BELT

    Institute of Scientific and Technical Information of China (English)

    Slobodan Jankovic

    2001-01-01

    Three global metallogenic belts were formed in the world during Mesozoic and post-Mesozoic times. Two of them are situated along the western and eastern Pacific margins, and the third one - the Tethyan Eurasian metallogenic belt (TEMB) is related to the domain of Eurasian plate and flanked on the south by the Afro-Arabian and Indian plates. The general tectonic evolution of the realm where the TEMB was formed is closely connected with the history of Tethys. The emplacement of ore deposits and the development of regional metallogenic units are related to a definitive time interval and to specific tectonic settings such as: (1) Intracontinental rifting along the northern margin of Gondwana and/or fragments already separated; (2) Oceanic environments (i.e. ophiolite complexes and ocean floor sediments) host podiform chromite deposits, volcano-sedimentary cupriferous pyrite deposits (Cyprus type), stratiform manganese deposits, and sporadically PGE deposits; (3) Subduction related settings involve mainly porphyry copper deposits, hydrothermal massive sulphide polymetallic deposits, and epithermal deposits. So far identified mineralization of porphyry copper exceeds in the TEMB over 100 million tons of copper metal; and(4) Collision and post-collision continent-continent setting includes deposits of lead-zinc, antimony, gold, in some sectors tin deposits, as well. The giant deposits of Li-pegmatite occur sporadically.The TEMB is almost a continuously mineralized belt, but within it, some sectors display specific features of tectonic settings, association of elements, minerals and morphogenetic types of mineralization.

  3. Revisions to the stratigraphic nomenclature of the Abiquiu Formation, Abiquiu and contiguous areas, north-central New Mexico

    Science.gov (United States)

    Maldonado, Florian; Kelley, Shari A.

    2009-01-01

    Stratigraphic studies and geologic mapping on the Abiquiu 7.5-min quadrangle have led to revision of the stratigraphic nomenclature for the Oligocene to Miocene Abiquiu Formation in north-central New Mexico. The Abiquiu Formation had previously been defined to include informal upper, middle (Pedernal chert member), and lower members. The basement-derived conglomeratic lower member in the northern Jemez Mountains and Abiquiu embayment is here redefined. We propose removing the "lower member" from the Abiquiu Formation because provenance of these coarse sediments is dramatically different than the volcaniclastic strata of the "upper member." Furthermore, we propose that the term "lower member of the Abiquiu Formation" be replaced with an existing unit name, the Ritito Conglomerate of Barker (1958), and that the name Abiquiu Formation be restricted to the volcaniclastic succession. The lower part of the Ritito Conglomerate in Arroyo del Cobre on the Abiquiu quadrangle is 47 m (155 ft) thick and is composed of arkosic conglomeratic beds interbedded with arkosic sands and siltstones. Clasts include, in descending order of abundance, Proterozoic quartzite, granite, metavolcanic rocks, quartz, schist, and gneiss and a trace of Mesozoic sandstone and Paleozoic chert. Clasts are predominantly of pebble and cobble size but range from granule to boulder size. Paleocurrent data collected in the Arroyo del Cobre area indicate that the Ritito Conglomerate was deposited by a south-flowing river system during the Oligocene, eroding Laramide highlands such as the Tusas Mountains to the northeast, which contain predominantly Proterozoic rocks. This depositional setting has also been suggested by previous workers. The middle member or Pedernal chert member is present both at the top of the Ritito Conglomerate and as lenses within the lower part of the Abiquiu Formation. This post-depositional diagenetic chert remains an informal unit called the Pedernal chert.

  4. Students and Teachers’ Reasons for Using the First Language Within the Foreign Language Classroom (French and English in Central Mexico

    Directory of Open Access Journals (Sweden)

    Mora Pablo Irasema

    2011-11-01

    Full Text Available

    The present study explores the use of the first language in a context of foreign language teaching. This qualitative research presents the classroom practice and points of view of French and English teachers and students within a public educational institute in central Mexico using the techniques of questionnaires and semi-structured interviews. The results show that teachers and the majority of students perceive the use of the first language as positive and part of the teaching and learning process. A small number of students do not like the use of the first language in the classroom and prefer that their teachers use the target language only.

     

    La presente investigación explora el uso de la lengua materna en un contexto de enseñanza de lenguas extranjeras. Esta investigación cualitativa presenta la práctica docente y los puntos de vista de maestros y alumnos de francés e inglés en el contexto de una universidad pública del centro de México, mediante el uso de las técnicas del cuestionario y la entrevista semiestructurada. Los resultados muestran que tanto los maestros como la mayoría de los alumnos perciben el uso de la lengua materna como algo positivo en el proceso de enseñanza-aprendizaje. Un número reducido de estudiantes rechaza el uso de la lengua materna y prefiere que su clase de lengua extranjera sea dirigida exclusivamente en la lengua meta. Palabras clave: investigación cualitativa, puntos de vista de alumnos y maestros, uso de la lengua materna.

  5. Initial Time Of Two High Altitude Crater Lakes (Nevado De Toluca, Central Mexico Recorded In Subfossil Cladocera

    Directory of Open Access Journals (Sweden)

    Szeroczyńska Krystyna

    2015-12-01

    Full Text Available The objective of this study was the recognition and reconstruction of the origin of two high altitude lakes and the ecological conditions of their early existence based on subfossil Cladocera and chemical analyses. The study focused on the oldest lacustrine sediments from Lake Sol and Lake Luna, located in the crater of Volcano Nevado de Toluca (Central Mexico. The Nevado de Toluca crater developed approximately 12 ka yr BP. According to the literature, the volcano was last active approximately 3.3 ka yr BP, and the lakes developed after that eruption. The remains of nine Cladocera species were found in the bottom sediments of both lakes. The most dominant taxa were two endemic littoral species: Alona manueli and Iliocryptus nevadensis. The total frequency of Cladocera specimens in both of the sediment cores was very low. No Cladocera remains were recorded in the sediment layer at depths between 123–103 m from Lake Luna. The results of the lithological and geochemical analyses showed that this sediment layer was composed of allochthonous material, probably originating from slid down from the volcanic cone. This was suggested by the content of silica (up to 13%, iron (up to 12%, and titanium (up to 4%. The Cladocera remains recorded in the bottom sediments suggested that both reservoirs developed as freshwater lakes at the beginning of the sedimentation. The calibrated radiocarbon dates obtained for the bottom samples were 4040 to 3990 yr BP for Lake Luna (129 cm and 4485 to 4485 yr BP for Lake Sol (89 cm. The obtained ages were older than the dates of the last eruption, which occurred approximately 3300 yr BP. This result was likely related to the type of radiocarbon dated materials (charcoals.

  6. Using ecological-niche modeling as a conservation tool for freshwater species: live-bearing fishes in central Mexico.

    Science.gov (United States)

    Domínguez-Domínguez, Omar; Martínez-Meyer, Enrique; Zambrano, Luis; De León, Gerardo Pérez-Ponce

    2006-12-01

    Ecological-niche modeling is an important tool for conservation assessment of terrestrial species; however, its applicability has been poorly explored in the aquatic realm. Goodeines are a monophyletic group of viviparous freshwater fishes that are well known in central Mexico, with 41 species in 19 genera. Given the number of threats to biodiversity in the region, goodeines represent an excellent model with which to test novel conservation approaches. We assessed the conservation status of the goodeines (37 species), based on their potential distributions predicted by ecological-niche models generated with the genetic algorithm for rule-set prediction (GARP). Predictions of species' distributions performed well in six out of eight species for which sufficient information was available to perform estimations of the area under the curve (AUC) in receiver operating characteristic plots. Extensive field surveys conducted in recent years in most cases confirm the models' predictions. Species richness exhibited a nested pattern, in which the number of species increased toward the center of the distribution of the group. At the basin level, the Río Ameca Basin had the highest number of species (11), chiefly because of the high number of microendemic species (6). Human activities within water bodies (e.g., extensive aquaculture) and drainages (e.g., agriculture, ranching, industrial activities) have affected most goodeines severely, given the deleterious effects of pollution and introductions of exotic species, such as carp (Cyprinus carpio, Ctenopharingodon idella) and tilapia (Oreochromis spp.). Our results paint a pessimistic picture for the long-term survival of many goodeines in their natural environment, and realistic conservation measures are complex and would require immediate protection of specific areas that we have identified. Ecological-niche modeling is a suitable tool for conservation assessment of freshwater species, but availability of environmental

  7. Linking hydropedology and ecosystem services: differential controls of surface field saturated hydraulic conductivity in a volcanic setting in central Mexico

    Directory of Open Access Journals (Sweden)

    A. Gómez-Tagle

    2009-03-01

    Full Text Available In this study the variation of field saturated soil hydraulic conductivity (Kfs as key control variable and descriptor of infiltration was examined by means of a constant head single ring infiltrometer. The study took place in five coverage types and land uses in a volcanic setting in central Mexico. The tested hypothesis was that there exist a positive relationship between plant cover and surface Kfs for the study area. The examined coverage types included; Second growth pine-oak forest, pasture land, fallow land, gully and Cupresus afforestation. Results indicate that Kfs did not depend exclusively of plant cover; it was related to surface horizontal expression of the unburied soil horizons and linked to land use history. Therefore the Kfs measured at a certain location did not depend exclusively of the actual land use, it was also influenced by soil bioturbation linked to plant succession patterns and land use management practices history. The hypothesis accounts partially the variation between sites. Kfs under dense plant cover at the Cupresus afforestation was statistically equal to that measured at the fallow land or the gully sites, while second growth pine-oak forest Kfs figures were over an order of magnitude higher than the rest of the coverage types. The results suggest the relevance of unburied soil horizons in the soil hydrologic response when present at the surface. Under these conditions loosing surface soil horizons due to erosion, not only fertility is lost, but environmental services generation potential. A conceptual model within the hydropedological approach is proposed. It explains the possible controls of Kfs, for this volcanic setting. Land use history driven erosion plays a decisive role in subsurface horizon presence at the surface and soil matrix characteristic determination, while plant succession patterns seem to be strongly linked to soil bioturbation and

  8. 78 FR 9731 - Gulf of Mexico, Outer Continental Shelf (OCS), Central Planning Area (CPA) Oil and Gas Lease Sale...

    Science.gov (United States)

    2013-02-11

    ...: Notice of Availability (NOA) of a Record of Decision (ROD) for CPA Lease Sale 227 in the Gulf of Mexico... Statement (Multisale FEIS). Authority: This NOA is published pursuant to the regulations (40 CFR...

  9. Feeding habits and trophic morphology of inshore lizardfish (Synodus foetens) on the central continental shelf off Veracruz, Gulf of Mexico

    OpenAIRE

    Cruz Escalona, Víctor Hugo; Peterson, M S; Campos Dávila, Lucia; Zetina Rejón, Manuel Jesús

    2005-01-01

    The inshore lizardfish, Synodus foetens, is one of the most common coastal demersal predators on the continental shelf of the Gulf of Mexico (GOM), but the biology and feeding ecology of this species is virtually unknown. Between November 2001 and January 2003 (10 collections), 603 individuals of S. foetens ranging from 112 to 420 mm standard length (SL) and 13 to 630 g (wet weight) were collected from the continental shelf of Alvarado, Veracruz, Mexico. About 60% of the individuals had empty...

  10. The economic impact of Los Alamos National Laboratory on North-Central New Mexico and the state of New Mexico. Fiscal Year 1995

    International Nuclear Information System (INIS)

    Los Alamos National Laboratory is a multidisciplinary, multiprogram laboratory with a mission to enhance national military and economic security through science and technology. Its mission is to reduce the nuclear danger through stewardship of the nation's nuclear stockpile and through its nonproliferation and verification activities. An important secondary mission is to promote U.S. industrial competitiveness by working with U.S. companies in technology transfer and technology development partnerships. Los Alamos has provided technical assistance to over 70 small New Mexico businesses enabling economic development activities in the region and state

  11. The economic impact of Los Alamos National Laboratory on North-Central New Mexico and the state of New Mexico. Fiscal Year 1995

    Energy Technology Data Exchange (ETDEWEB)

    Lansford, R.R. [New Mexico State Univ., Las Cruces, NM (United States). Dept. of Agricultural Economics and Agricultural Business; Adcock, L.D.; Gentry, L.M. [Dept. of Energy, Albuquerque, NM (United States); Ben-David, S. [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Economics

    1996-08-01

    Los Alamos National Laboratory is a multidisciplinary, multiprogram laboratory with a mission to enhance national military and economic security through science and technology. Its mission is to reduce the nuclear danger through stewardship of the nation`s nuclear stockpile and through its nonproliferation and verification activities. An important secondary mission is to promote U.S. industrial competitiveness by working with U.S. companies in technology transfer and technology development partnerships. Los Alamos has provided technical assistance to over 70 small New Mexico businesses enabling economic development activities in the region and state.

  12. The sources of the shallow, upper plate earthquakes in Central Mexico, and their possible triggering by the subduction earthquakes, 'normal' and slow

    Science.gov (United States)

    Manighetti, I.; Vergnolle, M.; Campillo, M.; Cotton, F.; Thollon, O.

    2008-12-01

    Large earthquakes have broken the Central Mexico upper plate in the historical time (1887, M5.3; 1912, M6.9; 1920, M6.5; 1976, M5.3; 1979, M5.3), but the faults responsible for those earthquakes are not precisely known. Nor is their link with the subduction, especially in terms of possible triggering between subduction and shallow earthquakes. To address those issues, we first identify the major active faults that cut the upper plate, and determine their slip mode and overall organization. For that, we conduct a morphological analysis of the region, based on the use of satellite and topographic images. The upper plate appears dissected by a dense network of hundreds of major active faults, which overall form 2 distinct large-scale systems, named Jalisco and Mexico. The Jalisco system is made of the N-S Colima normal fault system which runs from the coast to the Transmexican Belt (TMB) where it ends in a large fishtail centered on the Chapala Lake. The western branch of the fishtail is made of NW-striking, N-dipping faults that are both normal and left-lateral, while the eastern branch is made of ENE-trending, N-dipping normal faults. The Mexico system resembles a large-scale horsetail. It is made of a major NNW-trending left-lateral strike-slip fault that runs from the coast to the TMB, at the eastern edge of the Oaxaca region. As it enters the TMB, that NNW system connects to a series of E-W, N-dipping, normal-right-lateral faults, while extending further north through a series of NNW, E-dipping normal-left-lateral faults. Together these faults bound to the south and west a series of rhomboidal half-grabens, among those are the basins of Mexico City and Acambay. Mexico City is thus bounded by large active faults but also dissected by smaller ones, both E-W and NNW. The E-W fault system that bounds the Acambay half-graben to the south is likely the one to have ruptured in 1912. Second, we examine whether the subduction interface and the upper plate active faults

  13. Population size of the jumbo squid Dosidicus gigas in the central Gulf of California, Mexico, based on mark-recapture data

    OpenAIRE

    Morales Bojorquez, Enrique; Hernández Herrera, Agustin; Nevárez Martínez, Manuel O; Díaz Uribe, Juan Gabriel

    2012-01-01

    The use of mark-recapture data can be an alternative to other methods for estimating abundance of the jumbo squid Dosidicus gigas and can be used when catch-per-unit-effort data applied to depletion models or estimates from survey research are not available. Two mark-recapture events were analyzed in the central Gulf of California, Mexico, during October 2001 and April 2002 to assess the status of jumbo squid. Results from October 2001 yielded a population size of 20.2 million squid with a 95...

  14. Magnetic Mineralogy as Indicator of dry Conditions in Lacustrine Sediments From Santa María del Oro, Nayarit, Central Mexico

    Science.gov (United States)

    Ortega, B.; Vazquez, G.; Rodriguez, A.

    2007-05-01

    Combined magnetic and geochemical analysis were conducted on laminated sediments from Santa Maria del Oro, a crater lake in Nayarit (Mexico), to build up a model of paleoenvironmental conditions for the late Holocene. The occurrence of a severe drought at the end of the archeological Classic period (100 - 900 AD) has been documented in sites of central Mexico (Zirahuen lake and Lerma basin), the Gulf of Mexico coast (Los Tuxtlas) and the Yucatan peninsula. The effects of this climatic event are considered to have stressed the social and political situation in the Yucatan area and other sites in Mesoamerica, and resulted in the "collapse" of the Maya civilization. Santa Maria del Oro sediments between ca. 600 - 1140 AD are characterized by repeated sequences of ocher silt laminae with high inorganic carbon content, authigenic siderite, and low concentration of SD magnetic minerals, followed upward by an increase of concentrations of fine grained SD and SP ferrimagnetic minerals in brown silt laminae. This sequence is considered to represent dissolution-precipitation cycles of magnetic minerals in low erosion, concentrated waters and anoxic water-sediment interface environments. Dissolution of magnetite occurs in reductive conditions, which are considered as warmer and dryer periods. Above the ocher silt, precipitation of fine grained magnetite occurs when conditions change to oxic environments. Ostracode C and O isotopy document a negative precipitation/evaporation balance during this time period.

  15. Nematodes parasites of the gray fox (Urocyon cinereoargenteus Schreber, 1775) in the seasonally dry tropical highlands of central Mexico.

    Science.gov (United States)

    Hernández-Camacho, Norma; Pineda-López, Raul; López-González, Carlos A; Jones, Robert W

    2011-06-01

    The gray fox (Urocyon cinereoargenteus Schreber, 1775) is the most abundant and opportunistic wild canid in Mexico. However, the parasites of this canid in Mexico are poorly known, and an intensive parasite survey is lacking. A survey of gray fox parasitological feces was conducted in El Cimatario National Park, a protected area representative of the seasonally dry, tropical highlands of Mexico. Feces were collected in six 1-km-length transects during the summer of 2003 and spring of 2004. The coproparasitoscopical survey registered nine species of nematodes, typical of wild and domestic canids such as Strongyloides stercoralis, Uncinaria stenocephala, Toxocara canis, Toxascaris leonina, Dioctophyme renale, Trichuris vulpis, Trichuris sp., and Capillaria sp. Ecological factors such as temperature and humidity appear to play a more important role in the establishment of these species of parasites in this protected area than the presence of domestic dogs. PMID:21136079

  16. Analysis on tectonomagmatic evolution and metallogenic geological conditions of rich-large uranium deposits in Nanling uranium-polymetal metallogenic belt, South Jiangxi province

    International Nuclear Information System (INIS)

    Nanling is a complicated tectonomagmatic belt. It is also an important uranium-polymetallic metallogenic belt. On the basis of the research achievements of previous researchers, through the detailed stratigraphic, lithologic, litho-paleo-geographic, geochronologic and geochemical studies and the processing of gravimetric and magnetic data, as well as the information extraction of remote sensing data, the authors come to the following conclusions: (1) The Sannan-Xunwu fault is a long-lived (from the Early Sinian to recent time) EW-trending fault; (2) The earth crust in Nanling experienced three time opening-closing with different scales; (3) The Anyuan-Xunwu area is a large thermo-upwelling extensional structure; (4) The above area is considered to be favourable for the formation of rich-large uranium deposit

  17. Metallogenic Age of Dapinggou Gold Deposit in Northern Altun Area, Northwestern China

    Institute of Scientific and Technical Information of China (English)

    Chen Bailin; Wang Xiaofeng; Yang Yi; Chen Xuanhua

    2005-01-01

    Studying the metallogenic age of Dapinggou gold deposit may provide important material not only for the study of metallization and the further prospecting of gold deposits but also for research into tectonic evolution in the Altun area. In this study, we used Rb-Sr isotopic dating method of fluid inclusion in the Au-bearing quartz, combining field investigation, REE, sulfur isotopes, lead isotopes, strontium isotopes and hydrogen-oxygen isotope, to determine the metallogenic age of the Dapinggou gold deposit. The only newly-discovered medium-sized gold deposit in the northern Altun area, Dapinggou gold deposit, is controlled by a ductile shear zone. It is characterized by mainly altered mylonite-types with a little K-feldspar quartz vein-types. Data from REE, sulfur isotopes, lead isotopes and strontium isotopes show that the source materials of the deposit were derived mainly from the metamorphic rocks. The data from the inclusion and hydrogen-oxygen isotope indicate that the ore-forming fluid came mainly from dynamic metamorphic water and partly from remelting magmatic water, with a little influence from meteoric water. The density of the ore-forming fluid is 0.791-0.971 g/cm3 and it contains 2.36 %-5.5 % salinity. The gold deposit was formed at 1.61-2.68 km below the surface at a temperature of 198-290 ℃ and a pressure of (420-700)×105 Pa. The isotopic age from the Rb-Sr isochron of fluid inclusion in quartz is 487 Ma, which indicates that the mineralization occurred in the early Caledonian epoch. The study on the metallogenic age of Dapinggou gold deposit may provide important material not only for the study of metallization and the further prospecting of gold deposits but also for research into tectonic evolution in the Altun area.

  18. Models for Canadian unconformity deposits: An important component in metallogenic studies, exploration and mineral resource appraisals

    International Nuclear Information System (INIS)

    Canadian unconformity uranium deposits contain the world's largest high grade concentrations of uranium ores. Two models, a regional metallogenic model and a conceptual deposit model, have been developed from studies of the Athabasca Basin metallogenic province. The regional model, which has been derived from the well documented Cigar Lake - Key Lake and Rabbit Lake - Eagle Point trends and the Carswell Structure, includes specific lithological and structural controls within the large Athabasca intracratonic basin. The deposits are spatially related to Archean granitoid domes, such as the Swanson, Collins Bay and Dominique-Peter, which are flanked by a Lower Proterozoic metasedimentary sequence that contains layers of eucinic rocks. These basement rocks are capped by a regolith. They are uncomfortably overlain by a sequence of undisturbed sediments of the Athabasca Group. The Athabasca Group rocks have been subjected to high-temperature prograde diagenesis, which was followed by retrograde alteration. The deposit model, which has been derived from observations on the Cigar Lake, P2 North, Key Lake, Collins Bay and Cluff Lake deposits, postulates deposition of the metals and associated gangue minerals from highly saline brines at redox fronts. Uranium was transported in hexavalent form and deposited due to reduction to tetravalent form. The mineralization processes took place predominantly at the sub-Athabasca unconformity and, to a lesser degree, a short distance from it in the basement or in the cover rocks. At present these models are used in metallogenic studies, for delineation of new exploration targets, and in mineral potential appraisals of the Athabasca Basin frontier areas. (author). 11 refs, 18 figs

  19. Metallogenic geologic prerequisites of sandstone-type uranium deposits and target area selection. Taking Erlian and Ordos basins as examples

    International Nuclear Information System (INIS)

    Sandstone-type uranium deposit is the main target of recent uranium prospecting and exploration. According to the metallogenic characteristics, sandstone-type uranium deposits are divided into three groups: paleo-channel type, interlayer oxidation zone type and phreatic interlayer oxidation type. The author makes an analysis on the geologic prerequisites of the three types of uranium deposits, the similarities and difference, and preliminarily summarizes genetic models of different types of uranium deposits. Finally, taking Erlian and Ordos basins as examples, the author makes an evaluation and a strategic analysis on the uranium metallogenic prospect of the above two basins

  20. Metallogenic characteristic of Sasyk-kul lake water type uranium deposit

    International Nuclear Information System (INIS)

    Sasyk-kul lake water type uranium deposit is located in Pamirs uranium metallogenic area, the ore body is the lake water, uranium concentration of lake water reaches the level of industrial production solution, and can be regarded as one of special type of hydrogenic uranium deposit. Uranium metallogenesis not only includes surficial infiltration origin but also deep geothermal water origin, main reason of uranium concentration was caused by evaporation under condition of arid climate, and the deposit can be classified to the polygenetic uranium deposit. (authors)

  1. Endohelminth parasites of seven goodein species (Cyprinodontiformes: Goodeidae) from Lake Zacapu , Michoacán, Central Mexico Plateau

    OpenAIRE

    Andrés Martínez-Aquino; Rodolfo Pérez-Rodríguez; David I. Hernández-Mena; Lorena Garrido-Olvera; Rogelio Aguilar-Aguilar; Gerardo Pérez-Ponce de León

    2012-01-01

    A total of 11 parasitic endohelminth taxa were found in 7 freshwater fish species of the subfamily Goodeinae in Zacapu Lake, Michoacan, Mexico. Six were adults (Margotrema cf. bravoae, Phyllodistomum sp., Saccocoelioides sogandaresi, Rhabdochona lichtenfelsi, Bothriocephalus acheilognathi and Caryophillidae gen. sp.), while the remaining 5 taxa (Clinostomum complanatum, Posthodiplostomum minimum, Tylodelphis sp., Eustrongylides sp. and Polymorphus brevis) were larvae. The taxa S. sogandaresi,...

  2. 77 FR 29683 - Outer Continental Shelf (OCS) Consolidated Central Gulf of Mexico Planning Area Sale; 216/222

    Science.gov (United States)

    2012-05-18

    ... Mexico are specified as (1) less than 800 meters and (2) 800 meters or more. Per 64 FR 37560, if...-Spatial-Data.aspx . For the current status of all CPA leasing maps and OPD's, please refer to 66 FR 28002 (published May 21, 2001), 69 FR 23211 (published April 28, 2004), 72 FR 27590 (published May 16, 2007), 72...

  3. On the behavior of site effects in central Mexico (the Mexican volcanic belt – MVB), based on records of shallow earthquakes that occurred in the zone between 1998 and 2011

    OpenAIRE

    Clemente-Chavez, A.; Zúñiga, F. R.; Lermo, J.; A. Figueroa-Soto; Valdés, C.; M. Montiel; O. Chavez; Arroyo, M.

    2014-01-01

    The Mexican volcanic belt (MVB) is a seismogenic zone that transects the central part of Mexico with an east–west orientation. The seismic risk and hazard of this seismogenic zone has not been studied in detail due to the scarcity of instrumental data as well as because seismicity in the continental regime of central Mexico is not too frequent. However, it is known that there are precedents of large earthquakes (Mw > 6.0) that have taken place in this zone. The valley of Mex...

  4. Formation of sulphation deposits in cables in the electricity generation plant of Los Humeros geothermal field, Mexico; Sulfatacion de cables en la central geotermoelectrica Los Humeros, Puebla, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Vergara Rangel, Agustin [Comision Federal de Electricidad, Perote, Veracruz (Mexico)

    2000-12-01

    In the construction of a central electrical generation plant using geothermal fluids, high quality standards are applied in all aspects of engineering. Los Humeros generation units were installed through trenches, ducts and trays according to norms for cables of control, force and power, specifically in point to point cables and connections. Performance of the power plant has been affected by electric momentary and sequence flaws due to problems of cable sulfating, which were solved by tinning the conductors. [Spanish] En la construccion de centrales generadoras de electricidad con fluidos geotermicos se aplican criterios de calidad de diseno en todos los aspectos de la ingenieria. En Los Humeros Puebla, se realizo la instalacion conforme a normas de cables de control, fuerza y potencia a traves de trincheras, ductos y charolas y especificamente en el cableado asi como en las conexiones de punta a punta. Todos estos aspectos son referidos a planos de los componentes y equipos electricos existentes en una central. Al paso del tiempo existieron fallas electricas momentaneas y secuenciales por el problema de sulfatacion en cables, los cuales fueron resueltos con el estanado de conductores.

  5. The establishment of Central American migratory corridors and the biogeographic origins of seasonally dry tropical forests in Mexico

    OpenAIRE

    Willis, Charles G.; Franzone, Brian F.; Xi, Zhenxiang; Davis, Charles C.

    2014-01-01

    Biogeography and community ecology can mutually illuminate the formation of a regional species pool or biome. Here, we apply phylogenetic methods to a large and diverse plant clade, Malpighiaceae, to characterize the formation of its species pool in Mexico, and its occupancy of the seasonally dry tropical forest (SDTF) biome that occurs there. We find that the ~162 species of Mexican Malpighiaceae represent ~33 dispersals from South America beginning in the Eocene and continuing until the Pli...

  6. Accumulation, mobility and plant availability of heavy metals in soils irrigated with untreated sewage effluent in Central Mexico

    International Nuclear Information System (INIS)

    In Irrigation District 03, Tula, Mexico, wastewater from Mexico City has been used for irrigating agricultural land since the beginning of this century. Today, approximately 85 000 ha are irrigated, alfalfa and maize being the main crops. The sewage effluent does not receive any treatment previous to its evacuation to this irrigation district, and only a part of the water is stored in the Endho Dam before being used, receiving in this way a kind or primary treatment through the sedimentation processes taking place. The reuse of wastewater for agricultural purposes represents an economic source of water and nutrients and has become an important disposal alternative for Mexico City. Nevertheless the contaminants and pathogens contained in the water represent a potential public health hazard and the production capacity of the soils. The aim of the present investigation is to determine the actual contamination levels of heavy metals (Pb, Cd, Cu, Zn) in soils, analysing the accumulation tendencies in time and space, and also to characterize their mobility and plant availability and thus their ecotoxicity. (orig.)

  7. Origin and Superposition Metallogenic Model of the Sandstone-type Uranium Deposit in the Northeastern Ordos Basin, China

    Institute of Scientific and Technical Information of China (English)

    LI Ziying; CHEN Anping; FANG Xiheng; OU Guangxi; XIA Yuliang; SUN Ye

    2008-01-01

    This paper deals with the metallogenic model of the sandstone type uranium deposit in thenortheastern Ordos Basin from aspects of uranium source, migration and deposition. A superpositionmetallogenie model has been established due to complex uranium mineralization processes withsuperposition of oil-gas reduction and thermal reformation.

  8. Children’s Migration to the United States from Mexico and Central America: Evidence from the Mexican and Latin American Migration Projects

    Directory of Open Access Journals (Sweden)

    Katharine M. Donato

    2015-02-01

    Full Text Available In light of rising numbers of unaccompanied minors at the Mexico-US border in 2014, this article examines child migration from Mexico, Guatemala, El Salvador, Costa Rica, and Nicaragua. Using data from the Mexican and Latin American Migration Projects that permit us to go beyond simple descriptive analysis about children apprehended at the border, we investigate the extent to which children from these countries: (1 enter without legal authorization to do so; (2 are more likely to cross the border now than in the past; and (3 are tied to their parents’ migration. In theory, if immigration and refugee protections worked well for children and offered them legal pathways to reunify with their families, then we would expect low levels of unauthorized entry and no dramatic shifts over time. However, our examination of child migration shows that it is strongly linked to unauthorized entry, period of entry, and parents’ US experience.The findings show that the migration of children is closely linked to their parents’ migration history. Although the overall likelihood of a Mexican child making a first US trip is quite low, it is practically non-existent for children whose parents have no US experience. Thus, the increase in child migration from Central America, and the continued high levels of child migration from Mexico result from widespread migration networks and the United States’ long-standing reliance on the children’s parents as immigrant workers. The findings suggest that these children need protection in the form of family reunification and permanent legal status.

  9. Investigation on the age of mineralization in the Sungun porphyry Cu-Mo deposit, NW Iran with a regional metallogenic perspective

    Science.gov (United States)

    Simmonds, Vartan; Moazzen, Mohssen; Mathur, Ryan

    2016-04-01

    The Sungun porphyry copper deposit (PCD) is located in NW Iran, neighbouring several other PCDs and prospects in the region and the Lesser Caucasus (south Armenia). It lies on the Urumieh-Dokhtar magmatic arc (UDMA), which formed through the northeast-ward subduction of the Neo-Tethyan oceanic crust beneath the Central Iranian plate during late-Mesozoic and early-Cenozoic [1], and hosts the porphyry copper metallogenic belt of Iran. The Sungun PCD is the second largest deposit in Iran with ore reserves of about 850 Mt at 0.62 wt% Cu and 0.01 wt% Mo and probable reserves over 1Gt. The monzonitic to quartz monzonitic porphyry stock intruded the upper Cretaceous carbonates and Eocene volcano-sedimentary rocks. It produced a skarn-type mineralization at its contact zone with the carbonate rocks, as well as vast hydrothermal alteration zones and porphyry-type Cu and Mo mineralization. The zircon U-Pb age of the host porphyry stock is about 22.5±0.4 to 20.1±0.4 Ma [2]. Re-Os dating of four molybdenite separates from this PCD shows ages ranging between 22.9±0.2 to 21.7±0.2 Ma, with an average of 22.57±0.2 Ma, corresponding to the early Miocene (Aquitanian). These ages indicate that both the porphyry stock and the Cu-Mo mineralization are post-collisional events, similar to many other deposits and prospects in NW and central Iran and south Armenia, and the mineralization occurred shortly after the emplacement of the host stock, corresponding better to the ages obtained from the marginal parts of the stock. Magmatism and mineralization in Sungun coincides with the third metallogenic epoch in the Lesser Caucasus (Eocene to Miocene; [3]), though it is considerably younger than all of the dated PCDs and prospects in the south Armenia. It also postdates Cu-Mo mineralizations in the Saheb Divan (35 Ma), Qaradagh batholith (31.22±0.28 to 25.19±0.19 Ma), as well as Haft Cheshmeh PCD (28.18±0.42 to 27.05±0.37 Ma) in NW Iran, while it seems to be coeval with the Kighal

  10. Subsoil TPH and other petroleum fractions-contamination levels in an oil storage and distribution station in north-central Mexico.

    Science.gov (United States)

    Iturbe, Rosario; Flores, Carlos; Flores, Rosa Ma; Torres, Luis G

    2005-12-01

    Many oil industry related sites have become contaminated due to the activities characteristic of this industry, such as oil exploration and production, refining, and petro-chemistry. In Mexico, reported hydrocarbon spills for the year 2000 amounted to 185203, equivalent to 6252 tons (PEMEX, 2000). The first step for the remediation of these polluted sites is to assess the size and intensity of the oil contamination affecting the subsoil and groundwater, followed by a health risk assessment to establish clean up levels. The aim of this work was to characterize the soil and water in a north-central Mexico Oil Storage and Distribution Station (ODSS), in terms of TPHs, gasoline and diesel fractions, BTEX, PAHs, MTBE, and some metals. Besides, measurements of the explosivity index along the ODSS were made and we describe and discuss the risk health assessment analysis performed at the ODSS, as well as the recommendations arising from it. Considering soils with TPH concentrations higher than 2000 mg kg(-1), the contaminated areas corresponding to the railway zone is about 12776.5 m2, to the south of the storage tanks is about 6558 m2, and to the south of the filling tanks is about 783 m2. Total area to be treated is about 20107 m2 (volume of 20107 m3), considering 1m depth. PMID:15963553

  11. Paleomagnetic study of the eastern sector of chapala lake and implications for the tectonics of west-central mexico

    Science.gov (United States)

    Urrutia-Fucugauchi, J.; Rosas-Elguera, J.

    1994-12-01

    Western Mexico is characterized by several large-scale tectonic depressions which have been interpreted in terms of active continental rifting, tectonic transpression and coastal sinistral lateral transport of terranes. In this paper we report results of a paleomagnetic study of 148 samples from 22 sites in the Neogene volcanics from the eastern sector of the Chapala graben (western end of the E-W Chapala-Tula fault zone). Characteristic remanent magnetization directions have been isolated after detailed thermal demagnetization for sixteen sites. Six sites present reverse polarities and ten sites present normal polarities. Two sites show a low-latitude VGP and are considered as transitional. The normal and reverse polarity directions are almost antipodal. The overall characteristic pole position for the normal and reverse polarity sites, N = 16, pLAT = 74° N, Plong = 160° E, K = 25 and A95 = 7.6°, lies to the left of the Neogene segment of the North American or northern Mexico apparent polar wander path, which suggest the occurrence of a counterclockwise rotation of -15.5 ± 7.4 to -16.5 ± 6.9°. Results are interpreted in terms of counterclockwise vertical-axis rotation associated with regional transtension and left-lateral shear as a result of oblique subduction of the Cocos plate along the Middle American trench. We suggest that the Chapala graben developed early in the Miocene, in a left-lateral strike-slip environment within the regional E-W Chapala-Tula fault zone. Results support recent studies that propose relative motion for southern Mexico along the volcanic arc and trench-parallel strike-slip faulting.

  12. Mountain cloud forest and grown-shade coffee plantations: A comparison of tree biodiversity in central Veracruz, Mexico

    OpenAIRE

    Alfredo González-Zamora; Manuel Esperón-Rodríguez; Víctor L. Barradas

    2016-01-01

    Aim of the study: The objective of this work is to compare tree diversity and richness among one grown-shade coffee plantation (CAE) and two sites of montane cloud forests, one preserved (MCF1) and other perturbed (MCF2). We also develop an analysis of the importance of coffee plantations as a refuge of tree species, holding a potential role for conservation.Area of study: Our study area is the coffee region of Coatepec-Xico, in the state of Veracruz, Mexico.Material and methods: We compiled ...

  13. Evaluation of Recent Tectonomagmatic Discrimination Diagrams and their Application to the Origin of Basic Magmas in Southern Mexico and Central America

    Science.gov (United States)

    Verma, Surendra P.; Verma, Sanjeet K.; Pandarinath, Kailasa; Rivera-Gómez, María Abdelaly

    2011-08-01

    Discrimination diagrams to decipher tectonic settings have been in use for nearly 40 years. Although old diagrams have been extensively used, the recent ones based on discriminant functions of ratio variables, with or without log-transformation, proposed during 2004-2010 for the discrimination of four tectonic settings of island arc, continental rift, ocean-island and mid-ocean ridge, were newly evaluated to show their high success rates of 57.3-100% and 58.5-100% for major-element and immobile-element based diagrams, respectively. For the continental arc of the Andes evaluated for its similarity to island arc, these four sets of diagrams showed success rates of 62.1-83.8%. These four sets of five diagrams per set were therefore used to infer tectonic setting of the Mexican Volcanic Belt (MVB), Los Tuxtlas volcanic field (LTVF), and Central American Volcanic Arc (CAVA). Using this approach, the MVB, especially its western, central and eastern parts, and the LTVF of Southern Mexico show a dominantly continental rift setting and the CAVA shows an arc setting. The west-central part of the MVB is consistent with dual tectonics of arc and rift. These results confirm the application of an unusual mantle upwelling rift-model for the Mexican on-land volcanism, whereas the conventional plate tectonic subduction model seems to be applicable for the CAVA from Guatemala to north-western Costa Rica.

  14. Resource Assessment of the In-Place and Potentially Recoverable Deep Natural Gas Resource of the Onshore Interior Salt Basins, North Central and Northeastern Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Ernest A. Mancini; Donald A. Goddard

    2004-10-28

    The objectives of the study are: to perform resource assessment of the in-place deep (>15,000 ft) natural gas resource of the onshore interior salt basins of the North Central and Northeastern Gulf of Mexico areas through petroleum system identification, characterization and modeling and to use the petroleum system based resource assessment to estimate the volume of the in-place deep gas resource that is potentially recoverable and to identify those areas in the interior salt basins with high potential to recover commercial quantities of the deep gas resource. The principal research effort for Year 1 of the project is data compilation and petroleum system identification. The research focus for the first nine (9) months of Year 1 is on data compilation and for the remainder of the year the emphasis is on petroleum system identification.

  15. Out of operation in simultaneous way of the two reactors of nucleoelectric central of Laguna Verde(Mexico); Fuera de operacion, de maneira simultanea, los dos reactores de la central nucleoelectrica de Laguna Verde (Mexico)

    Energy Technology Data Exchange (ETDEWEB)

    Mar, Bernardo Salas, E-mail: salasmarb@yahoo.com.mx [Universidad Nacional Autonoma de Mexico, D.F. (Mexico). Facultad de Ciencias. Departamento de Fisica

    2013-11-01

    The two nuclear reactors that Mexico has in the Laguna Verde Nuclear Power Plant, were out of operation simultaneously in September 2012. First it was reported that one of the reactors had problems with the diesel generator, while the other had problems with the nuclear fuel reloading. The day after it was reported a problem related to sediment in the Obra de Toma, place the plant feeds seawater to cool the condenser the depth to which it must operate is 6 meters, with the current level of 1.5 meters, causing a lack of cooling water. Finally it was reported the cause of the suspension of operations, the cracks in jet pumps in both reactors. It is described a brief analysis of these opinions. The reactors are of cooling water of General Electric (BWR-5) and generate 1640 MWe each one.

  16. Extreme changes to barrier islands along the central Gulf of Mexico coast during Hurricane Katrina: Chapter 5C in Science and the storms-the USGS response to the hurricanes of 2005

    Science.gov (United States)

    Sallenger, Asbury; Wright, Wayne; Lillycrop, Jeff; Howd, Peter; Stockdon, Hilary; Guy, Kristy K.; Morgan, Karen

    2007-01-01

    Hurricane Katrina caused extreme changes to the barrier islands of the central Gulf of Mexico coast. Dauphin Island, Ala., migrated landward and stranded the remains of its oceanfront row homes in the sea. Chandeleur Islands, La., were completely stripped of their sand, leaving only marshy outcrops in the storm's wake.

