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Sample records for calico hills tuff

  1. Uniaxial strength testing of Calico Hills tuff, Yucca Mountain: Preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Li, Qizhi; Schultz, R.A. [Univ. of Nevada, Reno, NV (United States)

    1994-12-31

    A detailed investigation of the strength properties of Calico Hills tuff was undertaken to further characterize the behavior of this unit. Uniaxial compression test on 47 samples of massive and reworked tuff show a dependence of peak strength and Young`s modulus on the total porosity, and thus on the geologic history of the Calico Hills tuff. Controlled deformation of test specimens documents axial splitting and faulting as failure mechanisms in the post-peak region of these brittle tuffs.

  2. Lithostratigraphy of the Calico Hills Formation and Prow Pass Tuff (Crater Flat Group) at Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Moyer, T.C.; Geslin, J.K. [Science Applications International Corp., Las Vegas, NV (United States)

    1995-07-01

    Lithostratigraphic relations within the Calico Hills Formation and Prow Pass Tuff (Crater Flat Group) were reconstructed from analysis of core samples and observation of outcrop exposures. The Calico Hills Formation is composed of five nonwelded pyroclastic units (each formed of one or more pyroclastic-flow deposits) that overlie an interval of bedded tuff and a basal volcaniclastic sandstone unit. The Prow Pass Tuff is divided into four pyroclastic units and an underlying interval of bedded tuff. The pyroclastic units of the Prow Pass Tuff are distinguished by the sizes and amounts of their pumice and lithic clasts and their degree of welding. Pyroclastic units of the Prow Pass Tuff are distinguished from those of the Calico Hills Formation by their phenocryst assemblage, chemical composition, and ubiquitous siltstone lithic clasts. Downhole resistivity tends to mirror the content of authigenic minerals, primarily zeolites, in both for-mations and may be useful for recognizing the vitric-zeolite boundary in the study area. Maps of zeolite distribution illustrate that the bedded tuff and basal sandstone units of the Calico Hills Formation are altered over a wider area than the pyroclastic units of both the Calico Hills Formation and the upper Prow Pass Tuff.

  3. A summary and discussion of hydrologic data from the Calico Hills nonwelded hydrogeologic unit at Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Loeven, C.

    1993-01-01

    This report is a summary of available hydrologic data from in situ and laboratory testing of the Calico Hills nonwelded hydrogeologic unit, including hydraulic conductivity, porosity, saturation, pore-size distribution and parameters from curve-fits to pressure-saturation data. Sample statistics of hydraulic conductivity, porosity and saturation data for vitric, devitrified and zeolitic tuffs are presented and discussed. While a high degree of variability is observed in both laboratory and in situ hydraulic conductivity measurements, uncertainties arising from differences in size of laboratory test samples, sample handling, test procedures and insufficient number of samples point to the need for additional data of specific types to adequately characterize the unit. Hydrologic issues related to transport analysis in the Calico Hills nonwelded hydrogeologic unit at Yucca Mountain are discussed together with recommendations for future work. The compiled data are included as an appendix.

  4. Field-based description of rhyolite lava flows of the Calico Hills Formation, Nevada National Security Site, Nevada

    Science.gov (United States)

    Sweetkind, Donald S.; Bova, Shiera C.

    2015-01-01

    Contaminants introduced into the subsurface of Pahute Mesa, Nevada National Security Site, by underground nuclear testing are of concern to the U.S. Department of Energy and regulators responsible for protecting human health and safety. The potential for contaminant movement away from the underground test areas at Pahute Mesa and into the accessible environment is greatest by groundwater transport through fractured volcanic rocks. The 12.9 Ma (mega-annums, million years) Calico Hills Formation, which consists of a mixture of rhyolite lava flows and intercalated nonwelded and bedded tuff and pyroclastic flow deposits, occurs in two areas of the Nevada National Security Site. One area is north of the Rainier Mesa caldera, buried beneath Pahute Mesa, and serves as a heterogeneous volcanic-rock aquifer but is only available to study through drilling and is not described in this report. A second accumulation of the formation is south of the Rainier Mesa caldera and is exposed in outcrop along the western boundary of the Nevada National Security Site at the Calico Hills near Yucca Mountain. These outcrops expose in three dimensions an interlayered sequence of tuff and lava flows similar to those intercepted in the subsurface beneath Pahute Mesa. Field description and geologic mapping of these exposures described lithostratigraphic variations within lava flows and assisted in, or at least corroborated, conceptualization of the rhyolite lava-bearing parts of the formation.

  5. Geologic map of Paleozoic rocks in the Calico Hills, Nevada Test Site, southern Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Cole, J.C.; Cashman, P.H.

    1998-11-01

    The Calico Hills area in the southwestern part of the Nevada Test Site, Nye County, Nevada, exposes a core of pre-Tertiary rocks surrounded by middle Miocene volcanic strata. This map portrays the very complex relationships among the pre-Tertiary stratigraphic units of the region. The Devonian and Mississippian rocks of the Calico Hills are distinct from age-equivalent carbonate-shelf or submarine-fan strata in other parts of the Nevada Test Site. The Calico Hills strata are interpreted to have been deposited beyond the continental shelf edge from alternating silicic and carbonate clastic sources. Structures of the Calico Hills area record the compounded effects of: (1) eastward-directed, foreland-vergent thrusting; (2) younger folds, kink zones, and thrusts formed by hinterland-vergent deformation toward northwesterly and northerly directions; and (3) low-angle normal faults that displaced blocks of Middle Paleozoic carbonate strata across the contractionally deformed terrane. All of these structures are older than any of the middle Miocene volcanic rocks that were erupted across the Calico Hills.

  6. Electrical studies at the proposed Wahmonie and Calico Hills nuclear waste sites, Nevada Test Site, Nye County, Nevada

    Science.gov (United States)

    Hoover, D.B.; Chornack, Michael P.; Nervick, K.H.; Broker, M.M.

    1982-01-01

    Two sites in the southwest quadrant of the Nevada Test Site (NTS) were investigated as potential repositories for high-level nuclear waste. These are designated the Wahmonie and Calico Hills sites. The emplacement medium at both sites was to be an inferred intrusive body at shallow depth; the inference of the presence of the body was based on aeromagnetic and regional gravity data. This report summarizes results of Schlumberger VES, induced polarization dipole-dipole traverses and magnetotelluric soundings made in the vicinity of the sites in order to characterize the geoelectric section. At the Wahmonie site VES work identified a low resistivity unit at depth surrounding the inferred intrusive body. The low resistivity unit is believed to be either the argillite (Mississippian Eleana Formation) or a thick unit of altered volcanic rock (Tertiary). Good electrical contrast is provided between the low resistivity unit and a large volume of intermediate resistivity rock correlative with the aeromagnetic and gravity data. The intermediate resistivity unit (100-200 ohm-m) is believed to be the intrusive body. The resistivity values are very low for a fresh, tight intrusive and suggest significant fracturing, alteration and possible mineralization have occurred within the upper kilometer of rock. Induced polarization data supports the VES work, identifies a major fault on the northwest side of the inferred intrusive and significant potential for disseminated mineralization within the body. The mineralization potential is particularly significant because as late as 1928, a strike of high grade silver-gold ore was made at the site. The shallow electrical data at Calico Hills revealed no large volume high resistivity body that could be associated with a tight intrusive mass in the upper kilometer of section. A drill hole UE 25A-3 sunk to 762 m (2500 ft) at the site revealed only units of the Eleana argillite thermally metamorphosed below 396 m (1300 ft) and in part highly

  7. Geologic evaluation of six nonwelded tuff sites in the vicinity of Yucca Mountain, Nevada for a surface-based test facility for the Yucca Mountain Project

    Energy Technology Data Exchange (ETDEWEB)

    Broxton, D.E.; Chipera, S.J.; Byers, F.M. Jr. [Los Alamos National Lab., NM (United States); Rautman, C.A. [Sandia National Labs., Albuquerque, NM (United States)

    1993-10-01

    Outcrops of nonwelded tuff at six locations in the vicinity of Yucca Mountain, Nevada, were examined to determine their suitability for hosting a surface-based test facility for the Yucca Mountain Project. Investigators will use this facility to test equipment and procedures for the Exploratory Studies Facility and to conduct site characterization field experiments. The outcrops investigated contain rocks that include or are similar to the tuffaceous beds of Calico Hills, an important geologic and hydrologic barrier between the potential repository and the water table. The tuffaceous beds of Calico Hills at the site of the potential repository consist of both vitric and zeolitic tuffs, thus three of the outcrops examined are vitric tuffs and three are zeolitic tuffs. New data were collected to determine the lithology, chemistry, mineralogy, and modal petrography of the outcrops. Some preliminary data on hydrologic properties are also presented. Evaluation of suitability of the six sites is based on a comparison of their geologic characteristics to those found in the tuffaceous beds of Calico Hills within the exploration block.

  8. Mineralogy, petrology and whole-rock chemistry data compilation for selected samples of Yucca Mountain tuffs; Yucca Mountain Site Characterization Project

    Energy Technology Data Exchange (ETDEWEB)

    Connolly, J.R. [New Mexico Univ., Albuquerque, NM (United States)

    1991-12-01

    Petrologic, bulk chemical, and mineralogic data are presented for 49 samples of tuffaceous rocks from core holes USW G-1 and UE-25a{number_sign}1 at Yucca Mountain, Nevada. Included, in descending stratigraphic order, are 11 samples from the Topopah Spring Member of the Paintbrush Tuff, 12 samples from the Tuffaceous Beds of Calico Hills, 3 samples from the Prow Pass Member of the Crater Flat Tuff, 20 samples from the Bullfrog Member of the Crater Flat Tuff and 3 samples from the Tram Member of the Crater Flat Tuff. The suite of samples contains a wide variety of petrologic types, including zeolitized, glassy, and devitrified tuffs. Data vary considerably between groups of samples, and include thin section descriptions (some with modal analyses for which uncertainties are estimated), electron microprobe analyses of mineral phases and matrix, mineral identifications by X-ray diffraction, and major element analyses with uncertainty estimates.

  9. Mobility of Metal Tracers in Unsaturated Tuffs of Busted Butte

    Science.gov (United States)

    Groffman, A. R.

    2001-12-01

    A complex tracer mixture was injected continuously for over two years into a 10 m x 10 m x 7 m block of unsaturated tuff as part of the Busted Butte unsaturated-zone tracer test at Yucca Mountain. The test was designed to measure tracer transport within the Topopah Springs and Calico Hills tuffs, units that occur between the potential high-level nuclear waste repository at Yucca Mountain and the water table below. The mixture included nonreactive (Br, I, and fluorinated benzoic acids (FBAs)) and reactive tracers (Li, Ce, Sm, Ni, Co, and Mn). Bromide, I, FBAs, and Li were detected during the test on absorbent pads emplaced in a series of solute collection boreholes located beneath the injectors but the more strongly sorbing metals did not reach the collection boreholes during this period. To determine the distribution and mobility of these metals, tracer constituents were extracted from tuff samples collected during overcoring and mineback of the test block. Tracers were extracted from the tuff samples by leaching with a 5% nitric acid solution for metals and a bicarbonate-carbonate buffer for anions. Results from the overcore sample suite show that metals have migrated through the tuff in the region adjacent to and immediately below the tracer injectors. Consistent with laboratory sorption measurements and observed breakthrough in the collection boreholes, rock analyses showed that Li is the most mobile of the metals. Co and Ni behave similarly, traveling tens of cm from the injection sites, while Sm and Ce moved far less, possibly due to precipitation reactions in addition to sorption. Determination of Mn transport is complicated by high background concentrations in the tuff; additional background samples are currently being evaluated. As expected, our rock analyses show that the nonreactive tracers Br and FBAs have moved beyond the overcore region, corroborating results from collection boreholes.

  10. Stratigraphy, age, and depositional setting of the Miocene Barstow Formation at Harvard Hill, central Mojave Desert, California

    Science.gov (United States)

    Leslie, Shannon R.; Miller, David M.; Wooden, Joseph L.; Vazquez, Jorge A.

    2010-01-01

    New detailed geologic mapping and geochronology of the Barstow Formation at Harvard Hill, 30 km east of Barstow, CA, help to constrain Miocene paleogeography and tectonics of the central Mojave Desert. A northern strand of the Quaternary ENE-striking, sinistral Manix fault divides the Barstow Formation at Harvard Hill into two distinct lithologic assemblages. Strata north of the fault consist of: a green rhyolitic tuff, informally named the Shamrock tuff; lacustrine sandstone; partially silicified thin-bedded to massive limestone; and alluvial sandstone to pebble conglomerate. Strata south of the fault consist of: lacustrine siltstone and sandstone; a rhyolitic tuff dated at 19.1 Ma (U-Pb); rock-avalanche breccia deposits; partially silicified well-bedded to massive limestone; and alluvial sandstone and conglomerate. Our U-Pb zircon dating of the Shamrock tuff by SHRIMP-RG yields a peak probability age of 18.7 ± 0.1 Ma. Distinctive outcrop characteristics, mineralogy, remanent magnetization, and zircon geochemistry (Th/U) suggest that the Shamrock tuff represents a lacustrine facies of the regionally extensive Peach Spring Tuff (PST). Here we compare zircon age and geochemical analyses from the Shamrock tuff with those of the PST at Stoddard Wash and provide new insight into the age of zircon crystallization in the PST rhyolite. Results of our field studies show that Miocene strata at Harvard Hill mostly accumulated in a lacustrine environment, although depositional environments varied from a relatively deep lake to a very shallow lake or even onshore setting. Rock-avalanche breccias and alluvial deposits near the base of the exposed section indicate proximity to a steep basin margin and detrital studies suggest a southern source for coarse-grained deposits; therefore, we may infer a southern basin-margin setting at Harvard Hill during the early Miocene. Our geochronology demonstrates that deposition of the Barstow Formation at Harvard Hill extended from before

  11. A strategy to seal exploratory boreholes in unsaturated tuff; Yucca Mountain Site Characterization Project

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, J.A. [Sandia National Labs., Albuquerque, NM (United States); Case, J.B.; Givens, C.A.; Carney, B.C. [IT Corp., Albuquerque, NM (United States)

    1994-04-01

    This report presents a strategy for sealing exploratory boreholes associated with the Yucca Mountain Site Characterization Project. Over 500 existing and proposed boreholes have been considered in the development of this strategy, ranging from shallow (penetrating into alluvium only) to deep (penetrating into the groundwater table). Among the comprehensive list of recommendations are the following: Those boreholes within the potential repository boundary and penetrating through the potential repository horizon are the most significant boreholes from a performance standpoint and should be sealed. Shallow boreholes are comparatively insignificant and require only nominal sealing. The primary areas in which to place seals are away from high-temperature zones at a distance from the potential repository horizon in the Paintbrush nonwelded tuff and the upper portion of the Topopah Spring Member and in the tuffaceous beds of the Calico Hills Unit. Seals should be placed prior to waste emplacement. Performance goals for borehole seals both above and below the potential repository are proposed. Detailed construction information on the boreholes that could be used for future design specifications is provided along with a description of the environmental setting, i.e., the geology, hydrology, and the in situ and thermal stress states. A borehole classification scheme based on the condition of the borehole wall in different tuffaceous units is also proposed. In addition, calculations are presented to assess the significance of the boreholes acting as preferential pathways for the release of radionuclides. Design calculations are presented to answer the concerns of when, where, and how to seal. As part of the strategy development, available technologies to seal exploratory boreholes (including casing removal, borehole wall reconditioning, and seal emplacement) are reviewed.

  12. Rheomorphism of welded tuffs

    Science.gov (United States)

    Wolff, J. A.; Wright, J. V.

    1981-05-01

    Peralkaline welded tuffs from the islands of Gran Canaria, Canary Islands, and Pantelleria, Italy, show abundant evidence for post-depositional flow. It is demonstrated that rheomorphism, or secondary mass flowage, can occur in welded tuffs of ignimbrite and air-fall origin. The presence of a linear fabric is taken as the diagnostic criterion for the recognition of the process. Deposition on a slope is an essential condition for the development of rheomorphism after compaction and welding. Internal structures produced during rheomorphic flow can be studied by the methods of structural geology and show similar dispositions to comparable features in sedimentary slump sheets. It is shown that secondary flowage can occur in welded tuffs emplaced on gentle slopes, provided that the apparent viscosity of the magma is sufficiently low. Compositional factors favor the development of rheomorphism in densely welded tuffs of peralkaline type.

  13. 75 FR 65650 - Notice of Availability of the Record of Decision for the Calico Solar Project and Associated...

    Science.gov (United States)

    2010-10-26

    ... 230-kilovolt (kV) Calico Substation and 2-mile, 230-kv transmission line, and other project facilities..., operation, maintenance, and decommissioning of the 663.5 megawatt (MW), 4,604-acre Calico Solar Project..., 2010 (75 FR 47620). Publication of the NOA for the Final EIS initiated a 30-day protest period for...

  14. A Conceptual Overview of the History of the CALICO Journal: The Phases of CALL

    Science.gov (United States)

    Fischer, Robert

    2013-01-01

    Over the 30-year history of the "CALICO Journal", various areas of research and development in CALL have come to the fore in articles published in the journal at different points in time. These areas, which reflect the general concerns of the profession, can be conveniently categorized under the general acronym of ICT: Information and…

  15. Geohydrology of Bandelier Tuff

    Energy Technology Data Exchange (ETDEWEB)

    Abeele, M.V.; Wheeler, M.L.; Burton, B.W.

    1981-10-01

    The Los Alamos National Laboratory has been disposing of radioactive wastes since 1944. Environmental studies and monitoring for radioactive contamination started concurrently. In this report, only two mechanisms and rates by which the radionuclides can enter the environment are studied in detail: subsurface transport of radionuclides by migrating water, and diffusion of tritiated water (HTO) in the vapor phase. The report also includes a section concerning the influence of moisture on shear strength and possible resulting subsidences occurring in the pit overburdens. Because subsurface transport of radionuclides is influenced by the hydraulic conductivity and this in turn is regulated by the moisture content of any given material, a study was also undertaken involving precipitation, the most important climatic element influencing the geohydrology of any given area. Further work is in progress to correlate HTO emanation to atmospheric and pedological properties, especially including thermal characteristics of the tuff.

  16. The structure contours of the Calico sequence boundary in the Kaiparowits Plateau, southern Utah (csbstrc*g)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This is a polygon coverage of the structure contours of the Calico sequence boundary in the Kaiparowits Plateau, southern Utah. Sequence boundary elevations are...

  17. Carpenter Ridge Tuff, CO

    Science.gov (United States)

    Bachmann, Olivier; Deering, Chad D.; Lipman, Peter W.; Plummer, Charles

    2014-06-01

    The ~1,000 km3 Carpenter Ridge Tuff (CRT), erupted at 27.55 Ma during the mid-tertiary ignimbrite flare-up in the western USA, is among the largest known strongly zoned ash-flow tuffs. It consists primarily of densely welded crystal-poor rhyolite with a pronounced, highly evolved chemical signature (high Rb/Sr, low Ba, Zr, Eu), but thickly ponded intracaldera CRT is capped by a more crystal-rich, less silicic facies. In the outflow ignimbrite, this upper zone is defined mainly by densely welded crystal-rich juvenile clasts of trachydacite composition, with higher Fe-Ti oxide temperatures, and is characterized by extremely high Ba (to 7,500 ppm), Zr, Sr, and positive Eu anomalies. Rare mafic clasts (51-53 wt% SiO2) with Ba contents to 4,000-5,000 ppm and positive Eu anomalies are also present. Much of the major and trace-element variations in the CRT juvenile clasts can be reproduced via in situ differentiation by interstitial melt extraction from a crystal-rich, upper-crustal mush zone, with the trachydacite, crystal-rich clasts representing the remobilized crystal cumulate left behind by the melt extraction process. Late recharge events, represented by the rare mafic clasts and high-Al amphiboles in some samples, mixed in with parts of the crystal cumulate and generated additional scatter in the whole-rock data. Recharge was important in thermally remobilizing the silicic crystal cumulate by partially melting the near-solidus phases, as supported by: (1) ubiquitous wormy/sieve textures and reverse zoning patterns in feldspars and biotites, (2) absence of quartz in this very silicic unit stored at depths of >4-5 km, and (3) heterogeneous melt compositions in the trachydacite fiamme and mafic clasts, particularly in Ba, indicating local enrichment of this element due mostly to sanidine and biotite melting. The injection of hot, juvenile magma into the upper-crustal cumulate also imparted the observed thermal gradient to the deposits and the mixing overprint that

  18. Hill's equation

    CERN Document Server

    Magnus, Wilhelm

    2004-01-01

    The hundreds of applications of Hill's equation in engineering and physics range from mechanics and astronomy to electric circuits, electric conductivity of metals, and the theory of the cyclotron. New applications are continually being discovered and theoretical advances made since Liapounoff established the equation's fundamental importance for stability problems in 1907. Brief but thorough, this volume offers engineers and mathematicians a complete orientation to the subject.""Hill's equation"" connotes the class of homogeneous, linear, second order differential equations with real, period

  19. Effect of moisture on tuff stone degradation

    NARCIS (Netherlands)

    Lubelli, B.A.; Nijland, T.G.

    2016-01-01

    Tuff stone elements with a large length/width ratio often suffer damage in the form of cracks parallel to the surface and spalling of the outer layer. The response of tuff to moisture might be a reason for this behaviour. This research aimed at verifying if differential dilation between parts with d

  20. Isopachs of the combined thickness of the Calico and A-sequences of the Straight Cliffs Formation in the Kaiparowits Plateau study area, southern Utah (kjhthk*g)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This is a polygon coverage of isopachs of the combined thickness of the Calico and A-sequences in the Kaiparowits Plateau study area. The outside polygon defines the...

  1. Preliminary thermal expansion screening data for tuffs

    Energy Technology Data Exchange (ETDEWEB)

    Lappin, A.R.

    1980-03-01

    A major variable in evaluating the potential of silicic tuffs for use in geologic disposal of heat-producing nuclear wastes is thermal expansion. Results of ambient-pressure linear expansion measurements on a group of tuffs that vary treatly in porosity and mineralogy are presente here. Thermal expansion of devitrified welded tuffs is generally linear with increasing temperature and independent of both porosity and heating rate. Mineralogic factors affecting behavior of these tuffs are limited to the presence or absence of cristobalite and altered biotite. The presence of cristobalite results in markedly nonlinear expansion above 200{sup 0}C. If biotite in biotite-hearing rocks alters even slightly to expandable clays, the behavior of these tuffs near the boiling point of water can be dominated by contraction of the expandable phase. Expansion of both high- and low-porosity tuffs containing hydrated silicic glass and/or expandable clays is complex. The behavior of these rocks appears to be completely dominated by dehydration of hydrous phases and, hence, should be critically dependent on fluid pressure. Valid extrapolation of the ambient-pressure results presented here to depths of interest for construction of a nuclear-waste repository will depend on a good understanding of the interaction of dehydration rates and fluid pressures, and of the effects of both micro- and macrofractures on the response of tuff masss.

  2. Mechanical excavator performance in Yucca Mountain tuffs

    Energy Technology Data Exchange (ETDEWEB)

    Ozdemir, L. [Colorado School of Mines, Golden, CO (USA); Hansen, F.D. [Sandia National Labs., Albuquerque, NM (USA)

    1991-01-01

    A research effort of four phases is in progress at the Colorado School of Mines. The overall program will evaluate the cutability of welded tuff and other lithologies likely to be excavated at Yucca Mountain in the site characterization process. Several mechanical systems are considered with emphasis given to the tunnel boring machine. The research comprises laboratory testing, linear drag bit and disc cutter tests and potentially large-scale laboratory demonstrations to support potential use of a tunnel boring machine in welded tuff. Preliminary estimates of mechanical excavator performance in Yucca Mountain tuff are presented here. As phases of the research project are completed, well quantified estimates will be made of performance of mechanical excavators in the Yucca Mountain tuffs. 3 refs., 2 tabs.

  3. Development of waste packages for tuff

    Energy Technology Data Exchange (ETDEWEB)

    Rothman, A.J.

    1982-09-20

    The objective of this program is to develop nuclear waste packages that meet the Nuclear Regulatory Commission`s requirements for a licensed repository in tuff at the Nevada Test Site. Selected accomplishments for FY82 are: (1) Selection, collection of rock, and characterization of suitable outcrops (for lab experiments); (2) Rock-water interactions (Bullfrog Tuff); (3) Corrosion tests of ferrous metals; (4) Thermal modeling of waste package in host rock; (5) Preliminary fabrication tests of alternate backfills (crushed tuff); (6) Reviewed Westinghouse conceptual waste package designs for tuff and began modification for unsaturated zone; and (7) Waste Package Codes (BARIER and WAPPA) now running on our computer. Brief discussions are presented for rock-water interactions, corrosion tests of ferrous metals, and thermal and radionuclide migration modelling.

  4. Reconnaissance geochronology of tuffs in the Miocene Barstow Formation: implications for basin evolution and tectonics in the central Mojave Desert

    Science.gov (United States)

    Miller, D.M.; Leslie, S.R.; Hillhouse, J.W.; Wooden, J.L.; Vazquez, J.A.; Reynolds, R.E.

    2010-01-01

    Early to middle Miocene lacustrine strata of the Barstow Formation are well dated in just a few places, limiting our ability to infer basin evolution and regional tectonics. At the type section in the Mud Hills, previous studies have shown that the lacustrine interval of the Barstow Formation is between ~16.3 Ma and ~13.4 Ma. Elsewhere, lake beds of the Barstow Formation have yielded vertebrate fossils showing the Hemingfordian/Bartovian transition at ~16 Ma but are otherwise poorly dated. In an attempt to clarify the age and depositional environments of the lake deposits, we are mapping the Barstow Formation and dating zircons from interbedded tuffs, as well as testing ash-flow tuffs for the distinctive remanent magnetization direction of the widespread Peach Spring Tuff. Thus far, our new U-Pb zircon ages inficate that the Barstow lake beds contain tuff beds as old as 19.1 Ma and as young as 15.3 Ma. At Harvard Hill, Barstow lake beds contain a thick tuff dated at 18.7 Ma. On the basis of zircon ages, mineralogy, zircon chemistry, and paleomagnetic results, we consider the thick tuff to be a lacustrine facies of the Peach Spring Tuff. We have identified the Peach Spring Tuff by similar methods at eight localities over a broad area, providing a timeline for several fluvial and lacustrine sections. The new dates indicate that long-lived lacustrine systems originated before 19 Ma and persisted to at least 15 Ma. The onset of lacustrine conditions predates the Peach Spring Tuff in most Barstow Formation sections and may be older than 19.5 Ma in some places. The new data indicate that the central Mojave Desert contained narrow to broad lake basins during and after extension, and that Barstow lacustrine deposits did not exclusively postdate extensional tectonics. At present, it is unclear whether several separate, small lake basins coexisted during the early to middle Miocene, or if instead several small early Miocene basins gradually coalesced over about 6 millions

  5. Loess Hills of Iowa

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — This coverage outlines the boundary of the Loess Hills in Iowa at 1:100,000 scale. Criteria applied to the delineation of the Loess Hills included drainage density,...

  6. Arsenogoyazite in Cenozoic volcanic tuff at Tabalaopa Basin, Chihuahua, Mexico

    Science.gov (United States)

    Ren, M.; Rodriguez, A.; Goodell, P.

    2012-12-01

    Arsenogoyazite has been identified in Cenozoic volcanic tuff at Tabalaopa Basin, Chihuahua, Mexico. Tabalaopa Basin contains volcanic strata and the unconsolidated Quaternary deposit. Cenozoic volcanic tuff forms the low hill terrene in this area. It is a major reservoir for the City of Chihuahua groundwater. Arsenic anomaly (more than 20 ppb) has been observed at El Mimbre, northeast of the city. The exposed reddish color volcanic rocks are felsic welded tuff and rhyolite. Sanidine, quartz, and biotite phenocrysts show linear distribution within the fine grain matrix. The rocks contain large amount of vesicles which are lineated with the welding bends. White and colorless microsize crystals formed on the well of the cavities and the majority of them are K-feldspar. Quartz, Ti-magnetite, and arsenogoyazite are coexisting with feldspars. The sizes of the crystals in the cavities are 10 to several 10s of micrometers. The arsenic x-ray maps have been collected for the rock sections to locate the arsenic minerals. The crystals in cavities show euhedral shape. Most arsenic containing crystals have a near cubic form with triangle surfaces at some corners. The high resolution field-emission SEM images have been collected to study the symmetry of the crystals. EDS spectra for the high arsenic phases show three major elements As-Al-Sr and also minor amount of P-S-REE-Ca-Fe-Si. Since the arsenic minerals are growing on the wall of the vesicle, it is difficult to perform good electron microprobe analysis. Some primary microprobe data give following results in weight percent: SrO 11.8-13.1, CaO 0.2-0.3, FeO 0.3-0.5, Al2O3 28.6-30.9, La2O3 2.4-2.5, Ce2O3 2.3-.24, SiO2 1.1-3.6, As2O5 32.4-35.2, P2O5 1.7-1.9, SO3 0.8-1.4. This chemistry is similar to the reported arsenogoyazite chemical data. So this high arsenic phase is identified as arsenogoyazite. The arsenic anomaly in groundwater at El Mimbre, Chihuahua should be contributed from this arsenic mineral phase in the strata.

  7. Anisotropy of the Topopah Spring Member Tuff

    Energy Technology Data Exchange (ETDEWEB)

    Martin, R.J. III; Boyd, P.J.; Haupt, R.W. [New England Research, Inc., White River Junction, VT (United States); Price, R.H. [Sandia National Labs., Albuquerque, NM (United States)

    1992-07-01

    Mechanical properties of the tuffaceous rocks within Yucca Mountain are needed for near and far-field modeling of the potential nuclear waste repository. If the mechanical properties are significantly anisotropic (i.e., direction-dependent), a more complex model is required. Relevant data from tuffs tested in earlier studies indicate that elastic and strength properties are anisotropic. This scoping study confirms the elastic anisotropy and concludes some tuffs are transversely isotropic. An approach for sampling and testing the rock to determine the magnitude of the anisotropy is proposed.

  8. Properties of Tuffs, Grout and Other Materials.

    Science.gov (United States)

    1982-01-01

    Samples of tuff as-received have been wrapped in foil and sealed in beeswax in the field. Density and moisture content were determined from small pieces...received" density was deter- mined by weighing the chipped-off test specimen, coating it with wax, and measuring its volume using mercury displacement

  9. Evaluation of some Italian tuffs as compatible replacement stone for Römer tuff in the Netherlands

    NARCIS (Netherlands)

    Nijland, T.G.; Hees, R.P.J. van

    2007-01-01

    Rhenish tuffs from the volcanic Eifel region, Germany, are amongst the most prominent and voluminous natural stones in Dutch monuments. In particular, tuffs from the 11,900 bp Laacher See eruption have been used since Roman times, - hence the name Römer tuff-, and were widely used again in romanesqu

  10. Sorption of lanthanum ions by natural clinoptilolite tuff

    Science.gov (United States)

    Dampilova, B. V.; Zonkhoeva, E. L.

    2013-08-01

    The equilibrium and kinetics of sorption of lanthanum ions on natural clinoptilolite tuff are studied. It is demonstrated that sorption of lanthanum ions from diluted solutions occurs in micropores of clinoptilolite, and from concentrated solutions in the mesoporous structure of tuff. The main capacity of zeolite tuff is found in the secondary porous structure. The sorption of lanthanum ions is limited by diffusion in tuff grains. Lanthanum ions are regularly distributed in the tuff phase and interact with the Brønsted centers of large clinoptilolite cavities.

  11. Hydraulic characterization of hydrothermally altered Nopal tuff

    Energy Technology Data Exchange (ETDEWEB)

    Green, R.T.; Meyer-James, K.A. [Southwest Research Institute, San Antonio, TX (United States); Rice, G. [George Rice and Associates, San Antonio, TX (United States)

    1995-07-01

    Understanding the mechanics of variably saturated flow in fractured-porous media is of fundamental importance to evaluating the isolation performance of the proposed high-level radioactive waste repository for the Yucca Mountain site. Developing that understanding must be founded on the analysis and interpretation of laboratory and field data. This report presents an analysis of the unsaturated hydraulic properties of tuff cores from the Pena Blanca natural analog site in Mexico. The basic intent of the analysis was to examine possible trends and relationships between the hydraulic properties and the degree of hydrothermal alteration exhibited by the tuff samples. These data were used in flow simulations to evaluate the significance of a particular conceptual (composite) model and of distinct hydraulic properties on the rate and nature of water flow.

  12. Infiltration and Seepage Through Fractured Welded Tuff

    Energy Technology Data Exchange (ETDEWEB)

    T.A. Ghezzehei; P.F. Dobson; J.A. Rodriguez; P.J. Cook

    2006-06-20

    The Nopal I mine in Pena Blanca, Chihuahua, Mexico, contains a uranium ore deposit within fractured tuff. Previous mining activities exposed a level ground surface 8 m above an excavated mining adit. In this paper, we report results of ongoing research to understand and model percolation through the fractured tuff and seepage into a mined adit both of which are important processes for the performance of the proposed nuclear waste repository at Yucca Mountain. Travel of water plumes was modeled using one-dimensional numerical and analytical approaches. Most of the hydrologic properly estimates were calculated from mean fracture apertures and fracture density. Based on the modeling results, we presented constraints for the arrival time and temporal pattern of seepage at the adit.

  13. Structure of metal matrix composites with an addition of tuff

    Directory of Open Access Journals (Sweden)

    M. Łach

    2010-07-01

    Full Text Available The article presents preliminary results of tests of metal matrix composites structure which was modified by an addition of powderedvolcanic tuff. Distribution and shape of ceramic particles as well as the quality of the bonding along the tuff- metal matrix interface werestudied. Depth of tuff element diffusion in the matrix as well as diffusion in tuff particles were checked. Micro-hardness and porosity of the composites were also tested. The tuff from Filipowice near the town of Krzeszowice was used for the tests. Powder metallurgy wasapplied to obtain the composites and the matrix materials were copper and 316L steel powders. The tuff was introduced in 2, 5 and 10 %by weight. To remove water from the channels of aluminosilicates, the tuff was baked at 850 oC for 4 hours and then cooled together withthe oven. The tests revealed good quality of the bonding of the tuff particles and the matrix and their even distribution. The addition of tuff improved the hardness of the composites and reduced their porosity which has great significance because of possible applications of this kind of materials in general and copper composites in particular. This gives grounds for further studies on volcanic tuff use in metal composites

  14. A coverage that differentiates between areas where the total Calico and A-sequence coal-bearing interval is preserved and where the coal-bearing strata are partially eroded in the Kaiparowits Plateau, southern Utah

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This is a polygon coverage that represents areas underlain by the coal-bearing Calico and A-sequences of the Straight Cliffs Formation east of 112 degrees of...

  15. Magnetic, structural and geochronologic evidence bearing on volcanic sources and Oligocene Deformation of Ash Flow Tuffs, northeast Nevada

    Science.gov (United States)

    Palmer, H. C.; MacDonald, W. D.; Hayatsu, A.

    1991-02-01

    Magnetic properties of mid-Tertiary volcanic rocks west of Jiggs in northeast Nevada were investigated for the purposes of interpreting igneous, structural, and tectonic processes in this part of the Basin and Range province. Anisotropy of magnetic susceptibility (AMS) patterns reflect flow fabrics and suggest previously unknown sources for these ash flow tuffs. Paleomagnetic and structural evidence suggest counterclockwise relative rotation of the southern part of the area with respect to the north. New stratigraphic, chemical and K-Ar isotopic data support these interpretations. Dacite to rhyolite ash flow tuffs of the Indian Well Formation were subdivided into two main units: the lower and predominant tuff of Jiggs (35.8-37.0 Ma) and the unconformably overlying but areally restricted tuff of Hackwood (30.8 Ma). The Jiggs unit has two polarities whereas the Hackwood has only a reversed polarity remanence. Together these units with tilt correction define a pole (92°E, 87°N, dp = 6°, dm = 8°) for approximately 30-37 Ma. This pole is concordant with coeval North American reference poles, indicating that this zone of approximately 30 km NS extent has not undergone significant vertical axis rotation relative to the North American reference. Andesite lavas of normal magnetic polarity and of 32.5-Ma age characterize the Diamond Hills immediately to the south. We interpret this region, from both structural evidence and discordant paleomagnetic direction, to have rotated approximately 25° counterclockwise relative to the Indian Well volcanic units to the north. The apparent rotation of the Diamond Hills is possibly the result of drag on the left-lateral Garcia fault which limits the Diamond Hills on the southwest. Analysis of AMS data suggests, by patterns of the K1 axes, two distinct sources for the Jiggs unit: a northern buried source and a central partially buried source. Lithologic evidence consistent with proximal vent facies is found near the latter source. An

  16. David Keynes Hill.

    Science.gov (United States)

    Huxley, Andrew

    2003-01-01

    David Hill followed his father, A.V. Hill FRS, into the study of muscular contraction. Using a wide range of experimental techniques, he made several important advances of which the most important was the discovery of the 'short-range elastic component', a phenomenon which implied that even in the resting state there was an interaction between the thick (myosin) and thin (actin) filaments. He also studied physical changes in nerve when stimulated.

  17. Initial field testing definition of subsurface sealing and backfilling tests in unsaturated tuff; Yucca Mountain Site Characterization Project

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, J.A. [Sandia National Labs., Albuquerque, NM (United States); Case, J.B.; Tyburski, J.R. [I. T. Corp., Albuquerque, NM (United States)

    1993-05-01

    This report contains an initial definition of the field tests proposed for the Yucca Mountain Project repository sealing program. The tests are intended to resolve various performance and emplacement concerns. Examples of concerns to be addressed include achieving selected hydrologic and structural requirements for seals, removing portions of the shaft liner, excavating keyways, emplacing cementitious and earthen seals, reducing the impact of fines on the hydraulic conductivity of fractures, efficient grouting of fracture zones, sealing of exploratory boreholes, and controlling the flow of water by using engineered designs. Ten discrete tests are proposed to address these and other concerns. These tests are divided into two groups: Seal component tests and performance confirmation tests. The seal component tests are thorough small-scale in situ tests, the intermediate-scale borehole seal tests, the fracture grouting tests, the surface backfill tests, and the grouted rock mass tests. The seal system tests are the seepage control tests, the backfill tests, the bulkhead test in the Calico Hills unit, the large-scale shaft seal and shaft fill tests, and the remote borehole sealing tests. The tests are proposed to be performed in six discrete areas, including welded and non-welded environments, primarily located outside the potential repository area. The final selection of sealing tests will depend on the nature of the geologic and hydrologic conditions encountered during the development of the Exploratory Studies Facility and detailed numerical analyses. Tests are likely to be performed both before and after License Application.