  17. Hydrothermal Evolution of the Giant Cenozoic Kadjaran porphyry Cu-Mo deposit, Tethyan metallogenic belt, Armenia, Lesser Caucasus: mineral paragenetic, cathodoluminescence and fluid inclusion constraints

    Science.gov (United States)

    Hovakimyan, Samvel; Moritz, Robert; Tayan, Rodrik; Rezeau, Hervé

    2016-04-01

    The Lesser Caucasus belongs to the Central segment of the Tethyan metallogenic belt and it is a key area to understand the metallogenic evolution between the Western & Central parts of the Tethyan belt and its extension into Iran. Zangezur is the most important mineral district in the southernmost Lesser Caucasus. It is a component of the South Armenian block, and it was generated during the convergence and collision of the southern margin of the Eurasian plate and the northern margin of the Arabian plate, and terranes of Gondwana origin (Moritz et al., in press). The Zangezur ore district consists of the Tertiary Meghri-Ordubad composite pluton, which is characterized by a long-lasting Eocene to Pliocene magmatic, tectonic and metallogenic evolution. It hosts major porphyries Cu-Mo and epithermal Au - polymetallic deposits and occurrences, including the giant world class Kadjaran porphyry Cu-Mo deposit (2244 Mt reserves, 0.3% Cu, 0.05% Mo and 0.02 g/t Au). The Kadjaran deposit is hosted by a monzonite intrusion (31.83±0.02Ma; Moritz et al., in press). Detailed field studies of the porphyry stockwork and veins of the different mineralization stages, their crosscutting and displacement relationships and the age relationship between different paragenetic mineral associations were the criteria for distinction of the main stages of porphyry mineralization at the Kadjaran deposit. The economic stages being: quartz- molybdenite, quartz-molybdenite-chalcopyrite, and quartz-chalcopyrite. The main paragenetic association of the Kadjaran porphyry deposit includes pyrite, molybdenite, chalcopyrite, bornite, chalcocite, pyrrhotite, covellite, sphalerite, and galena. Recent field observations in the Kadjaran open pit revealed the presence of epithermal veins with late vuggy silica and advanced argillic alteration in the north-eastern and eastern parts of the deposit. They are distributed as separate veins and have also been recognized in re-opened porphyry veins and in

  18. A comment on the metallogenic theory of exogenetic uranium ore deposits

    International Nuclear Information System (INIS)

    The theory of exogenetic sandstone-type uranium followed the form process of construction in the early time, and discussed the uranium metallization by chemical enrichment during the phase of syn-deposition and diagenesis. Later, the epigenetic theory was put forward by emphasizing hydrodynamic influence on mineralization. The idea of uranium mineralization in open systems is a renovated metallogenic theory for uranium, which confirms the role of exogenesis playing in uranium mineralization. For open systems, this paper underlines that, as the most critical factors for uranium mineralization, both uranium sources and reduce agents should be open to form a dual-open system. Uranium ore deposits in the tectonic zone of eastern China formed in dual-open system, where uranium has been associated with coal, petroleum and natural gas in the sandstone sequence. (authors)

  19. Analysis on metallogenic conditions and prospects of hot-liquid uranium deposits in Bayinbaolige uplifted zone

    International Nuclear Information System (INIS)

    Bayinbaolige uplifted zone lies between the geosyncline fold system in the middle of Inner Mongolia and Xingan geosyncline and locates in the west of Mesozoic volcanic area in Daxinganling. Magmatic rocks developing in Paleozoic-Jurassic are widely distributed in this area. Based on previous data of geophysical including geochemical-Airborne gamma, aviation spectrum, automotive spectrum, stream sediment, with the analysis of uranium metallogenic conditions including structure, basement, magmatic rocks, alteration and so on, it's inferred that Weijin Rock between West Temple-Eric lattice Lot Temple has great potential of uranium mineralization. Contrasting to the uranium deposits of granite type in South China and alkaline metasomatic in Jiling, Gansu province, we predicted the spatial location and mineralization type of uranium deposits in this area. (author)

  20. Nature, diversity of deposit types and metallogenic relations of South China

    Science.gov (United States)

    Zaw, K.; Peters, S.G.; Cromie, P.; Burrett, C.; Hou, Z.

    2007-01-01

    The South China Region is rich in mineral resources and has a wide diversity of deposit types. The region has undergone multiple tectonic and magmatic events and related metallogenic processes throughout the earth history. These tectonic and metallogenic processes were responsible for the formation of the diverse styles of base and precious metal deposits in South China making it one of the resource-rich regions in the world. During the Proterozoic, the South China Craton was characterised by rifting of continental margin before eruption of submarine volcanics and development of platform carbonate rocks, and the formation of VHMS, stratabound copper and MVT deposits. The Phanerozoic metallogeny of South China was related to opening and closing of the Tethyan Ocean involving multiple orogenies by subduction, back-arc rifting, arc-continent collision and post-collisional extension during the Indosinian (Triassic), Yanshanian (Jurassic to Cretaceous) and Himalayan (Tertiary) Orogenies. The Late Palaeozoic was a productive metallogenic period for South China resulting from break-up and rifting of Gondwana. Significant stratabound base and precious metal deposits were formed during the Devonian and Carboniferous (e.g., Fankou and Dabaoshan deposits). These Late Palaeozoic SEDEX-style deposits have been often overprinted by skarn systems associated with Yanshanian magmatism (e.g., Chengmenshan, Dongguashan and Qixiashan). A number of Late Palaeozoic to Early Mesozoic VHMS deposits also developed in the Sanjiang fold belt in the western part of South China (e.g., Laochang and Gacun). South China has significant sedimentary rock-hosted Carlin-like deposits, which occur in the Devonian- to Triassic-aged accretionary wedge or rift basins at the margin of the South China Craton. They are present in a region at the junction of Yunnan, Guizhou, and Guangxi Provinces called the 'Southern Golden Triangle', and are also present in NW Sichuan, Gansu and Shaanxi, in an area known as

  1. The metallogenic condition analysis and prospecting direction of Chuanjing depression sandstone type uranium deposit

    International Nuclear Information System (INIS)

    Through the research on the metallogenic condition analysis of Chuanjing depression sandstone type uranium deposit come to a conclusion, that in terms of the Chuanjing depression, is qualified sandstone-type uranium deposits, but according to different districts. The basic conditions of uranium mineralization coupling is poorer, So, it is difficult to find large sandstone type uranium deposit in this area, at present, we have found some uranium mineralization and uranium abnormalities. But, it will be broken in the groundwater hydrodynamic conditions which are relatively good location, these area have good hydrogeology conditions, Channel sands are dominated by the ancient migration of underground water channel, with a complete and independent power system ground water for the migration of oxygenated water containing uranium to provide a good channel, but also for the enrichment of uranium to provide a better Space, lots more abundant in the reducing agent mineralization. future exploration of these sites is our main site. (author)

  2. Out of operation in simultaneous way of the two reactors of nucleoelectric central of Laguna Verde(Mexico)

    International Nuclear Information System (INIS)

    The two nuclear reactors that Mexico has in the Laguna Verde Nuclear Power Plant, were out of operation simultaneously in September 2012. First it was reported that one of the reactors had problems with the diesel generator, while the other had problems with the nuclear fuel reloading. The day after it was reported a problem related to sediment in the Obra de Toma, place the plant feeds seawater to cool the condenser the depth to which it must operate is 6 meters, with the current level of 1.5 meters, causing a lack of cooling water. Finally it was reported the cause of the suspension of operations, the cracks in jet pumps in both reactors. It is described a brief analysis of these opinions. The reactors are of cooling water of General Electric (BWR-5) and generate 1640 MWe each one

  3. A study of the metallogenic geochemistry at the bayantala deposit in the southern margin of tenggeer depression in Eren Basin, Inner Mongolia autonomous region

    International Nuclear Information System (INIS)

    Based on the multiple field reconnaissance samplings and analysis of a amount of geological information, the metallogenic characteristics of the phreatic oxidation zone type uranium deposits have been studied. According to uranium metallogenic process of 'source, transportation and precipitation,' the metallogenic mechanics of the deposit have been further discussed, and the metallogenic process has been quantitatively identified for each metallogenic stage in the paper. It is concluded that of the secondary reduction metallogenesis and the special metallogenic model of the transformation from the phreatic to interlayer oxidation zone in the area, some new knowledge and achievements through the research on palaeo-uranium field and uranium-differentiated field of the granite massive as the provenance area have been obtained. The important data for certaining the undulation and buried depth of the bedrock in the bottom of the distributary valleys in the study area and delineating the boundaries of all distributary valleys and detecting the deep structures as well has been provided by the high-precision magnetic survey. (authors)

  4. Use of Network Centrality Measures to Explain Individual Levels of Herbal Remedy Cultural Competence among the Yucatec Maya in Tabi, Mexico.

    Science.gov (United States)

    Hopkins, Allison

    2011-08-01

    Common herbal remedy knowledge varies and is transmitted among individuals who are connected through a social network. Thus, social relationships have the potential to account for some of the variation in knowledge. Cultural consensus analysis (CCA) and social network analysis (SNA) were used together to study the association between intracultural variation in botanical remedy knowledge and social relationships in Tabi, Yucatan, Mexico. CCA, a theory of culture as agreement, was used to assess the competence of individuals in a domain of herbal remedies by measuring individual competence scores within that domain. There was a weak but positive association between these competence scores and network centrality scores. This association disappeared when age was included in the model. People in Tabi, who have higher competence in herbal remedies tend to be older and more centrally located in the herbal remedy inquiry network. The larger implication of the application of CCA and SNA for understanding the acquisition and transmission of cultural knowledge is also explored. PMID:21909235

  5. Seismic stratigraphy and clay mineral distribution in shallow-marine siliciclastic deposits, central Mississippi sound, North-central Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Harper, G.G.; Manley, F.H.; Staheli, A.C.

    1983-03-01

    Three north-south high-resolution (7 kHz) seismic profiles and 16 20-foot cores taken at shot-point locations in central Mississippi Sound were utilized to determine: (1) any meaningful seismic reflector configurations in the subsurface; (2) the clay species dispersal pattern and its relation to transport systems that move sediment into the depositional basin; (3) any change in clay mineral species that has occurred through time with respect to deposition of 5 to 6 m (16 to 20 ft) of sediment. Interpretation of shallow seismic events (20 m (66 ft)) and clay mineral analysis indicates that extrinsic factors largely determined the clay mineral species and geologic history of Pleistocene and Holocene sedimentation in central Mississippi Sound. Trend surface maps, residual maps, profiles of the smectite (montmorillonite) to kaolinite ratios, and seismic profiles illustrate that: (1) Mississippi Sound has been influenced by transgressions and regressions associated with proglacial and interglacial stages; (2) a toplap seismic reflection configuration forms the probable Pleistocene-Holocene boundary; (3) at least one ancient barrier island is located inside the Holocene barrier system; (4) there is a late date for sea level reaching its present location (2500 years B.P.); (5) the influence of the Mississippi River system on sedimentation is soon after inundation of Mississippi Sound; (6) the longshore currents and flood tides supplied sediment rich in kaolinite to the study area; (7) the drainage systems emptying into the study area have local influence on clay mineral distribution; and (8) the dredging of ship channels affects the clay-mineral distribution within the sediments immediately below the sediment-water interface in central Mississippi Sound.

  6. The 1997 and 2001 lahars of Popocatépetl volcano (Central Mexico): textural and sedimentological constraints on their origin and hazards

    Science.gov (United States)

    Capra, L.; Poblete, M. A.; Alvarado, R.

    2004-03-01

    Popocatépetl volcano is the most active volcano in central Mexico, and represents a high risk for more than 40 million people, including Mexico City. In 1994, volcanic activity at Popocatépetl renewed with the formation of ash-rich plumes up to 7 km high. In April 1996, lava emissions filled the crater and were accompanied by a series of explosions that produced eruptive columns up to 8 km high. Associated with explosive events in 1997 and 2001, two major lahars events occurred, leaving debris flow deposits along Huiloac Gorge for as far as 15 km, to the town of Santiago Xalitzinta. The 1997 debris flow deposit originated after a prolonged emission of ash which caused glacier melt and a rapid release of water (1×10 7 m 3). The amount of melting water was sufficient to gradually erode the river bed causing a flood that gradually transformed from a debris flow to a hyperconcentrated flow. In contrast, the 2001 debris flow that originated from a post-depositional remobilization of a pumice flow deposit, did not experience any flow transformation and carried 25% water at maximum. The different behavior of these two lahars has important hazard implications. Both lahars reached Xalitzintla town, but at that point, the 1997 lahar had already transformed into a sediment-loaded stream flow. The 2001 lahar, by contrast, maintained the characteristics of a debris flow, being more competent, and with greater destructive power. What happened with these lahars demonstrates how important it is to take into consideration secondary volcanic phenomena. Even though they were not large flows, they were capable of threatening populated areas, even during periods of volcanic quiescence or reduced magmatic activity.

  7. Occurrence of entomopathogenic fungi and parasitic nematodes on Spodoptera frugiperda (Lepidoptera: Noctuidae) larvae collected in Central Chiapas, Mexico

    Science.gov (United States)

    Fall armyworm larvae (FAW), Spodoptera frugiperda (J. E. Smith) were collected from whorl-stage cornfields, between the V2 and V4 stages, in 22 localities of Central, Chiapas, México, called "La Frailesca" during late June 2009 to determine the occurrence of native entomopathogens and parasitic nema...

  8. Comparison of metallogenic conditions for sandstone-type uranium deposit between Erlian basin of China and sedimentary basins of Mongolia

    International Nuclear Information System (INIS)

    Based on the study of metallogenic background and basic metallogenic characteristics,this paper summarizes the main ore-controlling factors of sandstone-type uranium deposits in Erlian basin of China and basins in southeastern Mongolia with the theory of sandstone-type uranium metallogeny,and systematically analyses similarities and differences between the two areas. The general similarities of tectonic attribute, basin type and scale, uranium source, and tectonic evolution in both areas are proposed in this paper, and also their obvious differences in uranium-hosting strata, late tectonic activity and regional uranium mineralization occurrences, especially in tectonic activity and ore-controlling sedimentary system are proposed. The authors believe that the two areas have approximate uranium-productive potentialities, and propose the importence of prospecting 'Sumin-river model' sandstone-type uranium deposit in Erlian basin in the future. (authors)

  9. Research on metallogenic conditions of intersection-type uranium ore-deposits in Zhongdong area, Northern Guangdong province

    International Nuclear Information System (INIS)

    The methods following as field geological investigation, trace element geo- chemistry and isotope geochemistry were used in this project. Based on geological and geochemical characteristics of Xiaoshui uranium ore deposits in Zhongdong area, Xiazhuang ore-field, Guangdong province, it could be concluded that: (1) The Provenance of Cretaceous mantle is a enriched mantle; (2) Silicified zone-type and intersection-type uranium ore are distinctness in the metallogenic period and mineralization process, and main metallogenic period of Xiaoshui uranium ore-deposit is 73.5 Ma; (3) The sources of uranium mineralization substance derived from enriched mantle; and (4)The intersection-type high grade uranium deposits were controlled by substances derived from mantle (contain with U, CO2, F, et al), tracks of intersection of NWW-across with NNE-trending faults and lithology of diabase. (authors)

  10. 2009 Swine Flu Originated in Mexico

    Science.gov (United States)

    ... fullstory_159679.html 2009 Swine Flu Originated in Mexico Genetic analysis pinpoints source of the pandemic influenza ... in pigs in a small region of central Mexico, a new study reports. Researchers used genetic analysis ...

  11. Mexico Terrain Corrected Free Air Anomalies (97)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This 2' gravity anomaly grid for Mexico, North-Central America and the Western Caribbean Sea is NOT the input data set used in the development of the MEXICO97...

  12. The origin of groundwater arsenic and fluorine in a volcanic sedimentary basin in central Mexico: a hydrochemistry hypothesis

    Science.gov (United States)

    Morales-Arredondo, Iván; Rodríguez, Ramiro; Armienta, Maria Aurora; Villanueva-Estrada, Ruth Esther

    2016-01-01

    A groundwater sampling campaign was carried out in the summer of 2013 in a low-temperature geothermal system located in Juventino Rosas (JR) municipality, Guanajuato State, Mexico. This groundwater presents high concentrations of As and F- and high Rn counts, mainly in wells with relatively higher temperature. The chemistry of major elements was interpreted with different methods, like Piper and D'Amore diagrams. These diagrams allowed for classification of four groundwater types located in three hydrogeological environments. The aquifers are hosted mainly in alluvial-lacustrine sediments and volcanic rocks in interaction with fault and fracture systems. The subsidence, faults and fractures observed in the study area can act as preferential channels for recharge and also for the transport of deep fluids to the surface, especially in the basin plain. The formation of a piezometric dome and the observed hydrochemical behavior of groundwater suggest a possible origin of the As and F-. Geochemical processes occurring during water-rock interaction are related to high concentrations of As and F-. High temperatures and alteration processes (like rock weathering) induce dissolution of As and F--bearing minerals, increasing the content of these elements in groundwater.

  13. Analysis of fern spore banks from the soil of three vegetation types in the central region of Mexico.

    Science.gov (United States)

    Ramírez-Trejo, María Del Rosario; Pérez-García, Blanca; Orozco-Segovia, Alma

    2004-05-01

    The vertical structure of fern spore banks was studied in a xerophilous shrubland, montane rain forest, and pine-oak forest in Hidalgo, Mexico, using the emergence method. Soil samples were collected in April 1999 at depths of 0-10, 10-20, and 20-30 cm. Viable spores decreased significantly with depth in all vegetation types, and the highest number of prothallia and sporophytes was found in the uppermost layer. The montane rain forest and the xerophilous shrubland had the largest and the richest banks, respectively. Twenty-three fern taxa were registered in the aboveground vegetation, 12 in the soil banks, and 43.5% were in both. Aboveground and in the soil bank, the xerophilous shrubland, the montane rain forest, and the pine-oak forest had, 17 and 7, 1 and 6, and 7 and 3 taxa, respectively. These were distributed differentially in relation to depth. The Sørensen index indicated a similarity of 61.5% between the xerophilous shrubland and the montane rain forest, and the Czeckanovsky index indicated 19.75%. The presence of viable spores in the soil of all vegetation types confirmed the existence of natural spore banks. Long-distance dispersal was an important factor determining the specific composition of the xerophilous shrubland and the pine-oak forest. PMID:21653423

  14. The origin of groundwater arsenic and fluorine in a volcanic sedimentary basin in central Mexico: a hydrochemistry hypothesis

    Science.gov (United States)

    Morales-Arredondo, Iván; Rodríguez, Ramiro; Armienta, Maria Aurora; Villanueva-Estrada, Ruth Esther

    2016-06-01

    A groundwater sampling campaign was carried out in the summer of 2013 in a low-temperature geothermal system located in Juventino Rosas (JR) municipality, Guanajuato State, Mexico. This groundwater presents high concentrations of As and F- and high Rn counts, mainly in wells with relatively higher temperature. The chemistry of major elements was interpreted with different methods, like Piper and D'Amore diagrams. These diagrams allowed for classification of four groundwater types located in three hydrogeological environments. The aquifers are hosted mainly in alluvial-lacustrine sediments and volcanic rocks in interaction with fault and fracture systems. The subsidence, faults and fractures observed in the study area can act as preferential channels for recharge and also for the transport of deep fluids to the surface, especially in the basin plain. The formation of a piezometric dome and the observed hydrochemical behavior of groundwater suggest a possible origin of the As and F-. Geochemical processes occurring during water-rock interaction are related to high concentrations of As and F-. High temperatures and alteration processes (like rock weathering) induce dissolution of As and F--bearing minerals, increasing the content of these elements in groundwater.

  15. Alcohol and drug consumption, depressive features, and family violence as associated with complaints to the Prosecutor's Office in Central Mexico.

    Science.gov (United States)

    Rey, Guillermina Natera; García, Francisco Juárez; Icaza, María Elena Medina-Mora; Sainz, Marcela Tiburcio

    2007-01-01

    The article is aimed at reporting the characteristics of the population detected at State Prosecutors' Offices including the two such offices that existed in the city selected for the study, one located in a general hospital for the inspection of violence-related cases (n = 156); and the second in the facility where all detainees are taken when arrested (n = 129), and where victims can file a complaint (n = 186). A household survey undertaken among the population 18 to 65 years of age (n = 887) was used as a group of reference. Both studies were undertaken in Pachuca City, the capital of Hidalgo, located 100 km from Mexico City during the second half of 1996. Face-to-face questionnaires were used to obtain sociodemographic data, drug use and drinking patterns, depressive symptomatology, and family violence. Discriminant and logistic regression analysis were undertaken. The age group from 18 to 24 displayed the highest number of legal complaints and arrests (OR = 1.773). The likelihood for appearing at a State Prosecutor's Office was higher for those living in an atmosphere of threats and injuries within the family (OR = 19) and for those that reported alcohol consumption on the day of the event (OR = 14). Extremely high rates of family violence were obtained in this sample, increasing the likelihood of arriving at the Prosecutor's Office either because arrested or for being a victim. Results confirm the relationship between alcohol use, depression, and violence, reinforcing the need to prevent alcohol abuse, especially among youth. PMID:17918021

  16. Active mountain building and the distribution of “core” Maxillariinae species in tropical Mexico and Central America

    Science.gov (United States)

    Kirby, Stephen H.

    2011-01-01

    The observation that southeastern Central America is a hotspot for orchid diversity has long been known and confirmed by recent systematic studies and checklists. An analysis of the geographic and elevation distribution demonstrates that the most widespread species of “core” Maxillariinae are all adapted to life near sea level, whereas the most narrowly endemic species are largely distributed in wet highland environments. Drier, hotter lowland gaps exist between these cordilleras and evidently restrict the dispersal of the species adapted to wetter, cooler conditions. Among the recent generic realignments of “core” Maxillariinae based on molecular phylogenetics, the Camaridium clade is easily the most prominent genus in Central America and is largely restricted to the highlands of Costa Rica and Panama, indicating that this region is the ancestral home of this genus and that its dispersal limits are drier, lowland cordilleran gaps. The mountains of Costa Rica and Panama are among the geologically youngest topographic features in the Neotropics, reflecting the complex and dynamic interactions of numerous tectonic plates. From consideration of the available geological evidence, I conclude that the rapid growth of the mountain ranges in Costa Rica and Panama during the late Cenozoic times created, in turn, very rapid ranges in ecological life zones and geographic isolation in that part of the isthmus. Thus, I suggest that these recent geologic events were the primary drivers for accelerated orchid evolution in southeastern Central America.

  17. Nitrous oxide flux in maize and wheat cropped soils in the central region of Mexico during El nino year 1998

    Energy Technology Data Exchange (ETDEWEB)

    Longoria Ramirez, R. [Centro Nacional de Investigaciones y Desarrollo Tecnologico, Mexico, D.F. (Mexico); Carbajal Benitez, G.; Mar Morales, B.E.; Ruiz Suarez, G. [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, (UNAM), Mexico, D.F. (Mexico)

    2003-10-01

    Emissions of nitrous oxide (N{sub 2}O) were measured in agricultural lands used for farming wheat and maize during 1998 in the states of Hidalgo and Tlaxcala in Mexico. In an irrigated wheat field (El Tenhe, Hidalgo), an average flux of -10.85 {mu}g N{sub 2}O - N m{sup -}2 h{sup -}1 was obtained for the total cycle (155 days between December and May). There, high negative values were observed with Water Fill Porous Space (WFPS) close to 70%. The average flux of the complete cycle (269 days between March and December) in an irrigated maize field (El Progreso, Hidalgo) was 37.43 {mu}g N{sub 2}O - N m{sup -}2 h{sup -}1. In this case, more insignificant negative fluxes were found with WFPS close to 45% or less. These last results may have been influenced by the strong El Nino, which occurred in the middle of 1998. Twenty once percent of the measurements in the state of Hidalgo showed soil acting as a nitrous oxide sink. The samples from Tlaxcala showed that these fields acted as emitters. In the rain fed fields in the state of Tlaxcala, an average flux of 121 {mu}g N{sub 2}O - N m{sup -}2 h{sup -}1 was obtained for the wheat field. The farming season lasted 142 days, from July to December. In addition, for the maize field the averaged flux was 285.61 {mu}g N{sub 2}O - Nm{sup -}2h-1. The farming season lasted 246 days, from April to December. [Spanish] En 1998 se midieron las emisiones de oxido nitroso (N{sub 2}O) de suelos agricolas para cultivar trigo y maiz en los estados de Hidalgo y Tlaxcala, en Mexico. Para un campo irrigado de trigo (El Tenhe, Hidalgo), se obtuvo un flujo promedio de -10.85 {mu}g N{sub 2}O - N m{sup -}2 h{sup -}1 para el ciclo total (155 dias entre diciembre y mayo). En este caso se observaron valores negativos elevados en el espacio poroso relleno de agua (VFPS, pos sus siglas en ingles), cercanos a 70%. El flujo promedio para el ciclo completo (269 dias entre marzo y diciembre) en un campo irrigado de maiz fue de 37.43 {mu}g N{sub 2}O - N m

  18. Mountain cloud forest and grown-shade coffee plantations: A comparison of tree biodiversity in central Veracruz, Mexico

    Directory of Open Access Journals (Sweden)

    Alfredo González-Zamora

    2016-04-01

    Full Text Available Aim of the study: The objective of this work is to compare tree diversity and richness among one grown-shade coffee plantation (CAE and two sites of montane cloud forests, one preserved (MCF1 and other perturbed (MCF2. We also develop an analysis of the importance of coffee plantations as a refuge of tree species, holding a potential role for conservation.Area of study: Our study area is the coffee region of Coatepec-Xico, in the state of Veracruz, Mexico.Material and methods: We compiled a list of all tree species in each site to determine tree diversity and floristic similarity (dissimilarity. We used different similarity indices and a cluster analysis to show relations among sites.Main results: 2721 individuals from 154 species were registered in the montane cloud forests as a whole. In the grown-shade coffee plantation we registered 2947 individuals from 64 species. The most similar sites were the perturbed montane cloud forest and the grown-shade coffee plantation and the least similar were the preserved montane cloud forest and the grown-shade coffee plantation. The high biodiversity found in all sites and the differences in tree composition between the two montane cloud forests supports evidence of the ecosystems richness in the region.Research highlight: Diversity differences among sites determine that the grown-shade coffee plantation is not substitute for montane cloud forest. CAE’s are developed under similar environmental conditions than the MCF; therefore, coexistence and recombination (replacement of species make them particularly complementary. CAE’s in Veracruz have a potential role as refuge for biodiversity.

  19. Shallow structure of the Chichinautzin Range, southern Mexico basin, central Trans-Mexican Volcanic Belt. A gravity and seismic study

    Science.gov (United States)

    Campos-Enriquez, J. O.; Lermo-Samaniego, J. F.; Antahyua-Vera, Y. T.; Chavacan, M.; Ramón, V. M.; Hernández-García; Pita, C.

    2013-12-01

    Chichinautzin Range (ChR) closes to the S the Mexico Basin (MB). Initially based on height differences between MB and the to-he S-located Morelos Plataform (MP) , a major S-dipping fault was proposed. Depths differences to the limestone basement beneath MB and MP respectively supported its existence. This assumed fault was named La Pera. Earlier studies reported the existence of several faults affecting the ChR. New studies were focused to analyze the cinematic and dynamic character of faults to the W of ChR (Tenango Fault System) and of southern Sierra de la Cruces Range. Also based on a gravity study (Campos-Enríquez et al., 2000), the existence of a major N-dipping fault was inferred to delimit the MB to the S (i.e., delimiting the ChR to the N). Our study is based on gravity modelling, and local seismicity analysis. Accordingly, Mezosoic sandstones above metamorphic rocks constitute the basement underlying ChR. This structural high is faulted to the N and S. To the N, fault blocks displace the basement to larger depths (2-4 km). To the S the basement is shallower. The faults of the gravity model correlate with all reported faults, which collectively are refferred to as Aztlan Fault System. Two N-S MT profiles confirm the model. Several of these faults are associated with seismic activity with a N-S extension and a left-lateral component. The seismic event were located at depths of 7-15 km (i.e. the brittle crust). The system can be traced from the Nevado de Tolca volcano up to the Popocatépetl volcano and even further eastwards. The system is about 200 km long, 30-40 km wide, tectonically active. It enabled the fast emplacement of the ChR volcanic rocs. A flower-type structure was inferred to the S of ChR, further south, the profile is cut by faults belonging either to the Taxco-San Miguel de Allende Fault System or to the Chapala-Oaxaca Fault System. This profile shows how the transpressive tectonics, to the S, accomodates, with the N-S extension affecting

  20. Accumulation of pharmaceuticals, Enterococcus, and resistance genes in soils irrigated with wastewater for zero to 100 years in central Mexico.

    Directory of Open Access Journals (Sweden)

    Philipp Dalkmann

    Full Text Available Irrigation with wastewater releases pharmaceuticals, pathogenic bacteria, and resistance genes, but little is known about the accumulation of these contaminants in the environment when wastewater is applied for decades. We sampled a chronosequence of soils that were variously irrigated with wastewater from zero up to 100 years in the Mezquital Valley, Mexico, and investigated the accumulation of ciprofloxacin, enrofloxacin, sulfamethoxazole, trimethoprim, clarithromycin, carbamazepine, bezafibrate, naproxen, diclofenac, as well as the occurrence of Enterococcus spp., and sul and qnr resistance genes. Total concentrations of ciprofloxacin, sulfamethoxazole, and carbamazepine increased with irrigation duration reaching 95% of their upper limit of 1.4 µg/kg (ciprofloxacin, 4.3 µg/kg (sulfamethoxazole, and 5.4 µg/kg (carbamazepine in soils irrigated for 19-28 years. Accumulation was soil-type-specific, with largest accumulation rates in Leptosols and no time-trend in Vertisols. Acidic pharmaceuticals (diclofenac, naproxen, bezafibrate were not retained and thus did not accumulate in soils. We did not detect qnrA genes, but qnrS and qnrB genes were found in two of the irrigated soils. Relative concentrations of sul1 genes in irrigated soils were two orders of magnitude larger (3.15 × 10(-3 ± 0.22 × 10(-3 copies/16S rDNA than in non-irrigated soils (4.35 × 10(-5± 1.00 × 10(-5 copies/16S rDNA, while those of sul2 exceeded the ones in non-irrigated soils still by a factor of 22 (6.61 × 10(-4 ± 0.59 × 10(-4 versus 2.99 × 10(-5 ± 0.26 × 10(-5 copies/16S rDNA. Absolute numbers of sul genes continued to increase with prolonging irrigation together with Enterococcus spp. 23S rDNA and total 16S rDNA contents. Increasing total concentrations of antibiotics in soil are not accompanied by increasing relative abundances of resistance genes. Nevertheless, wastewater irrigation enlarges the absolute concentration of resistance genes in soils due to a

  1. A synthesis and review of geomorphic surfaces of the boundary zone Mt. Taylor to Lucero uplift area, West-Central New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Wells, S.G. [NEOTEC, Inc., Albuquerque, NM (United States)

    1989-01-01

    The Mt. Taylor volcanic field and Lucero uplift of west-central New Mexico occur in a transitional-boundary zone between the tectonically active Basin-and Range province (Rio Grande rift) and the less tectonically active Colorado plateau. The general geomorphology and Cenozoic erosional history has been discussed primarily in terms of a qualitative, descriptive context and without the knowledge of lithospheric processes. The first discussion of geomorphic surfaces suggested that the erosional surface underlying the Mt. Taylor volcanic rocks is correlative with the Ortiz surface of the Rio Grande rift. In 1978 a study supported this hypothesis with K-Ar dates on volcanic rocks within each physiographic province. The correlation of this surface was a first step In the regional analysis of the boundary zone; however, little work has been done to verify this correlation with numerical age dates and quantitatively reconstruct the surface for neotectonic purposes. Those geomorphic surfaces inset below and younger than the ``Ortiz`` surface have been studied. This report provides a summary of this data as well as unpublished data and a conceptual framework for future studies related to the LANL ISR project.

  2. Resource Assessment of the In-Place and Potentially Recoverable Deep Natural Gas Resource of the Onshore Interior Salt Basins, North Central and Northeastern Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Ernest A. Mancini; Donald A. Goddard

    2005-04-15

    The principal research effort for the first six months of Year 2 of the project has been petroleum system characterization. Understanding the burial and thermal maturation histories of the strata in the onshore interior salt basins of the North Central and Northeastern Gulf of Mexico areas is important in petroleum system characterization. The underburden and overburden rocks in these basins and subbasins are a product of their rift-related geohistory. Petroleum source rock analysis and thermal maturation and hydrocarbon expulsion modeling indicate that an effective regional petroleum source rock in the onshore interior salt basins, the North Louisiana Salt Basin, Mississippi Interior Salt Basin, Manila Subbasin and Conecuh Subbasin, was the Upper Jurassic Smackover lime mudstone. The Upper Cretaceous Tuscaloosa shale was an effective local petroleum source rock in the Mississippi Interior Salt Basin and a possible local source bed in the North Louisiana Salt Basin. Hydrocarbon generation and expulsion was initiated in the Early Cretaceous and continued into the Tertiary in the North Louisiana Salt Basin and the Mississippi Interior Salt Basin. Hydrocarbon generation and expulsion was initiated in the Late Cretaceous and continued into the Tertiary in the Manila Subbasin and Conecuh Subbasin. Reservoir rocks include Jurassic, Cretaceous and Tertiary siliciclastic and carbonate strata. Seal rocks include Jurassic, Cretaceous and Tertiary anhydrite and shale beds. Petroleum traps include structural and combination traps.

  3. Quantity and location of groundwater recharge in the Sacramento Mountains, south-central New Mexico (USA), and their relation to the adjacent Roswell Artesian Basin

    Science.gov (United States)

    Rawling, Geoffrey C.; Newton, B. Talon

    2016-06-01

    The Sacramento Mountains and the adjacent Roswell Artesian Basin, in south-central New Mexico (USA), comprise a regional hydrologic system, wherein recharge in the mountains ultimately supplies water to the confined basin aquifer. Geologic, hydrologic, geochemical, and climatologic data were used to delineate the area of recharge in the southern Sacramento Mountains. The water-table fluctuation and chloride mass-balance methods were used to quantify recharge over a range of spatial and temporal scales. Extrapolation of the quantitative recharge estimates to the entire Sacramento Mountains region allowed comparison with previous recharge estimates for the northern Sacramento Mountains and the Roswell Artesian Basin. Recharge in the Sacramento Mountains is estimated to range from 159.86 × 106 to 209.42 × 106 m3/year. Both the location of recharge and range in estimates is consistent with previous work that suggests that ~75 % of the recharge to the confined aquifer in the Roswell Artesian Basin has moved downgradient through the Yeso Formation from distal recharge areas in the Sacramento Mountains. A smaller recharge component is derived from infiltration of streamflow beneath the major drainages that cross the Pecos Slope, but in the southern Sacramento Mountains much of this water is ultimately derived from spring discharge. Direct recharge across the Pecos Slope between the mountains and the confined basin aquifer is much smaller than either of the other two components.

  4. Quantity and location of groundwater recharge in the Sacramento Mountains, south-central New Mexico (USA), and their relation to the adjacent Roswell Artesian Basin

    Science.gov (United States)

    Rawling, Geoffrey C.; Newton, B. Talon

    2016-04-01

    The Sacramento Mountains and the adjacent Roswell Artesian Basin, in south-central New Mexico (USA), comprise a regional hydrologic system, wherein recharge in the mountains ultimately supplies water to the confined basin aquifer. Geologic, hydrologic, geochemical, and climatologic data were used to delineate the area of recharge in the southern Sacramento Mountains. The water-table fluctuation and chloride mass-balance methods were used to quantify recharge over a range of spatial and temporal scales. Extrapolation of the quantitative recharge estimates to the entire Sacramento Mountains region allowed comparison with previous recharge estimates for the northern Sacramento Mountains and the Roswell Artesian Basin. Recharge in the Sacramento Mountains is estimated to range from 159.86 × 106 to 209.42 × 106 m3/year. Both the location of recharge and range in estimates is consistent with previous work that suggests that ~75 % of the recharge to the confined aquifer in the Roswell Artesian Basin has moved downgradient through the Yeso Formation from distal recharge areas in the Sacramento Mountains. A smaller recharge component is derived from infiltration of streamflow beneath the major drainages that cross the Pecos Slope, but in the southern Sacramento Mountains much of this water is ultimately derived from spring discharge. Direct recharge across the Pecos Slope between the mountains and the confined basin aquifer is much smaller than either of the other two components.

  5. Resource Assessment of the In-Place and Potentially Recoverable Deep Natural Gas Resource of the Onshore Interior Salt Basins, North Central and Northeastern Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Ernest A. Mancini; Paul Aharon; Donald A. Goddard; Roger Barnaby

    2005-10-28

    The principal research effort for Year 2 of the project has been petroleum system characterization and modeling. Understanding the burial, thermal maturation, and hydrocarbon expulsion histories of the strata in the onshore interior salt basins of the North Central and Northeastern Gulf of Mexico areas is important in hydrocarbon resource assessment. The underburden and overburden rocks in these basins and subbasins are a product of their rift-related geohistory. Petroleum source rock analysis and initial thermal maturation and hydrocarbon expulsion modeling indicated that an effective regional petroleum source rock in the onshore interior salt basins and subbasins, the North Louisiana Salt Basin, Mississippi Interior Salt Basin, Manila Subbasin and Conecuh Subbasin, was Upper Jurassic Smackover lime mudstone. The initial modeling also indicated that hydrocarbon generation and expulsion were initiated in the Early Cretaceous and continued into the Tertiary in the North Louisiana Salt Basin and the Mississippi Interior Salt Basin and that hydrocarbon generation and expulsion were initiated in the Late Cretaceous and continued into the Tertiary in the Manila Subbasin and Conecuh Subbasin. Refined thermal maturation and hydrocarbon expulsion modeling and additional petroleum source rock analysis have confirmed that the major source rock in the onshore interior salt basins and subbasins is Upper Jurassic Smackover lime mudstone. Hydrocarbon generation and expulsion were initiated in the Early to Late Cretaceous and continued into the Tertiary.

  6. Correlating Remote Sensing Data with the Abundance of Pupae of the Dengue Virus Mosquito Vector, Aedes aegypti, in Central Mexico

    Directory of Open Access Journals (Sweden)

    Max J. Moreno-Madriñán

    2014-05-01

    Full Text Available Using a geographic transect in Central Mexico, with an elevation/climate gradient, but uniformity in socio-economic conditions among study sites, this study evaluates the applicability of three widely-used remote sensing (RS products to link weather conditions with the local abundance of the dengue virus mosquito vector, Aedes aegypti (Ae. aegypti. Field-derived entomological measures included estimates for the percentage of premises with the presence of Ae. aegypti pupae and the abundance of Ae. aegypti pupae per premises. Data on mosquito abundance from field surveys were matched with RS data and analyzed for correlation. Daily daytime and nighttime land surface temperature (LST values were obtained from Moderate Resolution Imaging Spectroradiometer (MODIS/Aqua cloud-free images within the four weeks preceding the field survey. Tropical Rainfall Measuring Mission (TRMM-estimated rainfall accumulation was calculated for the four weeks preceding the field survey. Elevation was estimated through a digital elevation model (DEM. Strong correlations were found between mosquito abundance and RS-derived night LST, elevation and rainfall along the elevation/climate gradient. These findings show that RS data can be used to predict Ae. aegypti abundance, but further studies are needed to define the climatic and socio-economic conditions under which the correlations observed herein can be assumed to apply.

  7. Uranium hydrogeochemical survey of well waters from an area around Pie Town, Catron County, West-Central New Mexico, including concentrations of twenty-three additional elements

    International Nuclear Information System (INIS)

    As part of the Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) of the National Uranium Resource Evaluation (NURE) sponsored by the US Department of Energy (DOE), the Los Alamos Scientific Laboratory (LASL) conducted a detailed hydrogeochemical survey of well waters in a 4250-km2 area near Pie Town in west-central New Mexico. A total of 300 well samples was collected and analyzed for uranium and 23 other elements. The results of these analyses and carbonate and bicarbonate ion concentrations are presented in the Appendixes of this report. Uranium concentrations range from below the detection limit of 0.02 parts per billion (ppB) to 293.18 ppB and average 8.71 ppB. Samples containing high levels of uranium were collected from the Largo Creek valley west of Quemado, from a small area about 6 km east of Quemado, from a small area surrounding Pie Town, and from scattered locations in the area surrounding Adams Diggings north of Pie Town. Most of the samples containing high uranium concentrations were collected from wells associated with the volcanic sedimentary facies of the Datil formation. This formation is a likely source of mobile uranium that may be precipitating in the underlying Baca formation, a known uranium host unit. Bicarbonate ion concentration, while proportional to uranium concentration in some cases, is not a strong controlling factor in the uranium concentrations in samples from this area

  8. Two new species of Urocleidoides Mizelle et Price, 1964 (Monogenoidea) from the gill lamellae of profundulids and poeciliids from Central America and southern Mexico.

    Science.gov (United States)

    Mendoza-Franco, Edgar F; Caspeta-Mandujano, Juan Manuel; Salgado-Maldonado, Guillermo; Matamoros, Wilfredo Antonio

    2015-01-01

    During investigations of gill ectoparasites (Platyhelminthes) parasitising freshwater fish from Central America (Guatemala, Honduras, El Salvador and Panama) and southeastern Mexico (Guerrero, Oaxaca and Chiapas), the following dactylogyrid monogenoidean were found: Urocleidoides simonae sp. n. from Profundulus punctatus (Günther) (type host), Profundulus balsanus Ahl, Profundulus guatemalensis (Günther), Profundulus kreiseri Matamoros, Shaefer, Hernández et Chakrabarty, Profundulus labialis (Günther), Profundulus oaxacae (Meek), Profundulus sp. 1 and Profundulus sp. 2 (all Profundulidae); Urocleidoides vaginoclaustroides sp. n. from Pseudoxiphophorus bimaculata (Heckel) (type host) and Poeciliopsis retropinna (Regan) (both Poeciliidae); and Urocleidoides vaginoclaustrum Jogunoori, Kritsky et Venkatanarasaiah, 2004 from P. labialis, Profundulus portillorum Matamoros et Shaefer and Xiphophorus hellerii Heckel (Poeciliidae). Urocleidoides simonae sp. n. differs from all other congeneric species in having anchors with well-differentiated roots, curved elongate shaft and short point. Urocleidoides vaginoclaustroides sp. n. most closely resembles U. vaginoclaustrum, but differs from this species mainly in the shape of its anchors (i.e. evenly curved shaft and short point vs curved shaft and elongate point extending just past the tip of the superficial anchor root). The complexity of potential hosts for species of Urocleidoides and their effect on its distribution on profundulid and poeciliid fishes are briefly discussed. PMID:26580223

  9. Public Participation as an Aid to Conserve Little Known Species: The Case of the Neotropical Otter Lontra Longicaudis (Olfers, 1818 in Central Mexico

    Directory of Open Access Journals (Sweden)

    Eric Ramírez-Bravo

    2013-01-01

    Full Text Available Public participation is often disregarded during conservation projects despite the potential benefits as it can help to determine priority areas for conservation in highly fragmented landscapes or to increase knowledge of little known species. However, there is no information about its potential application in Central Mexico. We undertook a preliminary assessment based on 30 interviews preformed between December 2011 and May 2012 with hunters aimed to determine the presence, feeding habits, reproduction periods, and –threats of the neotropical otter (Lontra longicaudis in a fragmented landscape in the Sierra Madre Oriental. Twenty three of the interviewed hunters indicated that the species is rare and considered to be solitary however, they have observed cubs and pregnant females feeding mainly on fish and crustaceans were made. Pollution, shortage of prey, habitat disturbance, and hunting were the main threats on the species. We verified the presence responses of the neotropical otter through field work and the life history information was obtained by doing a literature review. We concluded that public participation can be confidently incorporated in conservation plans of the neotropical otter in the Sierra Madre Oriental.

  10. The Tonalá fault in southeastern Mexico: Evidence that the Central America forearc sliver is not being detached?

    Science.gov (United States)

    Guzman-Speziale, M.; Molina-Garza, R. S.