  18. Preferential Flow in Fractured Welded Tuffs

    Energy Technology Data Exchange (ETDEWEB)

    Salve, Rohit

    2004-08-15

    To better understand preferential flow in fractured rock, we carried out an in situ field experiment in the Exploratory Studies Facility at Yucca Mountain, Nevada. This experiment involved the release of {approx} 22 m3 of ponded water (at a pressure head of {approx} 0.04 m) over a period of 7 months, directly onto a 12 m2 infiltration plot located on a fractured welded tuff surface. As water was released, changes in moisture content were monitored along horizontal boreholes located in the formation {approx} 19-22 m below. Distinct flow zones, varying in flow velocity, wetted cross-sectional area, and extent of lateral movement, intercepted the monitoring boreholes. There was also evidence of water being diverted above the ceiling of a cavity in the immediate vicinity of the monitoring boreholes. Observations from this field experiment suggest that isolated conduits, each encompassing a large number of fractures, develop within the fractured rock formation to form preferential flow paths that persist if there is a continuous supply of water. In addition, in fractured welded tuffs the propensity for fracture-matrix interactions is significantly greater than that suggested by existing conceptual models,in which flow occurs along a section of fracture surfaces. An overriding conclusion is that field investigations at spatial scales of tens of meters provide data critical to the fundamental understanding of flow in fractured rock.

  19. Degraded dryland rehabilitation: boosting seedling survival using zeolitic tuff

    Science.gov (United States)

    Alhamad, Mohammad Noor; Alrbabah, Mohammad; Athamneh, Hana

    2016-04-01

    More than 90% of Jordan is broadly defined as rangelands. Most rangelands are located within the arid zone of the country. Extensive grazing occurs across much of the natural pastures resulting in serious environmental degradation of natural resources in these rangelands. Several programs were carried out for rangeland conservation and rehabilitation in the country. However, these programs face a major challenge of the low survival rate of transplanted shrub seedlings. Seeking innovative approaches to assure healthy establishment of seedling is a big challenge to achieve successful rehabilitation programs. Drought is considered one of the major problems in rehabilitation. Promoting survival and growth, using zeolitic tuff added to planting holes is suggested to be a possible solution. The experiment was conducted on a factorial arrangement within RCBD design. Two shrub species (Atriplex halimus, Atriplex nummularia) were transplanted into holes prepared with three levels of tuff treatments (mulching, mixing and control) under rainfed condition. The result showed insignificant effect of tuff on seedling survival percentage, when mixing tuff with plantation soil or adding tuff as mulch. Also, the two species showed similar survival percentages over two measured dates. However, mixing tuff with soil during hole preparation significantly enhanced seedling heights. Furthers, The Australian atriplex (Atriplex nummularia) species significantly grow higher than Atriplex halimus. The study results suggested that mixing zeoltic tuff with soil during transplantation of seedling is promising in improving the success of rangeland rehabilitation in dry areas in Jordan.

  20. Escape in Hill's Problem

    CERN Document Server

    Heggie, D C

    2000-01-01

    This didactic paper is motivated by the problem of understanding how stars escape from globular star clusters. One formulation of this problem is known, in dynamical astronomy, as Hill's problem. Originally intended as a model for the motion of the moon around the earth with perturbations by the sun, with simple modifications it also serves as a model for the motion of a star in a star cluster with perturbations by the galaxy. The paper includes introductory sections on the derivation of the equations of motion of Hill's problem, their elementary properties, and extensions to deal with non-point masses and non-circular orbits. We then show how the rate of escape may be calculated numerically and estimated theoretically, and discuss how this simple picture is modified if the stars in a cluster are also undergoing two-body relaxation. Finally we introduce some established ideas for obtaining the distribution of escape times.

  1. Notting Hill Carnival 1988.

    Science.gov (United States)

    Dalton, A M; Sharma, A; Touquet, R

    1989-06-01

    The injuries sustained at the 1988 Notting Hill Carnival were documented in order to suggest ways in which these might be reduced in future years. Sixty-four patients presented to six hospitals participating in the study over a 48-h period, most of whom were victims of accidents (63%) rather than assaults (37%). Many of the accidents were caused by motorized floats or by stepping on broken glass.

  2. Nose Hill Artifacts

    Science.gov (United States)

    Hansen, Vivian

    2008-01-01

    A Blackfoot woman, caught in the act of adultery, was condemned at this site to have her nose cut off as a penalty for her actions. People do not know her story. The tribe cast it on the ground. And so She, Nose Hill, was named. John Laurie Boulevard holds her mound in a circlet of asphalt, defining the map of her "terra incognita." She is a park…

  3. Evaluation of three Italian tuffs (Neapolitan Yellow Tuf, Tufo Romano and Tufo Etrusco) as compatible replacement stone for Römer tuff in Dutch built cultural heritage

    NARCIS (Netherlands)

    Nijland, T.G.; Hees, R.P.J. van; Bolondi, L.

    2010-01-01

    Rhenish tuffs from the volcanic Eifel region in Germany, in particular the so-called Römer tuff, are among the most prominent and voluminous natural stones in Dutch monuments. The Römer tuff has been used since Roman times, and was widely used again in Romanesque (and to a lesser extent Romano-Gothi

  4. Evaluation of three Italian tuffs (Neapolitan Yellow Tuf, Tufo Romano and Tufo Etrusco) as compatible replacement stone for Römer tuff in Dutch built cultural heritage

    NARCIS (Netherlands)

    Nijland, T.G.; Hees, R.P.J. van; Bolondi, L.

    2010-01-01

    Rhenish tuffs from the volcanic Eifel region in Germany, in particular the so-called Römer tuff, are among the most prominent and voluminous natural stones in Dutch monuments. The Römer tuff has been used since Roman times, and was widely used again in Romanesque (and to a lesser extent

  5. Photon Shielding Features of Quarry Tuff

    Directory of Open Access Journals (Sweden)

    Vega-Carrillo Hector Rene

    2017-01-01

    Full Text Available Cantera is a quarry tuff widely used in the building industry; in this work the shielding features of cantera were determined. The shielding characteristics were calculated using XCOM and MCNP5 codes for 0.03, 0.07, 0.1, 0.3, 0.662, 1, 2, and 3 MeV photons. With XCOM the mass interaction coefficients, and the total mass attenuation coefficients, were calculated. With the MCNP5 code a transmission experiment was modelled using a point-like source located 42 cm apart from a point-like detector. Between the source and the detector, cantera pieces with different thickness, ranging from 0 to 40 cm were included. The collided and uncollided photon fluence, the Kerma in air and the Ambient dose equivalent were estimated. With the uncollided fluence the linear attenuation coefficients were determined and compared with those calculated with XCOM. The linear attenuation coefficient for 0.662 MeV photons was compared with the coefficient measured with a NaI(Tl-based γ-ray spectrometer and a 137Cs source.

  6. Photon Shielding Features of Quarry Tuff

    Science.gov (United States)

    Vega-Carrillo, Hector Rene; Hernandez-Adame, Luis; Guzman-Garcia, Karen Arlete; Ortiz-Hernandez, Arturo Agustin; Rodriguez-Rodriguez, Jose Antonio; Juarez-Alvarado, Cesar Antonio

    2017-09-01

    Cantera is a quarry tuff widely used in the building industry; in this work the shielding features of cantera were determined. The shielding characteristics were calculated using XCOM and MCNP5 codes for 0.03, 0.07, 0.1, 0.3, 0.662, 1, 2, and 3 MeV photons. With XCOM the mass interaction coefficients, and the total mass attenuation coefficients, were calculated. With the MCNP5 code a transmission experiment was modelled using a point-like source located 42 cm apart from a point-like detector. Between the source and the detector, cantera pieces with different thickness, ranging from 0 to 40 cm were included. The collided and uncollided photon fluence, the Kerma in air and the Ambient dose equivalent were estimated. With the uncollided fluence the linear attenuation coefficients were determined and compared with those calculated with XCOM. The linear attenuation coefficient for 0.662 MeV photons was compared with the coefficient measured with a NaI(Tl)-based γ-ray spectrometer and a 137Cs source.

  7. Transport properties of Topopah Spring tuff

    Energy Technology Data Exchange (ETDEWEB)

    Lin, W.; Daily, W.

    1984-10-01

    Electrical resistivity, ultrasonic P-waves velocity, and water permeability were measured simultaneously on both intact and fractured Topopah Spring tuff samples at a confining pressure of 5.0 MPa, pore pressures to 2.5 MPa, and temperatures to 140{sup 0}C. The tested samples were subjected to three dehydration and rehydration cycles. The dehydrations were accomplished at a temperature of 140{sup 0}C, and the rehydrations were accomplished at various combinations of temperature and pore pressures so that the wetting fluid was either liquid water, steam or both. The electrical resistivity measurements indicate that for the intact sample, the drying and resaturation took place fairly uniformly throughout the sample. On the other hand, for the fractured sample, the drying and resaturation was spatially quite nonuniform. When samples had been subjected to 5 MPa of confining pressure and 140{sup 0}C for several weeks, a gradual monotonic drift in resistivity was measured (decreasing resistivity when dry; increasing resistivity when wet). This may be the result of either minerological changes or grain boundary movement. In any case, the phenomenon may have important consequences on long term repository performance, and should be studied further. The permeability of the intact sample was independent of temperature, dehydration and rehydration cycles, and time. The permeability of the fractured sample, initially dominated by the fracture, decreased by about one order of magnitude after each dehydration and rehydration cycle. 11 references, 12 figures, 3 tables.

  8. Compositional zoning of the bishop tuff

    Science.gov (United States)

    Hildreth, W.; Wilson, C.J.N.

    2007-01-01

    Compositional data for >400 pumice clasts, organized according to eruptive sequence, crystal content, and texture, provide new perspectives on eruption and pre-eruptive evolution of the >4600 km3 of zoned rhyolitic magma ejected as the BishopTuff during formation of Long Valley caldera. Proportions and compositions of different pumice types are given for each ignimbrite package and for the intercalated plinian pumice-fall layers that erupted synchronously. Although withdrawal of the zoned magma was less systematic than previously realized, the overall sequence displays trends toward greater proportions of less evolved pumice, more crystals (0-5 24 wt %), and higher FeTi-oxide temperatures (714-818??C). No significant hiatus took place during the 6 day eruption of the BishopTuff, nearly all of which issued from an integrated, zoned, unitary reservoir. Shortly before eruption, however, the zoned melt-dominant portion of the chamber was invaded by batches of disparate lower-silica rhyolite magma, poorer in crystals than most of the resident magma but slightly hotter and richer in Ba, Sr, andTi. Interaction with resident magma at the deepest levels tapped promoted growth ofTi-rich rims on quartz, Ba-rich rims on sanidine, and entrapment of near-rim melt inclusions relatively enriched in Ba and CO2.Varied amounts of mingling, even in higher parts of the chamber, led to the dark gray and swirly crystal-poor pumices sparsely present in all ashflow packages. As shown by FeTi-oxide geothermometry, the zoned rhyolitic chamber was hottest where crystal-richest, rendering any model of solidification fronts at the walls or roof unlikely.The main compositional gradient (75-195 ppm Rb; 0.8-2.2 ppm Ta; 71-154 ppm Zr; 0.40-1.73% FeO*) existed in the melt, prior to crystallization of the phenocryst suite observed, which included zircon as much as 100 kyr older than the eruption.The compositions of crystals, though themselves largely unzoned, generally reflect magma temperature and

  9. Petrographic and Geochemical Analyses of Kirana Hills Shield Rocks around Sargodha and Economic Potential

    Directory of Open Access Journals (Sweden)

    Muhammad Waseem Khan

    2017-04-01

    Full Text Available The present study deals with geochemical and petrographic analysis of the Kirana Hill shield rocks of Punjab plains from Buland, Hachi, Shaheen Abad, Shaikh and Machh hills. On basis of the current studies certain modifications have been made in the classification and nomenclature of rocks exposed in the study areas. Chemical analyses have also been carried out in order to calculate Cross Iddings, Pirsson, and Washington (CIPW norms”, to strengthen nomenclature scheme and finally rocks are classified by using “MAGMA SOFTWARE”. Rhyolites predominate over the basalts/dolerites, andesites, and phyllite/ slate. Rhyolitic rocks are light grey, greenish grey and light brown in color, aphanitic in nature. The observed microscopic textures are aphyric, phyric or porphyritic and micropoikilitc. Moreover, some rhyolitic rocks also show flow texture. They are either cryptocrystalline to microcrystalline or microcrystalline to cryptocrystalline. No glassy material has been observed in any thin section. Mafic rocks are characterized by the presence of ferromagnesian minerals with plagioclase. Andesites exhibit mainly porphyritic texture, but aphyric texture has also been observed in few samples. Hydrothermal alterations are also very common in these rocks. Other rock assemblages identified during laboratory studies from Kirana area include: tuffs i.e. (Lithic Crystal Tuff and Lithic Tuff, basaltic andesite, rhyodacite/ dacite, slate/ phyllite, ankeritic rocks/ veins and quartzofeldspathic veins. Our studies also reveal that no evidence of quartzite has been found in the samples collected from above mentioned areas of Kirana, although it has been reported in previous literature. Iron (Fe has been observed in rhyolite as well as other volcanic rocks of Kirana hills, its presence suggests magma from deep mantle instead of crustal melting / anatexis. In the present analysis some primary and secondary copper minerals including chalcopyrite, atacamite and

  10. Pyritic ash-flow tuff, Yucca Mountain, Nevada -- A discussion

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, S.I.; Larson, L.T.; Noble, D.C. [Univ. of Nevada, Reno, NV (United States)

    1994-12-31

    Textural and mineralogic evidence exists for at least one episode of widespread hydrothermal alteration of volcanic rocks deep in Yucca Mountain, Nevada. Despite this evidence, Castor et al. infer that most of the pyrite found in tuffs at Yucca Mountain was introduced as ejecta (lithic fragments) incorporated during the eruptions of the tuffs, rather than by in-situ hydrothermal activity. Their conclusions appear to be based on their observation that most of the pyrite resides in unaltered to variably altered and veined lithic fragments, whereas pyrite-bearing veins are absent in the tuff matrix, titanomagnetite and mafic phenocrysts in the matrix are generally not replaced by pyrite, and feldspar phenocrysts in the pyritic tuff matrix are generally unaltered. Castor et al. dismiss the much smaller quantities of pyrite disseminated in the tuff matrix, including relatively rare pyritized hornblende and biotite grains, as xenolithic as well. The pyritic tuffs belong to large-volume, subalkaline rhyolite ash-flow units (ca. > 150 to 250 km{sup 3} each). The interpretation of Castor et al. has broad implications for the temperature, fO{sub 2} and fS{sub 2} of major ash flow eruptions. Pyrite origin also bears on the nature of past fluid flow and water-rock reactions at Yucca Mountain, which in turn are important factors in assessing the potential for currently undiscovered mineral resources in the area of the proposed nuclear waste repository. We have studied core and cuttings from the same drill holes studied by Castor et al., as well as other drill holes. It is our contention that the inconsistent lateral and stratigraphic distribution of the pyrite, textural features of the pyrite, and phase stability considerations are incompatible with the {open_quotes}lithic{close_quotes} origin of Castor et al., and are more reasonably explained by in-situ formation from hydrothermal fluids containing low, but geochemically significant, concentrations of reduced sulfur.

  11. Biogas cleaning and upgrading with natural zeolites from tuffs.

    Science.gov (United States)

    Paolini, Valerio; Petracchini, Francesco; Guerriero, Ettore; Bencini, Alessandro; Drigo, Serena

    2016-01-01

    CO2 adsorption on synthetic zeolites has become a consolidated approach for biogas upgrading to biomethane. As an alternative to synthetic zeolites, tuff waste from building industry was investigated in this study: indeed, this material is available at a low price and contains a high fraction of natural zeolites. A selective adsorption of CO2 and H2S towards CH4 was confirmed, allowing to obtain a high-purity biomethane (CO2 zeolites from tuffs may successfully be used in a pressure/vacuum swing adsorption process.

  12. Timing of cut-and-fill sequences in the John Day Formation (Eocene-Oligocene), Painted Hills area, central Oregon

    Energy Technology Data Exchange (ETDEWEB)

    Bestland, E.A.; Retallack, G.J. (Univ. of Oregon, Eugene, OR (United States). Dept. of Geological Sciences); Swisher, C.C. III (Inst. of Human Origins, Berkeley, CA (United States)); Fremd, T.J. (John Day Fossil Beds National Monument, John Day, OR (United States))

    1993-04-01

    Large-scale cut-and-fill features in the Eocene-Oligocene part of the John Day Formation in the Pained Hills area of central Oregon can be interpreted as terrestrial depositional sequences, mapped as lithostratigraphic units, and correlated to North American Land Mammal Ages (NALMA). New laser-fusion 40Ar/39Ar single-crystal ages from the John Day Formation provide evidence for the timing of these sequences and a revised placement of the Eocene-Oligocene boundary. The sequences are bound by erosional surfaces that have relief of up to 60 m, are marked in places by claystone breccias full of reworked soil clasts, and separate otherwise conformable strata. The lowermost depositional sequence in the John Day Formation contains very well developed, Fe- and Al-rich paleosols, laterite horizons, and the welded tuff of member A (39.7 my), and probably correlates to the Duchesean and Chadronian NALMA. These brick-rid claystones are sharply truncated by prominent detrital laterite horizon. Overlying this basal sequence is a second sequence of much less well developed paleosols, abundant tuffs and lacustrine tuffaceous claystones. This sequence contains a distinctive biotite tuff (33 my) and the type locality of the Bridge Creek fossil flora and probably correlates to the Orellan NALMA. Above this biotite tuff are alternating red, dark gray, and tan paleosols and a prominent crystal vitric tuff (32.7 my). The Eocene-Oligocene boundary lies between these two sequences, associated with the laterite horizon that truncates the basal red beds. A major truncation surface cuts this sequence and is overlain by a third sequence of thin red paleosols which probably correlates with the Whitneyan NALMA. Above this is a fourth sequence (Arikareean NALMA) consisting of greenish-tan paleosols, a crystal vitric tuff near its base (29.8 my) and the Picture Gorge Ignimbrite (28.7 my).

  13. Governing the Hills

    DEFF Research Database (Denmark)

    Bennike, Rune Bolding

    local movements and global processes in novel ways. In fact, local place-making itself has been globalised. This dissertation asks what happens when the increasingly globalised production of places collides with a resilient national order of things in the Himalayan hills. It investigates movements...... for the establishment of a Limbuwan and Gorkhaland state on either side of the border between eastern Nepal and north-eastern India. Through the engagement with this area, the dissertation argues that we need to rethink the spatiality of government in order to understand the contemporary conditions for government...... as well as new opportunities in relation to the aspiration for a larger say in local decision-making: While global connections can provide normative leverage to demands for increased local autonomy, the consequence of global connectivity might also be new imperial arrangements of government at distance....

  14. Toilets in the hills.

    Science.gov (United States)

    Rosenfield, P; Holcombe, S J

    1990-04-01

    Population and Community Development Association (PDA) in Chieng Rai province in northern Thailand implemented its Environmental Sanitation for the Hill Tribes Project in March 1988 to reduce parasite infection and generate interest in self help development projects. As of early 1990, the hill tribes population growth rate stood at 4.5% compared to 1.5% in lowland Thailand. Other problems included villagers defecating around dwellings, not drinking safe water (since none was available), and not wearing shoes all of which contributed to a high rate of parasite infection. In fact, an analysis of stool samples revealed that parasites infected a mean of almost 70% of the villagers. PDA staff informed villagers about basic environmental health information which influenced them to improve sanitation conditions. They also demonstrated how to build the 1st model latrine. After that, each villager designed and constructed his own latrine. Each villager took out a Baht 150 (US$6) loan to pay for the construction materials (squat casings and cement) provided by PDA. Over the following 10 months, the staff returned to the villages to collect payments and to provide technical assistance. Those villagers that constructed a latrine persuaded others to also construct a latrine. In fact, villagers, not always PDA staff, have even transferred the knowledge to other villages. As of early 1990, villagers and staff have built 1000 squats and 993 latrines. With the health education and latrine use, PDA hoped to see a subsequent reduction in parasite infections. With the help of volunteer contraceptive distributors, PDA has also been able to expand its family planning program to 250 villages. It has also initiated a parasite control pilot project in the area in which infection rates have steadily decreased.

  15. Revised ages for tuffs of the Yellowstone Plateau volcanic field: Assignment of the Huckleberry Ridge Tuff to a new geomagnetic polarity event

    Science.gov (United States)

    Lanphere, M.A.; Champion, D.E.; Christiansen, R.L.; Izett, G.A.; Obradovich, J.D.

    2002-01-01

    40Ar/39Ar ages were determined on the three major ash-flow tuffs of the Yellowstone Plateau volcanic field in the region of Yellowstone National Park in order to improve the precision of previously determined ages. Total-fusion and incremental-heating ages of sanidine yielded the following mean ages: Huckleberry Ridge Tuff-2.059 ?? 0.004 Ma; Mesa Falls Tuff-1.285 ?? 0.004 Ma; and Lava Creek Tuff-0.639 ?? 0.002 Ma. The Huckleberry Ridge Tuff has a transitional magnetic direction and has previously been related to the Reunion Normal-Polarity Subchron. Dating of the Reunion event has been reviewed and its ages have been normalized to a common value for mineral standards. The age of the Huckleberry Ridge Tuff is significantly younger than lava flows of the Reunion event on Re??union Island, supporting other evidence for a normal-polarity event younger than the Reunion event.

  16. Physical properties of ash flow tuff from Yucca Mountain, Nevada

    Science.gov (United States)

    Nelson, Philip H.; Anderson, Lennart A.

    1992-05-01

    The density and porosity of 198 samples of ash flow tuffs from three boreholes at Yucca Mountain, Nevada, are measured and determined. The electrical properties, velocity, and permeability of many of these samples are also determined. Zeolites and clays are found to reduce the grain density, increase the electrical conductivity, reduce the compressional velocity, and reduce the permeability.

  17. The Hill and the Trees

    Institute of Scientific and Technical Information of China (English)

    王燕文

    2007-01-01

    Once there was a well-known hill here. There were many lush trees, beautiful flowers and green grasses on it. One day, the hill said to the trees proudly, “Look, how beautiful I am! But you look so ugly on my back. It must be better if I could drive you away.” One of the trees said, “You won't have beautiful and green clothing without us trees? If you leave us, you will die away.” The hill laughed and said again,”I feel very ashamed for I am staying with you together. Sooner or later I will drive you all...

  18. Are hills like white elephants?

    Directory of Open Access Journals (Sweden)

    Sunil Sharma

    2016-11-01

    Full Text Available 'Are Hills Like White Elephants?' is, of course, inspired by Hemingway; the tribute reflects on the abiding relevance of serious art in a changed world and extends the boundaries of his message to other human situations.

  19. Antigravity hills are visual illusions.

    Science.gov (United States)

    Bressan, Paola; Garlaschelli, Luigi; Barracano, Monica

    2003-09-01

    Antigravity hills, also known as spook hills or magnetic hills, are natural places where cars put into neutral are seen to move uphill on a slightly sloping road, apparently defying the law of gravity. We show that these effects, popularly attributed to gravitational anomalies, are in fact visual illusions. We re-created all the known types of antigravity spots in our laboratory using tabletop models; the number of visible stretches of road, their slant, and the height of the visible horizon were systematically varied in four experiments. We conclude that antigravity-hill effects follow from a misperception of the eye level relative to gravity, caused by the presence of either contextual inclines or a false horizon line.

  20. Martha N. Hill: transformational leader.

    Science.gov (United States)

    Coombs, V J

    1998-01-01

    Martha N. Hill, PhD, RN, FAAN, is a world-renowned researcher, educator, and nursing leader. Her election as president of the American Heart Association, effective June 1997, places her in one of the highest regarded positions in the field of cardiology. Despite her success on a national and international level, Dr. Hill has managed to continue to mentor and conduct clinical research with her nursing colleagues and students at The Johns Hopkins University in Baltimore, Maryland.

  1. The Hydrogeologic Character of the Lower Tuff Confining Unit and the Oak Springs Butte Confining Unit in the Tuff Pile Area of Central Yucca Flat

    Energy Technology Data Exchange (ETDEWEB)

    Drellack, Jr., Sigmund L.; Prothro, Lance B.; Gonzales, Jose L.; Mercadante, Jennifer M.

    2010-07-30

    The lower tuff confining unit (LTCU) in the Yucca Flat Corrective Action Unit (CAU) consists of a monotonous sequence of pervasively zeolitized volcanic tuff (i.e., mostly bedded with lesser nonwelded to poorly welded tuff; not fractured) (Bechtel Nevada, 2006). The LTCU is an important confining unit beneath Yucca Flat because it separates the alluvial and volcanic aquifers, where many underground nuclear tests were conducted, from the regional lower carbonate aquifer. Recent sub-CAU-scale modeling by Los Alamos National Laboratory in the Tuff Pile area of Yucca Flat (Boryta, et al., in review) includes postulated low-porosity, high-permeability zones (i.e., fractured welded-tuff aquifers) within the LTCU. This scenario indicates that such postulated low-porosity, high-permeability zones could provide fast-path lateral conduits to faults, and eventually to the lower carbonate aquifer. A fractured and faulted lower carbonate aquifer is postulated to provide a flow path(s) for underground test-derived contaminants to potential offsite receptors. The ramifications of such a scenario are obvious for groundwater flow and contaminant migration beneath Yucca Flat. This paper describes the reasoning for not including postulated low-porosity, high-permeability zones within the LTCU in the Tuff Pile area or within the LTCU in the Yucca Flat CAU-scale model. Both observational and analytical data clearly indicate that the LTCU in the Tuff Pile area consists of pervasively zeolitic, nonwelded to poorly welded tuffs that are classified as tuff confining units (i.e., high-porosity, low-permeability). The position regarding the LTCU in the Tuff Pile area is summarized as follows: • The LTCU in the Tuff Pile area consists of a monotonous sequence of predominantly zeolitic nonwelded to poorly welded tuffs, and thus is accurately characterized hydrogeologically as a tuff confining unit (aquitard) in the Yucca Flat-Climax Mine hydrostratigraphic framework model (Bechtel Nevada

  2. Clinoptilolite zeolitized tuff from Central Alborz Range, North Iran

    Science.gov (United States)

    Taghipour, Batoul

    2010-05-01

    Zeolites are hydrated alumino-silicates of the alkaline and alkaline earth cations, principally sodium, potassium, calcium, and magnesium (Iijima 1980; Hay 1981). Zeolites occur principally in unmetamorphosed sedimentary rocks and are particularly widespread in volcani-clastic strata (Hay, 1978). Clinoptilolite is a natural zeolite of the heulandite group with the simplified formula of (Na, K)6 Si30 Al6 O72 .nH2. It is the most common natural zeolite found mainly in sedimentary rocks of volcanic origin. Alborz zone is one of the important geological divisions in Iran. This zone is restricted to Kopeh dagh zone in North & Central Iranian zone in South and is a region of active deformation within the broad Arabian-Eurasia collision zone (Allen et al. 2003). The zeolitized green tuff belt from Central Alborz which introduce here are made of volcanoclastic sequence of Karaj Formation. This belt is about 40 km long along Alborz Range and is Eocene in age. Zeolites and associated minerals of this altered vitric tuff studied. Zeolitization took place in some beds of Karaj Formations, with average range of 3 to 300 meters thickness. There are several gypsum lenses which interbed with a widespread green tuff succession in the studied area. On the basis of chemical composition these tuffs are in the range of acid to intermediate volcanic rocks. Also magmatic affinity is calc-alkaline and geological setting of the area belongs to volcanic arc granitoid. Petrographic data has shown that various shape and size of shard glass are the main component of tuffs. Based on the field studies, detail microscopy, XRD and electron microprobe analysis (EMPA), the following main minerals are determined: Clinoptilolite+montmorillonite+crystobalite. Clinoptilolite and smectite are predominant minerals in all altered samples. Concerning the Si/Al ratio of 40 point analyses of glass shards the Alborz tuff has clinoptilolite composition. Otherwise the chemical composition of altered shard glass

  3. 蓝白相交的艺术--南通蓝印花布的纹样特色刍议%Blue & White Intersection of Art---Discussion on the Pattern Characteristics of Nantong Blue Calico

    Institute of Scientific and Technical Information of China (English)

    丁峰; 刘琛

    2013-01-01

    Nantong blue calico is one of China’s ancient manual dyeing textiles. Its elegant and impressive blue art reveals China’s culture. The article analyzes the unique feature of Nantong blue calico through the description of the forms, shapes, themes, meaning and innovation of its pattern.%南通蓝印花布是我国古老的手工印染纺织品之一,其淡雅不俗、蓝白相交的艺术形式透露出浓浓的文化底蕴。文章通过对南通蓝印花布纹样形式、纹样造型、题材、寓意和创新等方面的论述,分析了南通蓝印花布所独具的特点。

  4. Repository site data report for unsaturated tuff, Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Tien, P.L.; Updegraff, C.D.; Siegel, M.D.; Wahi, K.K.; Guzowski, R.V.

    1985-11-01

    The US Department of Energy is currently considering the thick sequences of unsaturated, fractured tuff at Yucca Mountain, on the southwestern boundary of the Nevada Test Site, as a possible candidate host rock for a nuclear-waste repository. Yucca Mountain is in one of the most arid areas in the United States. The site is within the south-central part of the Great Basin section of the Basin and Range physiographic province and is located near a number of silicic calderas of Tertiary age. Although localized zones of seismic activity are common throughout the province, and faults are present at Yucca Mountain, the site itself is basically aseismic. No data are available on the composition of ground water in the unsaturated zone at Yucca Mountain. It has been suggested that the composition is bounded by the compositions of water from wells USW-H3, UE25p-1, J-13, and snow or rain. There are relatively few data available from Yucca Mountain on the moisture content and saturation, hydraulic conductivity, and characteristic curves of the unsaturated zone. The available literature on thermomechanical properties of tuff does not always distinguish between data from the saturated zone and data from the unsaturated zone. Geochemical, hydrologic, and thermomechanical data available on the unsaturated tuffs of Yucca Mountain are tabulated in this report. Where the data are very sparse, they have been supplemented by data from the saturated zone or from areas other than Yucca Mountain. 316 refs., 58 figs., 37 tabs.

  5. Hourglass inclusions: Theory and application to the Bishop rhyolitic tuff

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, A.T. Jr. (Univ. of Chicago, IL (United States))

    Hourglass inclusions are bodies of bubble-bearing glass in volcanic phenocrysts that extend to the crystal rim through a narrow neck. Compared to enclosed inclusions, hourglass inclusions are less devitrified, contain more gas, but contain less dissolved H{sub 2}O, CO{sub 2}, and Cl. A quantitative model of rhyolitic hourglass emptying is developed and applied to Bishop Tuff hourglass inclusions. Those in plinian pumice suggest rapid ascent at 10 m/s consistent with theoretical eruption models. Hourglass inclusions from the Mono ash-flow lobe of the Bishop Tuff suggest (1) initial crystallization of quartz, formation of some enclosed and some hourglass inclusions at approximately 2,400 bars; (2) magma decompression to approximately 1,100 bars for at least a week (duration of eruption for the Bishop Tuff ) while hourglass inclusions further evolved and bubbles of gas attained a 50{mu}m diameter; (3) magma ascent from 1,100 to approximately 700 bars at approximately 1 m/s, consistent with theory for ash-flow-producing (collapsing) eruption columns; (4) entrainment of some crystals that had decompressed to a pressure of 400 bars for several weeks; (5) thermal quenching of hourglass evolution as magmatic foam disrupted into fast-moving spray, erupted, and entrained cold air. Uncertainties are large but can be reduced by future studies of postdepositional cooling, hourglass volatile compositions, temperature, and viscosity to obtain estimates of eruptive and preeruptive magma movement and crystallization rate.

  6. Selenite transport in unsaturated tuff from Yucca Mountain

    Energy Technology Data Exchange (ETDEWEB)

    Conca, J.L. [WSU Tri-Cities, Richland, WA (United States); Triay, I.R. [Los Alamos National Lab., NM (United States)

    1994-12-31

    Direct measurements of unsaturated selenite retardation coefficients and unsaturated hydraulic conductivity were obtained on two tuff samples from Yucca Mountain using the UFA{trademark} technology. The retardation factor for the selenite species was only 2.5 in both Yucca Mountain vitric member at 62.6% saturation and zeolitized nonwelded tuff from G-tunnel at 52.8% saturation with respect to J-13 well water from the Nevada Test Site contaminated with selenium at 1.31 mg/l (ppm). In batch tests on the same material using 1.2 mg/l (ppm), the average K{sub d} was determined to be 13, giving retardation factors higher than the UFA column breakthrough tests by an order of magnitude. The difference could result from preferential flow paths in the UFA column as might occur in the field or differences in residence times between the two types of tests. The unsaturated hydraulic conductivities during the experiments were 2.49 {times} 10{sup {minus}8} cm/s for the Yucca Mountain vitric member and 1.16 {times} 10{sup {minus}8} cm/s for the zeolited nonwelded tuff.

  7. Soufriere Hills Volcano

    Science.gov (United States)

    2002-01-01

    In this ASTER image of Soufriere Hills Volcano on Montserrat in the Caribbean, continued eruptive activity is evident by the extensive smoke and ash plume streaming towards the west-southwest. Significant eruptive activity began in 1995, forcing the authorities to evacuate more than 7,000 of the island's original population of 11,000. The primary risk now is to the northern part of the island and to the airport. Small rockfalls and pyroclastic flows (ash, rock and hot gases) are common at this time due to continued growth of the dome at the volcano's summit.This image was acquired on October 29, 2002 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet.ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products.The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance.Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. Science team leader; Bjorn Eng of JPL is the project manager. The Terra mission is part of NASA

  8. A Research on Nantong Blue Calico Development under the Premise of Standardized Production%标准化生产前提下南通蓝印花布发展研究

    Institute of Scientific and Technical Information of China (English)

    黄琦

    2015-01-01

    南通蓝印花布历史悠久,有较好的社会声誉。文章分析了南通蓝印花布标准化生产制度的形成及其在提升竞争力方面的作用,并针对新形势下南通蓝印花布发展的瓶颈,提出以标准化生产为前提,加强基地和传承人考核、加大扶持和管理力度、着力提高产品品质和市场适应度、团队“作战”合作共赢等对策。%Nantong blue calico boasts a long history and a good social reputation. This article analyzes the formation of standardized production system of Nantong blue calico and its role in enhancing competitiveness, and it proposes a way to strengthen the assessment base and inheritors exams, to provide greater support and management, to improve product quality and market fitness, team “operations”and win-win cooperation and other countermeasures regarding the development bottleneck of Nantong blue calico under the new situation.

  9. The behaviour of consolidated volcanic tuffs: weathering mechanisms under simulated laboratory conditions

    OpenAIRE

    Stück, H.; Forgó, L. Z.; Rüdrich, J.; S. Siegesmund; Török, Á.

    2008-01-01

    Five volcanic tuffs ranging from dacitic tuffs of Hungary to rhyolite, phonolite and basaltic tuffs of Germany were consolidated under laboratory conditions. Prior to consolidation an anti-hygro, a hydrous consolidant, which reduces the swelling ability of clay minerals, was applied. The three consolidants, a silicic acid ester (SAE), an elastic silicic acid ester (eSAE) and an acrylate resin (PMMA) were applied on test specimens under vacuum. Petrographic characterisation (polarizing microsc...

  10. Clarks Hill Lake Water Quality Study.

    Science.gov (United States)

    1982-06-01

    MACROINVERTEBRATE TAXONOMIC LIST CLARKS HILL LAKE 1981 Phylum Platyhelminthes Order Diptera Class Turbellaria Ablabesmyia parajanta unidentified Planariidae A...HILL LAKE 1981 Phylum Platyhelminthes Order Diptera (continued) Planaria sp.,’ Bezzia sp. 2 unidentified Planariidae Chaoborus punctipennis unidentified

  11. Hill & Knowlton's Two Ethical Dilemmas.

    Science.gov (United States)

    Pratt, Cornelius B.

    1994-01-01

    Presents arguments for and against the acceptance, in 1990, of two controversial client accounts by the public relations agency Hill & Knowlton. Examines the ethical implications of both accounts and concludes that whatever ethical infractions may have occurred reflect the agency's dominant public relations practices, not necessarily the "greedy…

  12. Eocene age of the Baranowski Glacier Group at Red Hill, King George Island, West Antarctica

    Directory of Open Access Journals (Sweden)

    Mozer Anna

    2015-12-01

    Full Text Available Radiometric and geochemical studies were carried out at Red Hill in the southern part of King George Island (South Shetland Islands, northern Antarctic Peninsula on the Bransfield Strait coast. The rock succession at Red Hill has been determined to represent the Baranowski Glacier Group that was previously assigned a Late Cretaceous age. Two formations were distinguished within this succession: the lower Llano Point Formation and the upper Zamek Formation. These formations have stratotypes defined further to the north on the western coast of Admiralty Bay. On Red Hill the Llano Point Formation consists of terrestrial lavas and pyroclastic breccia; the Zamek Formation consist predominantly of fine to coarse tuff, pyroclastic breccia, lavas, tuffaceous mud-, silt-, and sandstone, locally conglomeratic. The lower part of the Zamek Formation contains plant detritus (Nothofagus, dicotyledonous, thermophilous ferns and numerous coal seams (vitrinitic composition that confirm the abundance of vegetation on stratovolcanic slopes and surrounding lowlands at that time. Selected basic to intermediate igneous rocks from the succession have been analysed for the whole-rock K-Ar age determination. The obtained results indicate that the Red Hill succession was formed in two stages: (1 from about 51–50 Ma; and (2 46–42 Ma, i.e. during the Early to Middle Eocene. This, in combination with other data obtained from other Baranowski Glacier Group exposures on western coast of Admiralty Bay, confirms the recently defined position of the volcano-clastic succession in the stratigraphic scheme of King George Island. The new stratigraphic position and lithofacies development of the Red Hill succession strongly suggest its correlation with other Eocene formations containing fossil plants and coal seams that commonly occur on King George Island.

  13. Bond strength of cementitious borehole plugs in welded tuff

    Energy Technology Data Exchange (ETDEWEB)

    Akgun, H.; Daemen, J.J.K. [Arizona Univ., Tucson, AZ (USA). Dept. of Mining and Geological Engineering

    1991-02-01

    Axial loads on plugs or seals in an underground repository due to gas, water pressures and temperature changes induced subsequent to waste and plug emplacement lead to shear stresses at the plug/rock contact. Therefore, the bond between the plug and rock is a critical element for the design and effectiveness of plugs in boreholes, shafts or tunnels. This study includes a systematic investigation of the bond strength of cementitious borehole plugs in welded tuff. Analytical and numerical analysis of borehole plug-rock stress transfer mechanics is performed. The interface strength and deformation are studied as a function of Young`s modulus ratio of plug and rock, plug length and rock cylinder outside-to-inside radius ratio. The tensile stresses in and near an axially loaded plug are analyzed. The frictional interface strength of an axially loaded borehole plug, the effect of axial stress and lateral external stress, and thermal effects are also analyzed. Implications for plug design are discussed. The main conclusion is a strong recommendation to design friction plugs in shafts, drifts, tunnels or boreholes with a minimum length to diameter ratio of four. Such a geometrical design will reduce tensile stresses in the plug and in the host rock to a level which should minimize the risk of long-term deterioration caused by excessive tensile stresses. Push-out tests have been used to determine the bond strength by applying an axial load to cement plugs emplaced in boreholes in welded tuff cylinders. A total of 130 push-out tests have been performed as a function of borehole size, plug length, temperature, and degree of saturation of the host tuff. The use of four different borehole radii enables evaluation of size effects. 119 refs., 42 figs., 20 tabs.