    2012-12-01

    The Tonalá fault is a NW-SE oriented feature that flanks the Chiapas Massif on its southwestern side. Several authors coincide that the fault originally developed as a right-lateral structure in the Jurassic, but was reactivated as a left-lateral fault in the Miocene. Seismicity along the fault is low: Only one earthquake with magnitude 5.0 or larger is reported along the Tonalá fault in the years 1964 to present. Fault-plane solutions determined by the Mexican Seismological Survey for earthquakes along the fault show left-lateral, strike-slip faulting. The Tonalá fault lies on the northwestern continuation of the Central America volcanic arc. The volcanic arc is the site of medium-sized (magnitudes up to 6.5) shallow, right-lateral, strike-slip earthquakes. This has led several workers to propose that the forearc sliver is being detached from the Caribbean plate along the arc, moving northward. GPS studies have confirmed relative motion between the Chortis block and the forearc sliver. Recent and current motion along the Tonalá fault is in contradiction with motion and detachment of the forearc sliver along the Central America volcanic arc. Left-lateral motion along it cannot accomodate northwest displacement of the forearc sliver. Motion of the Central America forearc would require NW directed compression between the continental shelf of Chiapas and the forearc itself, which is not observed. Therefore, either another fault (or faults) accomodates right-lateral motion and detachment of the forearc sliver, or the sliver is not being detached and relative motion between the forearc sliver and the Chortis block corresponds to displacement of the latter. We suggest that, as proposed by previous authors, the Tonalá fault is instead part of a fault system that runs from the state of Oaxaca (the Valle Nacional fault), forming an arc concave to the northeast, and running perpendicular to the maximum slope of subduction in the area.

  11. Regional stratigraphy and distribution of epigenetic stratabound celestine, fluorite, barite and Pb-Zn deposits in the MVT province of northeastern Mexico

    Science.gov (United States)

    González-Sánchez, Francisco; Camprubí, Antoni; González-Partida, Eduardo; Puente-Solís, Rafael; Canet, Carles; Centeno-García, Elena; Atudorei, Viorel

    2009-04-01

    Northeastern Mexico hosts numerous epigenetic stratabound carbonate-hosted low-temperature hydrothermal deposits of celestine, fluorite, barite and zinc-lead, which formed by replacement of Mesozoic evaporites or carbonate rocks. Such deposits can be permissively catalogued as Mississippi Valley-type (MVT) deposits. The deposits studied in the state of Coahuila are associated with granitic and metasedimentary basement highs (horsts) marginal or central to the Mesozoic Sabinas Basin. These horsts controlled the stratigraphy of the Mesozoic basins and subsequently influenced the Laramide structural pattern. The Sabinas Basin consists of ~6,000-m-thick Jurassic to Cretaceous siliciclastic, carbonate and evaporitic series. The MVT deposits are mostly in Barremian and in Aptian-Albian to Cenomanian formations and likely formed from basinal brines that were mobilized during the Laramide orogeny, although earlier diagenetic replacement of evaporite layers (barite and celestine deposits) and lining of paleokarstic cavities in reef carbonates (Zn-Pb deposits) is observed. Fluid inclusion microthermometry and isotopic studies suggest ore formation due to mixing of basinal brines and meteoric water. Homogenization temperatures of fluid inclusions range from 45°C to 210°C; salinities range from 0 to 26 wt.% NaCl equiv., and some inclusions contain hydrocarbons or bitumen. Sulfur isotope data suggest that most of the sulfur in barite and celestine is derived from Barremian to Cenomanian evaporites. Regional geology and a compilation of metallogenic features define the new MVT province of northeastern Mexico, which comprises most of the state of Coahuila and portions of the neighboring states of Nuevo León, Durango and, perhaps extends into Zacatecas and southern Texas. This province exhibits a regional metal zonation, with celestine deposits to the south, fluorite deposits to the north and barite and Zn-Pb deposits mostly in the central part.

  12. A new species of Algansea (Actinopterygii: Cyprinidae) from the Ameca River basin, in Central Mexico Una especie nueva de Algansea (Actinopterygii: Cyprinidae) en la cuenca del río Ameca en el centro de México

    OpenAIRE

    Rodolfo Pérez-Rodríguez; Gerardo Pérez-Ponce de León; Omar Domínguez-Domínguez; Ignacio Doadrio

    2009-01-01

    A morphological comparative analysis was performed among different populations of the cyprinid Algansea tincella Valenciennes, 1844 from the Lerma-Chapala and Ameca River basins in central Mexico. A new species, Algansea amecae n. sp. is described from individuals collected from small tributary in the headwaters of the Ameca basin. The new species differs from Lerma-Chapala populations of A. tincella by having a lower number of transversal scales, a lower number of infraorbital pores, a promi...

  13. The structural architecture of the Los Humeros volcanic complex and geothermal field, Trans-Mexican Volcanic Belt, Central Mexico

    Science.gov (United States)

    Norini, Gianluca; Groppelli, Gianluca; Sulpizio, Roberto; Carrasco Núñez, Gerardo; Davila Harris, Pablo

    2014-05-01

    The development of geothermal energy in Mexico is a very important goal, given the presence of a large heat anomaly, associated with the Trans-Mexican Volcanic Belt, the renewability of the resource and the low environmental impact. The Quaternary Los Humeros volcanic complex is an important geothermal target, whose evolution involved at least two caldera events, that alternated with other explosive and effusive activity. The first caldera forming event was the 460 ka eruption that produced the Xaltipan ignimbrite and formed a 15-20 km wide caldera. The second collapse event occurred 100 ka with the formation of the Zaragoza ignimbrite and a nested 8-10 km wide caldera. The whole volcano structure, the style of the collapses and the exact location of the calderas scarps and ring faults are still a matter of debate. The Los Humeros volcano hosts the productive Los Humeros Geothermal Field, with an installed capacity of 40 MW and additional 75 MW power plants under construction. Recent models of the geothermal reservoir predict the existence of at least two reservoirs in the geothermal system, separated by impermeable rock units. Hydraulic connectivity and hydrothermal fluids circulation occurs through faults and fractures, allowing deep steam to ascend while condensate flows descend. As a consequence, the plans for the exploration and exploitation of the geothermal reservoir have been based on the identification of the main channels for the circulation of hydrothermal fluids, constituted by faults, so that the full comprehension of the structural architecture of the caldera is crucial to improve the efficiency and minimize the costs of the geothermal field operation. In this study, we present an analysis of the Los Humeros volcanic complex focused on the Quaternary tectonic and volcanotectonics features, like fault scarps and aligned/elongated monogenetic volcanic centres. Morphostructural analysis and field mapping reveal the geometry, kinematics and dynamics of

  14. Uranium mineralization environment and prospecting potential of Dawan ore field in Nanling metallogenic belt

    International Nuclear Information System (INIS)

    Located in the middle part of Jiuyishan complex pluton, Nanling metallogenic belt, Dawan uranium ore field in Hunan Province is an important uranium-producing and rare metal, nonferrous metal cluster area due to the favourable mineralization environment. The Cambrian is the main uranium source bed and their contact zone to the pluton is the favorable part for mineralization. The uranium deposits which have been explored are all located in the exocontact zone of Jinjiling pluton in the middle part of Jiuyishan complex pluton which is composed of the independent eastern and western magma evolution centers. In the west center, Jinjiling pluton is closely related to uranium mineralization where the trinity geologic setting was formed with magma evolution, hydrothermal fluid action and mineralization. The deep slitted and large faults provide the pathway and thermodynamic source for circulating migration of mineralizing fluid. The uranium mineralization mainly occurred in crustal stress conversion period of Late Cretaceous and related to the tensive NW extending fault and deep originated fluid. The gravity, aero magnetic, airborne gamma-ray spectrometry anomalies and radioactivity hydrochemical anomaly are important criteria for uranium prospecting. Based on the analysis of regional uranium mineralization environment, the prospecting potential is forecasted. (authors)

  15. The characteristics, origins, and geodynamic settings of supergiant gold metallogenic provinces

    Institute of Scientific and Technical Information of China (English)

    Robert; Kerrich[1; Richard; Goldfarb[2; David; Groves[3; Steven; Garwin[4

    2000-01-01

    There are six distinct classes of gold deposits, each represented by metallogenic provinces, having 100’s to > 1 000 tonne gold production. The deposit classes are: (1) erogenic gold; (2) Carlin and Carlin-like gold deposits; (3) epithermal gold-silver deposits; (4) copper-gold porphyry deposits; (5) iron-oxide copper-gold deposits; and (6) gold-rich volcanic hosted massive sul-fide (VMS) to sedimentary exhalative (SEDEX) deposits. This classification is based on ore and alteration mineral assemblages; ore and alteration metal budgets; ore fluid pressure(s) and compositions; crustal depth or depth ranges of formation; relationship to structures and/or magmatic intrusions at a variety of scales; and relationship to the P-T-t evolution of the host terrane. These classes reflect distinct geodynamic settings. Orogenic gold deposits are generated at mid-crustal (4-16 km) levels proximal to terrane boundaries, in transpressional subduction-accretion complexes of Cordilleran style erogenic belts; other orogeni

  16. Copper-Polymetal Metallogenic Series and Prospecting Perspective of Eastern Section of Gangdise

    Institute of Scientific and Technical Information of China (English)

    Zheng Youye; Xue Yingxi; Gao Shunbao

    2003-01-01

    Geological, geophysical, geochemical and remote sensing comprehensive studies show that big ore-prospecting potentiality is contained in the eastern section of the Gangdise Mountains, Tibet.There are various mineralization types with dominant types of porphyry and exhalation. According to their relations with tectonic evolution, they are divided into four kinds of metallogenic series as follows:magmatic type (Cr, Pt, Cu, Ni) and exhalation type (Cu, Pb, Zn, Ag) ore deposit series related to Neo-Tethys oceanic crust subduction action (125-96 Ma); epithermal type (Au, Ag, Pb, Zn, Sb), altered fractured rock type (Cu, Mo) and skarn rock type (Cu) ore deposit series related to arc-continental collision; porphyry type (Cu, Mo), cryptoexplosion breccia type (Cu, Au, Pb, Zn), shear zone type (Au, Ag, Sb) and skarn rock type (Cu, Fe) ore deposit series with relation to post-orogenic extensional strike-slip. From subductive complex to the north, zoning appears to be crystallization differentiation type (segregation type)-shear zone type (altered rock type)-skarn rock type, epithermal type-porphyry type-porphyry type and exhalation type-exhalation type-hydrothermal filling-replacement type.The ore deposit is characterized by multi-places from the same source, parity and multi-stage, hypabyssal rock from the deep source and poly genetic compound as a whole.

  17. Regional metallogenic essential factor of granite-type uranium deposits in Guangdong province

    International Nuclear Information System (INIS)

    The uranium origin, activation region, red basin, and fault depressed zone constitute the regional metallogenic essential factor of the four united like one granite-type uranium deposits in the post-Caledonian rise area in China. In the development of sub-geosyncline in the Caledonian, the clastic formation with widely deposited carbon, silicon, mud rich bearing organic matter, which drow a great amount of uranium formed the uranium-bearing system in the Sinian-Cambrian period. The magmagranite activation in a large scale in the Indosinian-Yenshanian period caused the continental crust to be suffered strong reformation and the uranium-bearing basement system to be eroded and remelted, and formed the rich uranium granite body. The multiple structure-magmatic movement further made the uranium in the rock body suffered the endogenic, structure, supergene active reformation, and produced mobile uranium concentrated area. Under the dry and hot paleoclimate condition in the Cretaceous-Tertiary period, strong weathering and hot water leaching forced uranium to be concentrated into the 'rock origin activation' type uranium deposits in the fault depressed zone

  18. Tepexpan revisited: A multiple proxy of local environmental changes in relation to human occupation from a paleolake shore section in Central Mexico

    Science.gov (United States)

    Sedov, Sergey; Lozano-García, Socorro; Solleiro-Rebolledo, Elizabeth; McClung de Tapia, Emily; Ortega-Guerrero, Beatriz; Sosa-Nájera, Susana

    2010-10-01

    Building up a scenario of Late Pleistocene-Holocene environmental change and human-landscape interactions in Central Mexico - one of the key areas for the natural and cultural history of America - requires development of local paleoenvironmental reconstructions. We studied the Tepexpan section at the edge of Texcoco a paleolake, near the mouth of Teotihuacan Valley as a multiproxy record of the environmental dynamics at the shore in the Basin of Mexico throughout the period of human occupation. The section is located in an ecotone affected by intensive and variable geomorphic processes and includes lacustrine, fluvial and volcanic sediments as well as paleosols. Our chronological scale is based on 6 AMS 14C dates from pollen concentrates and paleosol organic matter. The lower segment of the section dominated by the lacustrine sediments yielded pollen spectra; in the upper segment the record is based on the pedogenetic characteristics of paleosols. Different proxies agree in demonstrating the general trend (although some reversals are apparent) of decreasing effective moisture since MIS3: it is reflected first in the increase of herbaceous pollen after 27 ka BP, the decrease of lake level, the cessation of lacustrine sedimentation and beginning of marsh soil development at 10 ka BP and finally, the shift from hydromorphic to dryland semiarid pedogenesis in the Late Holocene. We assume that this trend was climatically controlled, whereas the deposition of sedimentary layers enriched with tephra are related to the pulses of volcanic activity; the pedosedimentary features associated with the upper soil are human-induced. Comparing the proposed scheme of environmental change with the archaeological record we propose that the initial settlers, Late Paleolithic hunters, could have utilized the wet swampy meadows which expanded on the Basin bottom as the lake level lowered and provided the niche for large herbivores during the Pleistocene-Holocene transition. Development

  19. Localized double-array stacking analysis of PcP: D″ and ULVZ structure beneath the Cocos plate, Mexico, central Pacific, and north Pacific

    Science.gov (United States)

    Hutko, Alexander R.; Lay, Thorne; Revenaugh, Justin

    2009-01-01

    A large, high quality P-wave data set comprising short-period and broadband signals sampling four separate regions in the lowermost mantle beneath the Cocos plate, Mexico, the central Pacific, and the north Pacific is analyzed using regional one-dimensional double-array stacking and modelling with reflectivity synthetics. A data-screening criterion retains only events with stable PcP energy in the final data stacks used for modelling and interpretation. This significantly improves the signal stacks relative to including unscreened observations, allows confident alignment on the PcP arrival and allows tight bounds to be placed on P-wave velocity structure above the core–mantle boundary (CMB). The PcP reflections under the Cocos plate are well modelled without any ultra-low velocity zone from 5 to 20°N. At latitudes from 15 to 20°N, we find evidence for two P-wave velocity discontinuities in the D″ region. The first is ∼182 km above the CMB with a δln Vp of +1.5%, near the same depth as a weaker discontinuity (<+0.5%) observed from 5 to 15°N in prior work. The other reflector is ∼454 km above the CMB, with a δln Vp of +0.4%; this appears to be a shallower continuation of the joint P- and S-wave discontinuity previously detected south of 15° N, which is presumed to be the perovskite to post-perovskite phase transition. The data stacks for paths bottoming below Mexico have PcP images that are well matched with the simple IASP91 structure, contradicting previous inferences of ULVZ presence in this region. These particular data are not very sensitive to any D″ discontinuities, and simply bound them to be <∼2%, if present. Data sampling the lowermost mantle beneath the central Pacific confirm the presence of a ∼15-km thick ultra-low velocity zone (ULVZ) just above the CMB, with δln Vp and δln Vs of around −3 to −4% and −4 to −8%, respectively. The ULVZ models predict previous S-wave data stacks well. The data for this region

  20. Contribution of Root Traits to Phosphorus Acqusition Efficiency by Maize Landraces in Acid Soils of the Highlands in Central Mexico

    International Nuclear Information System (INIS)

    Plants have a wide range of mechanisms and morphological features that increase availability and acquisition of orthophosphate from soil. Root growth, root branching, and root hair morphology are important for the efficient acquisition of phosphorus (P). The series of studies reported here was based on the hypothesis that Mexican maize landraces, which have developed mostly in environments with low P availability and have a well-developed root system, could be a source of variation for the improvement of phosphorus acquisition. Several studies were conducted to evaluate genotypic variation in both root (root architecture and morphology, including root hairs) and plant growth traits associated with P acquisition efficiency (PAE) and/or P utilization efficiency (PUE) of maize landraces in a P-deficient Andisol in the Central Mexican Highlands, and to identify genotypic differences, among both efficient and inefficient in P acquisition and responsive and non-responsive maize landraces to applied P. The results showed that accessions differed greatly in plant growth, grain yield, root morphology, total uptake of P, PAE, PUE, and P efficiency defined as growth with suboptimal P availability. Phosphorus-efficient accessions had not only greater biomass per unit of absorbed P, but also larger root systems, greater P uptake per unit root weight, more nodal roots, nodal root laterals, and greater root hair density of nodal root main axes and first-order laterals than did Pinefficient accessions under P deficiency. Root biomass allocation, as quantified by the allometric partitioning coefficient (K) was not altered by P availability in the efficient accessions, but inefficient accessions had less biomass partitioning to roots (i.e. a lower K) under low P conditions. Accessions with enhanced nodal rooting and laterals had greater P uptake and growth under low P. Dense root hairs on nodal root main axes and first-order laterals conferred a marked benefit under low P, as

  1. Can government be self-organized? A mathematical model of the collective social organization of ancient Teotihuacan, central Mexico.

    Science.gov (United States)

    Froese, Tom; Gershenson, Carlos; Manzanilla, Linda R

    2014-01-01

    Teotihuacan was the first urban civilization of Mesoamerica and one of the largest of the ancient world. Following a tradition in archaeology to equate social complexity with centralized hierarchy, it is widely believed that the city's origin and growth was controlled by a lineage of powerful individuals. However, much data is indicative of a government of co-rulers, and artistic traditions expressed an egalitarian ideology. Yet this alternative keeps being marginalized because the problems of collective action make it difficult to conceive how such a coalition could have functioned in principle. We therefore devised a mathematical model of the city's hypothetical network of representatives as a formal proof of concept that widespread cooperation was realizable in a fully distributed manner. In the model, decisions become self-organized into globally optimal configurations even though local representatives behave and modify their relations in a rational and selfish manner. This self-optimization crucially depends on occasional communal interruptions of normal activity, and it is impeded when sections of the network are too independent. We relate these insights to theories about community-wide rituals at Teotihuacan and the city's eventual disintegration. PMID:25303308

  2. Can government be self-organized? A mathematical model of the collective social organization of ancient Teotihuacan, central Mexico.

    Directory of Open Access Journals (Sweden)

    Tom Froese

    Full Text Available Teotihuacan was the first urban civilization of Mesoamerica and one of the largest of the ancient world. Following a tradition in archaeology to equate social complexity with centralized hierarchy, it is widely believed that the city's origin and growth was controlled by a lineage of powerful individuals. However, much data is indicative of a government of co-rulers, and artistic traditions expressed an egalitarian ideology. Yet this alternative keeps being marginalized because the problems of collective action make it difficult to conceive how such a coalition could have functioned in principle. We therefore devised a mathematical model of the city's hypothetical network of representatives as a formal proof of concept that widespread cooperation was realizable in a fully distributed manner. In the model, decisions become self-organized into globally optimal configurations even though local representatives behave and modify their relations in a rational and selfish manner. This self-optimization crucially depends on occasional communal interruptions of normal activity, and it is impeded when sections of the network are too independent. We relate these insights to theories about community-wide rituals at Teotihuacan and the city's eventual disintegration.

  3. Ignimbrite Flare-up in the North-Central Sierra Madre del Sur, Southern Mexico: a Continuation of the Sierra Madre Occidental Ignimbrite Province?

    Science.gov (United States)

    Moran-Zenteno, D. J.; Alba-Aldave, L.; Gonzalez-Torres, E. A.; Martiny, B.; Bravo-Diaz, B. A.; Sohn, E.

    2007-05-01

    The north-central Sierra Madre del Sur, immediately south of the Trans Mexican Volcanic Belt, is made up of a series of Eocene silicic volcanic centers distributed along a WNW trending 300 km long belt from Valle de Bravo to Huautla (98°50'-100°30'W longitude). This belt constitutes an inland arc near parallel to, and coeval with, the coastal batholitic belt of southern Mexico. It includes at least 9 exhumed volcanic edifices that display diverse caldera styles controlled by regional fracture zones and rheological contrasts in the host rocks. Initiation of the volcanism ranges from 37 Ma in the west to 32 Ma in the east, and extinction of magmatism was nearly simultaneous in the eastern half of the belt. Southwest of the silicic volcanic belt, andesitic volcanism is slightly younger (33-29 Ma) and the combined effect of post-Eocene uplift and erosion removed most of the extracaldera facies. The remnants of the silicic volcanic cover extend over an area of ~3000 km2. Reactivated fracture zones related to the volcanic activity include NW to W- trending faults that reveal a transition from left lateral to right lateral slip as result of a change in the stress field during the last stages of silicic volcanism. These and other groups of N-S to NNW trending faults accommodated the collapse structures and were the sites of emplacement of massive pyroclastic dikes. Immediately north of the Trans Mexican Volcanic Belt, ignimbrites and related rocks of the Mesa Central and southern Sierra Madre Occidental are slightly younger and display a westward 30 to ~15 Ma migration pattern accompanied by E-W regional extension. These patterns have been attributed to the roll back of the subducted slab, which caused the ascent of asthenospheric mantle and probably triggered ignimbrite flare-up. The distinct tectonic and geochronologic patterns of the arc volcanic rocks in the northern Sierra Madre del Sur and the southern Sierra Madre Occidental-Mesa Central suggests two slab segments

  4. RESOURCE ASSESSMENT OF THE IN-PLACE AND POTENTIALLY RECOVERABLE DEEP NATURAL GAS RESOURCE OF THE ONSHORE INTERIOR SALT BASINS, NORTH CENTRAL AND NORTHEASTERN GULF OF MEXICO

    Energy Technology Data Exchange (ETDEWEB)

    Ernest A. Mancini

    2004-04-16

    The University of Alabama and Louisiana State University have undertaken a cooperative 3-year, advanced subsurface methodology resource assessment project, involving petroleum system identification, characterization and modeling, to facilitate exploration for a potential major source of natural gas that is deeply buried (below 15,000 feet) in the onshore interior salt basins of the North Central and Northeastern Gulf of Mexico areas. The project is designed to assist in the formulation of advanced exploration strategies for funding and maximizing the recovery from deep natural gas domestic resources at reduced costs and risks and with minimum impact. The results of the project should serve to enhance exploration efforts by domestic companies in their search for new petroleum resources, especially those deeply buried (below 15,000 feet) natural gas resources, and should support the domestic industry's endeavor to provide an increase in reliable and affordable supplies of fossil fuels. The principal research effort for Year 1 of the project is data compilation and petroleum system identification. The research focus for the first nine (9) months of Year 1 is on data compilation and for the remainder of the year the emphasis is on petroleum system identification. The objectives of the study are: to perform resource assessment of the in-place deep (>15,000 ft) natural gas resource of the onshore interior salt basins of the North Central and Northeastern Gulf of Mexico areas through petroleum system identification, characterization and modeling and to use the petroleum system based resource assessment to estimate the volume of the in-place deep gas resource that is potentially recoverable and to identify those areas in the interior salt basins with high potential to recover commercial quantities of the deep gas resource. The project objectives will be achieved through a 3-year effort. First, emphasis is on petroleum system identification and characterization in the

  5. Fault kinematics in northern Central America and coupling along the subduction interface of the Cocos Plate, from GPS data in Chiapas (Mexico), Guatemala and El Salvador

    Science.gov (United States)

    Franco, A.; Lasserre, C.; Lyon-Caen, H.; Kostoglodov, V.; Molina, E.; Guzman-Speziale, M.; Monterosso, D.; Robles, V.; Figueroa, C.; Amaya, W.; Barrier, E.; Chiquin, L.; Moran, S.; Flores, O.; Romero, J.; Santiago, J. A.; Manea, M.; Manea, V. C.

    2012-06-01

    New GPS measurements in Chiapas (Mexico), Guatemala and El Salvador are used to constrain the fault kinematics in the North America (NA), Caribbean (CA) and Cocos (CO) plates triple junction area. The regional GPS velocity field is first analysed in terms of strain partitioning across the major volcano-tectonic structures, using elastic half-space modelling, then inverted through a block model. We show the dominant role of the Motagua Fault with respect to the Polochic Fault in the accommodation of the present-day deformation associated with the NA and CA relative motion. The NA/CA motion decreases from 18-22 mm yr-1 in eastern Guatemala to 14-20 mm yr-1 in central Guatemala (assuming a uniform locking depth of 14-28 km), down to a few millimetres per year in western Guatemala. As a consequence, the western tip of the CA Plate deforms internally, with ≃9 mm yr-1 of east-west extension (≃5 mm yr-1 across the Guatemala city graben alone). Up to 15 mm yr-1 of dextral motion can be accommodated across the volcanic arc in El Salvador and southeastern Guatemala. The arc seems to mark the northern boundary of an independent forearc sliver (AR), pinned to the NA plate. The inversion of the velocity field shows that a four-block (NA, CA, CO and AR) model, that combines relative block rotations with elastic deformation at the block boundaries, can account for most of the GPS observations and constrain the overall kinematics of the active structures. This regional modelling also evidences lateral variations of coupling at the CO subduction interface, with a fairly high-coupling (≃0.6) offshore Chiapas and low-coupling (≃0.25) offshore Guatemala and El Salvador.

  6. The implications of geology, soils, and vegetation on landscape morphology: Inferences from semi-arid basins with complex vegetation patterns in Central New Mexico, USA

    Science.gov (United States)

    Yetemen, Omer; Istanbulluoglu, Erkan; Vivoni, Enrique R.

    2010-04-01

    This paper examines the relationship between land surface properties (e.g. soil, vegetation, and lithology) and landscape morphology quantified by the catchment descriptors: the slope-area (S-A) relation, curvature-area (C-A) relation, and the cumulative area distribution (CAD), in two semi-arid basins in central New Mexico. The first site is composed of several basins located in today's desert elevations with mesic north-facing and xeric south-facing hillslopes underlain by different lithological formations. The second site is a mountainous basin exhibiting vegetation gradients from shrublands in the lower elevations to grasslands and forests at higher elevations. All three land surface properties were found to have significant influences on the S-A and C- A relations, while the power-law exponents of the CADs for these properties did not show any significant deviations from the narrow range of universal scaling exponents reported in the literature. Among the three different surface properties we investigated, vegetation had the most profound impact on the catchment descriptors. In the S-A diagrams of the aspect-controlled ecosystems, we found steeper slopes in north-facing aspects than south-facing aspects for a given drainage area. In elevation-controlled ecosystems, forested landscapes exhibited the steepest slopes for the range of drainage areas examined, followed by shrublands and grasslands in all soil textures and lithologies. In the C-A diagrams, steeper slopes led to a higher degree of divergence on hillslopes and a higher degree of convergence in the valleys than shallower slopes. The influence of functional types of vegetation detected on observed topography provided some initial understanding of the potential impacts of life on the organization of topography. This finding also emphasizes the critical role of climate in catchment development. We suggest that climatic fluctuations that are capable of replacing vegetation communities could lead to highly

  7. A detailed paleomagnetic and rock-magnetic investigation of the Matuyama-Bruhnes geomagnetic reversal recorded in tephra-paleosol sequence of Tlaxcala(Central Mexico

    Directory of Open Access Journals (Sweden)

    Ana Maria Soler-Arechalde

    2015-04-01

    Full Text Available Geomagnetic reversals are global phenomena, for about 50 years the paleomagnetists attempted to acquire as many detailed records as possible using the magnetic memory of sediments and lava flows. Yet, transitional field behavior remains poorly characterized largely because of sporadic aspect of volcanic eruptions. In some specific cases, paleosols such as those developed from alluvial or aeolian sediments, may also record the variations of the Geomagnetic Field across the polarity changes. Here, we report a detailed paleomagnetic and rock-magnetic investigation on some radiometrically dated chromic luvisols located in Central Mexico carrying detrital or chemical remanent magnetization. The research was developed in order i to demonstrate the primary origin of the magnetic remanence and ii to show that paleosoils are good candidates to provide a high resolution record of the behavior of geomagnetic field during reversals. The lower part of the paleosoil sequence shows a clearly defined reverse polarity magnetization followed by geomagnetically unstable transitional field and ended by normal polarity remanence. Our AMS and rock magnetic data suggest that magnetization is acquired during the initial stage of soil formation in context of active volcanic activity since magnetic fabric is essentially sedimentary and reverse and normal polarity paleodirections are almost antipodal. Titanomagnetites are identified as main magnetic carriers of rock-magnetic measurements including thermomagnetics and hysteresis cycles. We propose that the transition recorded in this study correspond to the B-M boundary, considering the K-Ar datings available at the sequence bottom and that the chromic luvisols are potentially good recorders of the paleosecular variation. The identification of the B-M boundary within the studied sequence has fundamental significance for improving the chronological scale of Tlaxcala paleosol-sedimentary sequence and its correlation with the

  8. A detailed paleomagnetic and rock-magnetic investigation of the Matuyama-Bruhnes geomagnetic reversal recorded in tephra-paleosol sequence of Tlaxcala(Central Mexico)

    Science.gov (United States)

    Soler-Arechalde, Ana; Goguitchaichvili, Avtandyl; Carrancho, Ángel; Sedov, Sergey; Caballero-Miranda, Cecilia; Ortega, Beatriz; Solís, Berenice; Morales Contreras, Juan; Urrutia-Fucugauchi, Jaime; Bautista, Francisco

    2015-04-01

    Geomagnetic reversals are global phenomena, for about 50 years the paleomagnetists attempted to acquire as many detailed records as possible using the magnetic memory of sediments and lava flows. Yet, transitional field behavior remains poorly characterized largely because of sporadic aspect of volcanic eruptions. In some specific cases, paleosols such as those developed from alluvial or aeolian sediments, may also record the variations of the Geomagnetic Field across the polarity changes. Here, we report a detailed paleomagnetic and rock-magnetic investigation on some radiometrically dated chromic luvisols located in Central Mexico carrying detrital or chemical remanent magnetization. The research was developed in order i) to demonstrate the primary origin of the magnetic remanence and ii) to show that paleosoils are good candidates to provide a high resolution record of the behavior of geomagnetic field during reversals. The lower part of the paleosoil sequence shows a clearly defined reverse polarity magnetization followed by geomagnetically unstable transitional field and ended by normal polarity remanence. Our AMS and rock magnetic data suggest that magnetization is acquired during the initial stage of soil formation in context of active volcanic activity since magnetic fabric is essentially sedimentary and reverse and normal polarity paleodirections are almost antipodal. Titanomagnetites are identified as main magnetic carriers of rock-magnetic measurements including thermomagnetics and hysteresis cycles. We propose that the transition recorded in this study correspond to the B-M boundary, considering the K-Ar datings available at the sequence bottom and that the chromic luvisols are potentially good recorders of the paleosecular variation. The identification of the B-M boundary within the studied sequence has fundamental significance for improving the chronological scale of Tlaxcala paleosol-sedimentary sequence and its correlation with the global proxies.

  9. A GIS-based methodology for highlighting fuelwood supply/demand imbalances at the local level: A case study for Central Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Ghilardi, Adrian; Guerrero, Gabriela; Masera, Omar [CIECO, Center for Ecosystems Research, Universidad Nacional Autonoma de Mexico, Antigua carretera a Patzcuaro 8701, 58 190 Morelia (Mexico)

    2009-06-15

    When fuelwood is harvested at a rate exceeding natural growth and inefficient conversion technologies are used, negative environmental and socio-economic impacts, such as fuelwood shortages, natural forests degradation and net GHG emissions arise. In this study, we argue that analyzing fuelwood supply/demand spatial patterns require multi-scale approaches to effectively bridge the gap between national results with local situations. The proposed methodology is expected to help 1) focusing resources and actions on local critical situations, starting from national wide analyses and 2) estimating, within statistically robust confidence bounds, the proportion of non-renewable harvested fuelwood. Starting from a previous work, we selected a county-based fuelwood hot spot in the Central Highlands of Mexico, identified from a national wide assessment, and developed a grid-based model in order to identify single localities that face concomitant conditions of high fuelwood consumption and insufficient fuelwood resources. By means of a multi-criteria analysis (MCA), twenty localities, out of a total of 90, were identified as critical in terms of six indicators related to fuelwood use and availability of fuelwood resources. Fuelwood supply/demand balances varied among localities from -16.2 {+-} 2.5 Gg y{sup -1} to 4.4 {+-} 2.6 Gg y{sup -1}, while fractions of non-renewable fuelwood varied from 0 to 96%. These results support the idea that balances and non-renewable fuelwood fractions (mandatory inputs for Clean Development Mechanism (CDM) cookstoves projects) must be calculated on a locality by locality basis if gross under or over-estimations want to be avoided in the final carbon accounting. (author)

  10. Analysis on metallogenic conditions and prospect of sandstone-type uranium deposits in Longchuan basin western Yunnan

    International Nuclear Information System (INIS)

    The author discusses geotectonics, geomorphologic landscape, and paleoclimate, uranium source, structural pattern and structural division of the Longchuan basin, lithologies and lithofaces of Upper Tertiary, hydrogeology and hydrogeochemistry, concentration of uranium and deep information, compares the above information with that of U-productive Longchuanjiang basin, and analyzes the metallogenic conditions of sandstone-type uranium deposits. It is considered that the tectonic-erosion depressions located on the hanging wall of water-blocking faults in the southeastern uplifted zone of the Longchuan basin, and containing abundant organic matter and carbonaceous matter are the prospective areas for sandstone-type uranium deposits in Longchuan basin

  11. Evaluation of Two Lupinus Species Native from Central Mexico in Relation with Solubilization of Nitrogen, Phosphorus and Potassium in an Andosol

    OpenAIRE

    Angel Alderete-Chavez; Vicente Espinosa Hernandez; Nancy De la Cruz-Landero; Enrique Ojeda Trejo; Hortencia Brito Vega

    2009-01-01

    In Mexico there are few studies about lupine native species. In the oriental slope of the Sierra Nevada Mexico five species of Lupinus growing in soil andosol were identified and seeds of the plants were collected. The Lupinus species play an important ecological role by providing favorable conditions for the restauration of soils in forest areas after fire, in agriculture acidification of soil and solubilization of nutrients. Data about the performance of lupine native species and the...

  12. Children’s Migration to the United States from Mexico and Central America: Evidence from the Mexican and Latin American Migration Projects

    OpenAIRE

    Donato, Katharine M.; Blake Sisk

    2015-01-01

    In light of rising numbers of unaccompanied minors at the Mexico-US border in 2014, this article examines child migration from Mexico, Guatemala, El Salvador, Costa Rica, and Nicaragua. Using data from the Mexican and Latin American Migration Projects that permit us to go beyond simple descriptive analysis about children apprehended at the border, we investigate the extent to which children from these countries: (1) enter without legal authorization to do so; (2) are more likely to cross the ...

  13. Deep-seated structure and metallogenic dynamics of the Ailaoshan polymetallic mineralization concentration area, Yunnan Province, China

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The Ailaoshan poly-metallic mineralization concentrated area (MCA) consists of the well known Ailaoshan metallogenic belt and adjacent mineral districts and/or deposits. Located in an area of several complex and intersecting tectonic units, the Ailaoshan poly-metallic MCA is controlled by deep crustal and mantle tectonism. Through interpretation of remote sensing images, we identified a large ring structure system that surrounds the MCA. This ring structure encloses regional deep-crustal faults, ductile shear zones, geothermal anomalies, magmatic rocks, and the major mineral deposits, all of which are the reflections of deep tectonic geodynamics that have been long active in this area. Geophysical data indicate that the crust is comprised of relatively stable two or three layers, with some irregular lower-velocity belts. The Moho in the ring sutures occurs as an area of local uplift. There exists an obvious transitional zone between the crust and mantle boundaries. Asthenopheric mantle shows multi-layer upwelling, which indicates multiple events during different geological epochs. It is believed that these mantle events or pulses were responsible for the formation of the regional shear zones, magmatic rocks, and polymetallic orebodies. Furthermore, an integrated metallogenic dynamics model related to the asthenopheric upwelling pulses in the MCA is established, defining events as old as Late Paleozoic.

  14. Deep-seated structure and metallogenic dynamics of the Ailaoshan polymetallic mineralization concentration area, Yunnan Province, China

    Institute of Scientific and Technical Information of China (English)

    GE LiangSheng; DENG Jun; GUO XiaoDong; ZOU YiLin; LIU YinChun

    2009-01-01

    The Ailaoshan poly-metalllc mineralization concentrated area (MCA) consists of the well known Aileoshan metallogenic belt and adjacent mineral districts and/or deposits. Located in an area of sev-eral complex and intersecting tectonic units, the Ailaoshan poly-metallic MCA is controlled by deep crustal and mantle tectonism. Through interpretation of remote sensing images, we identified a large ring structure system that surrounds the MCA. This ring structure encloses regional deep-crustal faults, ductile shear zones, geothermal anomalies, magmatic rocks, and the major mineral deposits, all of which are the reflections of deep tectonic geodynamics that have been long active in this area. Geo-physical data indicate that the crust is comprised of relatively stable two or three layers, with some irregular lower-velocity belts. The Moho in the ring sutures occurs as an area of local uplift. There ex-lets an obvious transitional zone between the crust and mantle boundaries. Asthenopheric mantle shows multi-layer upwelling, which indicates multiple events during different geological epochs. It is believed that these mantle events or pulses were responsible for the formation of the regional shear zones, magmatic rocks, and polymetallic orebodies. Furthermore, an integrated metallogenic dynamics model related to the asthenopheric upwelling pulses in the MCA is established, defining events as old as Late Paleozoic.

  15. PETROGENETIC AND METALLOGENETIC AGES FOR THE PORPHYRY COPPER DEPOSITS IN THE GANGDISE METALLOGENIC BELT IN SOUTHERN TIBET

    Institute of Scientific and Technical Information of China (English)

    LI Guangming; RUI Zongyao

    2004-01-01

    Recent examination and assessment about the porphyry copper deposits in Gangdise metallogenic belt in southern Tibet have revealed that these porphyry copper deposits are highly prospective. Several methods have been used for the isotopic dating of the Qulong, Tinggong and Chongjiang porphyry copper deposits, which gives out a petrogenetic age of 17.58±0.74Ma (single-zircon dating of SHRIMP), a metallogenetic age of 15.99±0.32Ma (Re-Os isochron dating) and an alteration age ranging between12.00Ma and 16.5Ma (K-Ar dating). The metallogenetic age is in general agreement with the alteration age.It can be seen that the petrogenetic and metallogenetic ages for the porphyry copper deposits in Gangdise metallogenic belt are noticeably later than the age for the collisional granitic intrusion in this belt. The authors contend that the porphyry copper deposits in the study area were formed in a post-collisional extensional tectonic setting, and are closely related to the delamination of the mountain roots of the orogenic belts and the uplifting of the Qinghai-Tibet Plateau.

  16. Diagenetic-metallogenic ages of pyritic cherts and their implications in Mojiang nickel-gold deposit in Yunnan Province, China

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Diagenetic-metallogenic ages of pyritic cherts formed by the syn-sedimentation of hydrothermal vent and ages of the Jinchang Rock Formation in the Mojiang large nickel-gold deposit in the Ailaoshan gold metallogenic belt have been discussed on the basis of chronology of isotopic geochemistry.. Nickel-gold.bearing pyritic cherts in the mining were formed by syn-sedimentation of hydrothermal vent in the Late Devonian, i.e. age by Sm-Nd isochronal method (t)= (358 4±8.6) (2σ) Ma and age by Rb-Sr isochronal method (t)= (354.74±0.72) (2σ) Ma. On the other hand, deep-water cherts from the Jinchang Rock Formation of the Upper Devonian in the area were initiated at the same time; that is,age by Sm-Nd isochronal method (t) = (359±21) (2σ) Ma and age by Rb-Sr isochronal method (t) = (358.02±0.30) (2σ)Ma.

  17. The water and energy exchange of a shaded coffee plantation in the lower montane cloud forest zone of central Veracruz, Mexico

    Science.gov (United States)

    Holwerda, F.; Bruijnzeel, L. A.; Barradas, V.; Cervantes, J.

    2012-12-01

    The water and energy fluxes of a shaded coffee plantation in the lower montane cloud forest (LMCF) zone of central Veracruz, Mexico, were measured over a two-year period (September 2006-August 2008) using the eddy covariance method. Complementary measurements of throughfall and stemflow were made to study rainfall interception. The sum of the observed sensible (H) and latent (λE) heat fluxes was almost 95% of the net radiation (Rn) minus the canopy heat storage fluxes, indicating very good energy balance closure. Monthly means of the mid-day (11:00-15:00 h) Bowen ratio (H/λE) and evaporative fraction (λE/Rn) averaged 0.74 +/- 0.12 and 0.56 +/- 0.05, respectively. Energy partitioning showed distinct seasonal variation, with significantly higher Bowen ratios prevailing during the dry season (0.81 +/- 0.13) compared to the rainy season (0.67 +/- 0.06). The lower evaporation rates during the dry season reflected a combination of lower soil moisture availability and a lower leaf area of the Inga shade trees during this part of the year. Both the eddy covariance, and the throughfall and stemflow measurements showed average wet-canopy evaporation rate to be very low (0.05 mm/h) compared to the corresponding rainfall rate (3.06 mm/h). As a result, and despite the low canopy storage capacity of the coffee plantation (Cm, 0.50 mm), interception was dominated by post-event evaporation of intercepted water rather than by within-event evaporation. Comparing the results for the coffee plantation with interception data from mature and secondary LMCFs in the study area suggests that the conversion of LMCF to shade-coffee may lead to a decrease in interception loss of 8-18% of incident rainfall. This decrease is caused by a three- to seven-fold decrease in Cm due to the lower leaf area and smaller epiphyte biomass of the coffee plantation. Comparing the eddy covariance-based estimate of dry-canopy evaporation for the coffee plantation with sapflow-based estimates of

  18. Effects of overcast and foggy conditions on transpiration rates of Pinus patula trees along a chronosequence within the cloud belt of the Sierra Madre Oriental, central Veracruz, Mexico

    Science.gov (United States)

    Alvarado-Barrientos, M. S.; Holwerda, F.; Asbjornsen, H.; Sauer, T.; Dawson, T. E.; Bruijnzeel, L. A.