  14. Accumulation, Biotransformation, Histopathology and Paralysis in the Pacific Calico Scallop Argopecten ventricosus by the Paralyzing Toxins of the Dinoflagellate Gymnodinium catenatum

    Science.gov (United States)

    Escobedo-Lozano, Amada Y.; Estrada, Norma; Ascencio, Felipe; Contreras, Gerardo; Alonso-Rodriguez, Rosalba

    2012-01-01

    The dinoflagellate Gymnodinium catenatum produces paralyzing shellfish poisons that are consumed and accumulated by bivalves. We performed short-term feeding experiments to examine ingestion, accumulation, biotransformation, histopathology, and paralysis in the juvenile Pacific calico scallop Argopecten ventricosus that consume this dinoflagellate. Depletion of algal cells was measured in closed systems. Histopathological preparations were microscopically analyzed. Paralysis was observed and the time of recovery recorded. Accumulation and possible biotransformation of toxins were measured by HPLC analysis. Feeding activity in treated scallops showed that scallops produced pseudofeces, ingestion rates decreased at 8 h; approximately 60% of the scallops were paralyzed and melanin production and hemocyte aggregation were observed in several tissues at 15 h. HPLC analysis showed that the only toxins present in the dinoflagellates and scallops were the N-sulfo-carbamoyl toxins (C1, C2); after hydrolysis, the carbamate toxins (epimers GTX2/3) were present. C1 and C2 toxins were most common in the mantle, followed by the digestive gland and stomach-complex, adductor muscle, kidney and rectum group, and finally, gills. Toxin profiles in scallop tissue were similar to the dinoflagellate; biotransformations were not present in the scallops in this short-term feeding experiment. PMID:22822356

  15. Accumulation, biotransformation, histopathology and paralysis in the Pacific calico scallop Argopecten ventricosus by the paralyzing toxins of the dinoflagellate Gymnodinium catenatum.

    Science.gov (United States)

    Escobedo-Lozano, Amada Y; Estrada, Norma; Ascencio, Felipe; Contreras, Gerardo; Alonso-Rodriguez, Rosalba

    2012-05-01

    The dinoflagellate Gymnodinium catenatum produces paralyzing shellfish poisons that are consumed and accumulated by bivalves. We performed short-term feeding experiments to examine ingestion, accumulation, biotransformation, histopathology, and paralysis in the juvenile Pacific calico scallop Argopecten ventricosus that consume this dinoflagellate. Depletion of algal cells was measured in closed systems. Histopathological preparations were microscopically analyzed. Paralysis was observed and the time of recovery recorded. Accumulation and possible biotransformation of toxins were measured by HPLC analysis. Feeding activity in treated scallops showed that scallops produced pseudofeces, ingestion rates decreased at 8 h; approximately 60% of the scallops were paralyzed and melanin production and hemocyte aggregation were observed in several tissues at 15 h. HPLC analysis showed that the only toxins present in the dinoflagellates and scallops were the N-sulfo-carbamoyl toxins (C1, C2); after hydrolysis, the carbamate toxins (epimers GTX2/3) were present. C1 and C2 toxins were most common in the mantle, followed by the digestive gland and stomach-complex, adductor muscle, kidney and rectum group, and finally, gills. Toxin profiles in scallop tissue were similar to the dinoflagellate; biotransformations were not present in the scallops in this short-term feeding experiment.

  16. On the origin of Hill's causal criteria.

    Science.gov (United States)

    Morabia, A

    1991-09-01

    The rules to assess causation formulated by the eighteenth century Scottish philosopher David Hume are compared to Sir Austin Bradford Hill's causal criteria. The strength of the analogy between Hume's rules and Hill's causal criteria suggests that, irrespective of whether Hume's work was known to Hill or Hill's predecessors, Hume's thinking expresses a point of view still widely shared by contemporary epidemiologists. The lack of systematic experimental proof to causal inferences in epidemiology may explain the analogy of Hume's and Hill's, as opposed to Popper's, logic.

  17. IMPLEMENTASI SANDI HILL UNTUK PENYANDIAN CITRA

    Directory of Open Access Journals (Sweden)

    JJ Siang

    2002-01-01

    Full Text Available Hill's code is one of text encoding technique. In this research, Hill's code is extended to image encoding. The image used is BMP 24 bit format. 2x2 and 3x3 matrices is used as a key. The results show that Hill's code is suitable for image whose RGB values vary highly. On the contrary, it is not suitable for less varied RGB images since its original pattern is still persisted in encrypted image. Hill's code for image encoding has also disadvantage in the case that the key matrix is not unique. However, for daily application, with good key matrix, Hill's code can be applied to encode image since it's process only deals with simple matrix operation so it become fast. Abstract in Bahasa Indonesia : Sandi Hill merupakan salah satu teknik penyandian teks. Dalam penelitian ini, pemakaian sandi Hill diperluas dari teks ke citra bertipe BMP 24 bit. Matriks yang dipakai berordo 2x2 dan 3x3. Hasil percobaan menunjukkan bahwa sandi Hill cocok untuk enkripsi citra dengan variasi nilai RGB antar piksel berdekatan yang tinggi (seperti foto, tapi tidak cocok untuk citra dengan variasi nilai RGB yang rendah (seperti gambar kartun karena pola citra asli masih tampak dalam citra sandi. Sandi Hill juga memiliki kelemahan dalam hal tidak tunggalnya matriks kunci yang dapat dipakai. Akan tetapi untuk pemakaian biasa, dengan pemilihan matriks kunci yang baik, sandi Hill dapat dipakai untuk penyandian karena hanya melibatkan operasi matriks biasa sehingga prosesnya relatif cepat. Kata kunci: Sandi Hill, Citra, Relatif Prima.

  18. Laboratory determined suction potential of Topopah Spring tuff at high temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Daily, W.; Lin, Wunan

    1991-01-01

    The purpose of this work is to experimentally determine the capillary suction potential of Topopah Spring tuff from Yucca Mountain, Nye County, Nevada. This data can be used to help characterize the unsaturated hydraulic properties of the densely welded tuff at this site. 7 refs., 4 figs., 1 tab.

  19. The unsaturated hydraulic characteristics of the Bandelier Tuff

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, D.B.; Gallaher, B.M.

    1995-09-01

    This report summarizes the physical and, unsaturated hydraulic properties of the Bandelier Tuff determined from laboratory measurements made on core samples collected at Los Alamos National Laboratory. We fit new van Genuchten-type moisture retention curves to this data, which was categorized according to member of the Bandelier Tuff and subunit of the Tshirege Member. Reasonable consistency was observed for hydraulic properties and retention curves within lithologic units, while distinct differences were observed for those properties between units. With the moisture retention data, we constructed vertical profiles of in situ matric suction and hydraulic head. These profiles give an indication of the likely direction of liquid water movement within the unsaturated zone and allow comparison of core-scale and field-scale estimates of water flow and solute transport parameters. Our core-derived transport velocities are much smaller than values estimated from tritium, Cl, and NO{sub 3} contamination found recently in boreholes. The contaminant tracer-derived transport velocities from Los Alamos Canyon are greater than corederived values found for the Otowi Member, and for Mortandad Canyon, greater than core-derived values for that borehole. The significant difference found for Mortandad Canyon suggests that fracture or other fast-path transport may be important there. The relatively small difference between observed and predicted velocities at Los Alamos Canyon may mean that vadose zone transport there occurs by unsaturated matrix flow.

  20. Colloid Facilitated Transport of Plutonium in Fractured Volcanic Tuff

    Science.gov (United States)

    Kersting, A. B.; Zhao, P.; Walensky, J. R.; Roberts, S. K.; Johnson, M. R.; Zavarin, M.; Ramon, E. C.

    2004-12-01

    The transport of low-solubility radionuclides in a colloidal- or colloidal bound state is frequently suspected or observed. Groundwater contaminated with radionuclides associated with underground nuclear tests was collected from several different well locations at the Nevada Test Site (NTS). In each case, the low-levels of plutonium detected in the groundwater were overwhelmingly (>95percent) associated with the colloidal and not the dissolved fraction of the groundwater. The colloidal fractions consisted of secondary minerals such as clays and zeolites. To better understand the mechanisms controlling the potential colloidal transport of plutonium, colloid-facilitated fracture flow laboratory experiments are being conducted. Pseudocolloids consisting of Pu(IV) sorbed to clinoptilolite were combined with a radionuclide solution cocktail consisting of Np, U, Cs, Sr, Sm and 3H and Re (analog to Tc) tracers in NTS-type synthetic groundwater (4.5mM NaHCO3-). The cocktail was injected into a smooth fracture in a volcanic tuff rock core from the NTS and the effluent analyzed. Autoradiography and secondary ion mass spectrometry will be used to understand the mineral -colloid-radionuclide interactions in the fracture volcanic tuff.

  1. Computerized tomographic analysis of fluid flow in fractured tuff

    Energy Technology Data Exchange (ETDEWEB)

    Felice, C.W.; Sharer, J.C. (Terra Tek, Inc., Salt Lake City, UT (United States)); Springer, E.P. (Los Alamos National Lab., NM (United States))

    1992-01-01

    The purpose of this summary is to demonstrate the usefulness of X-ray computerized tomography to observe fluid flow down a fracture and rock matrix imbibition in a sample of Bandelier tuff. This was accomplished by using a tuff sample 152.4 mm long and 50.8 mm in diameter. A longitudinal fracture was created by cutting the core with a wire saw. The fractured piece was then coupled to its adjacent section to that the fracture was not expected. Water was injected into a dry sample at five flow rates and CT scanning performed at set intervals during the flow. Cross sectional images and longitudinal reconstructions were built and saturation profiles calculated for the sample at each time interval at each flow rate. The results showed that for the test conditions, the fracture was not a primary pathway of fluid flow down the sample. At a slow fluid injection rate into the dry sample, the fluid was imbibed into the rock uniformly down the length of the core. With increasing injection rates, the flow remained uniform over the core cross section through complete saturation.

  2. Environmental effects on corrosion in the Tuff repository

    Energy Technology Data Exchange (ETDEWEB)

    Beavers, J.A.; Thompson, N.G. [Cortest Columbus, Inc., OH (USA)

    1990-02-01

    Cortest Columbus is investigating the long-term performance of container materials used for high-level waste packages as part of the information needed by the Nuclear Regulatory Commission to assess the Department of Energy`s application to construct a geologic repository for high-level radioactive waste. The scope of work consists of employing short-term techniques, to examine a wide range of possible failure modes. Long-term tests are being used to verify and further examine specific failure modes identified as important by the short-term studies. The original focus of the program was on the salt repository but the emphasis was shifted to the Tuff repository. This report summarizes the results of a literature survey performed under Task 1 of the program. The survey focuses on the influence of environmental variables on the corrosion behavior of candidate container materials for the Tuff repository. Environmental variables considered include: radiation, thermal and microbial effects. 80 refs., 44 figs., 44 tabs.

  3. Investigation of Using Waste Welded Tuff Material as Mineral Filler in Asphalt Concrete

    Directory of Open Access Journals (Sweden)

    Sebnem KARAHANCER

    2016-08-01

    Full Text Available In this paper, the welded tuff waste- known as koyke in Isparta region - was used in the hot mix asphalt (HMA as mineral filler for reduction of the moisture susceptibility of HMA. Optimum binder content was assessed with Marshall Design Method. First of all, welded tuff was substituted as filler with limestone filler in proportion of 50% and 100%. After that Marshall Stability test was performed on specimens. The results showed that the 50% substitution was more effective than the 100% substitution. Therefore, welded tuff was substituted with limestone filler in proportion of 25%, 50%, 65% and 75%. Next, Indirect Tensile Strength test was practiced on the fabricated specimens and the results were assessed. According to the Indirect Tensile Strength results, welded tuff with 65% was given higher strength than the limestone filler. As a result, it has come up that welded tuff can be used as mineral filler in the hot mix asphalt.

  4. Age and petrology of the Late-Pleistocene brown tuffs on Lipari, Italy

    Science.gov (United States)

    Crisci, G. M.; Delibrias, G.; de Rosa, R.; Mazzuoli, R.; Sheridan, M. F.

    1983-12-01

    Late-Pleistocene volcanic products on Lipari consist mainly of pyroclastic surge deposits (Monte Guardia sequence) and fine-grained brown tuffs. Radiometric age determination on carbon from thin soils at the top of the tuffs indicate that they have several ages of emplacement ranging from more than 35,000 to 16,800 years ago. Chemical and microprobe data on glass and mineral fragments from these tuffs show that they belong to a shoshonite or high-K series. This composition is compatible with an origin related to the magma system of Vulcano, but not with the magma system on Lipari. These tuffs have a widespread distribution on several of the Aeolian islands as well as on the northern part of Sicily. They have features typical of ash-flow tuffs of hydromagmatic origin. We propose that they originated from submarine eruptions from the Vulcanello vent before this volcano emerged above sea level.

  5. Magnetic fabric and welding processes in high-grade tuffs

    Science.gov (United States)

    Pioli, L.; Ort, M.; Lanza, R.; Rosi, M.

    2003-04-01

    The welding fabric of tuffs is generally quantified through two main parameters: porosity and fiamme aspect ratio. However, these parameters are not useful for high-grade ignimbrites that display features indicating extensive rheomorphic flow, partial to complete obliteration of primary vitroclastic textures, and syn-depositional welding rather than load-related compaction. In this case, a 3D-microstructural characterization of the rock fabric is a fundamental proxy for the assessment of the dynamics and duration of welding processes. We have investigated the relations between magnetic fabric and welding textures in a rhyolitic, high-grade ignimbrite from the Sulcis volcanic District (SW Sardinia, Italy). The ignimbrite is characterized by dense welding throughout its preserved thickness and by regular lateral and vertical variations of welding, devitrification and vesiculation facies. Field and structural data indicate that syn-depositional welding and non-particulate (NP) flow were extensive and continuous during the emplacement of the ignimbrite. Paleomagnetic measurements of AMS, NRM, and AIRM of samples from the tuff indicate that the magnetic fabric is strain-sensitive and it is not significantly affected by post-depositional, static processes such as devitrification and vapor-phase alteration; in particular, magnetic susceptibility of the rock and the welding texture correlate well in terms of shape and orientation of the anisotropy ellipsoid. The direction of the K1 axis is indicative of the flow direction in the site of measurement. The anisotropy degree (P) increases with increasing welding and foliation (F) and lineation (L) are directly related to the strain facies. Onset of welding increased the degree of anisotropy and foliation; a non particulate, laminar flow stage further deformed the fabric stretching it along the flow direction and thus increasing L. The intensity of L is strictly related to the duration and the effect of simple shear (laminar

  6. Neutron and gamma (density) logging in welded tuff

    Energy Technology Data Exchange (ETDEWEB)

    Lin, W

    1998-09-12

    This Technical Implementation Procedure (TIP) describes the field operation, and the management of data records pertaining to neutron logging and density logging in welded tuff. This procedure applies to all borehole surveys performed in support of Engineered Barrier System Field Tests (EBSFT), including the Earge Block Tests (LBT) and Initial Engineered Barrier System Field Tests (IEBSFT) - WBS 1.2.3.12.4. The purpose of this TIP is to provide guidelines so that other equally trained and qualified personnel can understand how the work is performed or how to repeat the work if needed. The work will be documented by the use of Scientific Notebooks (SNs) as discussed in 033-YMP-QP 3.4. The TIP will provide a set of guidelines which the scientists will take into account in conducting the mea- surements. The use of this TIP does not imply that this is repetitive work that does not require profes- sional judgment.

  7. Neutron and gamma (density) logging in welded tuff

    Energy Technology Data Exchange (ETDEWEB)

    Lin, W

    1998-09-12

    This Technical Implementation Procedure (TIP) describes the field operation, and the management of data records pertaining to neutron logging and density logging in welded tuff. This procedure applies to all borehole surveys performed in support of Engineered Barrier System Field Tests (EBSFT), including the Earge Block Tests (LBT) and Initial Engineered Barrier System Field Tests (IEBSFT) - WBS 1.2.3.12.4. The purpose of this TIP is to provide guidelines so that other equally trained and qualified personnel can understand how the work is performed or how to repeat the work if needed. The work will be documented by the use of Scientific Notebooks (SNs) as discussed in 033-YMP-QP 3.4. The TIP will provide a set of guidelines which the scientists will take into account in conducting the mea- surements. The use of this TIP does not imply that this is repetitive work that does not require profes- sional judgment.

  8. Hill climbing algorithms and trivium

    DEFF Research Database (Denmark)

    Borghoff, Julia; Knudsen, Lars Ramkilde; Matusiewicz, Krystian

    2011-01-01

    This paper proposes a new method to solve certain classes of systems of multivariate equations over the binary field and its cryptanalytical applications. We show how heuristic optimization methods such as hill climbing algorithms can be relevant to solving systems of multivariate equations....... A characteristic of equation systems that may be efficiently solvable by the means of such algorithms is provided. As an example, we investigate equation systems induced by the problem of recovering the internal state of the stream cipher Trivium. We propose an improved variant of the simulated annealing method...

  9. Hill climbing algorithms and trivium

    DEFF Research Database (Denmark)

    Borghoff, Julia; Knudsen, Lars Ramkilde; Matusiewicz, Krystian

    2011-01-01

    This paper proposes a new method to solve certain classes of systems of multivariate equations over the binary field and its cryptanalytical applications. We show how heuristic optimization methods such as hill climbing algorithms can be relevant to solving systems of multivariate equations....... A characteristic of equation systems that may be efficiently solvable by the means of such algorithms is provided. As an example, we investigate equation systems induced by the problem of recovering the internal state of the stream cipher Trivium. We propose an improved variant of the simulated annealing method...

  10. Welded tuff infilling a volcanic vent at Weolseong, Republic of Korea

    Science.gov (United States)

    Reedman, Antony John; Park, Ki Hwa; Merriman, Richard James; Kim, Seon Eok

    1987-06-01

    A plug of parataxitically welded tuff, with an elliptical (700 × 400 m) cross section, crops out in Weolseong district, Republic of Korea. It intrudes late Cretaceous granodiorite and extrusive tuffs of the Chisulryoung Volcanic Formation and displays a steeply inclined welding foliation, concordant with the intrusive contacts, and a subvertical stretching lineation. These fabrics are interpreted as resulting from laminar shearing in a boundary layer during deposition of the tuff by agglutination along the walls of a vent which served as a feeder for extrusive ignimbrites.

  11. Anisotropy of magnetic susceptibility in welded tuffs: application to a welded-tuff dyke in the tertiary Trans-Pecos Texas volcanic province, USA

    Science.gov (United States)

    Wolff, John A.; Ellwood, Brooks B.; Sachs, Scott D.

    1989-06-01

    Consideration of published anisotropy of magnetic susceptibility (AMS) studies on welded ignimbrites suggests that AMS fabrics are controlled by groundmass microlites distributed within the existing tuff fabric, the sum result of directional fabrics imposed by primary flow lineation, welding, and (if relevant) rheomorphism. AMS is a more sensitive indicator of fabric elements within welded tuffs than conventional methods, and usually yields primary flow azimuth estimates. Detailed study of a single densely welded tuff sample demonstrates that the overall AMS fabric is insensitive to the relative abundances of fiamme, matrix and lithics within individual drilled cores. AMS determinations on a welded-tuff dyke occurring in a choked vent in the Trans-Pecos Texas volcanic field reveals a consistent fabric with a prolate element imbricated with respect to one wall of the dyke, while total magnetic susceptibility and density exhibit axially symmetric variations across the dyke width. The dyke is interpreted to have formed as a result of agglutination of the erupting mixture on a portion of the conduit wall as it failed and slid into the conduit, followed by residual squeezing between the failed block and in situ wallrock. Irrespective of the precise mechanism, widespread occurrence of both welded-tuff dykes and point-welded, aggregate pumices in pyroclastic deposits may imply that lining of conduit walls by agglutionation during explosive volcanic eruptions is a common process.