    2010-12-01

    Pinus patula is a native tree species of the montane cloud belt of central Veracruz, Mexico, and one of the most popular species for regional reforestation efforts, both within and outside its natural range of occurrence. Projected regional climate change is likely to cause a rise in the average cloud condensation level by several hundred meters, thereby reducing fog occurrence, whilst overcast conditions are likely to remain similar. To improve our understanding of how water use of P. patula plantations is affected by changes in climatic conditions, we analyzed the response of transpiration rates to fine-scale variations in microclimate, particularly fog immersion and the occurrence of high clouds. We conducted measurements of micrometeorological parameters and transpiration (Et, using the heat ratio sap flow technique) of 15 pine trees representing a range of ages (10-34 years) and sizes (7-60 cm of dbh) during one and a half years (Nov 2008 - May 2010), covering two dry seasons and one wet season. Foggy days were defined using daytime “M-of-N” constructs (at least 4 hours with visibility 1000 m and a maximum incoming solar radiation (Sin) climatic conditions using the FAO reference evaporation ETo to allow determination of the proportional contributions to Et suppression by reductions in Sin and VPD relative to leaf wetness. We found that both foggy and overcast conditions without rainfall produced similar % of Et reduction compared to sunny conditions (60-70%). The strongest Et suppression effects occurred when foggy or overcast conditions were associated with rainfall. However, there was just a slight and non significant difference between the average Et/ETo ratio for foggy days with rainfall (i.e. partially wetted canopy) and fog-only days, suggesting that the suppression of Et was mainly caused by reductions in VPD and Sin. Further, reverse daytime sap flow rates (possibly due to water uptake by tree crowns) occurred almost exclusively during periods

  19. CENSUS AND STATISTICAL CHARACTERIZATION OF SOIL AND WATER QUALITY AT ABANDONED AND OTHER CENTRALIZED AND COMMERCIAL DRILLING-FLUID DISPOSAL SITES IN LOUISIANA, NEW MEXICO, OKLAHOMA, AND TEXAS

    Energy Technology Data Exchange (ETDEWEB)

    Alan R. Dutton; H. Seay Nance

    2003-06-01

    Commercial and centralized drilling-fluid disposal (CCDD) sites receive a portion of spent drilling fluids for disposal from oil and gas exploration and production (E&P) operations. Many older and some abandoned sites may have operated under less stringent regulations than are currently enforced. This study provides a census, compilation, and summary of information on active, inactive, and abandoned CCDD sites in Louisiana, New Mexico, Oklahoma, and Texas, intended as a basis for supporting State-funded assessment and remediation of abandoned sites. Closure of abandoned CCDD sites is within the jurisdiction of State regulatory agencies. Sources of data used in this study on abandoned CCDD sites mainly are permit files at State regulatory agencies. Active and inactive sites were included because data on abandoned sites are sparse. Onsite reserve pits at individual wells for disposal of spent drilling fluid are not part of this study. Of 287 CCDD sites in the four States for which we compiled data, 34 had been abandoned whereas 54 were active and 199 were inactive as of January 2002. Most were disposal-pit facilities; five percent were land treatment facilities. A typical disposal-pit facility has fewer than 3 disposal pits or cells, which have a median size of approximately 2 acres each. Data from well-documented sites may be used to predict some conditions at abandoned sites; older abandoned sites might have outlier concentrations for some metal and organic constituents. Groundwater at a significant number of sites had an average chloride concentration that exceeded nonactionable secondary drinking water standard of 250 mg/L, or a total dissolved solids content of >10,000 mg/L, the limiting definition for underground sources of drinking water source, or both. Background data were lacking, however, so we did not determine whether these concentrations in groundwater reflected site operations. Site remediation has not been found necessary to date for most abandoned

  20. Origin and evolution of ore-forming fluids in the Hemushan magnetite-apatite deposit, Anhui Province, Eastern China, and their metallogenic significance

    Science.gov (United States)

    Luo, Gan; Zhang, Zhiyu; Du, Yangsong; Pang, Zhenshan; Zhang, Yanwen; Jiang, Yongwei

    2015-12-01

    The Middle-Lower Yangtze River Metallogenic Belt in the northern Yangtze Block is one of the most important economic mineral districts in China. The Hemushan deposit is a medium-class Fe deposit located in the southern part of the Ningwu iron ore district of the Middle-Lower Yangtze River Metallogenic Belt. The Fe-orebodies are mainly hosted in the contact zone between diorite and Triassic marble. The actinolite-phlogopite-apatite-magnetite ore shows metasomatic/filling textures and disseminated/mesh-vein structures. Based on evidences and petrographic observations, the ore-forming process can be divided into three distinct periods-the early metallogenic period (albite-diopside stage), the middle metallogenic period (magnetite stage and hematite stage), and the late metallogenic period (quartz-pyrite stage and carbonate stage). Fluid inclusion studies show four types of inclusions: type I daughter mineral-bearing three-phase inclusions (L + V + S), type II vapor-rich two-phase inclusions (L + V), type III liquid-rich two phase inclusions (L + V), and minor type IV liquid-phase inclusions (L). Apatites from the magnetite stage contain type I, type II and type III inclusions; anhydrites from the hematite stage mainly contain abundant type II inclusions and relatively less type I inclusions; quartz and calcite from the late metallogenic stage are mainly characterized by type III inclusions. Laser Raman spectroscopy and microthermometry of fluid inclusions show that the ore-forming fluids broadly correspond to unsaturated NaCl-H2O system. From the magnetite stage to the carbonate stage, the ore-forming fluids evolved from moderate-high temperature (average 414 °C), moderate salinity (average 25.01 wt.% NaCl equiv.) conditions to low temperature (average 168 °C), low salinity (average 6.18 wt.% NaCl equiv.) conditions. Hydrogen and oxygen isotopic studies indicate that the ore-forming fluid during the early stage of middle metallogenic period was mainly of magmatic

  1. 1985 Mexico City, Mexico Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The magnitude 8.1 earthquake occurred off the Pacific coast of Mexico. The damage was concentrated in a 25 square km area of Mexico City, 350 km from the epicenter....

  2. Digital data and derivative products from a high-resolution aeromagnetic survey of the central San Luis basin, covering parts of Alamosa, Conejos, Costilla, and Rio Grande counties, Colorado, and Taos county, New Mexico

    Science.gov (United States)

    Bankey, Viki; Grauch, V.J.S.; Webbers, Ank; PRJ, Inc

    2005-01-01

    This report describes data collected from a high-resolution aeromagnetic survey flown over the central San Luis basin during October, 2004, by PRJ, Inc., on contract to the U.S. Geological Survey (USGS). The survey extends from just north of Alamosa, Colorado, southward to just northwest of Taos, New Mexico. It covers large parts of the San Luis Valley in Alamosa, Conejos, Costilla, and Rio Grande Counties, southern Colorado, and the Taos Plateau in Taos County, northern New Mexico. The survey was designed to complement two surveys previously acquired along the eastern borders of the San Luis Basin over the vicinities of Taos, New Mexico (Bankey and others, 2004a) and Blanca, Colorado (Bankey and others, 2004b). Our overall objective in conducting these surveys is to improve knowledge of the subsurface geologic framework in order to understand ground-water systems in populated alluvial basins along the Rio Grande. These USGS efforts are conducted in collaboration with other federal, state, and local governmental entities where possible.

  3. Analysis of the financial task generated by the construction of a nuclear power plant in Mexico; Analisis de la carga financiera generada por la construccion de una central nuclear en Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, G.; Ramirez, R.; Palacios, J.; Delfin, A., E-mail: gustavo.alonso@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2011-11-15

    The construction of new nuclear reactors requires of a high investment making them intensive projects in capital and that require as minimum of 5 years for its construction. The financial task that represents for the electric company is of vital importance, since in the case of privates in other countries prevents them of entering in this type of projects if they do not have its Government support. In the case of Mexico, being an electric company integrated vertically can have financing to carry out this investment type. In this study is analyzed the construction viability of new nuclear reactors in Mexico based on the financial task that represents for the Electric Company its construction. (Author)

  4. On the behavior of site effects in central Mexico (the Mexican volcanic belt - MVB), based on records of shallow earthquakes that occurred in the zone between 1998 and 2011

    Science.gov (United States)

    Clemente-Chavez, A.; Zúñiga, F. R.; Lermo, J.; Figueroa-Soto, A.; Valdés, C.; Montiel, M.; Chavez, O.; Arroyo, M.

    2014-06-01

    The Mexican volcanic belt (MVB) is a seismogenic zone that transects the central part of Mexico with an east-west orientation. The seismic risk and hazard of this seismogenic zone has not been studied in detail due to the scarcity of instrumental data as well as because seismicity in the continental regime of central Mexico is not too frequent. However, it is known that there are precedents of large earthquakes (Mw > 6.0) that have taken place in this zone. The valley of Mexico City (VM) is the sole zone, within the MVB, that has been studied in detail. Studies have mainly focused on the ground amplification during large events such as the 1985 subduction earthquake that occurred off coast of Michoacán. The purpose of this article is to analyze the behavior of site effects in the MVB zone based on records of shallow earthquakes (data not reported before) that occurred in the zone between 1998 and 2011. We present a general overview of site effects in the MVB, a classification of the stations in order to reduce the uncertainty in the data when obtaining attenuation parameters in future works, as well as some comparisons between the information presented here and that presented in previous studies. A regional evaluation of site effects and Fourier acceleration spectrum (FAS) shape was estimated based on 80 records of 22 shallow earthquakes within the MVB zone. Data of 25 stations were analyzed. Site effects were estimated by using the horizontal-to-vertical spectral ratio (HVSR) methodology. The results show that seismic waves are less amplified in the northeast sites of the MVB with respect to the rest of the zone and that it is possible to classify two groups of stations: (1) stations with negligible site amplification (NSA) and (2) stations with significant site amplification (SSA). Most of the sites in the first group showed small (understanding about the amplification behavior and of the expected seismic risk on central Mexico due to large earthquakes within

  5. On the behavior of site effects in Central Mexico (the Mexican Volcanic Belt – MVB, based on records of shallow earthquakes that occurred in the zone between 1998 and 2011

    Directory of Open Access Journals (Sweden)

    A. Clemente-Chavez

    2013-11-01

    Full Text Available The Mexican Volcanic Belt (MVB is a seismogenic zone that transects the central part of Mexico with an east–west orientation. The risk and hazard seismic of this seismogenic zone has not been studied at detail due to the scarcity of instrumental data as well as because seismicity in the continental regimen of Central Mexico is not too frequent, however, it is known that there are precedents of large earthquakes (Mw > 6.0 that have taken place in this zone. The Valley of Mexico City (VM is the sole zone, within the MVB, which has been studied in detail; mainly focusing on the ground amplification during large events such as the 1985 subduction earthquake that occurred in Michoacan. The purpose of this article is to analyze the behavior of site effects in the MVB zone based on records of shallow earthquakes (data not reported before that occurred in the zone between 1998 and 2011. We present a general overview of site effects on the MVB, a classification of the stations in order to reduce the uncertainty in the data to obtain attenuation parameters in future works, and some comparisons between the information presented here and that presented in previous studies. A regional evaluation of site effects and Fourier Acceleration Spectrum (FAS shape was estimated based on 80 records of 22 shallow earthquakes within the MVB zone. Data of 25 stations were analyzed. Site effects were estimated by using the Horizontal-to-Vertical Spectral Ratio (HVSR methodology. The results show that seismic waves are less amplified in the northeast sites of the MVB with respect to the rest of the zone and that it is possible to classify two groups of stations: (1 stations with Negligible Site Amplification (NSA and (2 stations with Significant Site Amplification (SSA. Most of the sites in the first group showed small ( These aspects help to advance the understanding about the amplification behavior and of the expected seismic risk on the Central Mexico due to large

  6. On the behavior of site effects in central Mexico (the Mexican volcanic belt - MVB), based on records of shallow earthquakes that occurred in the zone between 1998 and 2011

    Science.gov (United States)

    Clemente-Chavez, A.; Zúñiga, F. R.; Lermo, J.; Figueroa-Soto, A.; Valdés, C.; Montiel, M.; Chavez, O.; Arroyo, M.

    2014-06-01

    The Mexican volcanic belt (MVB) is a seismogenic zone that transects the central part of Mexico with an east-west orientation. The seismic risk and hazard of this seismogenic zone has not been studied in detail due to the scarcity of instrumental data as well as because seismicity in the continental regime of central Mexico is not too frequent. However, it is known that there are precedents of large earthquakes (Mw > 6.0) that have taken place in this zone. The valley of Mexico City (VM) is the sole zone, within the MVB, that has been studied in detail. Studies have mainly focused on the ground amplification during large events such as the 1985 subduction earthquake that occurred off coast of Michoacán. The purpose of this article is to analyze the behavior of site effects in the MVB zone based on records of shallow earthquakes (data not reported before) that occurred in the zone between 1998 and 2011. We present a general overview of site effects in the MVB, a classification of the stations in order to reduce the uncertainty in the data when obtaining attenuation parameters in future works, as well as some comparisons between the information presented here and that presented in previous studies. A regional evaluation of site effects and Fourier acceleration spectrum (FAS) shape was estimated based on 80 records of 22 shallow earthquakes within the MVB zone. Data of 25 stations were analyzed. Site effects were estimated by using the horizontal-to-vertical spectral ratio (HVSR) methodology. The results show that seismic waves are less amplified in the northeast sites of the MVB with respect to the rest of the zone and that it is possible to classify two groups of stations: (1) stations with negligible site amplification (NSA) and (2) stations with significant site amplification (SSA). Most of the sites in the first group showed small (seismicity regions. These variations were attributed to the location of the source. These aspects help to advance the understanding

  7. Two new species of Gyrodactylus von Nordmann, 1832 (Monogenea: Gyrodactylidae) parasitizing Girardinichthys multiradiatus (Cyprinodontiformes: Goodeidae), an endemic freshwater fish from central Mexico

    Czech Academy of Sciences Publication Activity Database

    Mendoza-Palmero, Carlos Alonso; Sereno-Uribe, A. L.; Salgado-Maldonado, G.

    2009-01-01

    Roč. 95, č. 2 (2009), s. 315-318. ISSN 0022-3395 Institutional research plan: CEZ:AV0Z60220518 Keywords : Monogenea * Cyprinodontiformes * fishes * Mexico * Gyrodactylus * taxonomy Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 1.195, year: 2009

  8. Gulf of Mexico sales 142 and 143: Central and western planning areas. Draft environmental impact statement. Volume 2. Sections IV.D through IX

    International Nuclear Information System (INIS)

    The EIS is a description of the environmental aspects and impacts of oil and gas activities resulting from these lease sales or the states bordering the Gulf of Mexico. The report provides a description of the areas, the affected environment, and the environmental consequences; it discusses the proposed actions, issues and areas of concern, and the major differences of holding these lease sales

  9. Gulf of Mexico Sales 142 and 143: Central and western planning areas. Draft environmental impact statement. Volume 1. Sections I through IV.C

    International Nuclear Information System (INIS)

    The EIS is a description of the environmental aspects and impacts of oil and gas activities resulting from these lease sales or the states bordering the Gulf of Mexico. The report provides a description of the areas, the affected environment, and the environmental consequences; it discusses the proposed actions, issues and areas of concern, and the major differences of holding these lease sales

  10. First Steps Towards the Paleoseismological History of the Pastores and Venta de Bravo Faults, Acambay Graben, Trans-Mexican Volcanic Belt, Central Mexico

    Science.gov (United States)

    Persaud, M.; Zúñiga, F. R.; Aguirre-Díaz, G.; Villamor, P.; Langridge, R.

    2006-12-01

    The Acambay graben is part of the Trans-Mexican Volcanic Belt (TMVB) which strikes ESE-WNW across central Mexico. The belt is an active, calc-alkaline volcanic arc that is related to the subduction of the Rivera and Cocos plates underneath the North American plate (e.g. Suter et al. 1995). The TMVB comprises a series of intra-arc basins that form the Chapala-Tula fault zone (450 km long, 50 km wide, Suter et al. 1995). The Acambay graben is c. 80 km long, 15 to 35 km wide and limited by four large E-W striking normal faults that are from west to east, the Epitacio-Huerta (EHF) and the Acambay-Tixmadejé faults (ATF) in the north and the Venta de Bravo (VBF) and the Pastores faults (PF) in the south. In the region, there is a low current seismicity but two known historic earthquakes occurred in the graben, the November 19, 1912, ms = 7.0 Acambay event and the February 22, 1979, ms = 4.9 Maravatío earthquake (Astíz-Delgado 1980). The paleoseismic history of the ATF has been previously studied by Langridge et al. (2000). Our focus lies on the paleoseismicity of the southern faults. The rupture history is assessed by tectonic geomorphology and paleoseismic trenches. To study the recent paleoseismic history of the two southern faults, we excavated two trenches on the PF. These trenches lie on young alluvial fans protruding from the Pastores fault scarp. Their location was chosen because of ' steps'\\ in the surface of the alluvial fan that might indicate the position of the most recent fault scarps, in combination with georadar profiles that confirmed vertical displacements in reflectors underneath those steps. The strata in the trenches consist of lake sediments at the base of one trench overlain by interbedded volcanic pyroclastic flows and ash falls which are found in both trenches. In both trenches we found evidence for one paleoearthquake respectively. We are in the process of dating these events by means abundant charcoal which we found in the pyroclastic

  11. Conformation of an evaluation process for a license renovation solicitude of a nuclear power plant in Mexico; Conformacion de un proceso de evaluacion para una solicitud de renovacion de licencia de una central nuclear en Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Serrano R, M. L., E-mail: mlserrano@cnsns.gob.mx [Comision Nacional de Seguridad Nuclear y Salvaguardias, Dr. Barragan No. 779, Col. Narvarte, 03020 Mexico D. F. (Mexico)

    2012-10-15

    So that the construction stages, of operation, closing, dismantlement and the radioactive waste disposal of a nuclear power plant (NPP) are carried out in Mexico, is necessary that the operator has a license, permission or authorization for each stage. In Mexico, these licenses, permissions or authorizations are granted by the Energy Secretariat with base in the verdict of the Comision Nacional de Seguridad Nuclear y Salvaguardias (CNSNS). The operation licenses ar the moment effective for the reactors of the Nuclear Power Plant of Laguna Verde (NPP-L V) they will expire respectively in the year 2020 and 2025 for the Unit 1 and Unit 2, for what the CNSNS has begun its preparation before a potential solicitude of the licensee to continue the operation of the NPP-L V. Defining the process to continue and to generate the documents that would help in this phase as normalization, guides, procedures, regulations, controls, etc., is the task that intends to be carried out the regulator body so that the evaluation process is effective and efficient, so much for the same regulator body as for the licensee. This work exposes the advance that the CNSNS has in this aspect and is centered specifically in the conformation of an evaluation process of license renovation solicitude, taking as base what the regulator body of the United States of North America (US NRC) established and following to the IAEA. Also, this work includes statistical of electric power production in Mexico, licensing antecedents for the NPP-L V, a world perspective of the license renovations and the regulation of the US NRC related to the license renovation of a NPP. (Author)

  12. Regulator process for the authorization of an amendment to the operation license of a nuclear power plant in Mexico; Proceso regulador para la autorizacion de una enmienda a la licencia de operacion de una central nuclear en Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Perez, R.; Espinosa V, J.M.; Salgado, J.R.; Mamani, Y.R. [CNSNS, Dr. Barragan 779, Col. Narvarte, 03020 Mexico D.F. (Mexico)

    2005-07-01

    The regulator process by which an authorization is granted from an amendment to the License of Operation of a nuclear power station in Mexico is described. It makes an appointment the effective legal mark, the technical characteristics of the modification, the evaluation process and deposition upon oath of tests and finally the elaboration of the Safety report and the Technical Verdict that is a correspondent for the regulator organism to the Secretary of Energy, the one that in turn is the responsible of granting the amendment the License just as it establishes it the Law. (Author)

  13. Computer input and output files associated with ground-water-flow simulations of the Albuquerque Basin, central New Mexico, 1901-94, with projections to 2020; (supplement one to U.S. Geological Survey Water-resources investigations report 94-4251)

    Science.gov (United States)

    Kernodle, J.M.

    1996-01-01

    This report presents the computer input files required to run the three-dimensional ground-water-flow model of the Albuquerque Basin, central New Mexico, documented in Kernodle and others (Kernodle, J.M., McAda, D.P., and Thorn, C.R., 1995, Simulation of ground-water flow in the Albuquerque Basin, central New Mexico, 1901-1994, with projections to 2020: U.S. Geological Survey Water-Resources Investigations Report 94-4251, 114 p.). Output files resulting from the computer simulations are included for reference.

  14. Used battery collection camping in central Mexico: statics and metal content report, advances in recycling technology and legislative/regulatory situation analysis

    International Nuclear Information System (INIS)

    Nowadays, environmental pollution produced by the disposal of used cells and batteries is a major concern in Mexico. The regulatory law proposal (NMX-AA-104-SCFI-2006) establish a content limit 20, 7.5 and 5 fold higher in Hg, Cd and Pb, respectively, than the European directive 2006/66/CE. Furthermore, transnational companies refused to have participation on the collection/recycling process, putting forward that pollution comes only from illegal market batteries. (Author)

  15. Suivi temporel de la zone de subduction d'Amérique Centrale et imagerie de la vallée de Mexico

    OpenAIRE

    Rivet, Diane

    2012-01-01

    Recent years have seen the development of a new method for imaging geological structures based on continuous seismic noise. In this work we used this approach in two different problems. The first is to monitor seismic waves velocity in the crust during slow slip events that occurred in the region of Guerrero in Mexico. These slow slip events are aseismic transients that were observed recently in the seismic gap of Guerrero. They are considered an important part of the strain relaxation in the...

  16. Radiological surveillance in Mexico, derived of the accident of the Fukushima Daiichi nuclear power plant; Vigilancia radiologica en Mexico, derivado del accidente en la central nuclear de Fukushima Daiichi

    Energy Technology Data Exchange (ETDEWEB)

    Aguirre G, J.; Nohpal J, X., E-mail: jaguirre@cnsns.gob.mx [Comision Nacional de Seguridad Nuclear y Salvaguardias, Departamento de Vigilancia Radiologica, Dr. Barragan No. 779, Col. Narvarte, 03020 Mexico D. F. (Mexico)

    2012-10-15

    March 11, 2011 an earthquake of 9.0 grades in the Richter scale, originated in the coast of Tohoku, Japan, in the Pacific Ocean gave origin to a tsunami that caused an accident in the Fukushima Daiichi nuclear power plant. Due to this accident, derived of the loss of the reactor cooling system, as well as of the prolonged absence of alternating and direct current, radiological protection actions were realized without being able to avoid the liberation of radioactive material to the atmosphere and ocean. The radiological impact of these liberations, not only in Japan but around the world, mainly in the north hemisphere of the Earth, was analyzed by means of environmental dose measurements and radionuclide concentrations in soil and water, among others. In the Mexico case, air samples data were obtained, as well as environmental dose celerity and full-length counts of the people coming from Japan near the disaster area. The present work contains the obtained results of the realized measurements in Mexico, same that have been used to make a summary and analysis of the dispersion in the environment in several countries of the world. (Author)

  17. Oil and Gas in Mexico

    OpenAIRE

    Víctor Gerardo Carreón Rodríguez; Juan Rosellón

    2012-01-01

    Mexico is a highly centralized federation. The states and municipalities are highly dependent on federal transfers and so equally at risk to the country’s fiscal dependence on oil. Although Mexico has become more truly federal since multiparty competition has become vibrant and several states are in opposition hands, the states remain very minor actors in relation to oil and gas. However, as the political system has democratized, states have had an increasing say regarding oil and gas activit...

  18. Geological and geochemical character and genesis of the Jinlongshan-Qiuling gold deposits in Qinling orogen: Metallogenic mechanism of the Qinling-pattern Carlin-type gold deposits

    Institute of Scientific and Technical Information of China (English)

    张复新,陈衍景,李超Department; of; Geology,; Peking; University,; Beijing; 100871,; China; ,张静Department; of; Geology,; Peking; University,; Beijing; 100871,; China; ,马建秦,李欣Department; of; Geology,; Peking; University,; Beijing; 100871,; China

    2000-01-01

    The Qinling Carlin-type gold deposit belt is the second largest Carlin-type gold ore concentrated area in the world and occurs in Mesozoic intracontinental collisional orogen, contrasting to the Carlin-type gold deposits in the Basin and Range province in Cenozoic active continental margin of West America. With ore-forming ages focussed at the range of 197.45-129.45 Ma, its metallogenic geodynamic background was the decornpression-pyrogenation regime at the transition stage from collisional compression to extension, indicating that gold mineralization synchronized with the Mesozoic continental collision. Geochemical studies discover that ore fluids and materials mainly came from the Hercynian-lndosinian tectonic layer. Mesozoic intracontinental subduction of Hercynian-lndosinian association along the Shuanghe-Gongguan fault led to the formation of Jinlongshan-Qiuling gold deposits. Accordingly, the tectonic metallogenic model is established for Qinling-pattern Carlin-type gold deposits.

  19. Appendix C: Summary of Major Metallogenic Belts in Northeast Asia (the Russian Far East, Yakutia, Siberia, Transbaikalia, Northern China, Mongolia, South Korea, and Japan)

    Science.gov (United States)

    Rodionov, Sergey M.; Obolenskiy, Alexander A.; Distanov, Elimir G.; Badarch, Gombosuren; Dejidmaa, Gunchin; Hwang, Duk-Hwan; Khanchuk, Alexander I.; Ogasawara, Masatsugu; Nokleberg, Warren J.; Parfenov, Leonid M.; Prokopiev, Andrei V.; Seminskiy, Zhan V.; Smelov, Alexander P.; Yan, Hongquan; Davydov, Yuriy V.V.; Fridovskiy, Valeriy Yu.; Gamyanin, Gennandiy N.; Gerel, Ochir; Kostin, Alexei V.; Letunov, Sergey A.; Li, Xujun; Nikitin, Valeriy M.; Ratkin, Vladimir V.; Shpikerman, Vladimir I.; Sudo, Sadahisa; Sotnikov, Vitaly I.; Spiridonov, Alexander V.; Stepanov, Vitaly A.; Sun, Fengyue; Sun, Jiapeng; Sun, Weizhi; Supletsov, Valeriy M.; Timofeev, Vladimir F.; Tyan, Oleg A.; Vetluzhskikh, Valeriy G.; Wakita, Koji; Yakovlev, Yakov V.; Zorina, Lydia M.

    2010-01-01

    The major purposes of this chapter are to provide (1) an overview of the regional geology, tectonics, and metallogenesis of Northeast Asia for readers who are unfamiliar with the region, (2) a general scientific introduction to the succeeding chapters of this volume, and (3) an overview of the methodology of metallogenic and tectonic analysis used in this study. We also describe how a high-quality metallogenic and tectonic analysis, including construction of an associated metallogenic-tectonic model will greatly benefit other mineral resource studies, including synthesis of mineral-deposit models; improve prediction of undiscovered mineral deposit as part of a quantitative mineral-resource-assessment studies; assist land-use and mineral-exploration planning; improve interpretations of the origins of host rocks, mineral deposits, and metallogenic belts, and suggest new research. Research on the metallogenesis and tectonics of such major regions as Northeast Asia (eastern Russia, Mongolia, northern China, South Korea, and Japan) and the Circum-North Pacific (the Russian Far East, Alaska, and the Canadian Cordillera) requires a complex methodology including (1) definitions of key terms, (2) compilation of a regional geologic base map that can be interpreted according to modern tectonic concepts and definitions, (3) compilation of a mineral-deposit database that enables a determination of mineral-deposit models and clarification of the relations of deposits to host rocks and tectonic origins, (4) synthesis of a series of mineral-deposit models that characterize the known mineral deposits and inferred undiscovered deposits in the region, (5) compilation of a series of metallogenic-belt belts constructed on the regional geologic base map, and (6) construction of a unified metallogenic and tectonic model. The summary of regional geology and metallogenesis presented here is based on publications of the major international collaborative studies of the metallogenesis and

  20. La geopolítica de México en Centro América: ¿una hegemonía regional? Mexico's geopolitics in Central America: regional hegemony?

    Directory of Open Access Journals (Sweden)

    Alberto Rocha

    2006-12-01

    analizar el Mecanismo de Diálogo y Concertación de Tuxtla-Gutiérrez y sus tres ámbitos de operación: 1. El ámbito político. 2. El ámbito del desarrollo. 3. El ámbito de la cooperación técnica regional. 4. El ámbito económico, comercial y financiero.Mexico as well as Brazil (first decade of 2000 started to release geo-economic and geo-political projections about their unmediated surroundings (their region of belonging and their mediated surroundings (their neighboring region, besides playing major political roles in their far surroundings (the Latin American and Caribbean region and their remote surroundings (the American continent. As a result, we have proposed and developed the idea that such situations and realities are those of processes of constitution of States with "sub-hegemonic" roles, with their respective functions of "sub-hegemony". We therefore ask the following question: Why are both Mexico and Brazil defining "sub-hegemonic" roles? Are such roles and functions possible within a continental space where a "superpower" exerts unquestionable "supremacy" besides seeking to redefine its "hegemony" (the one now undergoing a crisis? In order to work on the theme of Mexico's geopolitical relations with Central America, we have carried out four approximations: Mexico's current stance; historical background of the relations; process of institutionalization of cooperation; and field of action of the relations. Besides, the work is concluded with some ideas about Mexico's geopolitical view. The approximation to Mexico's structural stance in the world and in the American Continent seeks to highlight realities in its condition of semiperipheral and "sub-hegemonic" country. The historical approximation leads to the 1980s and the 1990s, when the background for Mexico's cooperation with Central America is established and that cooperation is started and strengthened. The institutional approximation, focused on the 1990s and the early 2000s, approaches the field of

  1. Resource Assessment of the In-Place and Potentially Recoverable Deep Natural Gas Resource of the Onshore Interior Salt Basins, North Central and Northeastern Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Ernest A. Mancini

    2006-09-30

    The objectives of the study were: (1) to perform resource assessment of the thermogenic gas resources in deeply buried (>15,000 ft) natural gas reservoirs of the onshore interior salt basins of the north central and northeastern Gulf of Mexico areas through petroleum system identification, characterization and modeling; and (2) to use the petroleum system based resource assessment to estimate the volume of the deep thermogenic gas resource that is available for potential recovery and to identify those areas in the interior salt basins with high potential for this thermogenic gas resource. Petroleum source rock analysis and petroleum system characterization and modeling, including thermal maturation and hydrocarbon expulsion modeling, have shown that the Upper Jurassic Smackover Formation served as the regional petroleum source rock in the North Louisiana Salt Basin, Mississippi Interior Salt Basin, Manila Subbasin and Conecuh Subbasin. Thus, the estimates of the total hydrocarbons, oil, and gas generated and expelled are based on the assumption that the Smackover Formation is the main petroleum source rock in these basins and subbasins. The estimate of the total hydrocarbons generated for the North Louisiana Salt Basin in this study using a petroleum system approach compares favorably with the total volume of hydrocarbons generated published by Zimmermann (1999). In this study, the estimate is 2,870 billion barrels of total hydrocarbons generated using the method of Schmoker (1994), and the estimate is 2,640 billion barrels of total hydrocarbons generated using the Platte River software application. The estimate of Zimmermann (1999) is 2,000 to 2,500 billion barrels of total hydrocarbons generated. The estimate of gas generated for this basin is 6,400 TCF using the Platte River software application, and 12,800 TCF using the method of Schmoker (1994). Barnaby (2006) estimated that the total gas volume generated for this basin ranges from 4,000 to 8,000 TCF. Seventy

  2. Geophysical and geochemical exploration research on basic metallogenic conditions of unconformity-related uranium deposits in the south part of Kangdian earth's axis

    International Nuclear Information System (INIS)

    In order to find out the unconformity-related large and super large uranium-rich deposits and to explore the prospecting model for the unconformity-related uranium deposits, the geophysical and geochemical exploration on the basic metallogenic conditions of the unconformity-related uranium deposits in the south part of the Kangdian earth's axis has been carried out after the investigation and research into large amounts of information in combination with the analysis and contrasts of the aeromagnetic, aero-radiometric and gravity data. On the basis of synthesizing the airborne survey information, land-based geophysical and geochemical exploration, the physical nature of many types of rocks and the multi-element analytical and determining results of the U, Th, Au, Cu in the soil samples, the geophysical prospecting models on the unconformity-related uranium deposits in this area has been put forward, and two uranium metallogenic prospect areas and one uranium metallogenic prospect belt have been divided. These results have laid a good foundation for finding out the unconformity-related uranium deposits in this area

  3. The effects of land use change on carbon content in the aerial biomass of an Abies religiosa (Kunth Schltdl. et Cham.) forest in central Veracruz, Mexico

    OpenAIRE

    M.R. Pineda Lopez; L. R. Sanchez-Velasquez; G. Vazquez-Dominguez; Rojo Alboreca, A.

    2013-01-01

    Aim of study.) Were analyzed patterns and dynamics of forest cover change and land use for the period 1995-2005, and estimated carbon content in biomass in a forest of fir (Abies religiosa).Area of study. Ejido El Conejo in the Cofre de Perote National Park, Veracruz, Mexico.Material and Methods. Spatial data (maps, orthophotographs) were used: (UTM); GRS 80 spheroid; zone 14, datum ITRF92; units: metres. Maps for 1995 and 2005 were constructed and compared. Carbon content in the aboveground ...

  4. Molecular Detection and Sensitivity to Antibiotics and Bacteriocins of Pathogens Isolated from Bovine Mastitis in Family Dairy Herds of Central Mexico

    OpenAIRE

    Ma. Fabiola León-Galván; Barboza-Corona, José E.; A. Arianna Lechuga-Arana; Mauricio Valencia-Posadas; Aguayo, Daniel D.; Carlos Cedillo-Pelaez; Erika A. Martínez-Ortega; Gutierrez-Chavez, Abner J.

    2015-01-01

    Thirty-two farms (n = 535 cows) located in the state of Guanajuato, Mexico, were sampled. Pathogens from bovine subclinical mastitis (SCM) and clinical mastitis (CLM) were identified by 16S rDNA and the sensitivity to both antibiotics and bacteriocins of Bacillus thuringiensis was tested. Forty-six milk samples were selected for their positive California Mastitis Test (CMT) (≥3) and any abnormality in the udder or milk. The frequency of SCM and CLM was 39.1% and 9.3%, respectively. Averages f...

  5. TPH and PAH concentrations in the subsoil of polyduct segments, oil pipeline pumping stations, and right-of-way pipelines from Central Mexico

    Science.gov (United States)

    Iturbe, Rosario; Castro, Alejandrina; Perez, Guillermina; Flores, Carlos; Torres, Luis G.

    2008-10-01

    For the year 1996, 366 incidents related with clandestine poaching of oil-products were reported in Mexico, 159 in 1997, and 240 in 1998. For the year 2003 (the most recently reported figure), there were 136 events. Petroleos Mexicanos (PEMEX), very concerned with the environmental agenda, has developed programs oriented to diminish contamination levels in all of its oil facilities. This work was aimed at characterizing zones around polyduct segments, pipelines, pumping stations, and right-of-way pipelines located in the center of Mexico. The TPH contaminated sites were, in decreasing order, polyduct km 39 + 150 > polyduct km 25 + 020 > Zoquital > Tepetitlan > Catalina > Venta Prieta > Ceiba. Most of the sampled points showed the presence of more than one of the 16 PAHs considered by USEPA as priority pollutants. Except point TEPE 2A, where no PAHs were detected, all the sampled points showed values from low to medium concentrations; however, values found at the sites did not exceed the limits according to the Mexican or the American legislation. The place with the largest contaminated area corresponded to the polyduct km 39 + 150, with 130 m2 and 260 m3 to be treated. The least contaminated area was that around the JUAN 4 point at Juandho station, with 20 m2 and 22 m3 of contaminated soil. The total area to be treated is about 230 m2 and 497 m3.

  6. Students and Teachers' Reasons for Using the First Language within the Foreign Language Classroom (French and English) in Central Mexico (Razones de alumnos y maestros sobre el uso de la primera lengua en el salón de lenguas extranjeras (francés e inglés) en el centro de México)

    Science.gov (United States)

    Mora Pablo, Irasema; Lengeling, M. Martha; Rubio Zenil, Buenaventura; Crawford, Troy; Goodwin, Douglas

    2011-01-01

    The present study explores the use of the first language in a context of foreign language teaching. This qualitative research presents the classroom practice and points of view of French and English teachers and students within a public educational institute in central Mexico using the techniques of questionnaires and semi-structured interviews.…

  7. Anthropogenic changes and environmental degradation in pre-Hispanic and post-Colonial periods: soil erosion modelled with WEPP during Late Holocene in Teotihuacán Valley (central Mexico)

    Science.gov (United States)

    Lourdes González-Arqueros, M.; Mendoza Cantú, Manuel E.

    2015-04-01

    Land use changes and support practices are a worldwide significant issue in soil erosion and subsequently, land degradation. Anthropogenic changes, along different periods of the history in the last 2000 years in the Valley of Teotihuacan (central Mexico), highlight that soil erosion varies depending on how the management and the intensity of soil use is handled, considering the soils as a main resource. As a part of a broader effort to reconstruct the erosion dynamics in the Teotihuacán Valley through geoarchaeological approaches, this study apply a process-based watershed hydrology and upland erosion model, Water Erosion Prediction Project (WEPP). This research aims to contribute with insights through modelling and to recreate soil erosion and sedimentation dynamics in several historical periods with different environmental and anthropogenic scenarios. The Geo-spatial interface for WEPP (GeoWEPP) was used to characterize location of detachment, depositions and erosion predicted on the profile through time, based on current and hypothetical reconstructed conditions in the watershed. Climate, topography, soil and land use were used as inputs for the WEPP model to estimate runoff fluxes, soil loss rates, and sediment delivery ratio (SDR) for three historical scenarios: current period, reconstructed Teotihuacán period (AD 1-650), and reconstructed Aztec period (AD 1325-1520). Over a simulated and stablished timeframe for those social periods, the runoff, soil loss rate and SDR were estimated to be greater during the Aztec period. We assume that in general the climate conditions for this period were wetter, compared with present, in agreement with several authors that proposed climate reconstructions for the center of Mexico. It is also highlighted that support practices were more effective in this period. The next period with higher values is the current one, and fewer rates are estimated for the Teotihuacán period. This comparison release new arguments in the

  8. Demand of natural uranium to satisfy the requirements of nuclear fuel of new nuclear power plants in Mexico; Demanda de uranio natural para satisfacer los requerimientos de combustible nuclear de nuevas centrales nucleares en Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez S, J. R.; Rios, M. del C.; Alonso, G.; Palacios H, J. [ININ, 52750 La Marquesa, Estado de Mexico (Mexico)]. e-mail: jrrs@nuclear.inin.mx

    2008-07-01

    Due to the expectation of that in Mexico new plants of nuclear energy could be installed, turns out from the interest to evaluate the uranium requirements to operate those plants and to also evaluate if the existing reserves in the country could be sufficient to satisfy that demand. Three different scenes from nuclear power plant expansion for the country are postulated here that are desirable for the diversification of generation technologies. The first scene considers a growth in the generation by nuclear means of two reactors of type ABWR that could enter operation by years 2015 and 2020, in the second considers the installation of four reactors but as of 2015 and new every 5 years, in the scene of high growth considers the installation of 6 reactors of the same type that in the other scenes, settling one every three years as of 2015. The results indicate that the uranium reserves could be sufficient to only maintain in operation to one of the reactors proposed by the time of their useful life. (Author)

  9. Egade, Mexico.

    Science.gov (United States)

    Kubany, Elizabeth

    2001-01-01

    Presents a business school design in Mexico, whose spiral building sits atop a parking structure creating a compact, symbolic form for an arid urban landscape. Includes seven photographs, a floor plan, and sectional drawing. (GR)

  10. Gulf of Mexico sales 147 and 150: Central and western planning areas. Draft environmental impact statement. Volume 2. Sections IV.D through IX. Draft report

    International Nuclear Information System (INIS)

    Contents: environmental impacts of the proposed actions and alternatives; proposed central gulf sale 147; proposed western gulf sale 150; analysis of a large oil spill; consultation and coordination; bibliography and special references; glossary; appendices

  11. 青海省东昆仑成矿带铁矿成矿规律与找矿方向研究%Metallogenic Law and Prospect Direction of Iron Deposits in the East Kunlun Metallogenic Belt in Qinghai

    Institute of Scientific and Technical Information of China (English)

    许长坤; 王红英; 张文君; 乔强; 刘世宝; 赵子基; 张梅芬; 张开成; 刘建华; 詹发余; 黄朝晖; 张钟月

    2012-01-01

    The East Kunlun metallogenic belt, located in the binding part between the south mobile belt of Xiyu block and South China block, belongs to the Kunlun suture belt of Qilian-Qinling suture system. It consists of three regional deep-seated faults trending from near EW to NWW in the south, middle and north of the Kunlun basin, and forms a complicated structure of this belt. Hence, three tectonic metallogenic units were divided: the north, middle and south belt of East Kunlun. All three fractures are the long-lived regional deep fractures cutting through the earth's crust or lithosphere, which not only form the boundary of each geologic unit but control the distribution of magmatic rock, uplifting of East Kunlun, sedimentary basins and formation of depression zone. Along with secondary NW-, NNW- and NE-trending faults, the three fractures cut strata of different era and some rock masses into fault blocks on various scales. Therefore, the fracture structures of different levels, which can be storage space for ore, provide excellent migration passages and occurrence space for formation of various ore deposits. The strata in the region were formed mainly in Precambrian, Ordovician-Silurian, Carboniferous-Permian, Triassic and Cenozoic Era. As for regional distribution, the outcrops in the middle and northern Kunlong belts are similar while there is significant difference between the south belt and other two belts. Magmatic activities were very strong and frequent, and are distributed extensively in fault-uplift zone of the north slope of Kunlun Mountain as well as the Qimantage region, with the famous granite belt formed in the major ridge of Kunlun mountain and small amount of intermediate-acid intrusive rocks exposed in the south slope. Lithological characters are shown as mafic, ultramafice and acid. The main active periods are Caledonian and Variscan, followed by Indosinian and Yanshanian, with minor mafic and ultramafic exhalative activities existing in Xingkai and

  12. Consideraciones e importancia social en torno al cultivo del frijol en el centro de México Considerations and social importance of the bean crop in central Mexico

    Directory of Open Access Journals (Sweden)

    Dora Ma. Sangerman-Jarquín

    Full Text Available En México, el grano de frijol por su alto contenido de proteína es básico para la alimentación de su población; ocupa el segundo lugar en importancia nacional después del maíz. La producción de las leguminosas, principalmente el frijol ha disminuido una tasa de 3.2%, con respecto a un crecimiento de población más rápido que la producción. El frijol es una leguminosa que constituye una fuente de proteínas e hidratos de carbono natural; además es abundante en vitamina B como: niacina, ácido fólico y tianina; también proporciona hierro, cobre, zinc, fósforo, potasio, magnesio y calcio, contiene un alto contenido de fibra. Existen múltiples variedades de frijol que se caracterizan por su tamaño, color, forma y tipo de crecimiento. Se considera que en total existen 70 especies; en México estás ascienden a 50, destacan cinco especies que se han domesticado Phaseolus vulgaris L. (frijol común, Phaseolus coccineus L. (frijol ayocote, Phaseolus lunatus L. (frijol comba, Phaseolus dumosus (frijol gordo y Phaseolus acutifolius Gray (frijol tepari. En México se cultivan cerca de 70 variedades, de acuerdo a la norma son: negros, pintos, bayos, amarillos y rosados. El cultivo del frijol presenta características propias y definidas en el marco de la soberanía alimentaria, en virtud de que representa un alimento principal para la población rural y urbana. El programa de mejoramiento genético de frijol del Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias (INIFAP del Campo Experimental Valle de México (CEVAMEX, ha contribuido en gran medida en generar la tecnología necesaria para que el país alcance la autosuficiencia alimentaria sostenida en este cultivo. Esta tecnología incluye la liberación de variedades con mayor capacidad de rendimiento y mejor calidad alimentaria y culinaria.In Mexico, common bean is an essential component in the diet of the population due to its high protein content; it ranks second

  13. Increase in surface runoff in the central mountains of Mexico: lessons from the past and predictive scenario for the next century

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    N. Gratiot

    2009-11-01

    Full Text Available The hydrological response of a medium scale mountainous watershed (Mexico is analysed over half a century. The hydrograph separation highlights an increasing surface runoff contribution since the early 1970's. This increase is attributed to land use changes while the meteorological forcing (rains remains statistically stable over the same period. As a consequence, the intensity of annual extreme floods has tripled up over the period of survey, increasing flood risks in the region. The paper ends with a climatic projection over the 21st century. The decrease of precipitation and the increase of temperature should accentuate the trend engaged since the 1970's by reducing groundwater resources and increasing surface-runoff and associated risks.

  14. The effects of land use change on carbon content in the aerial biomass of an Abies religiosa (Kunth Schltdl. et Cham. forest in central Veracruz, Mexico

    Directory of Open Access Journals (Sweden)

    M.R. Pineda Lopez

    2013-04-01

    Full Text Available Aim of study. Were analyzed patterns and dynamics of forest cover change and land use for the period 1995-2005, and estimated carbon content in biomass in a forest of fir (Abies religiosa.Area of study. Ejido El Conejo in the Cofre de Perote National Park, Veracruz, Mexico.Material and Methods. Spatial data (maps, orthophotographs were used: (UTM; GRS 80 spheroid; zone 14, datum ITRF92; units: metres. Maps for 1995 and 2005 were constructed and compared. Carbon content in the aboveground biomass of fir (Abies religiosa was estimated using an equation specific to species.Main results. After one decade, the forested area had increased slightly (0.25%. The main type of land cover change was from shrubland to forest (probability of change 0.41; the change from forestland to shrubland with trees was 0.05%, and from forest to agriculture was 0.02%. Data from 2008 confirmed that the A. religiosa forest located in the ejido is distributed in largely unconnected fragments, of which some have a high density of young trees. Estimated carbon content in the aboveground biomass (163.51 Mg ha-1 was higher than that estimated for other forests of the same species in Mexico.Research highlights. It is recommended that ecological corridors be established throughout the reforested area, in order to connect these fragments (and increase carbon sequestration and favour faunal and floral conservation. Finally, recognition should be given to the high vulnerability of A. religiosa forests to climate change, given their high degree of fragmentation and critical altitudinal limit.Key words: Aboveground biomass; carbon storage; ecological corridors; fir forest.

  15. The effects of land use change on carbon content in the aerial biomass of an Abies religiosa (Kunth Schltdl. et Cham.) forest in central Veracruz, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Pineda-Lopez, M. R.; Sanchez-Velasquez, L. R.; Vazquez-Dominguez, G.; Rojo-Alboreca, A.

    2013-05-01

    Aim of study.) Were analyzed patterns and dynamics of forest cover change and land use for the period 1995-2005, and estimated carbon content in biomass in a forest of fir (Abies religiosa). Area of study. Ejido El Conejo in the Cofre de Perote National Park, Veracruz, Mexico. Material and Methods. Spatial data (maps, ortho photographs) were used: (UTM); GRS 80 spheroid; zone 14, datum ITRF92; units: metres. Maps for 1995 and 2005 were constructed and compared. Carbon content in the aboveground biomass of fir (Abies religiosa) was estimated using an equation specific to species. Main results. After one decade, the forested area had increased slightly (0.25%). The main type of land cover change was from shrubland to forest (probability of change 0.41); the change from forestland to shrubland with trees was 0.05%, and from forest to agriculture was 0.02%. Data from 2008 confirmed that the A. religiosa forest located in the ejido is distributed in largely unconnected fragments, of which some have a high density of young trees. Estimated carbon content in the aboveground biomass (163.51 Mg ha-1) was higher than that estimated for other forests of the same species in Mexico. Research highlights. It is recommended that ecological corridors be established throughout the reforested area, in order to connect these fragments (and increase carbon sequestration) and favour faunal and floral conservation. Finally, recognition should be given to the high vulnerability of A. religiosa forests to climate change, given their high degree of fragmentation and critical altitudinal limit. (Author) 55 refs.

  16. Research on information model for metallogenic specialization of the intermediate-acid magmatic rocks in nanling region: a case of hydrothermal uranium deposit and hydrothermal tungsten and tin deposit

    International Nuclear Information System (INIS)

    Based on geochemistry analysis data of Nanling granite massifs, according to the granite hydrothermal mineralization principle, the article initially proposes the metallogenic specialization factor group target system using GIS geo-information model, establishes metallogenic specialization information model of the uranium and the tungsten mineral intrusions. According to mineralization granite rock element geochemical behavior and magmatic evolution, the paper suggests the measure that metallogenic specialization influence factor will divided into the acidity factor group, the alkalinity factor group, magmatic fractionation factor group, oxidation reduction factor group, rare-earth element factor group, source area factor group, geostructure environment factor group and so on. The paper selects the best factor group meeting the mechanism of mineralization geological and geochemical principles by using kind of statistical analysis model analyses the space and intrinsic relations of some factor. On the basis of the above aspects, it forecasts undistinguished granite massifs by using the model and the criterion. The result accords with geological fact, indicates that metallogenic specialization information model has objectivity and operability, realizes metallogenic specialization quantitative appraisal, and provides a scientific basis further distinguished the ore-bearing granite massifs. (authors)

  17. Mixed volcanogenic-lithogenic sources for Permian bauxite deposits in southwestern Youjiang Basin, South China, and their metallogenic significance

    Science.gov (United States)

    Yu, Wenchao; Algeo, Thomas J.; Du, Yuansheng; Zhang, Qilian; Liang, Yuping

    2016-07-01

    Bauxite deposits at the base of the Upper Permian Heshan Formation in the Youjiang Basin, South China, contain zircons with dominant age peaks at 263-262 Ma. During the Middle to Late Permian, the Youjiang Basin consisted of a number of isolated and attached carbonate platforms separated by inter-platform troughs. The bauxite deposits are limited to the isolated carbonate platform facies and are not present on attached carbonate platforms and inter-platform troughs. Discriminant plots based on the trace element composition of the zircons indicate a combination of within-plate/anorogenic and arc-related/orogenic sources. Geochemical and isotopic data suggest that the metallogenic materials of the bauxite deposit came from felsic volcanic rocks of the Emeishan Large Igneous Provence (ELIP) in South China and from the Truong Son volcanic arc located between the South China and Indochina cratons. The northwestern and southeastern parts of the Youjiang Basin received larger amounts of ELIP detritus and volcanic arc detritus, respectively. Coarser siliciclastic material in proximal attached carbonate platform and inter-platform trough settings was delivered by rivers, but finer siliciclastics that accumulated on distally located carbonate platforms in isolated deep-water areas was probably transported by wind.

  18. Endohelminth parasites of seven goodein species (Cyprinodontiformes: Goodeidae from Lake Zacapu , Michoacán, Central Mexico Plateau Endohelmintos parásitos de siete especies de godeinos (Cyprinodontiformes: Goodeidae del lago de Zacapu, Michoacán, en la Mesa Central de México

    Directory of Open Access Journals (Sweden)

    Andrés Martínez-Aquino

    2012-04-01

    Full Text Available A total of 11 parasitic endohelminth taxa were found in 7 freshwater fish species of the subfamily Goodeinae in Zacapu Lake, Michoacan, Mexico. Six were adults (Margotrema cf. bravoae, Phyllodistomum sp., Saccocoelioides sogandaresi, Rhabdochona lichtenfelsi, Bothriocephalus acheilognathi and Caryophillidae gen. sp., while the remaining 5 taxa (Clinostomum complanatum, Posthodiplostomum minimum, Tylodelphis sp., Eustrongylides sp. and Polymorphus brevis were larvae. The taxa S. sogandaresi, Tylodelphis sp., and R. lichtenfelsi reached the highest levels of prevalence and mean abundance among all hosts, while the cestodes B. acheilognathi and Caryophillidae gen. sp. showed the lowest values. This study contributes with the inventory of the freshwater fish helminth fauna in Central Mexico Plateau, and particularly with the previous work that has been done with Goodeinae, a subfamily of freshwater fishes endemic to that part of the country.En este trabajo se registran 11 taxa de helmintos endoparásitos de 7 especies de peces de la subfamilia Goodeinae del lago de Zacapu, Michoacán, en la mesa central de México. Seis taxa se registraron en estado adulto (Margotrema cf. bravoae, Phyllodistomum sp., Saccocoelioides sogandaresi, Rhabdochona lichtenfelsi, Bothriocephalus acheilognathi y Caryophillidae gen. sp., en tanto que los 5 restantes correspondieron a larvas (Clinostomum complanatum, Posthodiplostomum minimum, Tylodelphys sp. y Eustrongylides sp. y Polymorphus brevis. Los taxa S. sogandaresi, Tylodelphis sp. y R. lichtenfelsi presentaron los valores más altos de prevalencia y abundancia en los peces estudiados, mientras que los céstodos B. acheilognathi y Caryophillidae gen. sp. presentaron los valores más bajos. Este estudio contribuye al inventario de la fauna helmintológica de peces de agua dulce de la mesa central de México y en particular al que ha sido realizado con Goodeinae, una subfamilia de peces dulceacuícolas endémica de esa

  19. Molecular detection and sensitivity to antibiotics and bacteriocins of pathogens isolated from bovine mastitis in family dairy herds of central Mexico.

    Science.gov (United States)

    León-Galván, Ma Fabiola; Barboza-Corona, José E; Lechuga-Arana, A Arianna; Valencia-Posadas, Mauricio; Aguayo, Daniel D; Cedillo-Pelaez, Carlos; Martínez-Ortega, Erika A; Gutierrez-Chavez, Abner J

    2015-01-01

    Thirty-two farms (n = 535 cows) located in the state of Guanajuato, Mexico, were sampled. Pathogens from bovine subclinical mastitis (SCM) and clinical mastitis (CLM) were identified by 16S rDNA and the sensitivity to both antibiotics and bacteriocins of Bacillus thuringiensis was tested. Forty-six milk samples were selected for their positive California Mastitis Test (CMT) (≥3) and any abnormality in the udder or milk. The frequency of SCM and CLM was 39.1% and 9.3%, respectively. Averages for test day milk yield (MY), lactation number (LN), herd size (HS), and number of days in milk (DM) were 20.6 kg, 2.8 lactations, 16.7 animals, and 164.1 days, respectively. MY was dependent on dairy herd (DH), LN, HS, and DM (P Brevibacterium stationis, B. conglomeratum, and Staphylococcus agnetis. Bacterial isolates were resistant to penicillin, clindamycin, ampicillin, and cefotaxime. Bacteriocins synthesized by Bacillus thuringiensis inhibited the growth of multiantibiotic resistance bacteria such as S. agnetis, S. equorum, Streptococcus uberis, Brevibacterium stationis, and Brachybacterium conglomeratum, but they were not active against S. sciuri, a microorganism that showed an 84% resistance to antibiotics tested in this study. PMID:25815326

  20. Molecular Detection and Sensitivity to Antibiotics and Bacteriocins of Pathogens Isolated from Bovine Mastitis in Family Dairy Herds of Central Mexico

    Directory of Open Access Journals (Sweden)

    Ma. Fabiola León-Galván

    2015-01-01

    Full Text Available Thirty-two farms (n=535 cows located in the state of Guanajuato, Mexico, were sampled. Pathogens from bovine subclinical mastitis (SCM and clinical mastitis (CLM were identified by 16S rDNA and the sensitivity to both antibiotics and bacteriocins of Bacillus thuringiensis was tested. Forty-six milk samples were selected for their positive California Mastitis Test (CMT (≥3 and any abnormality in the udder or milk. The frequency of SCM and CLM was 39.1% and 9.3%, respectively. Averages for test day milk yield (MY, lactation number (LN, herd size (HS, and number of days in milk (DM were 20.6 kg, 2.8 lactations, 16.7 animals, and 164.1 days, respectively. MY was dependent on dairy herd (DH, LN, HS, and DM P<0.01, and correlations between udder quarters from the CMT were around 0.49 P<0.01. Coagulase-negative staphylococci were mainly identified, as well as Staphylococcus aureus, Streptococcus uberis, Brevibacterium stationis, B. conglomeratum, and Staphylococcus agnetis. Bacterial isolates were resistant to penicillin, clindamycin, ampicillin, and cefotaxime. Bacteriocins synthesized by Bacillus thuringiensis inhibited the growth of multiantibiotic resistance bacteria such as S. agnetis, S. equorum, Streptococcus uberis, Brevibacterium stationis, and Brachybacterium conglomeratum, but they were not active against S. sciuri, a microorganism that showed an 84% resistance to antibiotics tested in this study.

  1. Evolution of the 2014-2015 sea surface temperature warming in the central west coast of Baja California, Mexico, recorded by remote sensing

    Science.gov (United States)

    Robinson, Carlos J.

    2016-07-01

    Extraordinarily warm sea surface temperatures were present in the California Current System during 2014-2015. In several locations surface waters temperature registered new record high in the recent time series. This study focuses in the evolution of the warming in the southern part of the California Current System (CCS), off the west coast of Baja California, Mexico. Analysis of monthly sea surface temperature (SST), sea level pressure, and wind speed as measured by satellite from January 1988 to December 2015 show that recent warming occurred during two distinct periods. From May 2014 to April 2015, SST warming was related to weak coastal winds not associated to El Niño. During this period occurred the longest sustained record of 15 months of negative wind anomalies in the series. A reduction of wind stress suggests a weakened coastal upwelling, and consequently, cold water not transported into the surface. The second process of warming occurred from September to December 2015, during a strong El Niño condition.

  2. EXECUTIVE SUMMARY OF STATE DATA RELATED TO ABANDONED CENTRALIZED AND COMMERCIAL DRILLING-FLUID DISPOSAL SITES IN LOUISIANA, NEW MEXICO, OKLAHOMA, AND TEXAS

    Energy Technology Data Exchange (ETDEWEB)

    H. Seay Nance

    2003-03-01

    This 2003 Spring Semi-Annual Report contains a summary of the Final Technical Report being prepared for the Soil Remediation Requirements at Commercial and Centralized Drilling-Fluid Disposal (CCDD) Sites project funded by the United States Department of Energy under DOE Award No. DE-AC26-99BC15225. The summary describes (1) the objectives of the investigation, (2) a rationale and methodology of the investigation, (3) sources of data, assessment of data quality, and data availability, (4) examples of well documented centralized and commercial drilling-fluid disposal (CCDD) sites and other sites where drilling fluid was disposed of, and (5) examples of abandoned sites and measures undertaken for their assessment and remediation. The report also includes most of the figures, tables, and appendices that will be included in the final report.

  3. Middle to late cenozoic magmatism of the southeastern Colorado plateau and central Rio Grande rift (New Mexico and Arizona, U.S.A.) : a model for continental rifting

    Science.gov (United States)

    Baldridge, W.S.; Perry, F.V.; Vaniman, D.T.; Nealey, L.D.; Leavy, B.D.; Laughlin, A.W.; Kyle, P.; Bartov, Y.; Steinitz, G.; Gladney, E.S.

    1991-01-01

    The region of the present Rio Grande rift and southeastern Colorado Plateau underwent lithospheric extension during middle to late Cenozoic deformation affecting the entire southwestern U.S. Lithospheric mantle was disrupted, and in many regions displaced or replaced by asthenospheric mantle at depths from which basaltic magmas were derived and erupted to the surface. Study of the igneous rocks erupted or intruded during this deformation yields insights into processes of magmatism associated with extension of continental lithosphere. Magmatic rocks associated with an early (late Oligocene-early Miocene) ductile phase of extension are dominantly basaltic andesites and related, calc-alkaline intermediate to silicic derivative rocks. Mafic magmas were probably derived from isotopically "enriched" lithospheric mantle. Igneous rocks associated with a later (middle Miocene-Holocene), more brittle phase of extension include widespread basaltic rocks and localized central volcanoes of intermediate to silicic composition. Isotopic compositions of mafic rocks, which include both tholeiitic and alkalic basalts, correlate strongly with tectonic setting and lithospheric structure. Basalts erupted in areas of greatest crustal extension, such as the central and southern rift and Basin and Range province, were derived from isotopically "depleted" (correlated with "asthenospheric") mantle. Also, isotopic compositions of Pliocene to Holocene basalts are slightly more depleted than those of Miocene basalts, suggesting that subcrustal lithospheric mantle was thinned during late Miocene extension. Intermediate rocks of the central volcanoes formed by a complex combination of processes, probably dominated by fractional crystallization and by assimilation of upper and lower crust in isolated, small magma chambers. The petrologic, geochemical, and isotopic data are compatible with a model, derived first from geophysical data, whereby lithosphere is thinned beneath the central rift and

  4. the case of Mexico

    Directory of Open Access Journals (Sweden)

    D. Martínez Carrera

    2005-01-01

    Full Text Available Food products require efficient marketing systems to move from producers to consumers keeping high quality and price. In many developing countries, although mushroom production is well established and increasing, the marketing systems are poorly understood. During 1999-2004, we studied the channels of distribution for wild and cultivated mushrooms in central Mexico following an institutional approach (550 interviews. Most wild and cultivated mushrooms are marketed within this region. Representative places were selected for this study: a large city (Mexico, two medium cities (Puebla, Toluca, and a rural community (Cuetzalan. Several marketing channels were identified and described, involving middlemen, wholesalers, retailers, “tianguis”, public markets, retail food stores, and food services. The grower’s share, the gatherer’s share, and the mushroom marketing margin were also estimated. The present mushroom marketing system evolved from a small centralized process to a combination of centralized and decentralized marketing processes involving limited activities. During this series of changes, large private enterprises took over several marketing functions supporting the decentralization process, but discouraging the development of new firms specialized in mushroom marketing and processing. At the same time, changes also led to the market concentration of open-market sales in large private enterprises and functional wholesalers. Main structure, organization and trends of the Mexican mushroom marketing system are discussed.

  5. Crustal structure and geodynamics of the Middle and Lower reaches of Yangtze metallogenic belt and neighboring areas: Insights from deep seismic reflection profiling

    Science.gov (United States)

    Lü, Qingtian; Shi, Danian; Liu, Zhendong; Zhang, Yongqian; Dong, Shuwen; Zhao, Jinhua

    2015-12-01

    A 300 km long seismic reflection profile was acquired across the Middle and Lower Reaches of the Yangtze River (MLY) metallogenic belt and its adjacent areas. The objective of the survey was to establish the deep architecture and geodynamic framework of the region. Results based on the interpretation of the deep seismic data include (1) Tan-Lu fault appears as a subvertical thrust fault or transpression fault with its deep portion dipping toward the southeast; (2) the Zhangbaling uplift is squeezed out along this fault; (3) complex upper crustal deformation structures beneath the Chuquan depression include both kink bands, thrusts, imbrication and fold structures reflecting contraction deformation, and detachment fault and normal-fault structures reflecting extensional deformation; (4) the "crocodile" reflection structure emerging beneath the Tan-Lu fault and Ningwu-Lishui volcanic basin, which represents the decoupled deformation process of the upper and lower crust associated with intra-continental subduction; (5) further to the southeast, the upper crust deformation shows a large-scale "wave-form" pattern, making crustal scale syncline and anticline; (6) the entire section of the reflection Moho is clearly discernible at depth of 30.0-34.5 km, and the Moho beneath the Middle and Lower Reaches of Yangtze River metallogenic belt is shallowest, while the Moho beneath the North China block is deeper than that beneath the Yangtze block. The Moho offsets could be seen beneath the Ningwu volcanic basin. The seismic reflection data suggest that lithosphere delamination and asthenosphere upwelling that may result from the Mesozoic intra-continental orogenesis is responsible for the formation of large scale magmatism and mineralization in the MLY metallogenic belt.

  6. Differences in plant cover and species composition of semiarid grassland communities of Central Mexico and its effects on net ecosystem exchange

    Directory of Open Access Journals (Sweden)

    J. Delgado-Balbuena

    2012-12-01

    Full Text Available Changes in land use across the semiarid grasslands of Northern Mexico have driven a decline of plant cover and alteration of plant species composition. A number of different plant communities have resulted from these changes, however, their implications on the carbon cycle and regional carbon balance are still poorly understood. Here, we examined the effects of plant cover loss and changes in species composition on net ecosystem CO2 exchange (NEE and their biotic and abiotic controls. Five typical plant community types were examined in the semiarid grassland by encasing the entire above-ground ecosystem using the geodesic dome method. Sites included an oat crop (crop, a moderately grazed grassland (moderate grazing, a 28 yr-old grazing exclosure (exclosure, an overgrazed site with low perennial grass cover (overgrazed, and an overgrazed site presenting shrub encroachment (shrub encroachment. For natural vegetation, rates of daytime NEE for sites with a high plant cover (exclosure and moderate grazing were similar (P>0.05 as compared to sites with low plant cover (overgrazed and shrub encroachment. However, night time NEE (carbon loss was more than double (P<0.05 for sites with high plant cover compared to sites with low cover, resulting into slight C sinks for the low plant cover sites and neutral or sources for the high plant cover sites on an annual basis. Differences in plant cover and its associated biomass defined the sensitivity to environmental controls. Thus, daytime NEE in low plant cover sites reached light compensation points at lower PPFD values than those from high plant cover sites. Differences in species composition did not influence NEE rates even though there were transient or permanent changes in C3 vs. C4 functional groups.

  7. Age of the Katugin Ta-Nb ore deposit (Aldan-Stanovoy shield): the problem of distinguishing of new global rare-metal metallogenic epoch

    International Nuclear Information System (INIS)

    The age of zircons, separated from the Katugin complex granites, is determined through the U-Pb-dating method. It is shown that the age evaluation of 2066 ± 6 mln years, obtained with an account of the zircon morphological peculiarities proving its magmatic origin, should be considered as the above granites crystallization age and in the first approximation as the age evaluation of the Katugin deposit and a number of other rare-metal deposits; it is noted that there are all reasons foe separating the new rare-metal metallogenic epoch with the age of approximately 2.05-2.2 billion years

  8. SHRIMP zircon U-Pb dating of the intrusives in the Tongling metallogenic cluster and its dynamic setting

    Institute of Scientific and Technical Information of China (English)

    WU GanGuo; ZHANG Da; DI YongJun; ZANG WenShuan; ZHANG XiangXin; SONG Biao; ZHANG ZhongYi

    2008-01-01

    This paper selected five typical Mesozoic intrusives from the Tongling metallogenic cluster (Xiaotongguanshan,Fenghuangshan,Xinqiao,Dongguashan,and Shatanjiao plutons),and made a systemic SHRIMP zircon U-Pb dating for the five plutons,which produced an age range of 151.8±2.6-1 42.8±1.8 Ma.This work put an accurate constraint on the formation age of the intrusives in the Tongling metallogenic cluster.These age data indicate that magmatic activity reached a peak during Late Jurassic.The intrusive sequence of magma is generally from quartz monzonite(porphyry)through monzonite to granodiorite to quartz monzodiorite to pyroxene monzodiorite to gabbro-diabase.The intrusives of different lithology differed in crystallization age,probably implying the intrusives in the Tongling area underwent an evolutional process of magma,which was closely related to geodynamical setting in the depths of the area.A dynamic model was presented for the origin of the igneous rocks in the study area as follows.The assembly between the Yangtze craton and the North China craton finished at the end of T3,and then the stage of another compressional orogeny began in the Tongling area,i.e.,Pacific dynamic system.Along with the subduction of the Izanagi plate underneath the Eurasian plate at J2-J3,NW-trending compression toward the East China continent was produced,and compressional deformation also took place,forming NE-trending fold and resulting in thickening of the crust in the Tongling area.High-density eclogite-facies rocks were produced in the low part of the crust,resulting in the delamination of mantle lithosphere and lower crust,and upwelling of materials in asthenosphere.Decompression melting produced basaltic magma,and the materials in lower crust were heated by the underplating of the basaltic magma.Thus,melting of lower crust yielded granitic magma,which intruded along deep and large faults through various geological processes(J3-K1).The SHRIMP U-Pb zircon age of 151.8±2

  9. SHRIMP zircon U-Pb dating of the intrusives in the Tongling metallogenic cluster and its dynamic setting

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This paper selected five typical Mesozoic intrusives from the Tongling metallogenic cluster (Xiaotongguanshan, Fenghuangshan, Xinqiao, Dongguashan, and Shatanjiao plutons), and made a systemic SHRIMP zircon U-Pb dating for the five plutons, which produced an age range of 151.8±2.6- 142.8±1.8 Ma. This work put an accurate constraint on the formation age of the intrusives in the Tongling metallogenic cluster. These age data indicate that magmatic activity reached a peak during Late Jurassic. The intrusive sequence of magma is generally from quartz monzonite (porphyry) through monzonite to granodiorite to quartz monzodiorite to pyroxene monzodiorite to gabbro-diabase. The intrusives of different lithology differed in crystallization age, probably implying the intrusives in the Tongling area underwent an evolutional process of magma, which was closely related to geodynamical setting in the depths of the area. A dynamic model was presented for the origin of the igneous rocks in the study area as follows. The assembly between the Yangtze craton and the North China craton fini- shed at the end of T3, and then the stage of another compressional orogeny began in the Tongling area, i.e., Pacific dynamic system. Along with the subduction of the Izanagi plate underneath the Eurasian plate at J2-J3, NW-trending compression toward the East China continent was produced, and compres- sional deformation also took place, forming NE-trending fold and resulting in thickening of the crust in the Tongling area. High-density eclogite-facies rocks were produced in the low part of the crust, re- sulting in the delamination of mantle lithosphere and lower crust, and upwelling of materials in as- thenosphere. Decompression melting produced basaltic magma, and the materials in lower crust were heated by the underplating of the basaltic magma. Thus, melting of lower crust yielded granitic magma, which intruded along deep and large faults through various geological processes (J3-K1). The

  10. Mexico's Oxbridge.

    Science.gov (United States)

    Haussman, Fay

    1979-01-01

    For 400 years the National Autonomous University of Mexico has remained at the hub of the country's intellectual and political life. The history of the University from the Mayas and the Aztecs, University expansion, upward mobility of students, and student pressure groups and politics are described. (MLW)

  11. Juvenile Justice in Mexico

    OpenAIRE

    Martha Frías Armenta; Livier Gómez Martínez

    2014-01-01

    The first tribunal in Mexico was established in the central state of San Luis Potosi in 1926. The Law Regarding Social Prevention and Juvenile Delinquency for the Federal District and Mexican territories was promulgated in 1928. In 2005, Article 18 of the Mexican Constitution was modified to establish a comprehensive system (“Sistema Integral de justicia†in Spanish) of justice for juveniles between 12 and 18 years old who had committed a crime punishable under criminal law. Its objective ...

  12. Pb-Pb and U-Pb zircon ages of archean syntetocnic granites of the Carajas metallogenic province, northern Brazil

    International Nuclear Information System (INIS)

    The Carajas Metallogenic Province is located in the southeastern Amazonian Craton. It has been divided in two domains, the southernmost comprises the Rio Maria region and the northernmost corresponds to Caraj region (Souza et al. 1996). The former domain is made up of Archean greenstone sequences (2,97 Ga), TTG (2,9 Ga) and calc-alkaline granitoids (2,87 Ga) (Macambira and Lafon 1995, Leite et al. 1999, Althoff et al. 2000). The Carajas block is constituted of minor mafic granulites (3,00 Ga) and quartzofeldspathic gneisses (2,81 Ga), metavolcanosedimentary sequences (2,76 Ga) and granites (2,76 to 2,56 Ga) (Machado et al. 1991; Huhn et al. 1999, Pidgeon et al. 2000). Widespread anorogenic A-type granites are found in both areas (Docegeo 1988; Dall'Agnol et al. 1994). In the last two decades several authors (Lindenamyer et al. 1994, Barros and Barbey 1998, Huhn et al. 1999 and others) have emphasized the role of the Archean granite magmatism in the tectonicthermal evolution in the Carajas Province. In this paper we discuss the tectonic significance of the Pb- Pb and U-Pb ages obtained in some granitoids from the Carajas region. The Estrela Granite Complex and the granitoids located to the north of Parauapebas were dated by Pb- Pb evaporation zircon method (cf. Kober 1987). Data are presented considering 2σ∼. The Pb corrections have been done in the basis of the evolution model of Pb in double stage (cf. Stacey and Kramers 1975). U-Pb zircon method (cf. Krogh 1973, Stacey and Kramers 1975, Parrish 1987, Ludwuig 1999), recently put on routine in the Para-Iso laboratories, was employed to date the granite from the Serra do Rabo area. Analyses were carried on the Finnigan Mat 262 spectrometer (au)

  13. Clastic metasediments of the Early Proterozoic Broken Hill Group, New South Wales, Australia: Geochemistry, provenance, and metallogenic significance

    Science.gov (United States)

    Slack, J.F.; Stevens, B.P.J.

    1994-01-01

    Whole-rock analyses of samples of pelite, psammite, and psammopelite from the Early Proterozoic Broken Hill Group (Willyama Supergroup) in the Broken Hill Block, New South Wales, Australia, reveal distinctive geochemical signatures. Major-element data show high Al2O3 and K2O, low MgO and Na2O, and relatively high Fe2O3T MgO ratios, compared to average Early Proterozoic clastic metasediments. High field strength elements (HFSE) are especially abundant, including Nb (most 15-27 ppm), Ta (most 1.0-2.2 ppm), Th (17-36 ppm), Hf (4-15 ppm), and Zr (most 170-400 ppm); Y (33-74 ppm) is also high. Concentrations of ferromagnesian elements are generally low (Sc = Broken Hill Group by the erosion mainly of felsic igneous (or meta-igneous) rocks. High concentrations of HFSE, Y, and REEs in the metasediments suggest a provenance dominanted by anorogenic granites and(or) rhyolites, including those with A-type chemistry. Likely sources of the metasediments were the rhyolitic to rhyodacitic protoliths of local quartz + feldspar ?? biotite ?? garnet gneisses (e.g., Potosi-type gneiss) that occur within the lower part of the Willyama Supergroup, or chemically similar basement rocks in the region; alternative sources may have included Early Proterozoic anorogenic granites and(or) rhyolites in the Mount Isa and(or) Pine Creek Blocks of northern Australia, or in the Gawler craton of South Australia. Metallogenic considerations suggest that the metasediments of the Broken Hill Block formed enriched source rocks during the generation of pegmatite-hosted deposits and concentrations of La, Ce, Nb, Ta, Th, and Sn in the region. Li, Be, B, W, and U in pegmatite minerals of the district may have been acquired during granulite-facies metamorphism of the local metasediments. ?? 1994.

  14. Perspective and resource evaluation and metallogenic studies on sandstone-type uranium deposit in Qianjiadian depression of Songliao Basin

    International Nuclear Information System (INIS)

    The geotectonic evolution history of the southeastern part of Songliao Basin has been clearly described and it is pointed out that both of the provenance rocks and evolution features of the studied area are favorable to the formation of U-rich sandstone bodies, development of interlayered oxidation and providing uranium source for mineralization. Yaojia Formation in Qianjiadian depression has been found out to be the favorable target ore bed for looking for sandstone-type uranium deposit. On the basis of analysis of metallogenetic conditions, the perspective target area has been circled and a sandstone-type uranium deposit with a certain amounts of uranium tonnages has been discovered. The achievements and data have been gotten in the following aspects: constitution and features of ore-forming beds and sandstone bodies, uranium existence forms and mineralogical and chemical compositions of the ores, associated elements and their economic values for comprehensive mining. The study of metallogenetic features and mechanism of the uranium deposit suggested that pre-enrichment of uranium during the depositional-diagenetic stage provide a good basis for uranium mineralization, and hereafter interlayered oxidation as well as oil-gas reduction processes played a decisive role to uranium mineralization. U-Pb isotopic studies indicate that the ores have two isochron ages of 53±3 Ma and 7.0±0 Ma, corresponding to the periods of arid and semiarid paleo-climates which are favorable to interlayered oxidation development and uranium mineralization. It is concluded that the Qianjiadian sandstone-type uranium deposit is genetically related to interlayered oxidation and secondary reduction of oil-gas. The metallogenic model of Qianjiadian uranium deposit was set up. (authors)

  15. Tracking recent climate and anthropogenic change in Central America in sediments form the lower fan of the Rio Yaqui, Gulf of California, Mexico

    Science.gov (United States)

    Aiello, I. W.; Ravelo, A. C.; Moraes, R.; Swarzenski, P. W.

    2015-12-01

    We report the results of preliminary sedimentologic analyses of a ~3.3m long piston core (P13) collected in the lower fan of the Rio Yaqui (Guaymas Basin, Gulf of California; depth, 1859m) by UNAM's (Universidad Nacional Autónoma de México) research ship El Puma in 2014. The core was collected to test the potential for high-resolution reconstructions of basin-scale paleoclimate in the Pacific and the Mesoamerican region. Shipboard and post-cruise analyses include magnetic susceptibility (MS), smear slide counts and laser diffraction particle size analysis. The core is being analyzed for X-Ray Fluorescence (XRF) and color reflectance, and a 210Pb age model is being constructed. Preliminary results show that Rio Yaqui lower fan sediment differs significantly from that in the Guaymas Basin, which is dominantly diatom ooze. The lower ~2m of core P13 show prominent alternations (~10-20cm) between very-fine-grained, clay intervals characterized by higher MS and mixed diatom and clay intervals, with coarser grain size and lower MS values. In contrast, the upper ~1m has distinctive high MS sand turbidites alternating with diatom-rich layers. Previous core studies from nearby ODP Leg 64 site show sedimentation rates of ~1.2 m/ka; as these sites are further away from the Yaqui delta the sedimentation rates for core P13 should be higher possibly recording only the last few hundred years of sedimentation. Clay/diatom cycles in the lower part of the core could record decadal- or ENSO-scale wet/aridity cycles in the Sonoran Mainland. Conversely, the coarser siliciclastic intervals and the diatom layers in the upper part of the core could reflect the last few decades of land usage in the watershed of the Rio Yaqui, the most important river in the state of Sonora, Mexico. These include large modifications to the river's hydrography (e.g. construction of dams and aqueducts), rapidly expanding mass agricultural practices in the region, and increased eutrophication in the Gulf.

  16. Computer input and output files associated with ground-water-flow simulations of the Albuquerque Basin, central New Mexico, 1901-95, with projections to 2020; (supplement three to U.S. Geological Survey Water-resources investigations report 94-4251)

    Science.gov (United States)

    Kernodle, J.M.

    1996-01-01

    This report presents the computer input files required to run the three-dimensional ground-water-flow model of the Albuquerque Basin, central New Mexico, documented in Kernodle and others (Kernodle, J.M., McAda, D.P., and Thorn, C.R., 1995, Simulation of ground-water flow in the Albuquerque Basin, central New Mexico, 1901-1994, with projections to 2020: U.S. Geological Survey Water-Resources Investigations Report 94-4251, 114 p.) and revised by Kernodle (Kernodle, J.M., 1998, Simulation of ground-water flow in the Albuquerque Basin, 1901-95, with projections to 2020 (supplement two to U.S. Geological Survey Water-Resources Investigations Report 94-4251): U.S. Geological Survey Open-File Report 96-209, 54 p.). Output files resulting from the computer simulations are included for reference.

  17. Overview of the structural geology and tectonics of the Central Basin Platform, Delaware Basin, and Midland Basin, West Texas and New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Hoak, T. [Kestrel Geoscience, Littleton, CO (United States); Sundberg, K. [Phillips Petroleum Co., Bartlesville, OK (United States); Ortoleva, P. [Indiana Univ., Bloomington, IN (United States)

    1998-12-31

    The structural geology and tectonics of the Permian Basin were investigated using an integrated approach incorporating satellite imagery, aeromagnetics, gravity, seismic, regional subsurface mapping and published literature. The two primary emphases were on: (1) delineating the temporal and spatial evolution of the regional stress state; and (2) calculating the amount of regional shortening or contraction. Secondary objectives included delineation of basement and shallower fault zones, identification of structural style, characterization of fractured zones, analysis of surficial linear features on satellite imagery and their correlation to deeper structures. Gandu Unit, also known as Andector Field at the Ellenburger level and Goldsmith Field at Permian and younger reservoir horizons, is the primary area of interest and lies in the northern part of Ector county. The field trends northwest across the county line into Andrews County. The field(s) are located along an Ellenburger thrust anticline trap on the eastern margin of the Central Basin Platform.

  18. The environmental policy in Mexico: Crisis and perspectives; La politica ambiental en Mexico: Crisis y perspectivas

    Energy Technology Data Exchange (ETDEWEB)

    Urquidi, Victor [Colegio de Mexico, Mexico, D. F. (Mexico)

    1996-12-31

    In this paper some aspects of the environmental situation in Mexico are condensed. The main roll performed by the modality of the energy resources consumption and the evolution of the environmental policy in Mexico from 1971 to 1996 is analyzed. It is concluded that in Mexico it has not been able to define the environmental policy in all its extension requiring, therefore, a greater participation of all the sectors to protect Nature and fight against the industrial and municipal pollution [Espanol] En esta ponencia se resumen algunos aspectos de la situacion ambiental actual de Mexico. Se analiza el papel central desempenado por la modalidad del consumo de energeticos y la evolucion de la politica ambiental en Mexico desde 1971 hasta 1996. Se concluye en que la politica ambiental en Mexico no se ha podido definir todavia en todos sus alcances por lo que se requiere una mayor participacion de todos los sectores para proteger la naturaleza y combatir la contaminacion industrial y municipal

  19. Students and Teachers' Reasons for Using the First Language Within the Foreign Language Classroom (French and English) in Central Mexico Razones de alumnos y maestros sobre el uso de la primera lengua en el salón de lenguas extranjeras (francés e inglés) en el centro de México

    OpenAIRE

    Irasema Mora Pablo; M. Martha Lengeling; Buenaventura Rubio Zenil; Troy Crawford; Douglas Goodwin

    2011-01-01

    The present study explores the use of the first language in a context of foreign language teaching. This qualitative research presents the classroom practice and points of view of French and English teachers and students within a public educational institute in central Mexico using the techniques of questionnaires and semi-structured interviews. The results show that teachers and the majority of students perceive the use of the first language as positive and part of the teaching and learning ...

  20. RECHERCHE SUR LES MAQUILADORAS DU SUD DU MEXIQUE ET EN AMÉRIQUE CENTRALE : TRAVAIL, GENRE ET IDENTITÉ RESEARCH ON THE MAQUILADORAS OF SOUTHERN MEXICO AND CENTRAL AMERICA: WORK, GENDER AND IDENTITY

    OpenAIRE

    Labrecque, Marie-France; Beatriz Castilla RAMOS

    2010-01-01

    Les maquiladoras de la frontière nord du Mexique ont fait couler beaucoup d’encre particulièrement en ce qui a trait à la présence des femmes dans ce type d’usine. Celles du sud et de l’Amérique centrale sont pourtant de plus en plus importantes du point de vue numérique. Leur configuration est particulière dans la mesure où, du moins dans le sud du Mexique et au Guatemala en particulier, le facteur ethnique est davantage présent dans la composition de la force de travail. Dans cet article, l...

  1. Mexico - PROGRESA

    OpenAIRE

    IFPRI

    2002-01-01

    For many of the world's poor, public safety-net programs are the only hope for a life free from chronic poverty and undernutrition. But the proper combination of incentives and support can be difficult to achieve. The International Food Policy Research Institute's in-depth evaluation of Mexico's PROGRESA (Programa de Educación, Salud y Alimentación) indicates that antipoverty programs that combine education, health, and nutrition interventions in one package can be quite successful in improvi...

  2. Tectonic, magmatic, and metallogenic evolution of the Late Cretaceous arc in the Carpathian-Balkan orogen

    Science.gov (United States)

    Gallhofer, Daniela; Quadt, Albrecht von; Peytcheva, Irena; Schmid, Stefan M.; Heinrich, Christoph A.

    2015-09-01

    The Apuseni-Banat-Timok-Srednogorie Late Cretaceous magmatic arc in the Carpathian-Balkan orogen formed on the European margin during closure of the Neotethys Ocean. It was subsequently deformed into a complex orocline by continental collisions. The Cu-Au mineralized arc consists of geologically distinct segments: the Apuseni, Banat, Timok, Panagyurishte, and Eastern Srednogorie segments. New U-Pb zircon ages and geochemical whole rock data for the Banat and Apuseni segments are combined with previously published data to reconstruct the original arc geometry and better constrain its tectonic evolution. Trace element and isotopic signatures of the arc magmas indicate a subduction-enriched source in all segments and variable contamination by continental crust. The magmatic arc was active for 25 Myr (~92-67 Ma). Across-arc age trends of progressively younger ages toward the inferred paleo-trench indicate gradual steepening of the subducting slab away from the upper plate European margin. This leads to asthenospheric corner flow in the overriding plate, which is recorded by decreasing 87Sr/86Sr (0.70577 to 0.70373) and increasing 143Nd/144Nd (0.51234 to 0.51264) ratios over time in some segments. The close spatial relationship between arc magmatism, large-scale shear zones, and related strike-slip sedimentary basins in the Timok and Pangyurishte segments indicates mild transtension in these central segments of the restored arc. In contrast, the Eastern Srednogorie segment underwent strong orthogonal intraarc extension. Segmental distribution of tectonic stress may account for the concentration of rich porphyry Cu deposits in the transtensional segments, where lower crustal magma storage and fractionation favored the evolution of volatile-rich magmas.