  12. Stratigraphy, structure, and some petrographic features of Tertiary volcanic rocks in the USW G-2 drill hole, Yucca Mountain, Nye County, Nevada

    Science.gov (United States)

    Maldonado, Florian; Koether, S.L.

    1983-01-01

    A continuously cored drill hole designated as USW G-2, located at Yucca Mountain in southwestern Nevada, penetrated 1830.6 m of Tertiary volcanic strata composed of abundant silicic ash-flow tuffs, minor lava and flow breccias, and subordinate volcaniclastic rocks. The volcanic strata penetrated are comprised of the following in descending order: Paintbrush Tuff (Tiva Canyon Member, Yucca Mountain Member, bedded tuff, Pah Canyon Member, and Topopah Spring Member), tuffaceous beds of Calico Hills, Crater Flat Tuff (Prow Pass Member, Bullfrog Member, and Tram unit), lava and flow breccia (rhyodacitic), tuff of Lithic Ridge, bedded and ash-flow tuff, lava and flow breccia (rhyolitic, quartz latitic, and dacitic), bedded tuff, conglomerate and ash-flow tuff, and older tuffs of USW G-2. Comparison of unit thicknesses at USW G-2 to unit thicknesses at previously drilled holes at Yucca Mountain indicate the following: (1) thickening of the Paintbrush Tuff members and tuffaceous beds of Calico Hills toward the northern part of Yucca Mountain; (2) thickening of the Prow Pass Member but thinning of the Bullfrog Member and Tram unit; (3) thinning of the tuff of Lithic Ridge; (4) presence of approximately 280 m of lava and flow breccia not previously penetrated by any drill hole; and (5) presence of an ash-flow tuff unit at the bottom of the drill hole not previously intersected, apparently the oldest unit penetrated at Yucca Mountain to date. Petrographic features of some of the units include: (1) decrease in quartz and K-feldspar and increases in biotite and plagioclase with depth in the tuffaceous beds of Calico Hills; (2) an increase in quartz phenocrysts from the top to the bottom members of the Crater Flat Tuff; (3) a low quartz content in the tuff of Lithic Ridge, suggesting tapping of the magma chamber at quartz-poor levels; (4) a change in zeolitic alteration from heulandite to clinoptilolite to mordenite with increasing depth; (5) lavas characterized by a rhyolitic

  13. Colleges as Shining Cities on a Hill

    Science.gov (United States)

    Townsend, Kathleen Kennedy

    2012-01-01

    In this article, the author proposes that the notion of America be reintroduced as the "shining city on a hill," that abiding image from American history. The image of the shining city on a hill captures the imagination because it reflects the abiding truth that people become fully human in society, not outside of it. People need one…

  14. Geologic map of the northern White Hills, Mohave County, Arizona

    Science.gov (United States)

    Howard, Keith A.; Priest, Susan S.; Lundstrom, Scott C.; Block, Debra L.

    2017-07-10

    IntroductionThe northern White Hills map area lies within the Kingman Uplift, a regional structural high in which Tertiary rocks lie directly on Proterozoic rocks as a result of Cretaceous orogenic uplift and erosional stripping of Paleozoic and Mesozoic strata. The Miocene Salt Spring Fault forms the major structural boundary in the map area. This low-angle normal fault separates a footwall (lower plate) of Proterozoic gneisses on the east and south from a hanging wall (upper plate) of faulted middle Miocene volcanic and sedimentary rocks and their Proterozoic substrate. The fault is part of the South Virgin–White Hills Detachment Fault, which records significant tectonic extension that decreases from north to south. Along most of its trace, the Salt Spring Fault dips gently westward, but it also has north-dipping segments along salients. A dissected, domelike landscape on the eroded footwall, which contains antiformal salients and synformal reentrants, extends through the map area from Salt Spring Bay southward to the Golden Rule Peak area. The “Lost Basin Range” represents an upthrown block of the footwall, raised on the steeper Lost Basin Range Fault.The Salt Spring Fault, as well as the normal faults that segment its hanging wall, deform rocks that are about 16 to 10 Ma, and younger deposits overlie the faults. Rhyodacitic welded tuff about 15 Ma underlies a succession of geochemically intermediate to progressively more mafic lavas (including alkali basalt) that range from about 14.7 to 8 Ma, interfingered with sedimentary rocks and breccias in the western part of the map area. Upper Miocene strata record further filling of the extension-formed continental basins. Basins that are still present in the modern landscape reflect the youngest stages of extensional-basin formation, expressed as the downfaulted Detrital Valley and Hualapai Wash basins in the western and eastern parts of the map area, respectively, as well as the north-centrally located

  15. Laboratory investigation of constitutive property up-scaling in volcanic tuffs

    Energy Technology Data Exchange (ETDEWEB)

    Tidwell, V.C. [Sandia National Labs., Albuquerque, NM (United States). Geohydrology Dept.

    1996-08-01

    One of the critical issues facing the Yucca Mountain site characterization and performance assessment programs is the manner in which property up-scaling is addressed. Property up-scaling becomes an issue whenever heterogeneous media properties are measured at one scale but applied at another. A research program has been established to challenge current understanding of property up-scaling with the aim of developing and testing improved models that describe up-scaling behavior in a quantitative manner. Up-scaling of constitutive rock properties is investigated through physical experimentation involving the collection of suites of gas-permeability data measured over a range of discrete scales. To date, up-scaling studies have been performed on a series of tuff and sandstone (used as experimental controls) blocks. Samples include a welded, anisotropic tuff (Tiva Canyon Member of the Paintbrush Tuff, upper cliff microstratigraphic unit), and a moderately welded tuff (Tiva Canyon Member of the Paintbrush Tuff, Caprock microstratigraphic unit). A massive fluvial sandstone (Berea Sandstone) was also investigated as a means of evaluating the experimental program and to provide a point of comparison for the tuff data. Because unsaturated flow is of prime interest to the Yucca Mountain Program, scoping studies aimed at investigating the up-scaling of hydraulic properties under various saturated conditions were performed to compliment these studies of intrinsic permeability. These studies focused on matrix sorptivity, a constitutive property quantifying the capillarity of a porous medium. 113 refs.

  16. Intermediate composition magma production in an intracontinental setting: Unusual andesites and dacites of the mid-Miocene Santa Rosa-Calico volcanic field, Northern Nevada

    Science.gov (United States)

    Brueseke, Matthew E.; Hart, William K.

    2009-11-01

    The mid-Miocene Santa Rosa-Calico volcanic field (SC) of northern Nevada provides an outstanding example of the role open-system magmatic processes play in producing calc-alkaline and tholeiitic andesite-dacite magmas in an intracontinental setting. SC volcanism commenced at ˜ 16.7 Ma and is associated with the initial manifestations of the Yellowstone hotspot, the Columbia River-Steens flood basalt event(s), and the formation of the Northern Nevada rift. Locally a diverse package of magmatic products ranging from tholeiitic basalt to high-Si rhyolite was produced during an ˜ 2 myr duration. Within this package are the products of at least four distinct intermediate composition magmatic systems that may represent as much as 40% of the SC volcanic pile. These help differentiate the SC from contemporaneous Oregon Plateau volcanic fields (e.g. McDermitt, Lake Owyhee, Northwest Nevada) that are dominated by bimodal basalt-rhyolite assemblages. All SC intermediate units are characterized by textural and mineralogic complexities including xenoliths and xenocrysts of local crust and crystal clots of plagioclase ± clinopyroxene ± orthopyroxene ± oxide. SC intermediate units are dominantly tholeiitic, but include lava flows with transitional to calc-alkaline affinities. Relative to locally erupted Steens Basalt, SC intermediate lava flows have similar elemental enrichments and depletions, but dissimilar Sr and Nd isotopic compositions. These isotopic differences, coupled with the abundant disequilibrium features and variable incompatible element ratios, indicate that open system magmatic processes played a major role in the genesis of the intermediate units. SC silicic magmas were produced primarily via upper crustal melting of chemically and isotopically heterogeneous Cretaceous granitoid. Interaction between fractionating mafic Steens flood basalt magmas and the more evolved crustal melts ± assimilation of local upper crust provides a general template for the

  17. Geophysical tomography for imaging water movement in welded tuff

    Energy Technology Data Exchange (ETDEWEB)

    Daily, W.D.; Ramirez, A.L.

    1986-09-01

    Alterant tomography has been evaluated for its ability to delineate in-situ water flow paths in a fractured welded-tuff rock mass. The evaluation involved a field experiment in which tomographs of electromagnetic attenuation factor (or attenuation rate) at 300 MHz were made before, during, and after the introduction to the rock of two different water-based tracers: a plain water and dye solution, and salt water and dye. Alterant tomographs were constructed by subtracting, cell by cell, the attenuation factors derived from measurements before each tracer was added to the rock mass from the attenuation factors derived after each tracer was added. The alterant tomographs were compared with other evidence of water movement in the rock: borescope logs of fractures, and post experiment cores used to locate the dye tracer on the fractured surfaces. These comparisons indicate that alterant tomography is suitable for mapping water flow through fractures and that it may be useful in inferring which of the fractures are hydrologically connected in the image plane. The technique appears to be sensitive enough to delineate flow through a single fracture and to define fractures with a spatial resolution of about 10 cm on an imaging scale of a few meters. 9 refs., 3 figs.

  18. Surface complexation modeling of americium sorption onto volcanic tuff.

    Science.gov (United States)

    Ding, M; Kelkar, S; Meijer, A

    2014-10-01

    Results of a surface complexation model (SCM) for americium sorption on volcanic rocks (devitrified and zeolitic tuff) are presented. The model was developed using PHREEQC and based on laboratory data for americium sorption on quartz. Available data for sorption of americium on quartz as a function of pH in dilute groundwater can be modeled with two surface reactions involving an americium sulfate and an americium carbonate complex. It was assumed in applying the model to volcanic rocks from Yucca Mountain, that the surface properties of volcanic rocks can be represented by a quartz surface. Using groundwaters compositionally representative of Yucca Mountain, americium sorption distribution coefficient (Kd, L/Kg) values were calculated as function of pH. These Kd values are close to the experimentally determined Kd values for americium sorption on volcanic rocks, decreasing with increasing pH in the pH range from 7 to 9. The surface complexation constants, derived in this study, allow prediction of sorption of americium in a natural complex system, taking into account the inherent uncertainty associated with geochemical conditions that occur along transport pathways.

  19. The behavior of biogenic silica-rich rocks and volcanic tuffs as pozzolanic additives in cement

    Science.gov (United States)

    Fragoulis, Dimitris; Stamatakis, Michael; Anastasatou, Marianthi

    2015-04-01

    Cements currently produced, include a variety of pozzolanic materials, aiming for lower clinker addition and utilization of vast deposits of certain raw materials and/or mining wastes and byproducts. The major naturally occurring pozzolanic materials include glassy tuffs, zeolitic tuffs, diatomites and volcanic lavas rich in glassy phase, such as perlites. Therefore, based on the available raw materials in different locations, the cement composition might vary according to the accessibility of efficient pozzolanic materials. In the present investigation, the behavior of pozzolanic cements produced with representative samples of the aforementioned materials was studied, following the characterization of the implemented pozzolanas with respect to their chemical and mineralogical characteristics. Laboratory cements were produced by co-grinding 75% clinker, 5% gypsum and 20% pozzolana, for the same period of time (45 min). Regarding pozzolanic materials, four different types of pozzolanas were utilized namely, diatomite, perlite, zeolite tuff and glassy tuff. More specifically, two diatomite samples originated from Australia and Greece, with high and low reactive silica content respectively, two perlite samples originated from Turkey and from Milos Island, Greece, with different reactive silica contents, a zeolite tuff sample originated from Turkey and a glassy tuff sample originated from Milos Island, Greece. The above pozzolana samples, which were ground in the laboratory ball mill for cement production performed differently during grinding and that was reflected upon the specific surface area (cm2/gr) values. The perlites and the glassy tuff were the hardest to grind, whereas, the zeolite tuff and the Australian diatomite were the easiest ones. However, the exceedingly high specific surface area of the Australian diatomite renders cement difficult to transport and tricky to use for concrete manufacturing, due to the high water demand of the cement mixture. Regarding

  20. Eruption sequence of the Suwanoharu tuff ring in the Pliocene Oyano formation, western Kyushu, Japan

    Science.gov (United States)

    Kosugi, H.; Yokose, H.

    2005-12-01

    Volcanism in the Ariake sea region, west Kyushu, Japan, where is the northern extension of the Okinawa trough, have been active during the last 5 million years, from Pliocene to present Unzen volcano. The region has been subsided with development of the tectonic graben. Pliocene Oyano formation is predominated in shallow marine pyroclastic deposits including some base surge deposits. A series of stratified pyroclastic deposits, which were originated by phreatomagmatic eruption cycles is exposed on a sea cliff and is considered to be a remnant of tuff ring, which is called Suwanoharu tuff ring. Suwanoharu tuff ring is expected to preserve the complete eruption sequence. The sequence is basically alternation of massive white tuff layers and laminated gray coarse to lapilli tuff layers. We can identify seven eruption cycles bounded by the massive white air fall pyroclastic deposits (unit 1- 7). The gray pyroclastic deposits consist of massive dark gray medium tuff, crudely laminated medium to coarse-grained tuff, inversely graded lapilli tuff, cross-bedded lapilli tuff, and lapillistone and are considered to be a base surge deposit. Ascending to the eruption cycles, the thickness of massive white tuff layers is decreasing, but the gray layers are increasing. Representative samples were collected from 42 horizons of the tuff ring sequence and analyzed the bulk rock chemical compositions using XRF and the mineral assemblages using XRD. The bulk rock chemical compositions of the gray layers changes from andesite at the lower horizon to basalt at the upper horizon. On the other hand, massive white tuff layers have almost identical and are andesite. Because the compositions of basal layers are very similar to the silt of the basement rock, the beds in the unit 1 may have been deposited fragmented basement rocks by the first phreatomagmatic eruption. At the upper layers of the first eruption cycle (unit 1), chlorine contents are up to the maximum level (ca. 4%) and the

  1. Geologic character of tuffs in the unsaturated zone at Yucca Mountain, southern Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Scott, R.B.; Spengler, R.W.; Diehl, S.; Lappin, A.R.; Chornack, M.P.

    1982-12-31

    At Yucca Mountain, a potential site for a high-level nuclear waste repository on the Nevada Test Site in southern Nevada, evaluation of the geologic setting and rock physical properties, along with previous regional hydrologic studies, has provided background that can be used for construction of a preliminary conceptual hydrologic model of the unsaturated zone. The 500-m-thick unsaturated portion of Yucca Mountain consists of alternating layers of two contrasting types of tuff. One type consists of highly fractured, densely welded, relatively nonporous but highly transmissive ash-flow tuffs. The other type consists of relatively unfractured, nonwelded, highly porous but relatively nontransmissive, argillic and zeolitic bedded tuffs and ash-flow tuffs. The contrast between these two sets of distinctive physical properties results in a stratified sequence best described as "physical-property stratigraphy" as opposed to traditional petrologic stratigraphy of volcanic rocks. The vast majority of recharge through the unsaturated zone is assumed to be vertical; the dominant migration may occur in fractures of densely welded tuffs and in the matrix of nonwelded tuff, but the mode of fluid flow in these unsaturated systems is undetermined. Limited lateral flow of recharge may occur at horizons where local perched water tables may exist above relatively nontransmissive zeolitized nonwelded tuffs. The pervasive north-northwest-striking fractures may control the direction of lateral flow of recharge, if any, in the unsaturated zone, and certainly that direction coincides closely with the observed southeasterly flow direction in the saturated zone under Yucca Mountain. Empirical evaluation of this conceptual hydrologic model has begun. 41 refs., 18 figs., 2 tabs.

  2. New data on the Volcanic Tuff from Petrestii de Jos (Cluj District

    Directory of Open Access Journals (Sweden)

    Bedelean Horea

    2001-04-01

    Full Text Available The present study was carried out on the cineritic interlayers from Petreştii de Jos (closed quarry from Indolului Valley, in order to present their detailed mineralogical-petrographical features. Previous work already noticed the similarity of this tuff level with Dej Tuff Complex in other areas. The studied outcrop consists of a compact volcanic tuff interlayered with marls and tuffaceous clays. The analytical investigations: chemical analyses, X-ray diffraction, IR spectroscopy and electron microscopy reveal the nature of the diagenetic transformations dominated by zeolitization. Besides clinoptilolite, which is the typical zeolite for Dej Tuff from the Transylvanian Depression, our investigation evidenced also the presence of phillipsite. The process was stepwise: during the primary, syngenetic stage K-clinoptilolite formed, while during the late epigenetic stage Ca-phillipsite crystallized; on behalf of the latter one, Ca-clinoptilolite was also generated. It is worth to mention that the highest amounts of zeolites are to be found in the basal horizon, while this amount decreases in the interlayers associated with the marly-clayey levels. From genetic point of view, the lower horizon in the outcrop represents a primary fall-out tuff. The thin interlayers within the upper horizons are resedimented tuffs. The tuff from Petreştii de Jos represents a cheap raw material located in the neighborhood of the industrial area of Turda town. For using it, only a more detailed research and the removal of the vegetal and soil layer on the top would be necessary.

  3. Feldspar dissolution rates in the Topopah Spring Tuff, Yucca Mountain, Nevada

    Science.gov (United States)

    Bryan, C.R.; Helean, K.B.; Marshall, B.D.; Brady, P.V.

    2009-01-01

    Two different field-based methods are used here to calculate feldspar dissolution rates in the Topopah Spring Tuff, the host rock for the proposed nuclear waste repository at Yucca Mountain, Nevada. The center of the tuff is a high silica rhyolite, consisting largely of alkali feldspar (???60 wt%) and quartz polymorphs (???35 wt%) that formed by devitrification of rhyolitic glass as the tuff cooled. First, the abundance of secondary aluminosilicates is used to estimate the cumulative amount of feldspar dissolution over the history of the tuff, and an ambient dissolution rate is calculated by using the estimated thermal history. Second, the feldspar dissolution rate is calculated by using measured Sr isotope compositions for the pore water and rock. Pore waters display systematic changes in Sr isotopic composition with depth that are caused by feldspar dissolution. The range in dissolution rates determined from secondary mineral abundances varies from 10-16 to 10-17 mol s-1 kg tuff-1 with the largest uncertainty being the effect of the early thermal history of the tuff. Dissolution rates based on pore water Sr isotopic data were calculated by treating percolation flux parametrically, and vary from 10-15 to 10-16 mol s-1 kg tuff-1 for percolation fluxes of 15 mm a-1 and 1 mm a-1, respectively. Reconciling the rates from the two methods requires that percolation fluxes at the sampled locations be a few mm a-1 or less. The calculated feldspar dissolution rates are low relative to other measured field-based feldspar dissolution rates, possibly due to the age (12.8 Ma) of the unsaturated system at Yucca Mountain; because oxidizing and organic-poor conditions limit biological activity; and/or because elevated silica concentrations in the pore waters (???50 mg L-1) may inhibit feldspar dissolution. ?? 2009 Elsevier Ltd. All rights reserved.

  4. Geologic character of tuffs in the unsaturated zone at Yucca Mountain, southern Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Scott, R.B.; Spengler, R.W.; Diehl, S.; Lappin, A.R.; Chornack, M.P.

    1982-12-31

    At Yucca Mountain, a potential site for a high-level nuclear waste repository on the Nevada Test Site in southern Nevada, evaluation of the geologic setting and rock physical properties, along with previous regional hydrologic studies, has provided background that can be used for construction of a preliminary conceptual hydrologic model of the unsaturated zone. The 500-m-thick unsaturated portion of Yucca Mountain consists of alternating layers of two contrasting types of tuff. One type consists of highly fractured, densely welded, relatively nonporous but highly transmissive ash-flow tuffs. The other type consists of relatively unfractured, nonwelded, highly porous but relatively nontransmissive, argillic and zeolitic bedded tuffs and ash-flow tuffs. The contrast between these two sets of distinctive physical properties results in a stratified sequence best described as "physical-property stratigraphy" as opposed to traditional petrologic stratigraphy of volcanic rocks. The vast majority of recharge through the unsaturated zone is assumed to be vertical; the dominant migration may occur in fractures of densely welded tuffs and in the matrix of nonwelded tuff, but the mode of fluid flow in these unsaturated systems is undetermined. Limited lateral flow of recharge may occur at horizons where local perched water tables may exist above relatively nontransmissive zeolitized nonwelded tuffs. The pervasive north-northwest-striking fractures may control the direction of lateral flow of recharge, if any, in the unsaturated zone, and certainly that direction coincides closely with the observed southeasterly flow direction in the saturated zone under Yucca Mountain. Empirical evaluation of this conceptual hydrologic model has begun. 41 refs., 18 figs., 2 tabs.

  5. Intracrystalline diffusion in clinoptilolite: Implications for radionuclide isolation

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, S.K.; Viani, B.E.; Phinney, D.

    1995-11-16

    Experiments have been performed to measure the rate of exchange diffusion in the zeolite clinoptilolite (CL) for elements important to radionuclide isolation at Yucca Mountain, NV. Clinoptilolite is one of the major sorptive minerals in the tuffs at Yucca Mountain, and occurs both as a major component in zeolitized units (Calico Hills), and in fractures in non-zeolitized tuffs (Topopah Spring). Field evidence and numerical modeling suggests that the movement of fluids through the tuff rocks adjacent to the potential repository may occur via episodic flow through fractures. Under conditions of rapid fracture flow the effective sorptive capacity of fracture-lining clinoptilolite may be controlled by exchange diffusion rather than exchange equilibrium.

  6. A probabilistic approach to rock mechanical property characterization for nuclear waste repository design

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kunsoo; Gao, Hang [Columbia Univ., New York, NY (United States)

    1996-04-01

    A probabilistic approach is proposed for the characterization of host rock mechanical properties at the Yucca Mountain site. This approach helps define the probability distribution of rock properties by utilizing extreme value statistics and Monte Carlo simulation. We analyze mechanical property data of tuff obtained by the NNWSI Project to assess the utility of the methodology. The analysis indicates that laboratory measured strength and deformation data of Calico Hills and Bullfrog tuffs follow an extremal. probability distribution (the third type asymptotic distribution of the smallest values). Monte Carlo simulation is carried out to estimate rock mass deformation moduli using a one-dimensional tuff model proposed by Zimmermann and Finley. We suggest that the results of these analyses be incorporated into the repository design.

  7. Summary of lithologic logging of new and existing boreholes at Yucca Mountain, Nevada, August 1993 to February 1994

    Energy Technology Data Exchange (ETDEWEB)

    Geslin, J.K.; Moyer, T.C.; Buesch, D.C.

    1995-05-01

    Yucca Mountain, Nevada, is being investigated as a potential site for a high-level radioactive waste repository. This report summarizes the lithologic logging of new and existing boreholes at Yucca Mountain that was done from August 1993 to February 1994 by the Rock Characteristics Section, Yucca Mountain Project Branch, US Geological Survey (USGS). Units encountered during logging include Quaternary-Tertiary alluvium/colluvium, Tertiary Rainier Mesa Tuff, all units in the Tertiary Paintbrush Group, Tertiary Calico Hills Formation and Tertiary Prow Pass Tuff. We present criteria used for recognition of stratigraphic contacts, logging results as tables of contact depths for core from neutron (UZN) boreholes and graphical lithologic logs for core from non-UZN boreholes, and descriptions of several distinctive nonwelded tuffs recognized in the PTn hydrogeologic unit of the Paintbrush Group.

  8. The mineralogical and physicochemical properties of clinoptilolite tuff: A comparative study and an outlook for its potential use

    Energy Technology Data Exchange (ETDEWEB)

    Nistratova, I.E.; Novikova, V.A.; Marsii, I.M.; Sokolova, A.L. [Institute of Geology of Ore Deposits, Moscow (Russian Federation)

    1995-09-01

    Mineral and chemical composition, petrographical characteristics, mechanical strength, and ion exchange selectivity of clinoptilolite tuff were studied with the aim of estimating its potential use in water treatment.

  9. Sullys Hill herd resembles original plains bison

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This article is on recent findings on Sullys Hill National Game Preserve that show bison brought there nearly a century ago have remained closer to genetically pure...

  10. The Igwisi Hills extrusive 'kimberlites'

    Science.gov (United States)

    Reid, A. M.; Donaldson, C. H.; Dawson, J. B.; Brown, R. W.; Ridley, W. I.

    1975-01-01

    The petrography and mineral chemistry of volcanic rocks from the Igwisi Hills in Tanzania are discussed. There is considerable evidence to suggest that the Igwisi rocks are extrusive kimberlites: a two-component nature with high P-T minerals in a low P-T matrix; the presence of chrome pyrope, Al enstatite, chrome diopside, chromite and olivine; a highly oxidized, volatile-rich matrix with serpentine, calcite, magnetite, perovskite; high Sr, Zr, and Nb contents; occurrence in a narrow isolated vent within a stable shield area. The Igwisi rocks differ from kimberlite in the lack of magnesian ilmenite, the scarcity of matrix phlogopite, and the overall low alkali content. They apparently contain material from phlogopite-bearing garnet peridotites with a primary mineral assemblage indicative of equilibrium at upper mantle temperatures and pressures. This primary assemblage was brought rapidly to the surface in a gas-charged, carbonate-rich fluid. Rapid upward transport, extrusion, and rapid cooling have tended to prevent reaction between inclusions and the carbonate-rich matrix that might otherwise have yielded a more typical kimberlite.

  11. Preliminary survey of tuff distribution in Esmeralda, Nye, and Lincoln Counties, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Smith, G.V.; Pink, T.S.; Lawrence, J.R.; Woodward, L.A.; Keil, K.; Lappin, A.R.

    1981-02-01

    This report inventories the surface distribution of silicic tuffs in Nye, Esmeralda, and Lincoln Counties, NV, based on a review of available literature. The inventory was taken to provide a data base in evaluating tuff sites for the disposal of high-level nuclear waste. Silicic ash-flow tuffs that are about 11 to 34 million years (my) old are widespread in these counties. These rocks are locally deformed by right-lateral movement along Walker Lane and the Las Vegas Shear Zone, and left-lateral movement along a zone from near the Nevada Test Site (NTS) to the Utah border, and are commonly offset by steeply dipping normal faults. The normal faults that bound horsts, grabens, and tilted-fault blocks of the Basin-and-Range Province began to form 30 my ago; some are still active. Tuff distribution is discussed on a regional basis. Tuff thicknesses and alterations, structural complexity, and proximity to recent faulting, recent volcanism, and mineral resources are discussed for each area. Although the literature on which it is based is often incomplete and sketchy, this report is intended to serve as a basis for future, more detailed work that includes initial field inspection, detailed field and laboratory studies, and extrapolations to the subsurface.

  12. A model for the formation of vesiculated tuff by the coalescence of accretionary lapilli

    Science.gov (United States)

    Rosi, Mauro

    1992-07-01

    Observations on phreatomagmatic ash deposits of Phlegraean Fields and Vesuvius supply evidence for the origin of vesiculated tuff in a cool environment. Early deposition by fallout of a matrix-free bed of damp accretionary lapilli is followed by deposition of cohesive mud or a mud rain. The lapilli bed becomes partly or completely transformed into a vesiculated tuff by mud percolation and eventual coalescence of accretionary lapilli with consequent trapping of air originally contained in the interstices. The proposed mechanism accounts for vesiculated tuff formation in distal deposits beyond limits commonly attained by pyroclastic surges. This same mechanism may, nevertheless, also operate in proximal tuff-ring and cone deposits during fallout of phreatomagmatic ash separating bed sets in surge-dominated successions. The sequence of events in the proposed model fits well with the evolution of a cooling phreatomagmatic ash cloud in which early ash aggregation (accretionary lapilli fallout) is followed closely by steam condensation (mud or muddy rainfall). This new model invoking a cool-temperature origin is intended to be complementary to previously proposed theories. Although difficult to assess because of the often complete obliteration of original lapilli, the process is believed to be relatively common in the generasion of vesiculated tuffs within phreatomagmatic deposits.

  13. Geochemistry and Mineralogy of Tuff in Zhongliangshan Mine, Chongqing, Southwestern China

    Directory of Open Access Journals (Sweden)

    Jianhua Zou

    2016-05-01

    Full Text Available Coal-bearing strata that host rare metal deposits are currently a hot issue in the field of coal geology. The purpose of this paper is to illustrate the mineralogy, geochemistry, and potential economic significance of rare metals in the late Permian tuff in Zhongliangshan mine, Chongqing, southwestern China. The methods applied in this study are X-ray fluorescence spectrometry (XRF, inductively coupled mass spectrometry (ICP-MS, X-ray diffraction analysis (XRD plus Siroquant, and scanning electron microscopy in conjunction with an energy-dispersive X-ray spectrometry (SEM-EDX. The results indicate that some trace elements including Li, Be, Sc, V, Cr, Co, Ni, Cu, Zn, Ga, Zr, Nb, Cd, Sb, REE, Hf, Ta, Re, Th, and U are enriched in the tuff from Zhongliangshan mine. The minerals in the tuff mainly include kaolinite, illite, pyrite, anatase, calcite, gypsum, quartz, and traces of minerals such as zircon, florencite, jarosite, and barite. The tuff is of mafic volcanic origin with features of alkali basalt. Some minerals including florencite, gypsum, barite and a portion of anatase and zircon have been derived from hydrothermal solutions. It is suggested that Zhongliangshan tuff is a potential polymetallic ore and the recovery of these valuable elements needs to be further investigated.

  14. Bunker Hill Sediment Characterization Study

    Energy Technology Data Exchange (ETDEWEB)

    Neal A. Yancey; Debby F. Bruhn

    2009-12-01

    The long history of mineral extraction in the Coeur d’Alene Basin has left a legacy of heavy metal laden mine tailings that have accumulated along the Coeur d’Alene River and its tributaries (U.S. Environmental Protection Agency, 2001; Barton, 2002). Silver, lead and zinc were the primary metals of economic interest in the area, but the ores contained other elements that have become environmental hazards including zinc, cadmium, lead, arsenic, nickel, and copper. The metals have contaminated the water and sediments of Lake Coeur d’Alene, and continue to be transported downstream to Spokane Washington via the Spokane River. In 1983, the EPA listed the Bunker Hill Mining and Metallurgical Complex on the National Priorities List. Since that time, many of the most contaminated areas have been stabilized or isolated, however metal contaminants continue to migrate through the basin. Designation as a Superfund site causes significant problems for the economically depressed communities in the area. Identification of primary sources of contamination can help set priorities for cleanup and cleanup options, which can include source removal, water treatment or no action depending on knowledge about the mobility of contaminants relative to water flow. The mobility of contaminant mobility under natural or engineered conditions depends on multiple factors including the physical and chemical state (or speciation) of metals and the range of processes, some of which can be seasonal, that cause mobilization of metals. As a result, it is particularly important to understand metal speciation (National Research Council, 2005) and the link between speciation and the rates of metal migration and the impact of natural or engineered variations in flow, biological activity or water chemistry.

  15. Mo and Ni Removal from Drinking Water Using Zeolitic Tuff from Jordan

    Directory of Open Access Journals (Sweden)

    Khalil M. Ibrahim

    2016-11-01

    Full Text Available Mo and Ni metals could be hazardous in natural waters. The initial Mo and Ni concentration in the sampled domestic drinking water of north Jordan is 550 and 110 μg/L, respectively. The efficiency of using natural faujasite–phillipsite and phillipsite–chabazite tuffs in removing Mo and Ni from contaminated drinking water was tested. Batch experiments using different weights of the adsorbent were conducted at different contact times to determine the optimum conditions. The maximal uptake capacity of Mo from drinking water was equivalent to 440–420 μg/g adsorbent. The maximum removal efficiency of Mo by faujasite–phillipsite, phillipsite–chabazite, and the modified surfactant phillipsite–chabazite tuffs were 80%, 76%, and 78%, respectively. The proportional relationship between contact time and removal efficiency of Ni from water samples was observed. The maximum removal efficiency of Ni by the zeolitic tuffs is up to 90% compared to the original groundwater sample.

  16. ZE interviewt L.A. Hill (ZE Interviews L. A. Hill)

    Science.gov (United States)

    Zielsprache Englisch, 1975

    1975-01-01

    Hill feels that very soon after the introduction of the spoken word, the written word should be learned, using the same pictures, etc. Exercises should be contextualized and contrastive. On monolingual teaching, Hill takes a pragmatic position. A controlled state, with situational drills, should precede free conversation. Reading techniques are…

  17. Hydraulic Characterization of Overpressured Tuffs in Central Yucca Flat, Nevada Test Site, Nye County, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    K.J. Halford; R.J. Laczniak; D.L. Galloway

    2005-10-07

    A sequence of buried, bedded, air-fall tuffs has been used extensively as a host medium for underground nuclear tests detonated in the central part of Yucca Flat at the Nevada Test Site. Water levels within these bedded tuffs have been elevated hundreds of meters in areas where underground nuclear tests were detonated below the water table. Changes in the ground-water levels within these tuffs and changes in the rate and distribution of land-surface subsidence above these tuffs indicate that pore-fluid pressures have been slowly depressurizing since the cessation of nuclear testing in 1992. Declines in ground-water levels concurrent with regional land subsidence are explained by poroelastic deformation accompanying ground-water flow as fluids pressurized by underground nuclear detonations drain from the host tuffs into the overlying water table and underlying regional carbonate aquifer. A hydraulic conductivity of about 3 x 10-6 m/d and a specific storage of 9 x 10-6 m-1 are estimated using ground-water flow models. Cross-sectional and three-dimensional ground-water flow models were calibrated to measured water levels and to land-subsidence rates measured using Interferometric Synthetic Aperture Radar. Model results are consistent and indicate that about 2 million m3 of ground water flowed from the tuffs to the carbonate rock as a result of pressurization caused by underground nuclear testing. The annual rate of inflow into the carbonate rock averaged about 0.008 m/yr between 1962 and 2005, and declined from 0.005 m/yr in 2005 to 0.0005 m/yr by 2300.

  18. Hydraulic characterization of overpressured tuffs in central Yucca Flat, Nevada Test Site, Nye County, Nevada

    Science.gov (United States)

    Halford, Keith J.; Laczniak, Randell J.; Galloway, Devin L.

    2005-01-01

    A sequence of buried, bedded, air-fall tuffs has been used extensively as a host medium for underground nuclear tests detonated in the central part of Yucca Flat at the Nevada Test Site. Water levels within these bedded tuffs have been elevated hundreds of meters in areas where underground nuclear tests were detonated below the water table. Changes in the ground-water levels within these tuffs and changes in the rate and distribution of land-surface subsidence above these tuffs indicate that pore-fluid pressures have been slowly depressurizing since the cessation of nuclear testing in 1992. Declines in ground-water levels concurrent with regional land subsidence are explained by poroelastic deformation accompanying ground-water flow as fluids pressurized by underground nuclear detonations drain from the host tuffs into the overlying water table and underlying regional carbonate aquifer. A hydraulic conductivity of about 3 x 10-6 m/d and a specific storage of 9 x 10-6 m-1 are estimated using ground-water flow models. Cross-sectional and three-dimensional ground-water flow models were calibrated to measured water levels and to land-subsidence rates measured using Interferometric Synthetic Aperture Radar. Model results are consistent and indicate that about 2 million m3 of ground water flowed from the tuffs to the carbonate rock as a result of pressurization caused by underground nuclear testing. The annual rate of inflow into the carbonate rock averaged about 0.008 m/yr between 1962 and 2005, and declined from 0.005 m/yr in 2005 to 0.0005 m/yr by 2300.

  19. Decay of Rhenish Tuffs in Dutch Monuments. Part 2: Laboratory Experiments as a Basis for the Choice of Restoration Stone

    NARCIS (Netherlands)

    Van Hees, R.P.J.; Brendle, S.; Nijland, T.G.; De Haas, G.J.L.M.; Tolboom, H.J.

    2003-01-01

    Rhenish tuffs (Eifel, Germany), have been used as building material in the Netherlands since Roman times. They were the most important natural building stone in the Netherlands in early medieval times. In addition, tuff was used as raw material for production of trass, that served as a pozzolanic ad

  20. Decay of Rhenish Tuff in Dutch monuments. Part 2 : Laboratory experiments as a basis for the choice of restoration stone

    NARCIS (Netherlands)

    Hees, R.P.J. van; Brendle, S.; Nijland, T.G.; Haas, G.J.L.M. de; Tolboom, H.J.

    2003-01-01

    Rhenish tuffs (Eifel, Getmany), have been used as building material in the Netherlands since Roman times. They were the most important natural building stone in the Netherlands in early medieval times. In addition, tuff was used as raw material for production of trass, that served as a pozzolanic ad

  1. Some geochemical considerations for a potential repository site in tuff at Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Erdal, B.R.; Bish, D.L.; Crowe, B.M.; Daniels, W.R.; Ogard, A.E.; Rundberg, R.S.; Vaniman, D.T.; Wolfsberg, K.

    1982-12-31

    The Nevada Nuclear Waste Storage Investigations, which is evaluating potential locations for a high-level waste repository at the Nevada Test Site and environs, is currently focusing its investigations on tuff, principally in Yucca Mountain, as a host rock. This paper discusses some of the geochemical investigations. Particular emphasis is placed on definition of some basic elements and necessary technical approaches for the geochemistry data acquisition and modeling program. Some site-specific tuff geochemical information that is important for site selection and repository performance will be identified and the current status of knowledge will then be discussed.

  2. Hydrothermal convection and mordenite precipitation in the cooling Bishop Tuff, California, USA

    Science.gov (United States)

    Randolph-Flagg, N. G.; Breen, S. J.; Hernandez, A.; Self, S.; Manga, M.