  3. "CEZAC 06": nueva variedad de ajo tipo Jaspeado para la región norte centro de México "CEZAC 06": new Jaspeado garlic cultivar for the northem-central region of Mexico

    Directory of Open Access Journals (Sweden)

    Manuel Reveles-Hernández

    2011-08-01

    Full Text Available Alrededor de 5 200 hectáreas de ajo son cultivadas en México donde la región norte centro, es una de las principales áreas productoras de esta hortaliza. La falta de variedades de ajo localmente adaptadas es una seria desventaja para los productores de ajo. En este reporte se mencionan las principales características agronómicas de "CEZAC 06", una nueva variedad de ajo disponible para los productores de los estados de Zacatecas, Aguascalientes, Durango, Chihuahua y Coahuila. Las principales ventajas de esta variedad son rendimientos más altos, bulbos consistentemente redondos, menor número de dientes por bulbo y maduración homogénea. En parcelas comerciales el rendimiento se ha mejorado en 9-17% y se han alcanzado rendimientos de hasta 30 t ha-1 con el uso de "CEZAC 06".About 5 200 hectares of garlic are cultivated in Mexico; the north-central region is one of the main producing areas of this vegetable. The lack of locally adapted varieties of garlic is a serious disadvantage for garlic producers. In this paper are mentioned the main agronomic characteristics of "CEZAC 06", a new garlic variety available for producers of Zacatecas, Aguascalientes, Durango, Chihuahua and Coahuila. The main advantages of this variety are higher yield, consistently round bulbs, fewer numbers of cloves per bulb and homogeneous maturation. In commercial plots, yield has improved in 9-17% and there have been achieved yields of up to 30 t ha-1 using "CEZAC 06".

  4. Mexico: Imports or exports?

    International Nuclear Information System (INIS)

    This presentation provides an overview of Mexico's energy sector. Proven oil reserves place Mexico in ninth position in the world and fourth largest in natural gas reserves. Energy is one of the most important economic activities of the country, representing 3 per cent of Gross Domestic Product (GDP). Oil exports represent 8.4 per cent of total exports. Approximately 40 per cent of total public investment is earmarked for energy projects. The author discusses energy resources and energy sector limitations. The energy sector plan for the period 2001-2006 is discussed. Its goals are to ensure energy supply, to develop the energy sector, to stimulate participation of Mexican enterprises, to promote renewable energy sources, and to strengthen international energy cooperation. The regulatory framework is being adapted to increase private investment. Some graphs are presented, displaying the primary energy production and primary energy consumption. Energy sector reforms are reviewed, as are electricity and natural gas reforms. The energy sector demand for 2000-2010 and investment requirements are reviewed, as well as fuel consumption for power generation. The author discusses the National Pipeline System (SNG) and the bottlenecks caused by pressure efficiency in the northeast, flow restriction on several pipeline segments, variability of the Petroleos Mexicanos (PEMEX) own use, and pressure drop on central regions. The entire prospect for natural gas in the country is reviewed, along with the Strategic Gas Program (PEG) consisting of 20 projects, including 4 non-associated natural gas, 9 exploration and 7 optimization. A section dealing with multiple service contracts is included in the presentation. The authors conclude by stating that the priority is a national energy policy to address Mexico's energy security requirements, to increase natural gas production while promoting the diversification of imports, and a regulatory framework to be updated in light of current

  5. Mexico: prospects for democracy

    OpenAIRE

    Norton, Yvonne D.

    1996-01-01

    The purpose of this thesis is to analyze why Mexico has failed to democratize and offer recommendations for U.S. policy towards Mexico. The thesis examines the impact of three casual variables on the level of democracy in Mexico: civilian control of the military, the fairness of Mexico's political party system, and U.S. foreign policy towards Mexico. NA U.S. Navy (U.S.N.) author

  6. Basement Characteristics and Crustal Evolution of the Copper-Gold Metallogenic Belt in the Middle and Lower Reaches of the Yangtze River: Some Isotope Constraints

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Studies of the Pb, Sr and Nd isotopic composition of Mesozoic intrusive rocks indicate that the basement of the copper-gold metallogenic belt of the middle and lower reaches of the Yangtze River has "two-layer structure" and partly has "multi-layered structure", and is inhomogeneous and shows the distinct feature of E-W provincialism. The calculated model lead ages (t1) are mostly greater than 2600 Ma, and the model neodymium ages (TDM) vary from 953 to 2276 Ma and concentrate in two time intervals: 1800- 2000 Ma and 1200- 1600 Ma. It is concluded that the basement of the MBYR is composed of the Late Archaeozoic to Middle Proterozoic metamorphic series and that the crust was initiated in the Archaean and continued to grow in the Early and Middle Proterozoic, and the proportion of new crust formed by mantle differentiation during the Late Proterozoic is low.

  7. Petrogenesis of the Paleoproterozoic rapakivi A-type granites of the Archean Carajás metallogenic province, Brazil

    Science.gov (United States)

    Dall'Agnol, Roberto; Teixeira, Nilson P.; Rämö, O. Tapani; Moura, Candido A. V.; Macambira, Moacir J. B.; de Oliveira, Davis C.

    2005-03-01

    Three Paleoproterozoic A-type rapakivi granite suites (Jamon, Serra dos Carajás, and Velho Guilherme) are found in the Carajás metallogenic province, eastern Amazonian craton. Liquidus temperatures in the 900-870 °C range characterize the Jamon suite, those for Serra dos Carajás and Velho Guilherme are somewhat lower. Pressures of emplacement decrease from Jamon (3.2±0.7 kbar) through Serra dos Carajás (2.0±1.0 kbar) to Velho Guilherme (1.0±0.5 kbar). Oxidizing conditions (NNO+0.5) characterized the crystallization of the Jamon magma, the Velho Guilherme magmas were reducing (marginally below FMQ), and the Serra dos Carajás magmas were intermediate between the two in this respect. The three granite suites have Archean T DM model ages and strongly negative ɛNd values (-12 to -8 at 1880 Ma), and they were derived from Archean crust. The Jamon granite suite may have been derived from a quartz dioritic source, and the Velho Guilherme granites from K-feldspar-bearing granitoid rocks with some sedimentary input. The Serra dos Carajás granites either had a somewhat more mafic source than Velho Guilherme or were derived by a larger degree of melting. Underplating of mafic magma was probably the heat source for the melting. The petrological and geochemical characteristics of the Carajás granite suites imply considerable compositional variation in the Archean of the eastern Amazonian craton. The oxidized Jamon suite granites are similar to the Mesoproterozoic magnetite-series granites of Laurentia, and they were derived from Archean igneous sources that were more oxidized than the sources of the Fennoscandian rapakivi granites. The Serra dos Carajás and Velho Guilherme granites approach the classic reduced rapakivi series of Fennoscandia and Laurentia. No counterparts of the Mesoproterozoic two-mica granites of Laurentia have been found, however. Following the model of Hoffman [Hoffman, P., 1989. Speculations on Laurentia's first gigayear (2.0 to 1.0 Ga

  8. Time distribution of the main Brazilian mineral deposits. 2: metallogenic epochs; Distribuicao no tempo geologico dos principais depositos minerais brasileiros. 2: epocas metalogeneticas

    Energy Technology Data Exchange (ETDEWEB)

    Biondi, Joao C. [Parana Univ., Curitiba, PR (Brazil). Dept. de Geologia]. E-mail: jcbiondi@setuva.geologia.ufpr.br

    1999-12-01

    The metallogenic epochs of the main mineral deposit groups were defined with base on the ore's of the 194 main Brazilian mineral deposits. Mineral deposits are rare on epochs that: precede the beginning of juvenile accretion peak periods, and/or of cooling of rocks formed during each of the main brazilian thermo-tectonic events. Deposits are more frequent on epochs that are coincident or immediately younger than these peak periods. The most important metallogenic epoch, with about 30% of the selected deposits, is between 50 Ma and the Recent, and corresponds to the formation of supergenic and/or residual and placer deposits. Brazilian's volcanogenic (VHMS), Mississippi Valley (MTV) and mesothermal gold-lode deposits have discordant ages as compared with their equivalents in other countries, while deposits believed to be SEDEX have concordant ages. With the exception of Urucum, the primary iron and manganese ores of brazilian deposits are Archean. Primary tin deposits from Amazonas, Amapa and Goias State cluster between 1500 and 2300 Ma. Tin deposits from Rondonia and Mato Grosso are more recent and most formed between 1000 and 1600 Ma, in sequence with the other groups of tin deposits. Uranium deposits vary on genetic model and ages, due to the mobility of the element in all geologic environments. Most part of Brazilian deposits of phosphate, titanium, niobium, Rare Earths, diamond in kimberlites and of amethyst formed during the Mesozoic, and arte genetically related to the alkaline and basaltic magmatism that affected the brazilian territory in this period. Gemstone (tourmaline and aquamarine), talc and magnesite deposits are more frequent in the Brasiliano period. Gipsite, silvite and barite occur in Senonian to Aptian evaporites. (author)

  9. Alteration mineral mapping and metallogenic prediction using CASI/SASI airborne hyperspectral data in Mingshujing area of Gansu Province, NW China

    Science.gov (United States)

    Sun, Yu; Zhao, Yingjun; Qin, Kai; Tian, Feng

    2016-04-01

    Hyperspectral remote sensing is a frontier of remote sensing. Due to its advantage of integrated image with spectrum, it can realize objects identification, superior to objects classification of multispectral remote sensing. Taken the Mingshujing area in Gansu Province of China as an example, this study extracted the alteration minerals and thus to do metallogenic prediction using CASI/SASI airborne hyperspectral data. The Mingshujing area, located in Liuyuan region of Gansu Province, is dominated by middle Variscan granites and Indosinian granites, with well developed EW- and NE-trending faults. In July 2012, our project team obtained the CASI/SASI hyperspectral data of Liuyuan region by aerial flight. The CASI hyperspectral data have 32 bands and the SASI hyperspectral data have 88 bands, with spectral resolution of 15nm for both. The hyperspectral raw data were first preprocessed, including radiometric correction and geometric correction. We then conducted atmospheric correction using empirical line method based on synchronously measured ground spectra to obtain hyperspectral reflectance data. Spectral dimension of hyperspectral data was reduced by the minimum noise fraction transformation method, and then purity pixels were selected. After these steps, image endmember spectra were obtained. We used the endmember spectrum election method based on expert knowledge to analyze the image endmember spectra. Then, the mixture tuned matched filter (MTMF) mapping method was used to extract mineral information, including limonite, Al-rich sericite, Al-poor sericite and chlorite. Finally, the distribution of minerals in the Mingshujing area was mapped. According to the distribution of limonite and Al-rich sericite mapped by CASI/SASI hyperspectral data, we delineated five gold prospecting areas, and further conducted field verification in these areas. It is shown that there are significant gold mineralized anomalies in surface in the Baixianishan and Xitan prospecting

  10. Anthropometric variation in west-central Mexico.

    Science.gov (United States)

    Christensen, A F

    2001-06-01

    Anthropometric data from five indigenous Mexican groups, collected by Carlos and Manuel Basauri in 1933, were reanalyzed and compared with serological and cranial non-metric data. Ten cranial and 14 postcranial measurements were used, both separately and together. Bias-corrected r0 and FST values were slightly higher for the postcranial analysis (0.033) than for the cranial analysis (0.024). Given the degree of linguistic differentiation among the Mexican populations, not to mention the different histories of the communities sampled, this result is surprisingly low. The two groups which were closest linguistically and geographically, the Cora and Huichol, were also close biologically. The other three groups, Tarascan, Aztecan, and Otomi, were not closely related to each other or to the Cora-Huichol pair. More interesting than the relationship between populations in this case are those within them. The Aztecas of Tuxpan, Jalisco, exhibit high rii values and lower-than-expected phenotypic variance, suggesting the pronounced action of genetic drift. The Otomi of Ixmiquilpan and Cora of the Sierra de Nayarit, despite their very different histories, both exhibit low rii values and higher-than-expected phenotypic variance, indicating a high level of gene flow. Despite the phenotypic similarities between the Cora and Huichol, their residual variance is very different; this mirrors serological investigations of relative admixture. Over all, recent population history, and especially non-indigenous admixture, are at least as explicative of the observed biological variation as historical linguistic ties are. PMID:11441457

  11. Freshwater epiphitic Chamaesiphonaceae from Central Mexico

    Czech Academy of Sciences Publication Activity Database

    Gold-Morgan, M.; Montejano, G.; Komárek, Jiří

    1996-01-01

    Roč. 117, č. 83 (1996), s. 257-271. ISSN 0342-1120. [Symposium of the International Association for Cyanophyte Research /13./. Frascati, 26.08.1995-03.09.1995] R&D Projects: GA AV ČR IAA6005704 Impact factor: 1.881, year: 1996

  12. New archeointensity results from Teotihuacan (Central Mexico)

    Science.gov (United States)

    Rodriguez, M.; Gogichaishvili, A.; Morales, J.; Manzanilla, L.; Chauvin, A.; Urrutia, J.; Robles, J.

    2007-05-01

    We carried out systematic rock-magnetic and archeointensity invetigations on 84 pottery fragments (about 549 samples) of Teotihuacan ceramics. Three localities are sampled: Xalla, Teopancazco and Cueva de las Varillas. The principal aim of this study is to try to establish first archeointensity reference curve for Mesoamerica from 300 a.C. and 1500 d.C. The samples selected are related to about 50 C14 and AMS radiometric data available. Thus there are almost ideal conditions to know absolute geomagnetic intensity variation trough time. Rock-magnetic investigation included susceptibility vs temperature and hystresis measurements. In addition some X-Ray and microscopy studies were performed on selected specimens. The samples are characterized by stable remanent magnetization observed upon both thermal and alternating field demagnetizations. Both Ti-poor and Ti-rich titanomagnetites are responsible for the magnetization. 61 out 84 fragments yielded acceptable archeointensity results yielding an extremely high success rate. The cooling rate and anisotropy correction were applied to all samples. The mean intensities found range from 72.8 to 15.9 microT showing very low within fragment dispersion.

  13. Gulf of Mexico sperm whale photo-ID catalog

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Photo-identification data on sperm whales occupying the north central Gulf of Mexico have been collected during vessel surveys. Photographs of sperm whales are...

  14. Gulf of Mexico Sperm Whale Acoustic Prey Study

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Large vessel surveys were conducted during the summer of 2009 and the winter of 2010 in the north-central Gulf of Mexico to examine the spatial distribution of...

  15. Mexico Gravity Data per 2 min Cell (97)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This 2' gravity density grid for Mexico, North-Central America, and the Western Caribbean Sea shows the distribution of about one million terrestrial and marine...

  16. Large clusters of gold deposits and large-scale metallogene-sis in the Jiaodong Peninsula, Eastern China

    Institute of Scientific and Technical Information of China (English)

    ZHAI; Mingguo

    2001-01-01

    [1]Tu, G. C., The unique nature in ore deposition, geological background and metallogenic mechanism of non-conventional superlarge ore deposits: A preliminary discussion, Science in China (in Chinese), Ser. D, 1998, 41 (sup.): 1-6.[2]Pei, R. F., Qiu, X. P., Yin, B. C. et al., The Explosive anomaly of ore-forming processes and super-accumulation of metals, Mineral Deposits (in Chinese), 1999, 18 (4): 333-340.[3]Zhai, Y. S., De, J., Li, X. B., Essentials of Metallogeny (in Chinese), Beijing: Geological Publishing House, 1999: 1-288.[4]Mao, J. W., Hua, R. M., Li, X. B., A preliminary study of large-scale metallogenesis and large clusters of mineral deposits, Mineral Deposits (in Chinese), 1999, 18(4): 291-298.[5]Zhang, C. H., Gu, D. L., Study on the microstructure and deformation mechanism of the sinistral slick ductile shear zone in the middle of the northern Jiaonan uplift, in Tectonic and Geological Evolution of the Northern Jiaonan Uplift (in Chi-nese) (eds. Gu, D. L., Zhang, C. H.), Beijing: China University of Geosciences Press, 1996, 96-104.[6]Zhai, M. G., Guo, J. H., Wang, Q. C. et al., Division of geological-tectonic units in the northern Sulu ultra-high pressure zone: An example of thick-skin thrust of crystalline units, Scientica Geologica Acta (in Chinese), 2000, 35(1): 16-26.[7]Zhai, M. G., Guo, J. H., Cong, B. L. et al., Sm-Nd geochronolgy and petrography of garnet pyroxene granulites in the northern Sulu region and their geotectonic implication, Scientica Geologica Acta (in Chinese), 1999, 34(3): 301-310.[8]Zhai, M. G., Cong, B., Guo, J., Sm-Nd geochronology and petrography of garnet pyroxene granulites in the northern Sulu region of China and their geotectonic implication, Lithos, 2000, 52: 23-33.[9]Jahn, B. M., Geochemical and isotopic study of UHP terrain in China (abstract), in First Workshop on UHP Metamor-phism and Tectonics, Stanford: Stanford University, 1994, A71-74.[10]Li, S. G., Jagoutz

  17. New Mexico National Cemeteries

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The United States Department of Veterans Affairs National Cemetery Administration maintains 2 national cemeteries in the state of New Mexico; the Fort Bayard...

  18. New Mexico Golf Courses

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This dataset provides an initial version of the locations of golf courses in New Mexico, in point form, with limited attributes, compiled using available data from...

  19. New Mexico Parks

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This dataset provides an initial version of the locations of parks in New Mexico, in point form, with limited attributes, compiled using available data from a...

  20. New Mexico Convention Centers

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This dataset provides an initial version of the locations of convention centers in New Mexico, in point form, with limited attributes, compiled using available data...

  1. New Mexico Ghost Towns

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This data provides locations and non-spatial attributes of many ghost towns in the State of New Mexico, compiled from various sources. Locations provided with...

  2. New Mexico State Parks

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This dataset provides an initial version of the generalized physical boundaries of New Mexico State Parks, in polygonal form with limited attributes, compiled using...

  3. Mexico; Selected Issues

    OpenAIRE

    International Monetary Fund

    2009-01-01

    This Selected Issues paper on Mexico presents econometric investigation of the cyclical determinants of remittances to Mexico. The aggregate U.S. business cycle is not necessarily relevant for remittances. Remittances to Mexico do show a significant relationship with employment conditions in certain regions of the United States. Employment conditions in the U.S. construction sector seem to be especially important as well as remittances for certain regions of Mexico with high rates of emigrati...

  4. Mexico; Selected Issues

    OpenAIRE

    International Monetary Fund

    2006-01-01

    This Selected Issues paper is a wide-ranging survey of the conditions for, and obstacles to, the growth in Mexico. It frames the issue of Mexico’s growth record, and presents the paper’s prior assumptions and approach. It highlights the main observations and conclusions emerging from the survey of growth conditions in Mexico. It also presents an overview of remittances in Mexico, motivated by their recent increase and possible macroeconomic implications.

  5. Psychology in Mexico

    Science.gov (United States)

    Ruiz, Eleonora Rubio

    2011-01-01

    The first formal psychology course taught in Mexico was in 1896 at Mexico's National University; today, National Autonomous University of Mexico (UNAM in Spanish). The modern psychology from Europe and the US in the late 19th century were the primary influences of Mexican psychology, as well as psychoanalysis and both clinical and experimental…

  6. Lead isotope geochemistry of the Chessy deposit and the volcanosedimentary mineralization of the Brevenne series (French Massif Central). Metallogenic implications and significance for exploration

    International Nuclear Information System (INIS)

    Thirty eight lead isotope analyses made on the Devonian sulphide mineralization of Chessy (Rhone) provide new data on the composition and sources of the hydrothermal fluids that gave rise to the massive sulphide ores of the Brevenne volcanosedimentary district. A partial mantle origin is indicated for the main episode of mineralization, with a remarkable homogeneity in the isotopic signatures of the different ores of the Chessy massive sulphide deposit (galenas with 206Pb/204Pb = 18.163 and 207Pb/204Pb = 15.558). This mantle contribution resulted from leaching, by the mineralizing fluids, of the tholeiitic facies of the underlying volcanic pile. A second episode of mineralization, also associated with submarine silicic volcanic activity, did not give rise to economic concentrations. It is characterised by lead isotope signatures that are more radiogenic (206Pb/204Pb > 18.34 and 207Pb/204Pb > 15.63) without mantle participation

  7. Flor de Mayo Eugenia, nueva variedad de frijol para riego y temporal en el centro de México Flor de Mayo Eugenia, new bean cultivar for irrigated and rainfall conditions in Central Mexico

    Directory of Open Access Journals (Sweden)

    Jorge Alberto Acosta Gallegos

    2010-12-01

    Full Text Available Dentro del frijol tipo Flor de Mayo, el subtipo 'media oreja' esta cobrando importancia en el norte-centro de México, éste es de tamaño mediano, forma alargada y color rosa atractivo. Se describe una nueva variedad de este tipo de frijol, Flor de Mayo Eugenia (FME. FME se derivó de una cruza interracial entre Flor de Mayo Anita (FMA (raza Jalisco y Rayado Rojo (raza Nueva Granada. El rendimiento promedio de FME en temporal varia de 0.8 a 2.0 t ha-1 y bajo riego el máximo rendimiento ha sido de 3.8 t ha-1. El peso de 100 semillas promedio de diferentes localidades de FME es significativamente superior al de FMA en condiciones de temporal, 32 vs 26 g 100 semillas, y riego 35 vs 31 g 100 semillas. En cuanto la calidad del grano, el tiempo promedio de cocción de FME en cocedor tipo Mattson es 97 min, mientras que el de FMA es de 109 min; el contenido promedio de proteína del grano de FME es 19% en base a peso seco, similar al de FMA, mientras que el contenido de hierro de FME resultó superior al de FMA con 6.1 vs 5 mg 100 g. FME es tolerante a las razas de roya presentes en el Altiplano de México, a la raza 292 de antracnosis y tolerante a los tizones común y de halo.Within 'Flor de Mayo' bean type, the 'media oreja' subtype is becoming important in North-Central México; this last type has a mid-size elongated seed with showy pink color. A new bean cv. of 'media oreja' subtype is described: Flor de Mayo Eugenia (FME. FME was derived from an interracial cross between Flor de Mayo Anita (FMA (Jalisco breed and Rayado Rojo (Nueva Granada breed. The seed yield of FME under rainfall conditions varied from 0.8 to 2.0 t ha-1 and under irrigation the highest yield recorded was 3.8 t ha-1. The 100-seed weight of FME across different locations was significantly superior to the weight of FMA, 32 vs 26 g per 100 seeds under rainfall conditions and 35 vs 31 g per 100 seeds under irrigation conditions. In regard to seed quality, cooking time average of

  8. A new species of Algansea (Actinopterygii: Cyprinidae from the Ameca River basin, in Central Mexico Una especie nueva de Algansea (Actinopterygii: Cyprinidae en la cuenca del río Ameca en el centro de México

    Directory of Open Access Journals (Sweden)

    Rodolfo Pérez-Rodríguez

    2009-08-01

    Full Text Available A morphological comparative analysis was performed among different populations of the cyprinid Algansea tincella Valenciennes, 1844 from the Lerma-Chapala and Ameca River basins in central Mexico. A new species, Algansea amecae n. sp. is described from individuals collected from small tributary in the headwaters of the Ameca basin. The new species differs from Lerma-Chapala populations of A. tincella by having a lower number of transversal scales, a lower number of infraorbital pores, a prominent dark lateral stripe along the body, a black caudal spot extending onto the medial caudal inter-radial membranes, and a pigmented ("dotted" lateral line. This new species increases the high level of endemism in the freshwater ichthyofauna of the Ameca basin. It appears to be most closely related to populations in the Lerma-Chapala-Santiago system, as is the case for several other species in the Ameca basin. This pattern of relationship provides evidence for a historical connection between the 2 basins, and implies that a vicariance event led to the isolation of populations and a subsequent speciation event. Due to the limited distributional range of Algansea amecae n. sp., and the environmental deterioration of the Ameca River, we propose that this new species should be designated as a protected species under Mexican law.Se realizó un análisis morfológico comparando diferentes poblaciones del ciprínido Algansea tincella Valenciennes, 1844 correspondientes a los sistemas hidrológicos Lerma-Chapala y cuenca del río Ameca. Con base en este análisis se describe una nueva especie, Algansea amecae n. sp. a partir de los individuos recolectados en un pequeño afluente del alto Ameca, en el centro de México. La nueva especie difiere de las poblaciones de A. tincella del sistema Lerma-Chapala-Santiago por presentar un menor número de escamas transversales, un menor número de poros infraorbitales, una franja obscura lateral muy marcada a lo largo del

  9. Two new species of the genus Notropis Rafinesque, 1817 (Actinopterygii, Cyprinidae from the Lerma River Basin in Central Mexico Dos nuevas especies del género Notropis Rafinesque, 1817 (Actinopterygii, Cyprinidae, de la cuenca del río Lerma, México central

    Directory of Open Access Journals (Sweden)

    Omar Domínguez-Domínguez

    2009-08-01

    Full Text Available Prior findings suggest the existence of undescribed species among the cyprinids of central Mexico. Within the genus Notropis distributed across central Mexico and adjacent areas sometimes reaching southern basins, two groups have been recognized: a Southern Mexican clade and a central Mexican clade. Within this last clade, Notropis calientis has been defined as a species complex of four small minnows inhabiting upland areas. Here we describe two new species of this complex based on morphometric, meristic and genetic characters. Notropis marhabatiensis sp. nov. was diagnosed according to the following set of characters: 7, rarely 8, branched pelvic fin rays (vs. 8, rarely 7 or 9, in other species of the N. calientis complex and 9, rarely 8, scales in a transverse series (vs. 10, rarely 9 or 11 in N.grandis & N. calientis; a dark, narrow lateral stripe running from around the pectoral fin to the caudal peduncle origin; and twenty-six fixed nucleotide positions in the cytochrome b gene. The diagnosis of Notropis grandis sp. nov. was based on: 6, rarely 7, branched fin rays (vs. 7, rarely 6 or 8, in N. marhabatiensis, N. calientis and N. aulidion and 8, rarely 7 or 9, in N. calbazas and N. amecae, 42, rarely 40-41, or 43-45 scales in a lateral series (vs. 40, rarely 37-39, in N. calabazas; 35-36, rarely 37-39, or 33-34 in N. amecae; 35, rarely 31-34, or 36 in N. marhabatiensis and N. calientis and 34, rarely 30-33, or35 in N. aulidion and 11 rarely 10 or 12 gill rakers in the first arch; a dark lateral stripe widening from approximately the pectoral fin origin to the dorsal fin origin, forming a slightly convex segment; adult animals larger (n=30, or = 42.6, SD=4.69 relative to N. calientis (n=55, or = 33.3, SD= 3.28 and N. marhabatiensis sp. nov. (n=30, or = 30.5, SD=7.57 (F = 16.87; p or = 6.3% to 8.1% for N. grandis.Diversos estudios sugieren la existencia de especies no descritas de ciprínidos en el centro de México. Las especies del g

  10. The diagenetic and metallogenic depth:main constriants and the estimation methods%成岩成矿深度:主要影响因素与压力估算方法

    Institute of Scientific and Technical Information of China (English)

    张德会; 徐九华; 余心起; 李健康; 毛世德; 王科强; 李泳泉

    2011-01-01

    成岩成矿深度是金属矿床成矿地质体的重要空间参数,受到地质构造、岩浆岩、围岩等诸多因素的影响.初步讨论了成矿深度的主要影响因素:岩浆因素和构造因素.内生矿床,特别是岩浆热液矿床的形成深度与岩浆作用的深度有关,岩浆侵位深度限定了矿床形成深度的下限,而岩浆上升和侵位过程中分异出的热液的深度直接决定了成矿深度.构造变形直接控制了多孔介质的渗透率,渗透率制约了流体的流动,成矿流体运移和就位则直接与成矿深度相关联.还阐述了成岩成矿深度(压力)的估算方法,以流体包裹体温压计为主,结合其它矿物地质温度计和压力计,并综合考虑成矿地质构造、岩浆岩、围岩等因素,才能获得合理和符合地质实际的成矿深度,为找矿勘查提供经得起检验的深度参数.%Rock-forming and metallogenic depth are the important spatial parameters for mineralized geologic bodies of metallic ore deposit, and affected by many factors including geological structures, magmatic rock and wall rock. The major influencing factors on metallogenic depth are discussed preliminarily, including magma and structure factors. The depth of endogenic mineralization, especially the formation depth of magmatic-hydrothermal mineral deposits, is related to the depth of magmatism and magma emplacement.The depth of magmatic emplacement restricts the lower limit of the formation depth of mineral deposits, while the depth of magmatic hydrothermal fluid exsolved from ascending magma and intrusion directly determines metallogenic depth. Structural deformation directly controls the permeability of porous medium, and permeability restricts fluid flow, while ore-forming fluid migration and accumulation are directly associated with metallogenic depth. Estimation methods for diagenetic and metallogenic depth (or pressure) are also discussed. Finally, the author indicated that the reasonable

  11. Modernization of the Electric Power Systems (transformers, rods and switches) in the Laguna Verde Nuclear Power Plant (Mexico); Modernizacion de los Sistemas Electricos de Potencia (Transformadores de Principales, Interruptor de Generacion, Barras de Fase Aislada) de la Central Nuclear de Laguna Verde (Mexico)

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Solarzano, J. J.; Gabaldon Martin, M. A.; Pallisa Nunez, J.; Florez Ordeonez, A.; Fernandez Corbeira, A.; Prieto Diez, I.

    2010-07-01

    Description of the changes made in the Electric Power Systems as a part of the power increase project in the Laguna Verde Nuclear Power Plant (Mexico). The main electrical changes to make, besides the turbo group, are the main generation transformers, the isolated rods and the generation switch.

  12. A new species of Metathelazia (Nematoda: Pneumospiruridae) from the lungs of a nine-banded armadillo in Central Mexico Especie nueva de Metathelazia (Nematoda: Pneumospiruridae) de los pulmones de un armadillo del centro de México

    OpenAIRE

    F. Agustín Jiménez; Rogelio Rosas-Valdez; Scott L. Gardner

    2013-01-01

    Twenty-four worms were collected from the bronchioles in both lungs of a male nine-banded armadillo Dasypus novemcinctus Linnaeus, 1758 captured in Teacalco, Morelos, Mexico. The worms, herein named Metathelazia mexicana n. sp., show a constriction in the esophagus at the level of the nerve ring; males of the species have 7 pairs of papillae, fewer than the other species in the genus. Metathelazia capsulata is the most similar species to Metathelazia mexicana; however, the latter has much sho...

  13. Radon in soil concentration levels in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Segovia, N.; Tamez, E.; Mena, M

    1991-09-15

    Radon in soil surveys in Mexico have been carried out since 1974 both for uranium prospectus and to correlate mean values of the gas emanation with local telluric behaviour. The mapping includes the northern uranium mining region, the Mexican Neo volcanic Belt, the coastal areas adjacent to the zone of subduction of the Cocos Plate under the North American Plate, some of the active volcanoes of Southern Mexico and several sedimentary valleys in Central Mexico. Recording of {sup 222} Rn alpha decay is systematically performed with LR115 track detectors. Using mean values averaged over different observation periods at fixed monitoring stations, a radon in soil map covering one third of the Mexican territory is presented. The lowest mean values have been found in areas associated with active volcanoes. The highest levels are found in uranium ore zones. Intermediate values are obtained in regions with enhanced hydrothermal activity and stations associated with intrusive rocks. (Author)

  14. Radon in soil concentration levels in Mexico

    International Nuclear Information System (INIS)

    Radon in soil surveys in Mexico have been carried out since 1974 both for uranium prospectus and to correlate mean values of the gas emanation with local telluric behaviour. The mapping includes the northern uranium mining region, the Mexican Neo volcanic Belt, the coastal areas adjacent to the zone of subduction of the Cocos Plate under the North American Plate, some of the active volcanoes of Southern Mexico and several sedimentary valleys in Central Mexico. Recording of 222 Rn alpha decay is systematically performed with LR115 track detectors. Using mean values averaged over different observation periods at fixed monitoring stations, a radon in soil map covering one third of the Mexican territory is presented. The lowest mean values have been found in areas associated with active volcanoes. The highest levels are found in uranium ore zones. Intermediate values are obtained in regions with enhanced hydrothermal activity and stations associated with intrusive rocks. (Author)

  15. Organic beekeeping in Mexico

    OpenAIRE

    Garibay, Salvador V.; Vandame, Rémy

    2011-01-01

    Mexico is often described as a cornucopia, a land with high diversity in ecosystems, crops, fauna and flora. These are superb preconditions for organic honey production. Already the pre-hispanic Maya cultures produced honey from the native stingless bee (Meliponini) before the Spanish introduced European honey bee (Apis mellifera L). The main beekeeping product in Mexico is honey. Mexico ranks sixth in the world in honey production (57,000 t) and third as an exporter (25,000 t).

  16. Mexico; Selected Issues

    OpenAIRE

    International Monetary Fund

    2005-01-01

    This Selected Issues paper considers the “informal sector†in Mexico. In Mexico and many other countries, the informal sector represents a large share of total employment. The paper reviews the literature on informality, with special focus on findings for Mexico, and develops a theoretical model that highlights the importance of externalities and the distortion associated with the informal sector. The analysis provides insight into the kinds of policy measures that might sustainably reduce...

  17. Organic Beekeeping in Mexico

    OpenAIRE

    Garibay, Salvador; Gänz, Peter; Vandame, Rémy

    2010-01-01

    Mexico is often described as a cornucopia, a land with high diversity in ecosystems, crops, fauna and flora. These are superb preconditions for organic honey production. Already the pre-hispanic Maya cultures produced honey from the native stingless bee (Meliponini) before the Spanish introduced European honey bee (Apis mellifera L). The main beekeeping product in Mexico is honey. Mexico ranks sixth in the world in honey production (57,000 t) and third as an exporter (25,000 t). Two condit...

  18. Nutritional value of forage species from the Central Highlands Region of Mexico at different stages of maturity Valor nutricional de espécies forrageiras nativas da Região Central Montanhosa do México em diferentes estádios de maturidade

    Directory of Open Access Journals (Sweden)

    Adolfo Armando Rayas Amor

    2012-04-01

    Full Text Available This paper has two objectives, the first is to determine the chemical composition, gas production parameters and the gas release kinetics, at different stages of maturity, of three grasses and a legume commonly found in long established pastures in Mexico central highland plateau. The second is to combine the gas release kinetics analysis and the GP fitted to a mathematical model in order to improve the biological understanding of the fermentation kinetics obtained from the GP technique. Representative samples of Pennisetum clandestinum (kikuyu grass, Sporobolus indicus (mouse tail, Eleocharis dombeyana (reed, Trifolium amabile (Aztec clover plus a composite sample were collected in the growing season (July, September and November 2003 and analysed using an in vitro gas production (GP technique. The accumulated GP was fitted to the model described in PALMER et al. (2005. Significant differences (PO uso da análise de cinética de produção de gases, em conjunto com a análise de prova de curva e as propriedades químicas da forragem permitem uma melhor descrição das características nutritivas das forragens. Objetivou-se estudar a composição nutritiva e características de fermentação de ruminal de três gramíneas, uma leguminosa e uma mistura composta de pastagens do Planalto Montanhoso Central do México. As amostras representativas de Pennisetum clandestinum (kikuyu grama, Sporobolus indicus (rabo de rato, Eleocharis dombeyana (cana, Trifolium amabile (trevo asteca mais uma amostra composta foram coletadas durante os meses de Julho, Setembro e Novembro de 2003. Foi utilizada a técnica de produção de gás in vitro (GP. Os perfis de GP foram ajustados ao modelo descrito por PALMER et al. (2005. As diferenças (P<0.001 foram observadas entre espécies e períodos quanto à composição química, matéria orgânica e digestibilidade da fibra em detergente neutro. As diferenças (P<0.05 dos parâmetros de fermentação e cinética de

  19. Competition Policy in Mexico

    OpenAIRE

    Ernesto Estrada Gonzalez

    2008-01-01

    The CFC faces significant challenges from cartel activity, prevailing regulatory restrictions on competition, and exclusionary practices undertaken by some of the most powerful corporations in Mexico.

  20. Endemic Mimosa species from Mexico prefer alphaproteobacterial rhizobial symbionts

    OpenAIRE

    Bontemps, C.; Rogel, M. A.; Wiechmann, A.; Mussabekova, A.; Moody, S.; Simon, M F; Moulin, Lionel; Elliott, G. N.; Lacercat-Didier, L.; Dasilva, C.; Grether, R; Camargo-Ricalde, S. L.; Chen, W.M.; SPRENT, J. I.; Martinez-Romero, E.

    2016-01-01

    The legume genus Mimosa has > 500 species, with two major centres of diversity, Brazil (c. 350 spp.) and Mexico (c. 100 spp.). In Brazil most species are nodulated by Burkholderia. Here we asked whether this is also true of native and endemic Mexican species. We have tested this apparent affinity for betaproteobacteria by examining the symbionts of native and endemic species of Mimosa in Mexico, especially from the central highlands where Mimosa spp. have diversified. Nodules were tested for ...

  1. Richness and endemism of the freshwater fishes of Mexico

    OpenAIRE

    T. Contreras-MacBeath; M. B. Rodríguez; Sorani, V.; Goldspink, C.; G. McGregor Reid

    2014-01-01

    A study of richness and endemism of the freshwater fishes of Mexico, was carried out in order to identify hotspots and inform conservation efforts. This was done by mapping and overlaying individual species distributions by means of geographical information systems based on museum data. The study was able to confirm several previously proposed centres of freshwater fish richness (Southeastern Mexico, the Mesa Central, the Bravo-Conchos river system and the Panuco and Tuxpan-Nautla rivers). Se...

  2. An overview of the geology and major ore deposits of Central Africa: Explanatory note for the 1:4,000,000 map “Geology and major ore deposits of Central Africa”

    Science.gov (United States)

    Milesi, J. P.; Toteu, S. F.; Deschamps, Y.; Feybesse, J. L.; Lerouge, C.; Cocherie, A.; Penaye, J.; Tchameni, R.; Moloto-A-Kenguemba, G.; Kampunzu, H. A. B.; Nicol, N.; Duguey, E.; Leistel, J. M.; Saint-Martin, M.; Ralay, F.; Heinry, C.; Bouchot, V.; Doumnang Mbaigane, J. C.; Kanda Kula, V.; Chene, F.; Monthel, J.; Boutin, P.; Cailteux, J.

    2006-04-01

    This paper is prepared within the frameworks of IGCP Project 470 and the associated BRGM scientific project "Africa 1999-2004" to accompany the 1:4,000,000 scale map "Geology and major ore deposits of Central Africa, presented at the 20th Colloquium of African Geology in Orleans in June 2004. It incorporates geological and metallogenic data from eight countries in Central Africa (Angola, Cameroon, Chad, Central African Republic, Congo Brazzaville, Democratic Republic of Congo (DRC), Equatorial Guinea and Zambia). The map is a harmonised and geo-referenced preliminary map, based on a GIS at 1:2,000,000 scale, and focusses on the spatial and temporal distribution of selected major deposits.

  3. 蓝屋顶多金属矿床地质特征及成矿模式探讨%Discussion on Geological Characteristics and Metallogenic Model of Lanwuding Deposit in Lianping County,Guangdong Province

    Institute of Scientific and Technical Information of China (English)

    文昌生; 王军

    2015-01-01

    The Lanwuding mining area is situated in Jiulian town,Lianping county of Guandong Province.It is adjacent to the large polymetallic ore of Jubangkeng,which is in the nortern of Yaolin-Shirenzhang-Meiziwo-Dajishan-Jubangkeng tungsten mineralization zone of Nanling multi-metallic mineralized belt.The tungsten mineralization belt is an important metallogenic belt of the Naling area,which is characterized as a wealth of vein-type tungsten deposits with five leveling zoning feature.The metallogenic prognosis exploration and geochemical anomaly investigation indicate that Lanwuding has the similar multi-metallic mineralization type and gangue mineral assemblages with Jubangkeng,which could be the five level zoning metallogenic model.%蓝屋顶矿区位于广东省连平县东北九连镇,紧邻重要的多金属矿锯板坑矿区,即南岭成矿带中的瑶岭—石人嶂—梅子窝—大吉山—锯板坑钨矿带的东端,该钨矿带是南岭地区最为重要的成矿带之一,以大量出现“五层楼”式脉状钨矿床为特色。成矿预测勘查和化学异常调查表明,蓝屋顶矿区与锯板坑矿区的多金属矿化类型和脉石矿物组合类似,可能具有“五层楼”模式。

  4. Mexico Agriculture Policy Review

    OpenAIRE

    Cahill, Carmel; Jotanovic, Aleksandar; Abraham, Cally

    2008-01-01

    As a NAFTA partner and Canada's third largest export market for agri-food products, developments in Mexico are of direct interest to Canada. Rural poverty, low productivity, poor infrastructure and unclear property rights for both land and water still inhibit the efforts of Mexico's government to improve competitiveness of its agricultural sector.

  5. Variation of molybdenum isotopes in molybdenite from porphyry and vein Mo deposits in the Gangdese metallogenic belt, Tibetan plateau and its implications

    Science.gov (United States)

    Wang, Yong; Zhou, Lian; Gao, Shan; Li, Jian-Wei; Hu, Zhi-Fang; Yang, Lu; Hu, Zhao-Chu

    2016-02-01

    We present Mo isotopic ratios of molybdenite from five porphyry molybdenum deposits (Chagele, Sharang, Jiru, Qulong, and Zhuonuo) and one quartz-molybdenite vein-type deposit (Jigongcun) along the Gangdese metallogenic belt in the Tibetan Plateau. These deposits represent a sequence of consecutive events of the India-Asia collision at different periods. Additional molybdenite samples from the Henderson Mo deposit (USA), the oceanic subduction-related El Teniente (Chile), and Bingham (USA) porphyry Cu-(Mo) deposits were analyzed for better understanding the controls on the Mo isotope systematics of molybdenite. The results show that molybdenite from Sharang, Jiru, Qulong, and Zhuonuo deposits have similar δ97Mo (˜0 ‰), in agreement with the values of the Henderson Mo deposit (-0.10 ‰). In contrast, samples from the Changle and Jigongcun deposit have δ97Mo of 0.85 ‰ to 0.88 ‰ and -0.48 %, respectively. Molybdenite from the El Teniente and Bingham deposits yields intermediate δ97Mo of 0.27 and 0.46 ‰, respectively. The Mo isotopes, combined with Nd isotope data of the ore-bearing porphyries, indicate that source of the ore-related magmas has fundamental effects on the Mo isotopic compositions of molybdenite. Our study indicates that molybdenite related to crustal-, and mantle-derived magmas has positive or negative δ97Mo values, respectively, whereas molybdenite from porphyries formed by crust-mantle mixing has δ97Mo close to 0 ‰. It is concluded that the Mo isotope composition in the porphyry system is a huge source signature, without relation to the tectonic setting under which the porphyry deposits formed.

  6. The origin of the Avram Iancu U-Ni-Co-Bi-As mineralization, Băiţa (Bihor) metallogenic district, Bihor Mts., Romania

    Science.gov (United States)

    Zajzon, Norbert; Szentpéteri, Krisztián; Szakáll, Sándor; Kristály, Ferenc

    2015-10-01

    The Băiţa metallogenic district in the Bihor Mountains is a historically important mining area in Romania. Uranium mining took place between 1952 and 1998 from various deposits, but very little is known about the geology and mineralogy of these deposits. In this paper, we describe geology and mineralogy of uranium mineralization of the Avram Iancu uranium mine from waste dump samples collected before complete remediation of the site. Texturally and mineralogically complex assemblages of nickeline, cobaltite-gersdorffite solid solution, native Bi, Bi-sulfosalts, molybdenite, and pyrite-chalcopyrite-sphalerite occur with uraninite, "pitchblende," and brannerite in most of the ore samples. The association of nickel, cobalt, and arsenic with uranium is reminiscent of five-element association of vein type U-Ni-Co-Bi-As deposits; however, the Avram Iancu ores appear to be more replacement-type stratiform/stratabound. Avram Iancu ore samples contain multistage complex, skarn, uranium sulfide, arsenide assemblages that can be interpreted to have been formed in the retrograde cooling stages of the skarn hydrothermal system. This mineralizing system may have built-up along Upper Cretaceous-Paleogene "Banatite" intrusions of diorite-to-granite composition. The intrusions crosscut the underlying uraniferous Permian formations in the stacked NW-verging Biharia Nappe System. The mineralization forms stacked, multilayer replacement horizons, along carbonate-rich lithologies within the metavolcanic (tuffaceous) Muncel Series. Mineral paragenesis and some mineral chemistry suggest moderate-to-high solid solutions associated with minute but abundant uranium minerals. Within the later arsenide-sulfarsenide mineral assemblage, there is great variation in Ni, Co, and S content with generally increasing arsenic content. Uranium minerals in this late-stage assemblage include very fine euhedral uraninite and brannerite inclusions in arsenide-sulfarsenide minerals. Native bismuth and Bi

  7. Geochronology and geochemistry of the Badaguan porphyry Cu-Mo deposit in Derbugan metallogenic belt of the NE China, and their geological significances

    Science.gov (United States)

    Gao, Bingyu; Zhang, Lianchang; Jin, Xindi; Li, Wenjun; Chen, Zhiguang; Zhu, Mingtian

    2016-03-01

    The Badaguan porphyry Cu-Mo deposit belongs to the Derbugan metallogenic belt, which is located in the Ergun block, NE China. In the mining area, the Cu-Mo mineralization mainly occurs in quartz diorite porphyry and is hosted within silicified-sericitized and sericite alteration zone. Geochemical results of the host porphyry is characterized by high SiO2, high Al2O3, low MgO, weak positive Eu anomalies and clearly HREE depletion, high Sr, low Y and low Yb, similar to those of adakite. The Sr-Nd isotopic composition of the host porphyry displays an initial (87Sr/86Sr)i ratio of 0.7036-0.7055 and positive Nd( t) values of +0.1 to +0.6, which are similar to the OIB, reflecting the source of the host porphyry may derive from subducted ocean slab, and the new lower crust also had some contribution to the magma sources. The SIMS zircon U-Pb age from the host porphyry is 229 ± 2 Ma. The Re-Os isochron age for the molybdenite in the deposit is 225 ± 2 Ma closed to zircon U-Pb age of the host porphyry, indicating that Cu-Mo mineralization event occurred in Triassic. Combining the geology-geochemistry of the host porphyry and the regional tectonic evolution, we infer that the subduction processes of Mongol-Okhotsk oceanic slab under the Ergun block led to the formation of the Badaguan porphyry Cu-Mo deposit during the Triassic.

  8. Zircon U-Pb dating of Maherabad porphyry copper-gold prospect area: evidence for a late Eocene porphyry-related metallogenic epoch in east of Iran

    Directory of Open Access Journals (Sweden)

    Azadeh Malekzadeh Shafaroudi

    2011-04-01

    Full Text Available Eastern Iran has great potential for porphyry copper deposits, as a result of its past subduction zone tectonic setting that lead to extensive alkaline to calc-alkaline magmatic activity in Tertiary time. Maherabad is the first porphyry Cu-Au prospecting area which is discovered in eastern Iran. This is related to a succession o f monzonitic to dioritic porphyries stocks that were emplaced within volcanic rocks. Monzonitic porphyries have basic role in mineralization. Hydrothermal alteration zones are well developed including potassic, sericitic-potassic, quartz-sericite-carbonate-pyrite, quartz-carbonate-pyrite, silicified-propylitic, propylitic, carbonate and silicified zones. Mineralization occurs as Disseminated, stockwork and hydrothermal breccia. Based on early stage of exploration, Cu is between 179- 6830 ppm (ave. 3200 ppm and Au is up to 1000 ppb (ave. 570 ppb. This prospect is gold- rich porphyry copper deposit. Laser-ablation U-Pb dating of two samples from ore-related intrusive rocks indicate that these two monzonitic porphyries crystallized at 39.0 ± 0.8 Ma to 38.2 ± 0.8 Ma, within a short time span of less than ca. 1 Ma during the middle Eocene. This provides the first precise ages for metallogenic episode of porphyry-type mineralization. Also, the initial 87Sr/86Sr and (143Nd/144Ndi was recalculated to an age of 39 Ma. Initial 87Sr/86Sr ratios for monzonitic rocks are 0.7047-0.7048. The (143Nd/144Ndi isotope composition are 0.512694-0.512713. Initial ε Nd isotope values 1.45-1.81. Based on isotopic data the magma had originated beyond the continental crust. The study will be used for tectonic-magmatic setting and evolution of eastern Iran. Keywords: Lut block, Middle Eocene, Zircon, Geochronology, Laser ablation ICP-MS,

  9. Trends in Production, Trafficking and Consumption of Methamphetamine and Cocaine in Mexico

    OpenAIRE

    Brouwer, Kimberly C.; Case, Patricia; Ramos, Rebeca; Magis-Rodríguez, Carlos; Bucardo, Jesus; PATTERSON, THOMAS L.; Strathdee, Steffanie A

    2006-01-01

    Over the past decade, Mexico has experienced a significant increase in trafficking of cocaine and trafficking and production of methamphetamine. An estimated 70% of U.S. cocaine originating in South America passes through the Central America-Mexico corridor. Mexico-based groups are now believed to control 70%–90% of methamphetamine production and distribution in the U.S. Increased availability of these drugs at reduced prices has led to a parallel rise in local drug consumption. Methamphetami...

  10. C and S isotope characteristics of bitumen, calcite, Fe and Cu sulfides in the metallogenic analysis of the Ocoita metallotec

    International Nuclear Information System (INIS)

    As a result of a significant increase in the rate of convergence of the Phoenix and South American plates during the Early Cretaceous (120 -100 Ma.), a basin, defined by Aberg et al., (1984) as an 'Aborted Marginal Basin', developed in Central Chile. In the late stages of this back-arc marine basin, submarine lava flows extruded through the thinned continental crust underlying the bottom of the shallow sea. The porphyritic lavas of the Pabellon Formation are the northernmost units of this event and are very similar to those of the Ocoa member in the Veta Negra Formation (Cisternas et al. 1999). The lava sequence lies conformably above calcareous rocks of the Pabellon Formation (Barremian-Aptian) and average 70 meters of thickness. The whole sequence dips to the east with a north-south directed strike. A notable characteristic of these lavas are the abundant (>40%) centimeter-size plagioclase phenocrysts, which can be associated with the 'lavas ocoiticas' or 'ocoitas' of the Ocoa member in the Veta Negra Formation of Central Chile. Geochemical analysis of the Pabellon formation lavas indicates that these lavas were derived from K-rich calc-alkaline to transitional magmas, typical of a continental margin subduction, however with an important component of intra-plate contamination (Galindo 1998; Cisternas et al., 1999). The basal rocks are cut by intrusives (119-93 ma.), the same age as the lavas. These intrusives are believed to be the source of heat needed for the thermal maturation of organic matter in the underlying beds. The organic matter rich limestones of the Nantoco formation are the most probable source of the hydrocarbons, which were mobilized by hydrothermal fluids and deposited in veinlets and voids in the lavas (au)

  11. Census Snapshot: New Mexico

    OpenAIRE

    Romero, Adam P; Rosky, Clifford J; Badgett, M.V. Lee; Gates, Gary J.

    2008-01-01

    Using data from the U.S. Census Bureau, this report provides demographic and economic information about same-sex couples and same-sex couples raising children in New Mexico. We compare same-sex “unmarried partners,” which the Census Bureau defines as an unmarried couple who “shares living quarters and has a close personal relationship,” to different-sex married couples in New Mexico. In many ways, the more than 6,000 same-sex couples living in New Mexico are similar to married couple...

  12. Mexico; Selected Issues

    OpenAIRE

    International Monetary Fund

    2007-01-01

    This Selected Issues paper analyzes external shocks and business cycle fluctuations in Mexico. The paper examines the relative importance of U.S. demand shocks—and other foreign disturbances—in explaining Mexican output fluctuations. It identifies the dynamic response of Mexico’s output to those shocks. The paper investigates which U.S. variables are most relevant to explaining business cycles in Mexico. It analyses potential spillovers and channels of transmission underlying the linkag...

  13. Mexico; Selected Issues

    OpenAIRE

    International Monetary Fund

    2004-01-01

    This Selected Issues paper analyzes reserve adequacy in Mexico. Reserve adequacy has been of renewed interest, as the authorities have introduced a new rules-based mechanism of U.S. dollar sales to reduce the rate of reserve accumulation. The paper examines the recent experience with Mexico’s fiscal management tools in light of the need for further consolidation. It reviews evidence on the cyclical behavior of fiscal policy in Mexico, finding that it has generally been procyclical since the...

  14. Mexico; Selected Issues

    OpenAIRE

    International Monetary Fund

    2013-01-01

    This Selected Issues paper analyzes reforms to Mexico’s fiscal framework. Mexico’s resilient economic performance would be consolidated by increasing fiscal policy buffers and preparing for challenges associated with long-term budget pressures. In the short term, reducing public debt levels can create space to implement countercyclical fiscal policies and reduce exposure to high financing and hedging costs, which would protect Mexico’s credit rating at times of distress. The paper highl...

  15. Morfología, diversidad y distribución de los Cyclopoida (Copepoda de zonas áridas del centro-norte de México. I. Cyclopinae Morphology, diversity, and distribution of the Cyclopoida (Copepoda from arid areas of central-north Mexico. I. Cyclopinae

    Directory of Open Access Journals (Sweden)

    Nancy F. Mercado-Salas

    2011-04-01

    Full Text Available Los copépodos ciclopoides de aguas continentales representan un grupo cuya diversidad y biogeografía han sido estudiadas en distintas zonas de México pero su conocimiento en los ambientes áridos, principalmente en la región centro-norte del país, era muy limitado. A partir de muestras previamente obtenidas (1985-2008 y de nuevas recolecciones, se revisaron los copépodos de la subfamilia Cyclopinae de los cuerpos de agua de esta extensa zona árida de México. El estudio abarcó tres eco-regiones prioritarias (CONABIO que incluyen los estados de Aguascalientes, Zacatecas, San Luis Potosí, Durango, Chihuahua y Coahuila. Se encontraron 16 especies de Cyclopinae, incluyendo 3 especies no descritas (una de Acanthocyclopsy dos de Microcyclops y otras posiblemente endémicas de esta región del país; se registra por primera vez al género Metacyclops en México. Se proporcionan diagnosis e ilustraciones taxonómicas de las especies encontradas y se hacen análisis comparativos de los especímenes examinados. Se presentan 22 nuevos registros estatales de ciclópinos; se trata, además, del primer estudio taxonómico de los copépodos continentales enfocado a esta región árida de México. Con los hallazgos presentados el número de especies de Cyclopinae presentes en México aumentó de 37 a 43 (16%.Freshwater cyclopoid copepods represent a group whose diversity and biogeography has been studied in different areas of Mexico, but its knowledge in arid environments, mainly in the Central-Northern region of the country, was still limited. From samples previously obtained (1985-2008 and also from new collections, we reviewed the copepod of the subfamily Cyclopinae from water bodies of this extense arid zone of Mexico. This study incorporated three priority eco-regions (CONABIO, that include the states of Aguascalientes, Zacatecas, San Luis Potosí, Durango, Chihuahua and Coahuila. Up to 16 species of the subfamily Cyclopinae were found, including

  16. 1973 Veracruz, Mexico Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — South of Veracruz, southeastern Mexico. Damage: Severe. The earthquake caused heavy damage in the states of Morelos, Puebla, and Veracruz. Thousands were left...

  17. New Mexico Mountain Ranges

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The Geographic Names Information System (GNIS) actively seeks data from and partnerships with Government agencies at all levels and other interested organizations....

  18. New Mexico Federal Lands

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This map layer consists of federally owned or administered lands of the United States, Puerto Rico, and the U.S. Virgin Islands. Only areas of 640 acres or more are...

  19. Mexico - Surface Weather Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Mexican Surface Daily Observations taken at 94 observatories located throughout Mexico, beginning in 1872 and going up through 1981. The data resided on paper...

  20. Occupational health in Mexico.

    Science.gov (United States)

    Carreón, Tania; Santos-Burgoa, Carlos; Baron, Sherry; Hernández, Sendy

    2002-01-01

    The authors discuss the maquiladoras and child labor, and offer an overview of the history of occupational safety and health in Mexico that covers laws and regulations, social security, unions, and enforcement of legislation. The organization and structure of the various institutions responsible for occupational safety and health (OSH), as well as administrative procedures, are described. This article concludes with a list of the new challenges for OSH in Mexico. PMID:12028953

  1. Doing Business in Mexico

    OpenAIRE

    Zimmermann, Thomas A.

    2002-01-01

    On 1 July 2001, a far-reaching free trade agreement between the EFTA States and Mexico entered into force. ”Doing Business in Mexico” provides targeted assistance to Swiss Small and Medium-Sized Enterprises (SME) that wish to tap the potential of Mexico as both an export destination and investment location. This comprehensive guide contains information and advice on market research, market entry, and investment in this fascinating country. Part I introduces the reader to this fascinating ...

  2. Privatization in Mexico

    OpenAIRE

    Chong, Alberto; Lopez-de-Silanes, Florencio

    2004-01-01

    Over the last 20 years, Mexico redefined the role of the state in its economy through an ambitious program to liberalize trade, promote efficiency and reduce the size and scope of the state-owned sector. In Mexico, privatization led to a significant improvement in firm performance, as profitability increased 24 percentage points and converged to levels similar to those of private firms. From this increase, at most 5 percent can be attributed to higher prices and 31 percent to transfers from w...

  3. Mexico; Selected Issues Paper

    OpenAIRE

    International Monetary Fund

    2010-01-01

    This Selected Issues paper analyzes the global crisis and potential growth in Mexico. The paper uses two methodologies to assess to what extent the global crisis is likely to weigh on Mexico’s growth potential. The first approach is sectoral, examining the historical relationship between financial stress and growth in manufacturing industries. The second approach uses a growth-accounting framework to take a closer look at likely developments in the factors that drive potential growth. The p...

  4. Mexico; Selected Issues

    OpenAIRE

    International Monetary Fund

    2011-01-01

    Mexico’s growth process in trend and cyclical factors, with implications for policy decisions, is discussed. Mexico’s trade integration has been important for growth. But the high export growth experienced has been followed by a more muted performance. Reforms to improve productivity are important to sustain export dynamism. Fiscal credibility, underpinned by prudent fiscal management and a strong fiscal framework, permitted a countercyclical fiscal response during the global crisis. Howe...

  5. REDD+ i Mexico

    OpenAIRE

    Leithoff Christensen, Anneliese; Bondo Vester, Rasmus; Q. Madsen, Camilla Henriette

    2014-01-01

    Mexico joined the REDD+ program (Reducing emissions from deforestation and forest degradation) in 2010, and has since worked on the design of a national strategy to be implemented in the country. Through ACF's theoretical perspective, we analyze advocacy coalitions and belief systems of the actors in the subsystem in the design of Mexico's REDD+ national strategy. All coalitions in the subsystem share a deep core belief that REDD+ as vision has the potential to tackle deforestation problems. ...

  6. Poverty alleviation in Mexico

    OpenAIRE

    Levy, Santiago

    1991-01-01

    This paper is concerned with the problem of poverty in Mexico. Its four objectives are to : i) present evidence; ii) analyze economic determinants; iii) discuss policy options; and iv) assess existing poverty programs. The author begins by giving a very brief discussion of recent economic events, as these set the stage for poverty programs in the 1990's. The paper goes on to discuss the concept of poverty measurement. The author presents evidence of the extent of poverty in Mexico. He aims at...

  7. Bottlenose dolphin age structure and growth in the Mississippi Sound region of the Gulf of Mexico

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Teeth were collected from bottlenose dolphins that stranded within the north-central Gulf of Mexico between 1986-2003. These teeth were sectioned and growth rings...

  8. Radon-in-soil concentration levels in Mexico

    International Nuclear Information System (INIS)

    Radon-in-soil surveys in Mexico have been carried out since 1974 both for uranium prospecting and to correlate mean values of the gas emanation with local telluric behaviour. The mapping covers the northern uranium mining region, the Mexican Neovolcanic Belt, the coastal areas adjacent to the zone of subduction of the Cocos Plate under the North American Plate, some of the active volcanoes of Southern Mexico and several sedimentary valleys in Central Mexico. Recording of 222Rn alpha decay is systematically performed with LR115 track detectors. Using mean values averaged over different observation periods at fixed monitoring stations, a radon-in-soil map covering one third of the territory of Mexico is presented. The lowest mean values occur in areas associated with active volcanoes. The highest levels are found in uranium ore zones. Intermediate values are obtained in regions with enhanced hydrothermal activity and stations associated with intrusive rocks. (author)

  9. Geological, geochronological, and mineralogical constraints on the genesis of the Chengchao skarn Fe deposit, Edong ore district, Middle-Lower Yangtze River Valley metallogenic belt, eastern China

    Science.gov (United States)

    Yao, Lei; Xie, Guiqing; Mao, Jingwen; Lü, Zhicheng; Zhao, Caisheng; Zheng, Xianwei; Ding, Ning

    2015-04-01

    The Edong ore district is located within the westernmost Middle-Lower Yangtze River Valley metallogenic belt (MLYRB), and hosts the largest concentration of skarn Fe deposits in China, although the origin of these deposits remains controversial. The Chengchao deposit is the largest skarn Fe deposit so far discovered within the MLYRB, and provides a good opportunity to address the debate surrounding the origin of these skarn Fe deposits. Here, we present geological, geochronological, and mineralogical data from the Chengchao skarn deposit and associated intrusions, and discuss the relationships between granitoids and mineralization in the Chengchao deposit. The NW-SE-striking orebodies in the study area have porphyritic quartz monzonite and/or granite footwalls, and Triassic marble or diorite hangingwalls, indicating a spatial relationship between these intrusions and Fe mineralization. Zircon U-Pb data from the granite, porphyritic quartz monzonite, diorite, and porphyritic diabase dike within the deposit show ages of 129 ± 1, 128 ± 1, 140 ± 1, and 126 ± 1 Ma, respectively. These ages and the previously reported ages on the timing of mineralization suggest that the porphyritic quartz monzonite and granite are coeval with the formation of the skarn Fe deposit. Our data confirm that the granitic rocks are temporally associated with Fe mineralization. The prograde substage of skarn development is characterized by two stages of andradite (Adr98-38Grs61-2Prp2-0Sps1-0Alm1-0) and diopside (Di95-61Hd37-5Jo3-0), including an early stage of garnet and pyroxene formation that is genetically associated with the mineralization. The early stage garnets are more andradite-rich (Adr98-50Grs49-2Prp1-0Sps1-0Alm0) than the late veinlet garnets characterized by intermediate grandite compositions (Adr67-37Grs61-31Prp2-0Sps1-0Alm1-0). The early stage pyroxenes (Di95-74Hd26-5Jo1-0) are compositionally distinct from the late stage pyroxenes (Di84-61Hd37-16Jo3-0). Compositional

  10. Apatite trace element and halogen compositions as petrogenetic-metallogenic indicators: Examples from four granite plutons in the Sanjiang region, SW China

    Science.gov (United States)

    Pan, Li-Chuan; Hu, Rui-Zhong; Wang, Xin-Song; Bi, Xian-Wu; Zhu, Jing-Jing; Li, Chusi

    2016-06-01

    The abundances of trace elements including Sr, Ga and rare earth elements (REE) and halogens in apatite crystals from four intermediate-felsic plutons in the Zhongdian terrane in the Sanjiang region have been determined using electron microprobe and laser ablation inductively coupled plasma mass spectrometry to evaluate the potential of apatite as a petrogenic-metallogenic indicator. The selected plutons include one that is not mineralized (the Triassic Xiuwacu pluton, or the TXWC pluton), one that hosts a porphyry-type Cu deposit (the Pulang pluton, or the PL pluton), one that hosts a porphyry-type Mo deposit (the Tongchanggou pluton, or the TCG pluton), and one that hosts a vein-type Mo deposit (the Cretaceous Xiuwacu pluton, or the CXWC pluton). Except for the CXWC pluton, the other three plutons have adakite-like trace element signatures in whole rocks. The results from this study show that REE, Sr and halogens in apatite can be used to track magma compositions, oxidation states and crystallization history. Apatite crystals from the adakite-like plutons are characterized by much higher Sr/Y and δEu than the non-adakite-type pluton. This means that apatite, which is not susceptible to alteration, is a useful tool for identifying the adakite-like plutons that no longer preserve the initial Sr/Y ratios in whole rocks due to weathering and hydrothermal alteration. Based on apatite Ga contents and δEu values, it is inferred that the parental magmas for the two adakite-like plutons containing porphyry-type Cu and Mo mineralization are more oxidized than that for the non-adakite-type pluton containing vein-type Mo mineralization. Apatite crystals from the vein-type Mo deposit have much lower Cl/F ratios than those from the porphyry-type Cu and Mo deposits. Apatite crystals from the adakite-like pluton without Cu or Mo mineralization is characterized by much lower Cl/F ratios than those from the adakite-like plutons that host the porphyry-type Cu and Mo deposits. The

  11. A new species of Metathelazia (Nematoda: Pneumospiruridae from the lungs of a nine-banded armadillo in Central Mexico Especie nueva de Metathelazia (Nematoda: Pneumospiruridae de los pulmones de un armadillo del centro de México

    Directory of Open Access Journals (Sweden)

    F. Agustín Jiménez

    2013-03-01

    Full Text Available Twenty-four worms were collected from the bronchioles in both lungs of a male nine-banded armadillo Dasypus novemcinctus Linnaeus, 1758 captured in Teacalco, Morelos, Mexico. The worms, herein named Metathelazia mexicana n. sp., show a constriction in the esophagus at the level of the nerve ring; males of the species have 7 pairs of papillae, fewer than the other species in the genus. Metathelazia capsulata is the most similar species to Metathelazia mexicana; however, the latter has much shorter spicules. This is the fourth species in the genus known to occur in the New World.Se recolectó un total de 24 nemátodos de las cavidades bronquiales de un armadillo de 9 bandas Dasypus novemcinctus Lineo, 1758 en la localidad de Teacalco, Morelos, México. Los nemátodos, descritos con el nombre Metathelazia mexicana, muestran una constricción en el esófago al nivel del anillo nervioso y 7 pares de papilas caudales en los machos, número que es menor al observado en las otras especies del género. Metathelazia mexicana es semejante a Metathelazia capsulata en varios rasgos morfológicos pero difiere en el tamaño de las espículas, que son más cortas en la especie aquí descrita. Esta es la cuarta especie del género registrada en el continente americano.

  12. Geology Spatial Data Mining Method for Regional Metallogenic Prediction%基于地质空间数据挖掘的区域成矿预测方法

    Institute of Scientific and Technical Information of China (English)

    何彬彬; 崔莹; 陈翠华; 陈建华

    2011-01-01

    以多源地质空间数据库和空间数据挖掘技术为基础,顾及地质数据的空间特征和不确定性,提出一种基于地质空间数据挖掘的区域成矿预测方法,主要包括:连续型地质空间数据离散化、成矿空间关系提取及属性化、成矿关联规则提取及质量评价、成矿关联规则综合评价与潜力制图.最后,以青海省东昆仑地区铁矿资源潜力预测为例进行实验,并将地质空间数据挖掘预测结果与传统的证据权模型预测结果进行对比.实验对比结果表明,基于地质空间数据挖掘的预测结果较传统的证据权模型方法预测精度更高,该方法用于区域成矿预测效果良好.%Spatial data mining (SDM) refers to extracting and "mining" the hidden, implicit, valid, novel and interesting spatial or non-spatial patterns or rules from a large amount of, incomplete, noisy, fuzzy, random, and practical spatial databases. At present, SDM mainly concentrates on the efficiency of mining algorithm itself. Another important issue-application in SDM-has not been paid much attention to. Geological data are typical spatial data, which include geological, geophysical, geochemical, and remote sensing data. Regional metallogenic prediction and quantitative resource assessment have been recognized as important when integrating multi-source geological spatial data in recent years. The statistical and mathematical approaches that have developed recently for multiresources geological spatial data integration include weights-of -evidence modelling, and the logistic regression modeling. The fuzzy logic model, artificial neural networks model and the fractal method have been applied in the prediction and assessment of mineral resources potential. These methods promote the effectiveness of mineral resource prospecting. However, under the shortage of mineral resources and the leap cost of prospecting and exploring, how to make full use of the existing multi-sources geo

  13. H-66 híbrido de maíz para los valles altos de los estados de México y Tlaxcala H-66 maize hybrid for the central highlands of the Mexico and Tlaxcala states

    Directory of Open Access Journals (Sweden)

    José Luis Arellano Vázquez

    Full Text Available El nuevo maíz híbrido H-66 fue desarrollado en el Campo Experimental Valle de México (CEVAMEX del Instituto Nacional de Investigaciones Forestales Agrícolas y Pecuarias (INIFAP; este híbrido se adapta a los Valles Altos (> 2 200 m en el Estado de México y Tlaxcala. H-66 se obtuvo de tres líneas (M43/M44//M52; M52 es una línea del programa de maíz del Centro Internacional de Mejoramiento de Maíz y Trigo (CIMMYT, mientras que las líneas M43 y M44 se derivaron de un criollo colectado en una localidad de la parte alta del estado de Michoacán. H-66 es un híbrido cuyo grano es de color blanco y se recomienda para condiciones de riego y temporal. El rendimiento del híbrido H-66 varía de 6.5 a 10.5 t ha-1, supera entre 7 y 12% el rendimiento de híbridos comerciales de compañías privadas, que se cultivan en la región bajo las mismas condiciones. Es resistente al acame y a enfermedades que se presentan en la región, como son: pudrición de la mazorca (Fusarium moniliforme Sheldon, estado perfecto Giberella fujikuroi Sawada y carbón de la espiga (Sporisorium reilianum= Sphacelotheca reiliana. El grano de maíz H-66 se recomienda para la industria de la masa y la tortilla.The new maize hybrid H-66 was developed in the Valley of Mexico Experimental Field (CEVAMEX of the National Forestry, Agriculture and Cattle Research Institute (INIFAP. This hybrid adapts to the high valleys (> 2 200 m in the states of Mexico and Tlaxcala. H-66 was obtained from three lines (M43/M44//M52; M52 is a line of the maize program of the International Maize and Wheat Improvement Center (CIMMYT, while lines M43 and M44 were derived from a creole line derived from a location in the higher area in the state of Michoacán. H-66 is a hybrid with a white grain, recommended for irrigation and rainy conditions. The yield of hybrid H-66 varies from 6.5 to 10.5 t ha-1, and surpasses by 7 to 12% the yield of commercial hybrids from private companies, which are grown in

  14. Juvenile Justice in Mexico

    Directory of Open Access Journals (Sweden)

    Martha Frías Armenta

    2014-08-01

    Full Text Available The first tribunal in Mexico was established in the central state of San Luis Potosi in 1926. The Law Regarding Social Prevention and Juvenile Delinquency for the Federal District and Mexican territories was promulgated in 1928. In 2005, Article 18 of the Mexican Constitution was modified to establish a comprehensive system (“Sistema Integral de justicia” in Spanish of justice for juveniles between 12 and 18 years old who had committed a crime punishable under criminal law. Its objective was to guarantee juveniles all the due process rights established for adults, in addition to the special ones recognized for minors. The constitutional reform also provides a framework that includes special tribunals as well as alternative justice options for juveniles. With these reforms, institutionalization of minors was to be considered an extreme measure applicable only to felonies and to juveniles older than 14. In 2006, all states within the Mexican federation enacted the “Law of justice for adolescents”. This system, at both the federal and state levels, formalizes a new global paradigm with regard to the triangular relationship between children, the State and the Law. It recognizes that children are also bearers of the inherent human rights recognized for all individuals, instead of simply objects in need of protection. However, despite formally aligning Mexican juvenile justice law with the Convention on the Rights of the Child (CRC, issues of actual substantive rights remained and new ones have appeared. For example, juveniles younger than 14 who have not committed a felony are released from institutions without any rehabilitation or treatment options, and alternative forms of justice were included without evaluating their possibilities of application or their conditions for success. In addition, the economic status of most juvenile detainees continues to be one of the most important determining factors in the administration of justice

  15. American visceral leishmaniasis in Chiapas, Mexico.

    Science.gov (United States)

    Pastor-Santiago, Jorge A; Chávez-López, Susana; Guzmán-Bracho, Carmen; Flisser, Ana; Olivo-Díaz, Angélica

    2012-01-01

    We report the results of a study conducted during 1990-2006 with 89 cases of American visceral leishmaniasis in Chiapas State in southeastern Mexico and a seroprevalence study performed with 726 persons and 224 dogs that lived near cases of American visceral leishmaniasis. Clinical aspects, epidemiologic profiles, and risk factors are described. Most cases were in children ≤ 5 years of age, the prevalence of seropositive persons was 77%. The main risk factors associated with this disease were having 1-3 rooms in a house compared with ≥ 4 rooms, having a roof that was not made of cement, and having domestic animals. In contrast, only 19% of dogs were seropositive, suggesting that this species is not important in the transmission cycle of Leishmania. These data indicate that active transmission is taking place in the central valley of Chiapas State, Mexico, in communities located < 1,000 meters above sea level near the Grijalva River. PMID:22232459

  16. Distribution of hydrous minerals in the subduction system beneath Mexico

    Science.gov (United States)

    Kim, YoungHee; Clayton, Robert W.; Jackson, Jennifer M.

    2012-08-01

    Teleseismic converted phases are used to probe the composition of the downgoing oceanic crust as a function of depth along the Cocos slab in central and southern Mexico. Previously, modeling of the receiver function (RF) conversion amplitude of the flat Cocos slab beneath central Mexico at 45 km depth revealed a thin low-velocity upper oceanic crust of a thickness of 4±1 km, which has much lower seismic velocities (∼20-30% reduction in shear wave velocities) than (normal) lower crust. High Vp/Vs ratio (∼2.0) also suggested a large concentration of hydrous minerals such as talc in combination of high pore-fluid pressure in the horizontal segment. We extend this previous effort to examine seismic properties of both the steeply subducting Cocos oceanic crust beneath the Trans-Mexican Volcanic Belt (TMVB) in central Mexico and the shallowly dipping crust beneath southern Mexico. Inverted seismic velocities using the converted amplitudes at the top and bottom of the dipping oceanic crust are compared with experimentally constrained seismic velocities of candidate mineral phases in a range of likely pressures and temperatures. The composition of the oceanic crust downdip in the steep part of slab beneath the TMVB includes the minerals such as lawsonite and zoisite at 60-100 km depth, and the eclogitization occurs around 100 km depth. This is related to arc volcanism in the TMVB directly above the slab as well as the slab rollback. In contrast, the dominant mineral phase in the upper oceanic crust of southern Mexico beneath the Isthmus of Tehauntepec is amphibole on top of unaltered gabbroic oceanic crust. The difference in mineral assemblages of the subducted oceanic crust may help explain the difference in slab geometries between central and southern Mexico.

  17. New Mexico Voting Precincts (2008)

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This dataset contains the New Mexico Voting Precinct Boundaries as of July 2006. It is in a vector digital shapefile created to show the voting precinct coverage...

  18. New Mexico State Forestry Districts

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This dataset contains boundaries of the New Mexico Forestry Districts, plus the names of the district offices. It is in a vector digital structure digitized from a...

  19. HSIP Hospitals in New Mexico

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Hospitals in New Mexico The term "hospital" ... means an institution which- (1) is primarily engaged in providing, by or under the supervision of physicians, to...

  20. New Mexico Property Tax Districts

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This layer represents boundaries for New Mexico tax district "OUT" categories and incorporated/municipal "IN" categories as identified on the "Certificate of Tax...

  1. Humboldt's works on Mexico

    Directory of Open Access Journals (Sweden)

    Ulrike Leitner

    2000-10-01

    Full Text Available Article in English, Abstracts in Spanish and English. Humboldt wrote about Mexico from the perspective of a scientific explorer and naturalist. His works include his diaries, the Essai politique sur le royaume de la Nouvelle-Espagne, the Tablas géograficas, the Vues des Cordillères and a geographic atlas. Concerning the scientific aspect, the lack of a section on Mexico in the Relation historique is not a real deficit, since this can be found in the Essai. But only the diaries and letters from the journey, both published by the Alexander-von-Humboldt Research Centre, Berlin, can be considered an adequate substitute.The following will show the origin of Humboldt's writings on Mexico, offer historical and bibliographical facts and present the publications "Beiträge zur Alexander von Humboldt-Forschung", as well as Humboldt’s handwritten estate as far as they are available to us.

  2. Mexico; Selected Issues

    OpenAIRE

    International Monetary Fund

    2004-01-01

    This Selected Issues paper analyzes the sources of Mexico’s economic growth since the 1960s, and compares various decompositions of historical growth into trend and cyclical components. The role of the implied output gaps in the inflation process is assessed. The paper presents medium-term paths for GDP based on alternative productivity growth rates. The paper also describes the significant steps Mexico has taken to strengthen the structure of its public debt in recent years, both in terms ...

  3. Mexico; Selected Issues

    OpenAIRE

    International Monetary Fund

    2012-01-01

    Mexico is an open economy with strong real and financial links to the rest of the world with risks of spillovers from global turbulence. Recent gains in market share in the U.S. manufacturing market are owed to improved relative unit labor costs and reemergence of a location advantage. Mexico’s current fiscal framework requires measures to offset the emerging challenges of a decline in oil revenues and the projected increase in health- and pensions-related spending. The sustained increase o...

  4. Firearms in New Mexico.

    OpenAIRE

    Wiktor, S. Z.; Gallaher, M M; Baron, R C; Watson, M E; Sewell, C M

    1994-01-01

    To determine the prevalence of firearm ownership and storage practices in New Mexico, we did a random-digit-dialing survey of New Mexico residents in October 1991. Of 200 households surveyed, 79 (40%) had 1 or more firearms in the home. Rural households were more likely than urban households to have firearms (44% versus 30%), and households with annual incomes of greater than $25,000 were more likely to have a firearm than households with incomes of $25,000 or less (41% versus 33%). Household...

  5. Geological Fluid Mapping in the Tongling Area: Implications for the Paleozoic Submarine Hydrothermal System in the Middle-Lower Yangtze Metallogenic Belt, East China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The Tongling area is one of the 7 ore-cluster areas in the Middle-Lower Yangtze metallogenic belt, East China, and has tectonically undergone a long-term geologic history from the late Paleozoic continental rifting, through the Middle Triassic continent-continent collision to the Jurassic-Cretaceous intracontinental tectono-magmatic activation. The Carboniferous sedimentary-exhalative processes in the area produced widespread massive sulfides with ages of 303-321 Ma, which partly formed massive pyrite-Cu deposits, but mostly provided significant sulfur and metals to the skarn Cu mineralization associated with the Yanshanian felsic intrusions.To understand the Carboniferous submarine hydrothermal system, an area of about 1046 km2 was chosen to carry out the geological fluid mapping. Associated with massive sulfide formation, footwall sequences 948 m to 1146 m thick, composed of the Lower Silurian-Upper Devonian sandstone, siltstone and thin-layered shale, were widely altered. This hydrothermal alteration is interpreted to reflect largescale hydrothermal fluid flow associated with the late Paleozoic crustal rifting and subsidence. Three hydrothermal alteration types, i.e., deep-level semiconformable silicification (S1), fracture-controlled quartz-sericite-pyrite alteration (S2-3), and upper-level sub-discordant quartz-sericite-chlorite alteration (D3), were developed to form distinct zones in the mapped area. About 50-m thick semiconformable siliclfication zones are located at ~1-km depth below massive sulfides and developed between an impermeable shale caprock (S1) and the underlying Ordovician unaltered limestone.Comparisons with modern geothermal systems suggest that the alteration zones record a sub-seafloor aquifer with the most productive hydrothermal fluid flow. Fracture-controlled quartz-sericite-pyrite alteration formed transgressive zones, which downward crosscut the semiconformable alteration zones,and upwards grade into sub-discordant alteration zones

  6. [Food security in Mexico].

    Science.gov (United States)

    Urquía-Fernández, Nuria

    2014-01-01

    An overview of food security and nutrition in Mexico is presented, based on the analysis of the four pillars of food security: availability, access, utilization of food, and stability of the food supply. In addition, the two faces of malnutrition in Mexico were analyzed: obesity and undernourishment. Data were gathered from the food security indicators of the United Nations's Food and Agriculture Organization, from the Mexican Scale of Food Security, and from the National Health and Nutrition Survey. Mexico presents an index of availability of 3 145 kilocalories per person per day, one of the highest indexes in the world, including both food production and imports. In contrast, Mexico is affected by a double burden of malnutrition: whereas children under five present 14% of stunt, 30% of the adult population is obese. Also, more than 18% of the population cannot afford the basic food basket (food poverty). Using perception surveys, people reports important levels of food insecurity, which concentrates in seven states of the Mexican Federation. The production structure underlying these indicators shows a very heterogeneous landscape, which translates in to a low productivity growth across the last years. Food security being a multidimensional concept, to ensure food security for the Mexican population requires a revision and redesign of public productive and social policies, placing a particular focus on strengthening the mechanisms of institutional governance. PMID:25649459

  7. New Mexico's Challenge 2000.

    Science.gov (United States)

    Price, Robert M.; And Others

    This report presents a comprehensive strategy developed by the New Mexico Education Technology Planning Committee to maximize resources in educational technology to achieve the long-range goals adopted for education in the state. Four basic strategies are recommended: (1) to forge relationships between schools and businesses, and partnerships…

  8. The Art of Mexico.

    Science.gov (United States)

    Saccardi, Marianne

    1997-01-01

    Provides an annotated bibliography of books for grades K and up which explores the folklore, poetry, fiction, and art of Mexico, and focuses on the Mayans and Aztecs and Diego Rivera and Frida Kahlo. Also suggests various research, reading, drama, music, social studies, physical education, and art activities and lists related videos and Internet…

  9. Mexico Policy Notes

    OpenAIRE

    World Bank

    2013-01-01

    This note presents an overview of Mexico's forthcoming reform agenda-from the World Bank's vantage point. It distills the main messages in the policy notes that make up this compendium. The purpose is not to provide definitive answers to the many policy questions likely to occupy the New Mexican administration, or to provide a comprehensive account of progress to date and policy recommenda...

  10. Electroacoustic Music in Mexico

    OpenAIRE

    Rodrigo Sigal

    2010-01-01

    Mexico has been an outsider to the electroacoustic music movement. Countries likeArgentina, Cuba and Chile were pioneers in establishing electronic music centers in thecontinent. This texts aim to illustrate briefly the story behind the first initiatives in Mexicoandthe actual situation and characteristics of the institutional electroacoustic music scene.

  11. Human Rickettsialpox, Southeastern Mexico

    OpenAIRE

    Zavala-Castro, Jorge E.; Zavala-Velázquez, Jorge E.; Peniche-Lara, Gaspar F.; Uicab, Justo E. Sulú

    2009-01-01

    The detection of Rickettsia akari in 2 human patients increased the diversity of rickettsioses affecting the public health in the southeast of Mexico. Rickettsialpox should be considered in the differential diagnosis with other febrile illnesses for the correct diagnosis and accurate treatment of this potential threat to human health.

  12. Three-dimensional attenuation and velocity structure of the Cocos subduction zone in Mexico

    Science.gov (United States)

    Chen, T.; Clayton, R. W.

    2010-12-01

    The 3D P-wave attenuation and velocity structure of the Cocos subduction zone in Mexico is imaged using about 700 local events recorded by the MASE (100 seismometers running across central Mexico, 2005-2007) and VEOX (47 seismometers running across southern Mexico, 2007-2009) arrays, supplemented by stations from the National Seismic Network in Mexico (SSN). Using a spectral-decay method, we obtain a path attenuation operator t* for each seismogram in the frequency band 1 to 30 Hz, depending on the signal quality. These measurements are then inverted for 3D spatial variations in attenuation. Direct P wave arrivals are used for velocity inversion. Inversion results show low attenuation associated with the Cocos slab, and show the slab dip angle increases from central to southern Mexico. High attenuation is imaged in the mantle wedge and the crust above. The highest attenuation is found in the crust near the active Los Tuxtlas volcanic field, probably related to the dehydration and melting process. Cocos slab is also traced as high-velocity strucuture from velocity inversion. Low velocity is imaged in the mantle wedge and crust above. Anomalous high velocity structure is found near the Isthmus of Tehuantepec in southern Mexico dipping south from the Gulf of Mexico. This structure is also seen in receiver function images, and may be related to the collision between the Yucatan Block and Mexico in the Miocene.

  13. 77 FR 74213 - Environmental Documents Prepared for Oil, Gas, and Mineral Operations by the Gulf of Mexico Outer...

    Science.gov (United States)

    2012-12-13

    ... INFORMATION: BOEM prepares SEAs and FONSIs for certain proposals that relate to exploration, development... Geophysical Survey, SEA L12-005. Planning Area of the Gulf of Mexico. Cobalt International Energy, Located in the Central 7/3/2012 L.P., Exploration Plan, SEA R- Planning Area of the 5605. Gulf of Mexico,...

  14. ENDEMIC ORTHOPOXVIRUS CIRCULATING IN PROCYONIDS IN MEXICO.

    Science.gov (United States)

    Gallardo-Romero, Nadia F; Aréchiga-Ceballos, Nidia; Emerson, Ginny L; Martínez-Martínez, Flor O; Doty, Jeffrey B; Nakazawa, Yoshinori J; Rendón-Franco, Emilio; Muñoz-García, Claudia I; Villanueva-García, Claudia; Ramírez-Cid, Citlali; Gama-Campillo, Lilia M; Gual-Sill, Fernando; Aguilar-Setién, Álvaro; Carroll, Darin S

    2016-07-01

    Limited serosurveillance studies suggested that orthopoxviruses (OPXV) are widespread in the US (e.g., Raccoonpox virus, Skunkpox virus, Volepox virus) and Brazil (Vaccinia virus); however, their animal reservoir(s) remain unconfirmed. Mexican mammal diversity includes several species related to those in which evidence for OPXV infections has been found (Oryzomys, Peromyscus, Microtus, and Procyonidae). The presence of these groups of mammals in Mexico and the evidence of their possible involvement in the maintenance of OPXV in nature suggest the same or similar OPXV are circulating in Mexico. We tested 201 sera from 129 procyonids via modified enzyme-linked immunosorbent assay (ELISA) and Western blot (WB) to estimate OPXV antibody prevalence in these animals. We detected a prevalence of 16.67% in Nasua narica (white-nosed coati), 35% in Procyon lotor (raccoon), and 30.4% in Bassariscus astutus (ring-tailed cat) when tested by either ELISA or WB. Western blot results presented protein bands consistent with the size of some OPXV immunodominant bands (14, 18, 32, 36, and 62 kDa). These results support the hypothesis that OPXV circulate in at least three genera of Procyonidae in Central and Southeast Mexico. PMID:27224209

  15. Mexico’s monetary policy communication and money markets

    OpenAIRE

    Alicia Garcia-Herrero; Eric Girardin; Arnoldo Lopez Marmolejo

    2015-01-01

    Central bank communication is becoming a key aspect of monetary policy. How much financial markets listen and, possibly, understand Banco de Mexico’s communication on its monetary policy stance should be a key consideration for the central bank to further modernize its monetary policy toolkit

  16. Energetic sustainability: Challenges and options in Mexico; Sustentabilidad energetica: Retos y opciones en Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Rosas Flores, Dionicio; Sheinbaum Pardo, Claudia [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

    2000-07-01

    In this report present a general overview of energy trends and objectives of policy for Mexico, in the context of sustainable development. The work is divided in two main parts: the first one presents trends in energy use and potential, energy sector reform, social and economics indicators and revision of efficiency and renewable energy. The second part discusses options and instruments of energy politics for the country in regard of the sustainable development. The energy is central to concerns of sustainable development, affecting economic; the local and global environment, and social problems as poverty, population, health and education. Mexico should promote political energy that permit the fulfillment the energy requirements while developing strategies that help to alleviate the social problems and productivity, based on lesser environmental impacts. [Spanish] Este reporte presenta una vision sobre las tendencias energeticas de Mexico y plantea prioridades y objetivos de politica para el pais, en el contexto de desarrollo sustentable. El trabajo muestra dos partes principales: la primera seccion presenta tendencias en el uso de energia, potenciales energeticos e indicadores economicos y sociales, ademas de una revision de eficiencias y politicas de energias renovables. La segunda parte discute opciones, instrumentos y restricciones en el contexto del desarrollo energetico sustentable en el pais. La energia es un elemento central en el desarrollo ya que esta relacionado con la economia, el ambiente local y global y aspectos sociales como pobreza, poblacion, salud y educacion. Esto obliga en Mexico a promover politicas que permitan la cobertura de los requerimientos energeticos, las cuales deben desarrollarse de manera conjunta con estrategias, para ayudar a disminuir los problemas, productivos y sociales con menores impactos ambientales.

  17. U.S.-Mexico energy

    International Nuclear Information System (INIS)

    This paper reports that while Mexico's petrochemical industry has grown rapidly, it now faces shortages both in investment funds and in supplies of basic petrochemicals due to a financial crisis in the 1980s. Mexico has undertaken a series of policy reforms aimed at encouraging foreign and private investment, but these efforts have generally failed to entice U.S. investment in Mexico. U.S. petrochemical companies have cited unfavorable market conditions, insufficient basic petrochemical capacity in Mexico, concern about the reversibility of Mexican reforms, inadequate Mexican protection of intellectual property rights, and lack of investment protection for U.S. businesses as impediments to investment in Mexico. Cooperation between the two nations in overcoming these obstacles could help U.S. petrochemical companies maintain their positions in a competitive global market, while at the same time provide Mexico with much needed capital investment and technological expertise

  18. Radon availability in New Mexico

    International Nuclear Information System (INIS)

    The New Mexico Bureau of Mines and Mineral Resources (NMBMMR) in cooperation with the Radiation Licensing and Registration Section of the New Mexico Environment Department (NMED) and the US Environmental Protection Agency (EPA) have been evaluating geologic and soil conditions that may contribute to elevated levels of indoor radon throughout New Mexico. Various data have been integrated and interpreted in order to determine areas of high radon availability. The purpose of this paper is to summarize some of these data for New Mexico and to discuss geologic controls on the distribution of radon. Areas in New Mexico have been identified from these data as having a high radon availability. It is not the intent of this report to alarm the public, but to provide data on the distribution of radon throughout New Mexico

  19. Acoustics lecturing in Mexico

    Science.gov (United States)

    Beristain, Sergio

    2002-11-01

    Some thirty years ago acoustics lecturing started in Mexico at the National Polytechnic Institute in Mexico City, as part of the Bachelor of Science degree in Communications and Electronics Engineering curricula, including the widest program on this field in the whole country. This program has been producing acoustics specialists ever since. Nowadays many universities and superior education institutions around the country are teaching students at the B.Sc. level and postgraduate level many topics related to acoustics, such as Architectural Acoustics, Seismology, Mechanical Vibrations, Noise Control, Audio, Audiology, Music, etc. Also many institutions have started research programs in related fields, with participation of medical doctors, psychologists, musicians, engineers, etc. Details will be given on particular topics and development.

  20. A perspective from Mexico.

    Science.gov (United States)

    López, Mario Henry Rodríguez-

    2008-04-01

    As Binder et al. describe in their article in this issue of the Journal, most of the work of National Public Health Institutes (NPHIs) falls into the category of public goods. This is certainly true for the National Institute of Public Health (Instituto Nacional de Salud Publica (INSP)) of Mexico. Our mission is to contribute to social equity by improving public health in Mexico and Latin America, through the generation of knowledge, innovation in health systems, and public health training. At INSP, we believe that public health is a collective responsibility and that the state has a primary role in promoting and protecting the population's health. Binder et al. have performed a service by drawing attention to the importance of NPHIs and the challenges associated with funding public goods functions. PMID:18368016

  1. ALARA development in Mexico

    International Nuclear Information System (INIS)

    Even though the ALARA philosophy was formally implemented in the early 1980's, to some extent, ALARA considerations already had been incorporated into the design of most commercial equipment and facilities based on experience and engineering development. In Mexico, the design of medical and industrial facilities were based on international recommendations containing those considerations. With the construction of Laguna Verde Nuclear Power Station, formal ALARA groups were created to review some parts of its design, and to prepare the ALARA Program and related procedures necessary for its commercial operation. This paper begins with a brief historical description of ALARA development in Mexico, and then goes on to discuss our regulatory frame in Radiation Protection, some aspects of the ALARA Program, efforts in controlling and reducing of sources of radiation, and finally, future perspectives in the ALARA field

  2. Mexico and the CTBT

    International Nuclear Information System (INIS)

    The Comprehensive Nuclear Test-Ban-Treaty (CTBT) is a treaty that prohibits all the nuclear explosions by anybody and in any place, either on the terrestrial surface, in the atmosphere, under the sea or underground. From the adoption of this Treaty by the United Nations, Mexico has had interest for its entrance in vigor, as integral part to assure the international peace. For this reason, our country signed the Treaty since it was open in September 24, 1996 and three years later ratified it, due to Mexico is part of the group of necessary countries for their entrance in vigor. During 13 years, the country has been committed and helped to the installation of monitoring stations, actions that allow the strengthening of the International System of Surveillance. The purpose of this work is to divulge the Treaty,its technologies and benefits; and also to diffuse the works realized by Mexico regarding the radionuclides monitoring station and noble gases both certified ones for the CTBT. Besides the radionuclides technology, Mexico has taken charge of the installation and operation of the seismic stations and hydro-acoustics that have been certified too. The radionuclides station Rn-44 located in Guerrero Negro, BCS has two technologies, an automated sampler of suspended particles in air brand Cinderella/ARAME and a noble gases system Sauna used for the particles detection of radioactive material gamma emitting and Xenon radioisotopes product of nuclear assays. Both technologies are transmitting data in real time to the International Center of Data. These technologies are shown in this work. (Author)

  3. Idle Youth in Mexico

    OpenAIRE

    de Hoyos, Rafael; Gutierrez Fierros, Carlos; Vargas M., J. Vicente

    2016-01-01

    The present study combines data from Mexico's employment surveys (Encuesta Nacional de Empleo and Encuesta Nacional de Ocupación y Empleo) with the country's official statistics on murder rates to create a state-level panel data set covering the period 1995 to 2013. Including most of the common controls identified by the literature, the results show that the rate of male youth ages 19 to 2...

  4. Mexico; Selected Issues

    OpenAIRE

    International Monetary Fund

    2014-01-01

    This Selected Issues paper analyzes the impact of Mexico’s energy reform on hydrocarbons production. These reforms aim to increase oil and gas production by eliminating the state oil company’s (PEMEX) monopoly on exploration and production of hydrocarbons, while retaining the prime directive that these resources are the property of the Mexican nation. This paper focuses on the nature of reforms and what problems these reforms are addressing. It presents illustrative production scenarios f...

  5. Mexico; Selected Issues

    OpenAIRE

    International Monetary Fund

    2002-01-01

    This Selected Issues paper assesses the potential financial vulnerabilities of the corporate sector in Mexico. It provides an overview of salient features of the Mexican corporate sector. The paper also presents the formal stress tests that estimate the potential effects of some macroeconomic and financial shocks, such as a sharp depreciation of the exchange rate, a sustained increase in interest rates, a slowdown in demand, and a prolonged international market closure on the corporate sector.

  6. Mexico's Fiscal Crisis

    OpenAIRE

    Looney, R.E.

    1987-01-01

    Socio-Economic Planning Sciences, vol. 21, no.6, 1987. Refereed Journal Article Mexico's current crisis has its origins in a number of structural conditions that developed in the 1970s. This paper examines one of these structural impediments, the country's fiscal disequilibrium. An empirical analysis of the country's tax structure indicates that there is ample scope for major tax reforms geared to introducing more responsiveness into the country's tax collection system. Given t...

  7. Mexico environmental services project

    OpenAIRE

    Comisión Nacional Forestal (CONAFOR)

    2007-01-01

    Metadata only record The Mexico Environmental Services Project aims to improve water quality, biodiversity, and carbon sequestration from areas with globally significant biodiversity. Eight pilot sites will be chosen to overlap with existing high-priority biodiversity conservation areas. The project objectives will be met through "(i) strengthening the capacity of CONAFOR, INE, community associations, and NGOs to increase flexibility and improve efficiency of existing service provision to ...

  8. Inequality in Mexico

    OpenAIRE

    Prát, Šárka

    2013-01-01

    This thesis project has the aim of analysing the development of inequality in Mexico, income redistribution, and future possibilities of investment into the educational system. Human capital is one of the determinants of economic growth. Although human capital includes health, education, and social capital, the major focus of this diploma thesis is on education. Education becomes a suitability criterion for employment in all sectors of industry. Everyone is rewarded for exercising the knowled...

  9. Doing Business in Mexico

    OpenAIRE

    World Bank; International Finance Corporation

    2006-01-01

    This report investigates the scope and manner of regulations that enhance business activity and those that constrain it. Quantitative indicators on business regulations and their enforcement have been created for 12 cities and states, which can now be compared with Mexico City, and to 154 countries around the world. The indicators cover four "Doing Business" topics: starting a business, registering property, getting credit and enforcing contracts. The 12 cities and states are: Aguascalientes,...

  10. Caracterización de Propiedades Químicas y Fisicoquímicas de Chorizos Comercializados en la Zona Centro de México Characterization of Chemical and Physicochemical Properties of Sausages Marketed in the Central Region of Mexico

    Directory of Open Access Journals (Sweden)

    Roberto González-Tenorio

    2013-01-01

    Full Text Available Se analizaron cuarenta chorizos de cuatro tipos; dos tradicionales (de mercados rurales y carnicerías locales y dos industriales (de centrales de abasto y supermercados con el fin de determinar las condiciones técnicas de elaboración y comercialización de los chorizos que pueden afectar su calidad. El chorizo es un embutido crudo que se comercializa en prácticamente todo México y su elaboración se realiza tanto de modo artesanal como industrial. Se determinó el valor de pH, la actividad de agua, el contenido de humedad, grasa, proteína, cenizas, sal y colágeno, y el perfil de ácidos grasos. Se completó la caracterización analizando la morfología de los chorizos, así como el color y textura. Se encontró variación en las características de los chorizos, dependiendo principalmente del origen de los mismos.Forty sausages (chorizos of four types; two traditional (rural markets and local butchers and two industrial (wholesale large-city markets and supermarkets were analyzed for determining the quality of the elaboration process and of the commercialization that could affect sausage quality. Chorizos are raw sausage elaborated in most places in Mexico either by small producers or by food industries. The pH, water activity values, moisture, fat, protein, common salt and collagen contents and the fatty acid profile were determined. Additionally, morphological parameters, color and texture were assessed to complete the characterization. As expected, variations in the properties of chorizo depended on the type and origin.

  11. Students and Teachers' Reasons for Using the First Language Within the Foreign Language Classroom (French and English in Central Mexico Razones de alumnos y maestros sobre el uso de la primera lengua en el salón de lenguas extranjeras (francés e inglés en el centro de México

    Directory of Open Access Journals (Sweden)

    Irasema Mora Pablo

    2011-10-01

    Full Text Available The present study explores the use of the first language in a context of foreign language teaching. This qualitative research presents the classroom practice and points of view of French and English teachers and students within a public educational institute in central Mexico using the techniques of questionnaires and semi-structured interviews. The results show that teachers and the majority of students perceive the use of the first language as positive and part of the teaching and learning process. A small number of students do not like the use of the first language in the classroom and prefer that their teachers use the target language only.La presente investigación explora el uso de la lengua materna en un contexto de enseñanza de lenguas extranjeras. Esta investigación cualitativa presenta la práctica docente y los puntos de vista de maestros y alumnos de francés e inglés en el contexto de una universidad pública del centro de México, mediante el uso de las técnicas del cuestionario y la entrevista semiestructurada. Los resultados muestran que tanto los maestros como la mayoría de los alumnos perciben el uso de la lengua materna como algo positivo en el proceso de enseñanza-aprendizaje. Un número reducido de estudiantes rechaza el uso de la lengua materna y prefiere que su clase de lengua extranjera sea dirigida exclusivamente en la lengua meta.

  12. Presencia de Circulifer tenellus Baker y Beet mild curly top virus en maleza durante el invierno en el centro norte de México Circulifer tenellus Baker and Beet mild curly top virus presence in weeds during the winter in north-central Mexico

    Directory of Open Access Journals (Sweden)

    Rodolfo Velásquez-Valle

    2012-07-01

    Full Text Available Una de las enfermedades más importantes del chile para secado en el norte centro de México es la denominada amarillamientos del chile. Existe poca información acerca de la interacción entre el vector (Circulifer tenellus Baker, el Beet mild curly top virus y la maleza durante el invierno en esta región, consecuentemente el objetivo del trabajo fue identificar maleza de invierno que sirve como refugio para el vector y hospedero del virus en esta región. Entre enero y marzo de 2011 se muestrearon 26 manchones de maleza en los estados de Aguascalientes y Zacatecas. Se capturaron adultos de C. tenellus en 69.2% de los manchones de maleza muestreados; la mayoría (75.5% de los especímenes eran hembras. El Beet mild curly top fue identificado sólo 15.4% de los sitios de muestreo infectando especies de maleza como Eruca sativa, Reseda sp., Chenopodium sp. y Solanum rostratum L.One of the most important diseases of chili pepper for drying in the north-central Mexico is called yellowing of chili. There is little information about the interaction between the vector (Circulifer tenellus Baker, the Beet mild curly top virus and weeds during the winter in this region; therefore, the objective was to identify winter weeds that serve as are fuge for the vector and host of the virus in this region. Between January and March, 2011, 26 patches of weed were sampled in Aguascalientes and Zacatecas. Adult C. tenellus were captured in 69.2% of the weed sampled patches; most of the specimens were females (75.5%. Beet mild curly top was identified in only 15.4% of the sampling sites, infecting weed species suchas Eruca sativa, Reseda sp., Chenopodium sp. and Solanum rostratum L.

  13. Mobile exhibition in Mexico

    International Nuclear Information System (INIS)

    Since January this year, a mobile atomic energy exhibition has been touring the principal cities of Mexico. In organizing this exhibition, the National Nuclear Energy Commission of Mexico was assisted by the International Atomic Energy Agency which has placed its second mobile radioisotope laboratory at the disposal of the Mexican authorities. In many States of the Republic, the visit of the mobile laboratory has given a powerful impetus to atomic training and research. Universities have made use of the laboratory for the training of young scientists in the basic isotope techniques. As a sequel to the work initiated with its aid, some universities are planning to start regular training courses in this field. The laboratory, which is a gift to the Agency from the United States, has been put to its first assignment in Mexico. It will shortly be sent to Argentina for a period of six months for use in training courses. IAEA's first mobile radioisotope unit, also donated by the United States, has been used for training purposes in Austria, the Federal Republic of Germany, Greece and Yugoslavia, and has now been sent to the Far East

  14. Simulation of the concentration of SO{sub 2} issued by major stationary sources in 2003 in northwestern Chiapas and central Tabasco, Mexico; Simulacion de la concentracion de SO{sub 2} emitido por fuentes fijas mayores durante 2003 en el noroeste de Chiapas y centro de Tabasco, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Valdes Manzanilla, Arturo [Division Academica de Ciencias Biologicas, UJAT, Villahermosa, Tabasco (Mexico)]. E-mail: avmanzanilla@hotmail.com; Fernandez Garcia, German [Universidad Autonoma de Guadalajara Campus Tabasco, Villahermosa, Tabasco (Mexico); Ramos Herrera, Sergio [Division Academica de Ciencias Biologicas, UJAT, Villahermosa, Tabasco (Mexico); Bautista Margulis, Raul G. [Division Academica de Ciencias Biologicas, UJAT, Villahermosa, Tabasco (Mexico)

    2008-05-15

    The CALPUFF dispersion model was used to simulate the spatial distribution of the SO{sub 2} emitted by Petroleos Mexicanos (PEMEX) gas-processing complexes in Cactus, NW Chiapas, Nuevo PEMEX and Ciudad PEMEX, in central Tabasco, during 2003. It was found that the zone with the highest concentrations of SO{sub 2} is located SW from the PEMEX facilities. The zone, where the World Health Organization's norm for SO{sub 2} is surpassed (20 {mu}g/m{sup 3}), includes the city of Reforma, Chiapas and Ciudad PEMEX, Tabasco. [Spanish] El modelo de dispersion CALPUFF fue usado para simular la distribucion espacial de la concentracion de SO{sub 2} emitido por los complejos procesadores de gas de Petroleos Mexicanos (PEMEX) en Cactus, en el noroeste de Chiapas, Nuevo PEMEX y Ciudad PEMEX, en el centro de Tabasco, durante 2003. Se encontro que la zona con mayor concentracion de SO{sub 2} esta localizada al suroeste de las instalaciones de la empresa petrolera. La zona, donde la norma de la Organizacion Mundial de la Salud para el SO{sub 2} es sobrepasada (20 {mu}g/m{sup 3}), incluye la ciudad de Reforma, Chiapas y Ciudad PEMEX, Tabasco.

  15. Natal origins of migratory monarch butterflies at wintering colonies in Mexico: New isotopic evidence

    OpenAIRE

    Wassenaar, Leonard I.; Keith A. Hobson

    1998-01-01

    Each year, millions of monarch butterflies from eastern North America migrate to overwinter in 10–13 discrete colonies located in the Oyamel forests of central Mexico. For decades efforts to track monarch migration have relied on observations and tag-recapture methods, culminating with the discovery of the wintering colonies in 1975. Monarch tag returns from Mexico, however, are few and primarily from two accessible colonies, and therefore tag-recapture techniques have not quantified natal or...

  16. Evidence of pre-Columbian settlements in the forest of the Tuxtla Volcanic Field, Veracruz, Mexico

    OpenAIRE

    Araceli Zamora-Camacho; Juan Manuel Espíndola; Peter Schaaf; Angel Ramírez; María de Lourdes Godínez Calderón

    2015-01-01

    The basaltic Los Tuxtlas Volcanic Field (LTVF) is located at the western margin of the Gulf of Mexico in the State of Veracruz, Mexico. The field is a massif composed of four large volcanic structures and hundreds of scoria cones, lava domes and maars. This area was in the past covered by a dense forest in whose margins flourished several of the ancient cities of importance in central and southern Veracruz. Within the forest no enduring archeological ruins have been found; but ...

  17. Earthquake Damage in Mexico City, Mexico, September 19, 1985

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — On September 19, 1985, a magnitude 8.1 earthquake occurred off the Pacific coast of Mexico. The damage was concentrated in a 25 km2 area of Mexico City, 350 km from...

  18. Mexico: Rasgos de Su Historia. (Mexico: Highlights of Its History).

    Science.gov (United States)

    Orozco, Cecilio

    Intended for both teachers and students, this publication, written in Spanish, briefly traces Mexico's history from its Conquest in 1519 to the overthrow of Porfirio Diaz in 1910. The following are briefly discussed: Mexico's Conquest in 1519; events immediately after the fall of Tenochtitlan; the War for Independence; Texas' separation from…

  19. A review of power-sector economics in Mexico

    International Nuclear Information System (INIS)

    Economic data about Mexico's electricity supply industry (ESI) are difficult to interpret in any rigorous systematic way. Consolidated information (i.e., including the two state-owned power-sector companies) is particularly hard to integrate and, in the author's opinion, many of the existing accounts are inconsistent. There are technical and methodological problems also with the information released by the national utility - the Federal Electricity Commission (CFE) - and by other official sources. The problems mainly arise from inexpedience of several series concerned with power-sector finance and from unexplained changes in financial accounting procedures and methodologies introduced by the originators of official information. In these circumstances, caution must be taken when interpreting trends and making comparisons between Mexico's ESI and electricity industries elsewhere. While parts of the available information had to be adjusted in order to conform to uniform series, the author tried to agree primarily with CFE data. At times, only data referring to CFE are used (i.e., excluding the smaller distribution company - Central Light and Power Company or CLFC - that serves the metropolitan area of Mexico City and Central Mexico) in view of significant disparities in official accounts of the consolidated power sector. Also, conversion of all figures into constant US dollars introduces distortions in the Mexican case due to substantial devaluations of the national currency over an extended period. He believes that analysis in constant Mexican pesos would be more truthful of the underlying trends. 15 refs., 11 figs., 2 tabs

  20. Hydrocarbons prospecting using an integrated approach of petrography, geochemistry and modeling of organic matter transformation. Analysis and reconstitution of the thermal history of the central carboniferous basins of Asturias (Spain) and of the Sabinas - Piedras Negras basin (Coahuila, Mexico); Prospection des hydrocarbures par une approche integree de petrographie, geochimie et modelisation de la transformation de la matiere organique. Analyse et reconstitution de l'histoire thermique des Bassins Carbonifere Central des Asturies (Espagne) et Sabinas - Piedras Negras (Coahuila, Mexique)

    Energy Technology Data Exchange (ETDEWEB)

    Piedad-Sanchez, N.

    2004-09-01

    Solid knowledge of the transformation and evolution of organic matter during hydrocarbon generation in sedimentary basins serves to improve natural gas exploration. With this geological problem in mind, the thermal influence on organic matter was analyzed in two basins containing different characteristics (age, composition of organic matter, litho-stratigraphy, depth, thickness of the layers of rock, the maturation of organic matter, etc.) in order to understand the natural processes in generating oil and natural gas. With a view to studying this geological phenomenon, this work outlines the study of the chemical and macerals composition, the coal rank and geochemical characteristics of organic matter in these two sedimentary basins for the first time: The Asturian Central Carboniferous Basin (Spain) and Sabinas - Piedras Negras Basin (Mexico). Moreover, an approach to shed light on the thermal history and evolution of organic matter through 1D modeling in the two basins is developed. The Central Carboniferous Basin in Asturias is an important coal mining area where coal types range from bituminous carbons with high content in volatile matter to anthracite. The petrographical and geochemical study in this region has shown that at the moment of oil and gas exploration, the coals correspond to an efficient expulsion of oil and have been formed in an environment of swamp with a facies rich in vitrinite, low in sulfur and ash and varying in mineral content. As regards the paleo-environmental reconstruction, the bio-markers suggest a swamp with a relatively high water table and a humid climate. The coal type, the vitrinite reflectance and the volatile matter content in the basin show a N-S trend which could be correlated to the paleo-temperatures calculated in this study. These data point to the influence of two thermal gradients in the region: A normal thermal gradient of long duration and an oblique thermal gradient of short duration due to a pluton. The evolution of

  1. Mexico: Democracy and the Future

    Science.gov (United States)

    Bruhn, Kathleen

    2009-01-01

    During most of the twentieth century, Mexico was governed by one of the longest-ruling authoritarian parties in the contemporary world. Even as most Latin American countries democratized in the 1980s, Mexico remained under the control of the Institutional Revolutionary Party (PRI). It was not until the 2000 presidential election that a two-party…

  2. Mexico's National Educational Videoconferencing Network.

    Science.gov (United States)

    Pisanty, Alejandro

    This paper begins with background on the National University of Mexico (UNAM) and its networks. Other distance education projects in Mexico are described, including projects of the Instituto Politecnico Nacional (IPN), the National Distance Education Program operated by the Secretary of Education, and the Instituto Tecnologico y de Estudios…

  3. Mosses new to New Mexico

    Science.gov (United States)

    A bryophyte inventory was conducted in the Valles Caldera National Preserve (VCNP), New Mexico, from 2009 to 2011. Specimens representing 113 species of bryophytes were collected. Of those bryophytes, seven of the mosses were new to New Mexico: Atrichum tenellum (Rohling) Bruch & Schimper, Dicranum ...

  4. Natural gas in Mexico

    International Nuclear Information System (INIS)

    A series of overhead viewgraphs accompanied this presentation which focused on various aspects of the natural gas industry in Mexico. Some of the viewgraphs depicted statistics from 1998 regarding natural gas throughput from various companies in North America, natural gas reserves around the world, and natural gas reserves in Mexico. Other viewgraphs depicted associated and non-associated natural gas production from 1988 to 1998 in million cubic feet per day. The Burgos Basin and the Cantarell Basin gas production from 1997 to 2004 was also depicted. Other viewgraphs were entitled: (1) gas processing infrastructure for 1999, (2) cryogenic plant at Cd. PEMEX, (3) average annual growth of dry natural gas production for 1997-2004 is estimated at 5.2 per cent, (4) gas flows for December 1998, (5) PGPB- interconnect points, (6) U.S. Mexico gas trade for 1994-1998, (7) PGPB's interconnect projects with U.S., and (8) natural gas storage areas. Technological innovations in the industry include more efficient gas turbines which allow for cogeneration, heat recovery steam generators which reduce pollutant emissions by 21 per cent, cold boxes which increase heat transfer efficiency, and lateral reboilers which reduce energy consumption and total costs. A pie chart depicting natural gas demand by sector shows that natural gas for power generation will increase from 16 per cent in 1997 to 31 per cent in 2004. The opportunities for cogeneration projects were also reviewed. The Comision Federal de Electricidad and independent power producers represent the largest opportunity. The 1997-2001 investment program proposes an 85 per cent sulphur dioxide emission reduction compared to 1997 levels. This presentation also noted that during the 1998-2001 period, total ethane production will grow by 58 tbd. 31 figs

  5. Environmental lead in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Albert, L.A.; Badillo, F. (Centro de Ecodesarrollo (Mexico))

    1991-01-01

    From the data presented here, it can be concluded that environmental exposure to lead is a particularly severe problem in Mexico. As has been shown, there are very important sources of exposure to this metal: (a) for rural populations who manufacture and/or utilize lead-glazed pottery, (b) for urban populations who are exposed to high air lead concentrations due to the continued use of lead fuel additives, (c) for workers of several industries, mainly those of batteries and pigments, (d) for consumers who routinely eat canned foods such as hot peppers and fruit products, and (e) for the general population living in the vicinity of smelters, refineries and other industries that emit lead. Therefore, in Mexico only those native populations living in very primitive communities, far away from all civilized life, could be expected to be free from this exposure. At the same time, and despite the relatively few data available, it can be stated that the exposure to lead of populations in Mexico could be approaching levels that might be highly hazardous, in particular for the neuropsychological health of children. Regarding the presence of lead in the environment, despite the fact that the available studies are not enough, it is evident that pollution by this metal is widespread and that there is a serious lack of studies for most regions of the country, including several that might be expected to be highly polluted. At the same time, it is evident that the official attention paid to the problem, either in regulations, support of further studies, or implementation of effective control measures has been far from the level needed according to the available data.

  6. Mexico 68: Official Report

    OpenAIRE

    2014-01-01

    Intitulé “Mexico 68”, le rapport officiel publié en 1969 atteint un nouveau record avec plus de 2300 pages. Il se compose de quatre principaux volumes (Le pays ; L’organisation ; Les Jeux sportifs ; L’Olympiade culturelle) auxquels s’ajoute un coffret contenant divers souvenirs : médailles, tickets, cartes postales. Ce « cinquième volume » est assez méconnu. Le rapport officiel a été publié en 4 langues, sous la forme de deux éditions bilingues français-anglais et espagnol-allemand. Vol.1 Par...

  7. [Psychiatry in ancient Mexico].

    Science.gov (United States)

    Calderón Narváez, G

    1992-12-01

    Using studies on prehispanic and early post-conquest documents of Ancient Mexico--such as the Badianus Manuscript, also known as Libellus de Medicinalibus Indorum Herbis, and Brother Bernardino de Sahagún's famous work History of the Things of the New Spain, a description of some existing medical and psychiatric problems, and treatments Ancient Aztecs resorted to, is presented. The structure of the Aztec family, their problems with the excessive ingestion of alcoholic beverages, and the punishments native authorities had implemented in order to check alcoholism up are also described. PMID:1341125

  8. Port of Altamira, Mexico

    OpenAIRE

    Croonen, K.; Froeling, D.; Marbus, G.; Bemmel, M. van

    2006-01-01

    Master project report. The Port of Altamira is one of the fast growing ports in the world and is together with Veracruz and Coatzacoalcos one of the biggest ports of Mexico at the Gulf coast. It is an industrial Port with a lot of potential for expanding. However, the breakwaters of the Port extending into the sea caused severe erosion at the downdrift side of the Port (south side). This ongoing erosion is threatening a precious lagoon and some important land. The erosion can also cause a bre...

  9. [Health technology in Mexico].

    Science.gov (United States)

    Cruz, C; Faba, G; Martuscelli, J

    1992-01-01

    The features of the health technology cycle are presented, and the effects of the demographic, epidemiologic and economic transition on the health technology demand in Mexico are discussed. The main problems of science and technology in the context of a decreasing scientific and technological activity due to the economic crisis and the adjustment policies are also analyzed: administrative and planning problems, low impact of scientific production, limitations of the Mexican private sector, and the obstacles for technology assessment. Finally, this paper also discusses the main support strategies for science and technology implemented by the Mexican government during the 1980s and the challenges and opportunities that lie ahead. PMID:1411774

  10. Caryospora neofalconis and other enteroparasites in raptors from Mexico

    OpenAIRE

    Santana-Sánchez, G.; I.T. Flores-Valle; M. González-Gómez; Vega-Sánchez, V.; C. Salgado-Miranda; E. Soriano-Vargas

    2015-01-01

    A coprological survey of enteroparasites in raptors (60 Falconiformes) from Central Mexico is reported. Three samples contained coccidian unsporulated oocysts, one contained Eimeria sp., one contained trematode eggs and one contained capillarid and trematode eggs and Eimeria sp. After sporulation at the laboratory, oocysts from a Falco peregrinus were identified as Caryospora neofalconis. The phylogenetic analysis of the C. neofalconis (GenBank accession number KT037081) showed a close relati...

  11. Rainfall interception in the semiarid plateau of center of Mexico

    OpenAIRE

    E. Gonzalez-Sosa; Mastachi Loza, C.; I. Braud; Guevara Escobar, A.

    2009-01-01

    The strong pressure over natural ressources and the accelerated population growth modify natural ecosystems and decrease the canopy cover. The ecosystems of central Mexico plateau are not an exception. Although it is a natural semi-arid region induced by the continental screen effect of the Sierra mountains that regulates the humidity entrance from the Gulf and the Pacific, the semi-arid ecosystems are degraded day after day, showing a clear tendency to desertification. The aim of the stud...

  12. 76 FR 58772 - Safety & Security Trade Mission; Mexico City and Monterrey, Mexico

    Science.gov (United States)

    2011-09-22

    ... International Trade Administration Safety & Security Trade Mission; Mexico City and Monterrey, Mexico AGENCY... Safety and Security trade mission to Mexico City and Monterrey, Mexico, for January 30-February 2, 2012... traveling to Mexico independently, will enhance the companies' ability to secure meetings with...

  13. 21 CFR 808.81 - New Mexico.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false New Mexico. 808.81 Section 808.81 Food and Drugs... and Local Exemptions § 808.81 New Mexico. The following New Mexico medical device requirement is... from preemption under section 521(b) of the act: New Mexico Statutes Annotated, section 67-36-16(F)....

  14. Paleomagnetism and Tectonic Evolution of Mexico: Precambrian to Recent

    Science.gov (United States)

    Fucugauchi, J. U.

    2007-05-01

    It is 20yr since publication of the last synthesis of country-wide paleomagnetic data and almost 30yr of first attempt to construct an apparent polar wander path for Mexico. During this time, data has increased ten-fold and a new synthesis may appear long overdue. Mexico constitutes the southern portion of the North American plate, and tectonic models long suggested a complex evolution involving ocean-basin closure, continental collision/break-up, terrane accretion, large-scale motions, orogenic deformation, oceanic plate reorganizations and oceanic basin development. Paleoreconstructions of Atlantic-bordering continents show major overlap of northern South America onto Mexico, highlighting the geometric problem, allocthonous nature and opening room for a diversity of models. Paleomagnetism appears well-suited to tackle these problems, and data had early been used to evaluate tectonic models. Likewise, the larger database is now used to assess models and develop alternatives. This task is greatly aided by new available geochronological, geophysical and geological data. Our new synthesis still shows data gaps, with Paleozoic and Precambrian units poorly represented. Paleomagnetic data and tectonic models require complex large-scale motions of Precambrian and Paleozoic blocks, solutions for opening of Gulf of Mexico and Caribbean Sea, and post-Triassic-Jurassic amalgamation of Mexico and Central America. The southern edge of the North American craton is positioned in northern Mexico, marking the limit for accreted terranes to the south. Possible southern extension of Marathon-Ouachita Paleozoic belt, obscured or truncated when it comes into Mexico, remains unstudied paleomagnetically. Left-lateral motions along faults related to opening of Gulf of Mexico are not supported by paleomagnetism. The Western Cordilleran belt appears laterally displaced in southern US and into Mexico, where the paleomagnetic signature of northward latitudinal translations and clockwise

  15. Responses to emergencies in Mexico and Central America

    International Nuclear Information System (INIS)

    Radiation emergencies have two main aspects: radiation safety, which concerns control of the radiation source, and, more importantly, health effects, which entail diagnoses, treatment, and rehabilitation. The physician participates directly in a radiation emergency because he or she is the professional who knows best the human body and the methodology to re-establish health. However, because these types of incidents are infrequent, many physicians are poorly prepared to deal with such emergencies. Two main aspects of emergency response plans are: (1) prevention, including public education for behavior and planning for appropriate response; and (2) application, including prophylactic measures, assessing the extent of exposure and contamination, controlling public anxiety, and managing and treating the victims

  16. Enel Green Power Restructuring Project for Mexico and Central America

    OpenAIRE

    Duda, Yurij

    2013-01-01

    Enel Green Power, established in December of 2008, is the Enel Group Company dedicated to developing and managing energy generation from renewable sources at an international level, with a presence in Europe and the American continents. Enel Green Power is a major global operator in the field of energy generation from renewable sources (solar, wind, hydro, geothermal, biomass). (Enel 2012) Our initial project assignment was the organizational, system and process restructuring for the Administ...

  17. Aerosol composition from Tlaxcoapan, Hidalgo in central Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Martinez C, M. A.; Solis, C.; Andrade, E. [UNAM, Instituto de Fisica, Circuito Exterior, Ciudad Universitaria, 04510 Mexico D. F. (Mexico); Issac O, K. [Universidad Autonoma del Estado de Mexico, Facultad de Medicina, Paseo Tollocan y Jesus Carranza s/n, 50120 Toluca, Estado de Mexico (Mexico); Beltran H, R. I. [Universidad Autonoma del Estado de Hidalgo, Centro de Investigaciones Quimicas, Carretera Pachuca-Tulancingo Km. 4.5, 42174 Pachuca, Hidalgo (Mexico); Medina M, S. A.; Martinez R, G.; Ramirez R, A.; Lucho C, C. A. [Universidad Politecnica de Pachuca, Programa de Ingenieria en Biotecnologia, Carretera Pachuca-Cd. Sahagun Km. 20, Ex-Hacienda de Santa Barbara, Municipio de Zempoala, Hidalgo (Mexico); Del Razo, L. M. [IPN, Centro de Investigacion y de Estudios Avanzados, Seccion Externa de Toxicologia, Ticoman, 07360 Mexico D. F. (Mexico)

    2010-02-15

    Air quality mexican regulations about atmospheric aerosols refer to particle sizes and to the total suspended particle. None of these norms establishes the allowed values based on the particulate chemical composition. Mexican environmental legislation also considers as critical zones those with high concentration of contaminants in the atmosphere. One of these zones is the Tula-Vito-Apasco corridor where no chemical composition characterization in terms of trace metal associated to the air particulate matter has been made. Along this corridor near Tlaxcoapan there are important contaminant sources as petrochemical and electric power plants, metal-mechanical industry, limestone quarry and contaminated soils. In this work PIXE and Sem-EDS were applied to the PM{sub 10} fraction collected on filters. The trace element values thus determined were compared with those of a similar critical zone. It was found that most of the coarse particles come from limestone quarry as fugitive dusts while V, Ni, Cr and Pb values are moderately high and seems to be associated to industrial activities and contaminated soil as well. (Author)

  18. Analysis of the Socorro hydrogeothermal system: Central New Mexico

    Science.gov (United States)

    Barroll, M. W.; Reiter, M.

    1990-12-01

    Analysis of new geothermal subsurface hydrogeologic data from the Socorro area provides new insight into both the geothermal regime and groundwater flow system. Geothermal data from the Socorro area, originally obtained by industry investigators, further delineate a known geothermal high in the Socorro mountain block and reveal a profound geothermal low west of the mountain block in La Jencia Basin. Anomalously low heat flows in La Jencia Basin suggest hydrologic downflow, but hydrologic and geothermal evidence indicates that no infiltration of surface recharge occurs in this area. We conclude that eastward flowing groundwater is forced to flow down beneath a claystone aquitard in eastern La Jencia Basin, reducing near-surface heat flows. High heat flows in the Socorro mountain block occur in areas where relatively permeable volcanic rocks crop out at the surface. We conclude that groundwater flows upward in these areas from beneath the claystone aquitard, enhanced by subsurface barriers to horizontal flow, elevating near-surface heat flows. Upper crustal magma in the Socorro area (suggested by seismic evidence) may also contribute heat to the system. Finite difference modeling demonstrates that the hydrogeology of the Socorro area could indeed produce the hydrologic phenomena we postulate, which in turn, could produce the geothermal anomalies observed in the Socorro area. We find that forced convection alone, without anomalous heat sources, could produce the observed geothermal anomalies. Analysis of the heat balance of the Socorro system is also consistent with the hypothesis that anomalous crustal heat sources need not play a substantial roll in the Socorro geothermal system in order to produce the flux of heat observed at the surface.

  19. U.S. Coastal Relief Model - Central Gulf of Mexico

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NGDC's U.S. Coastal Relief Model (CRM) provides the first comprehensive view of the U.S. coastal zone integrating offshore bathymetry with land topography into a...

  20. Aerosol composition from Tlaxcoapan, Hidalgo in central Mexico

    International Nuclear Information System (INIS)

    Air quality mexican regulations about atmospheric aerosols refer to particle sizes and to the total suspended particle. None of these norms establishes the allowed values based on the particulate chemical composition. Mexican environmental legislation also considers as critical zones those with high concentration of contaminants in the atmosphere. One of these zones is the Tula-Vito-Apasco corridor where no chemical composition characterization in terms of trace metal associated to the air particulate matter has been made. Along this corridor near Tlaxcoapan there are important contaminant sources as petrochemical and electric power plants, metal-mechanical industry, limestone quarry and contaminated soils. In this work PIXE and Sem-EDS were applied to the PM10 fraction collected on filters. The trace element values thus determined were compared with those of a similar critical zone. It was found that most of the coarse particles come from limestone quarry as fugitive dusts while V, Ni, Cr and Pb values are moderately high and seems to be associated to industrial activities and contaminated soil as well. (Author)