    2014-12-01

    We present field observations of erosional columns in the Bishop Tuff and then use laboratory results and numerical models to argue that these columns are evidence of relict convection in a cooling ignimbrite. Many square kilometers of the Bishop Tuff have evenly-spaced, vertical to semi-vertical erosional columns, a result of hydrothermal alteration. These altered regions are more competent than the surrounding tuff, are 0.1-0.7 m in diameter, are separated by ~ 1 m, and in some cases are more than 8 m in height. JE Bailey (U. of Hawaii, dissertation, 2005) suggested that similar columns in the Bandelier Tuff were formed when slumping allowed water to pool at the surface of the still-cooling ignimbrite. As water percolated downward it boiled generating evenly spaced convection cells similar to heat pipes. We quantify this conceptual model and apply it the Bishop Tuff to understand the physics within ignimbrite-borne hydrothermal systems. We use thin sections to measure changing porosity and use scanning electron microscope (SEM) and x-ray diffraction (XRD) analyses to show that pore spaces in the columns are cemented by the mineral mordenite, a low temperature zeolite that precipitates between 120-200 oC (Bish et al., 1982), also found in the Bandelier Tuff example. We then use scaling to show 1) that water percolating into the cooling Bishop Tuff would convect and 2) that the geometry and spacing of the columns is predicted by the ignimbrite temperature and permeability. We use the computer program HYDROTHERM (Hayba and Ingebritsen, 1994; Kipp et al., 2008) to model 2-phase convection in the Bishop Tuff. By systematically changing permeability, initial temperature, and topography we can identify the pattern of flows that develop when the ignimbrite is cooled by water from above. Hydrothermally altered columns in ignimbrite are the natural product of coupled heat, mass, and chemical transport and have similarities to other geothermal systems, economic ore deposits

  3. Late Triassic tuff intervals in the Ordos basin, Central China: Their depositional, petrographic, geochemical characteristics and regional implications

    Science.gov (United States)

    Qiu, Xinwei; Liu, Chiyang; Mao, Guangzhou; Deng, Yu; Wang, Feifei; Wang, Jianqiang

    2014-02-01

    Tuff intervals of Upper Triassic Yanchang Formation are laterally widespread in the Ordos basin, Central China. This paper focuses on magmatic origins and potential source regions of these tuff intervals through detail depositional, petrographic and geochemical analyses. Most of the tuff intervals are well-documented at the bottom of the Chang7 oil reservoir unit and can be correlated laterally, and certain tuff beds are reworked by turbidity current or seismic activity. Petrographic studies of the Chang7 tuffs indicate that they are composed of crystal shards, lithic shards and altered glass shards, and the crystal shards include plagioclase, quartz and biotite. Alteration of the Chang7 tuffs is ubiquitous, thus, most of these tuffs transformed into illite/smectite (I/S) mixed-layers which are identified by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Less common minerals are also detected in the Chang7 tuffs such as zircon, hematite, siderite, anatase. Major elements are determined by the X-ray fluorescence (XRF) analysis, the results indicate that the Chang7 tuffs are enriched in K2O (average 4.21%), the ratio of SiO2/Al2O3 ranges from 1.73 to 2.85 (average 2.17), and the ratio of TiO2/Al2O3 varies between 0.006 and 0.032 (average 0.017), which imply that the Chang7 tuffs originated from a felsic parental magma. Trace elements are determined by inductively coupled plasma mass spectrometry (ICP-MS), indicating the total rare earth element (∑REE) concentrations are variable, and range from 117.46 to 466.83 ppm (average 251.88 ppm). REE distribution pattern of the Chang7 tuffs presents a LREE rightward incline with flat HREE curve. The value of δEu ranges from 0.151 to 0.837 (average 0.492), suggesting a strong to weak negative Eu anomaly. The Chang7 tuffs show positive anomalies in Rb, Th and U and negative anomalies in Nb, Sr and Eu on a primitive mantle normalized spidergram. A preliminary analysis of the geochemical composition of the

  4. Estimation of engineering properties of selected tuffs by using grain/matrix ratio

    Science.gov (United States)

    Korkanç, Mustafa; Solak, Burak

    2016-08-01

    Petrographic properties of rocks substantially affect their physical and mechanical properties. In the present study, for the purpose of examining the relationship between the petrographic and geomechanical properties of pyroclastic rocks, fresh samples were taken from tuffs of different textural properties that have wide distribution in Cappadocia region. Experimental studies were conducted on 20 fresh samples to determine their engineering properties through petrographic examinations. Dry and saturated unit weights, water absorption by weight, effective porosity, capillary water absorption, slake durability index, P-wave velocity, point load index, uniaxial compressive strength and nail penetration index of the samples were determined. Higher geomechanical values were obtained from the samples of Kavak tuffs affected by hydromechanical alteration and by tuffs with high welded rates. On thin sections prepared with the fresh samples, petrographic studies were carried out by using a point counter with a polarizing microscope, and mineral composition, texture, void ratio, volcanic glass presence and state of these fragments within the rock, secondary mineral formation and opaque mineral presence were determined. Grain/matrix ratio (GMR) was calculated by using the ratios of phenocrysts, microlites, volcanic glass, voids and opaque minerals after point counting on thin sections. A potential relationship between the petrographic and geomechanical properties of fresh samples was tried to determine by counting correlation analysis. Such a relationship can be significantly and extensively suggestible for engineering applications. For this purpose, we used the poorly-welded Kavak and densely-welded Kızılkaya tuff samples in our study.

  5. Corrosion testing of type 304L stainless steel in tuff groundwater environments

    Energy Technology Data Exchange (ETDEWEB)

    Westerman, R.E.; Pitman, S.G.; Haberman, J.H.

    1987-11-01

    The stress-corrosion cracking (SCC) resistance of Type 304L stainless steel (SS) to elevated temperatures in tuff rock and tuff groundwater environments was determined under irradiated and nonirradiated conditions using U-bend specimens and slow-strain-rate tests. The steel was tested both in the solution-annealed condition and after sensitization heat treatments. The material was found to be susceptible to SCC in both the solution-annealed and solution-annealed-and-sensitized conditions when exposed to an irradiated crushed tuff rock environment containing air and water vapor at 90{sup 0}C. A similar exposure at 50{sup 0}C did not result in failure after a 25-month test duration. Specimens of sensitized 304 SS conditioned with a variety of sensitization heat treatments resisted failure during a test of 1-year duration in which a nonirradiated environment of tuff rock and groundwater held at 200{sup 0}C was allowed to boil to dryness on a cyclical basis. All specimens of sensitized 304 SS exposed to this environment failed. Slow-strain-rate studies were performed on 304L, 304, and 316L SS specimens. The 304L SS was tested in J-13 well water at 150{sup 0}C, and the 316L SS at 95{sup 0}C. Neither material showed evidence of SCC in these tests. Sensitized 304 SS did exhibit SCC in J-13 well water in tests conducted at 150{sup 0}C. 12 refs., 27 figs., 13 tabs.

  6. Cerro Xalapaxco: An Unusual Tuff Cone with Multiple Explosion Craters, in Central Mexico (Puebla)

    Science.gov (United States)

    Abrams, M. J.; Siebe, C.

    1994-01-01

    The Xalapaxco tuff cone is located on the northeast flank of La Malinche stratovolcano in central Mexico. An unusually large number (10) of explosion craters, concentrated on the central and on the uphill side of the cone, expose alternating beds of stratified surge deposits and massive fall deposits.

  7. Maximum likelihood Bayesian averaging of airflow models in unsaturated fractured tuff using Occam and variance windows

    NARCIS (Netherlands)

    Morales-Casique, E.; Neuman, S.P.; Vesselinov, V.V.

    2010-01-01

    We use log permeability and porosity data obtained from single-hole pneumatic packer tests in six boreholes drilled into unsaturated fractured tuff near Superior, Arizona, to postulate, calibrate and compare five alternative variogram models (exponential, exponential with linear drift, power, trunca

  8. Variability of the physical properties of tuff at Yucca Mountain, NV

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, P.J.; Martin, R.J. III [New England Research, Inc., White River Junction, VT (United States); Price, R.H. [Sandia National Labs., Albuquerque, NM (United States)

    1994-12-31

    Lateral and vertical variabilities in the bulk and mechanical properties of silicic volcanic tuff at the potential nuclear waste repository site in Yucca Mountain, NV have been evaluated. Laboratory measurements have been performed on tuff specimens recovered from boreholes located to support the design of the Exploratory Studies Facility/North Ramp. The data include dry and saturated bulk densities, average grain density, porosity, compressional and shear wave velocities, elastic moduli, and compressional and tensional fracture strengths. Data from eight boreholes aligned in a northwest-southeast direction have been collected under the required quality assurance program. Three boreholes have penetrated the potential repository horizon. The information collected provides for an accurate appraisal of the variability of rock properties in the vicinity of the boreholes. As expected, there is substantial variability in the bulk and mechanical properties of the tuff with depth (lithology). This is due to variations in gross characteristics of the tuffs (e.g., cooling units, mode of deposition, etc.), as well as smaller scale features (welding, porosity, and internal structures) that have developed as a result of depositional and post-depositional mechanisms. An evaluation of the lateral variability in bulk and mechanical properties is somewhat limited, at this time, due to a lack of borehole control to the north and south (parallel to the depositional flow direction). Initial observations indicate that there is minimal lateral variability within lithologic units. There are observable differences however, that can be related to variability in specific properties (e.g., porosity, and internal structures).

  9. Cerro Xalapaxco: An Unusual Tuff Cone with Multiple Explosion Craters, in Central Mexico (Puebla)

    Science.gov (United States)

    Abrams, M. J.; Siebe, C.

    1994-01-01

    The Xalapaxco tuff cone is located on the northeast flank of La Malinche stratovolcano in central Mexico. An unusually large number (10) of explosion craters, concentrated on the central and on the uphill side of the cone, expose alternating beds of stratified surge deposits and massive fall deposits.

  10. Occurrence of rhyolytic tuffs at deep sea drilling project site 219 on the Laccadive Ridge

    Digital Repository Service at National Institute of Oceanography (India)

    Siddiquie, H.N.; Sukheswala, R.N.

    A study of thin sections from the lower and middle parts of Unit 5 (Paleocene) from Site 219 shows that these largely consist of acidic or rhyolitic tuffs. The overlying limestones in Unit 5 (Paleocene) and Unit 4 (Lower Eocene) also contain...

  11. Experimental study on the Neapolitan Yellow Tuff: Salt weathering and consolidation

    Science.gov (United States)

    La Russa, Mauro Francesco; Ruffolo, Silvestro Antonio; Alvarez de Buergo, Monica; Ricca, Michela; Belfiore, Cristina Maria; Pezzino, Antonino; Mirocle Crisci, Gino

    2016-04-01

    Salt crystallization is one of the major weathering agents in porous building materials due to the crystallization pressure exerted by salt crystals growing in confined pores. The consolidation of such degraded stone materials is a crucial issue in the field of Cultural Heritage restoration.
 This contribution deals with laboratory experimentation carried out on the Neapolitan Tuff, a pyroclastic rock largely used in the Campanian architecture. Several specimens, collected from a historical quarry nearby the city of Naples, were treated with two different consolidating products: a suspension of nanosilica in water (Syton X30®) and ethyl silicate (Estel 1000®) dispersed in organic solvent (TEOS). Then, in order to assess the effectiveness of consolidation treatments, both treated and untreated samples underwent accelerated degradation through salt crystallization tests. A multi-analytical approach, including mercury intrusion porosimetry, peeling tests and point load test, was employed to evaluate the correlation between the salt crystallization and the micro-structural features of the examined tuff specimens. In addition, the calculation of the crystallization pressures was also performed in order to make a correlation between the porous structure of the tuff and its susceptivity to salt crystallization. Obtained results show that both the tested products increase the resistance of tuff to salt crystallization, although inducing an increase of crystallization pressure. Ethyl silicate, however, shows a better behaviour in terms of superficial cohesion, even after several degradation cycles.

  12. In-situ tuff water migration/heater experiment: experimental plan

    Energy Technology Data Exchange (ETDEWEB)

    Johnstone, J.K.

    1980-08-01

    Tuffs on the Nevada Test Site (NTS) are currently under investigation as a potential isolation medium for heat-producing nuclear wastes. The National Academy of Sciences has concurred in our identification of the potentially large water content ({le}40 vol %) of tuffs as one of the important issues affecting their suitability for a repository. This Experimental Plan describes an in-situ experiment intended as an initial assessment of water generation/migration in response to a thermal input. The experiment will be conducted in the Grouse Canyon Welded Tuff in Tunnel U12g (G-Tunnel) located in the north-central region of the NTS. While the Grouse Canyon Welded Tuff is not a potential repository medium, it has physical, thermal, and mechanical properties very similar to those tuffs currently under consideration and is accessible at depth (400 m below the surface) in an existing facility. Other goals of the experiment are to support computer-code and instrumentation development, and to measure in-situ thermal properties. The experimental array consists of a central electrical heater, 1.2 m long x 10.2 cm diameter, surrounded by three holes for measuring water-migration behavior, two holes for measuring temperature profiles, one hole for measuring thermally induced stress in the rock, and one hole perpendicular to the heater to measure displacement with a laser. This Experimental Plan describes the experimental objectives, the technical issues, the site, the experimental array, thermal and thermomechanical modeling results, the instrumentation, the data-acquisition system, posttest characterization, and the organizational details.

  13. Origin, Age, and Geochemistry of the Tuff of Saguache Creek, Southwestern Colorado

    Science.gov (United States)

    Turner, K. J.; Young, M. D.; Wendlandt, R. F.

    2003-12-01

    A crystal-poor, rhyolitic, ash-flow tuff in the Eastern San Juan Volcanic Field currently known as the tuff of Saguache Creek (TSC) was reinterpreted by Simon and Wendlandt (1999) as not being distal Sapinero Mesa Tuff. Currently there is no source caldera established for this tuff thereby leaving uncertainties in the volcanic history. Regional mapping of the TSC has subsequently been completed to constrain a possible source caldera. Petrographic studies, and EPMA and LA-ICPMS analyses of the mineral assemblage have been performed to characterize further the tuff, enable correlation of mapped TSC, and constrain petrogenetic models. Petrographic and chemical identification of the TSC builds on characteristics set forth by Simon (2000). These characteristics include abundant feldspar clusters, alkali feldspar mantled plagioclase, no modal quartz, Fe-Ti oxides (often with apatites and zircons), and sparse biotite and pyroxene. Pyroxenes show curiously high MnO (avg 2.70 wt%) and Mg# (avg 79.2) and might be xenocrystic. In comparison, biotites have much lower MnO (avg 0.82 wt%). Average sanidine (Or50) and plagioclase (Ab71) compositions fall within the documented range (Simon, 2000) and show little trace element substitution including Eu Conejos age volcanic deposits. Similarly, an andesitic topographic high just west of Trickle Mtn has TSC vitrophyre on the east-facing slope suggesting strong north-south channeling of the flow unit by paleo-topographic lows. Outcrop elevations also decrease from north to south supporting a possible source caldera to the north. This source could be explained by a distinct circular gravity low on the southeastern slope of the Continental Divide. The low is bordered to the north by a circular arrangement of peaks as well as debris breccias, andesitic flow breccias, and lahars.

  14. Heulandite and mordenite-rich tuffs from Greece: a potential source for pozzolanic materials

    Science.gov (United States)

    Kitsopoulos, K. P.; Dunham, A. C.

    1996-09-01

    The microcystalline mass of the Pliocene tuffs of Santorini and Polyegos islands, in the South Aegean Volcanic Arc, Greece, is very rich in zeolite minerals, more specifically heulandite type 3, i.e. clinoptilolite, and mordenite. In Santorini, clinoptilolite is the dominant authigenic phase and it was formed in a semi-closed system, by the activity of interstitial water within the volcaniclastic sequence. In Polyegos, mordenite dominates and it was formed by hydrothermal alteration of pyroclastics. Experiments described in this work show that the presence of the zeolite minerals has created materials with excellent pozzolanic properties. Tuffs from the two areas were calcined at 760 °C and for 12 h and then mixed with lime in a constant ratio of 1 part lime to 3 parts calcined tuff. As a result, the free lime content of the lime-calcined tuff mixtures was reduced from 25% to 2.05% (Santorini) and 1.31% (Polyegos). Compressive strength tests were carried out on concrete cubes made with 100% Portland cement as the cementitious agent, to be used as reference cubes, and concrete cubes in which the Portland cement has been replaced in 4% and 7% proportions by the calcined tuff as pozzolans. The free lime estimation and the compressive strength tests were all carried out in accordance with the British Standards Institution (BS 4550 and BS 1881) guidelines. Early stage measurements of the compressive strength showed that pozzolan-bearing concrete cubes reached values as high as 140% of the reference cubes. The pozzolan-bearing concrete cubes maintained this superior strength throughout the entire one year period of the experiments. After 360 days, they finally maintained 107% of the compressive strength of the reference cubes.

  15. Evenly-spaced columns in the Bishop Tuff as relicts of hydrothermal convection

    Science.gov (United States)

    Randolph-Flagg, N. G.; Breen, S. J.; Hernandez, A.; Self, S.; Manga, M.

    2015-12-01

    A few square km of the Bishop Tuff in eastern California, USA have evenly spaced erosional columns. These columns are more resistant to erosion due to the precipitation of the low-temperature zeolite (120-200 ºC), mordenite, which is not found in the surrounding tuff. Similar features observed in the Bandelier Tuff were hypothesized to form when cold water from above infiltrated into the still-hot tuff interior. This water would become gravitationally unstable and produced convection with steam upwellings and liquid water downwellings. These downwellings became cemented with mordenite while the upwellings were too dry for chemical reactions. We use two methods to quantitatively assess this hypothesis. First, scaling that ignores the effects of latent heat and mineral precipitation suggests the Rayleigh number (Ra, a measure of convective vigor) for this system is ~103 well above the critical Ra of 4π2. Second, to account for the effect of multiphase flow and latent heat, we use two-dimensional numerical models in the finite difference code HYDROTHERM. We find that the geometry of flow is consistent with field observations and confirm that geometry is sensitive to permeability and topography. These tests suggest a few things about low-pressure hydrothermal systems. 1) The geometry of at least some convection appears to be broadly captured by linear stability theory that ignores reactive transport, heterogeneity of host rock, and the effects of latent heat. 2) Topographic flow sets the wavelength of convection meaning that these columns formed somewhere without topography—probably a lake. Finally, these observations imply a wet paleoclimate in the Eastern Sierra namely that, in the aftermath of the Long Valley eruption, either rain or snow was able to pool in the caldera before the tuff cooled on the order of a hundred years after the eruption.

  16. The Tala Tuff, La Primavera caldera Mexico. Pre-eruptive conditions and magma processes before eruption

    Science.gov (United States)

    Sosa-Ceballos, G.

    2015-12-01

    La Primavera caldera, Jalisco Mexico, is a Pleistocenic volcanic structure formed by dome complexes and multiple pyroclastic flows and fall deposits. It is located at the intersection of the Chapala, Colima, and Tepic grabens in western Mexico. The first volcanic activity associated to La Primavera started ~0.1 Ma with the emission of pre-caldera lavas. The caldera collapse occurred 95 ka and is associated to the eruption of ~20 km3of pumice flows known as the Tala tuff (Mahood 1980). The border of the caldera was replaced by a series of domes dated in 75-30 ky, which partially filled the inner depression of the caldera with pyroclastic flows and falls. For more than a decade the Federal Commission of Electricity in Mexico (CFE) has prospected and evaluated the geothermal potential of the Cerritos Colorados project at La Primavera caldera. In order to better understand the plumbing system that tapped the Tala tuff and to investigate its relation with the potential geothermal field at La Primavera we performed a series of hydrothermal experiments and studied melt inclusions hosted in quartz phenocrysts by Fourier Infra red stectroscopy (FTIR). Although some post caldera products at La Primavera contain fayalite and quartz (suggesting QFM conditions) the Tala tuff does not contain fayalite and we ran experiments under NNO conditions. The absence of titanomagnetite does not allowed us to calculate pre-eruptive temperature. However, the stability of quartz and plagioclase, which are natural phases, suggest that temperature should be less than 750 °C at a pressure of 200 MPa. The analyses of H2O and CO2 dissolved in melt inclusions yielded concentrations of 2-5 wt.% and 50-100 ppm respectively. This data confirm that the pre-eruptive pressure of the Tala tuff is ~200 MPa and in addition to major elements compositions suggest that the Tala tuff is either, compositionally zoned or mixed with other magma just prior to eruption.

  17. In-situ tuff water migration/heater experiment: experimental plan

    Energy Technology Data Exchange (ETDEWEB)

    Johnstone, J.K.

    1980-08-01

    Tuffs on the Nevada Test Site (NTS) are currently under investigation as a potential isolation medium for heat-producing nuclear wastes. The National Academy of Sciences has concurred in our identification of the potentially large water content ({le}40 vol %) of tuffs as one of the important issues affecting their suitability for a repository. This Experimental Plan describes an in-situ experiment intended as an initial assessment of water generation/migration in response to a thermal input. The experiment will be conducted in the Grouse Canyon Welded Tuff in Tunnel U12g (G-Tunnel) located in the north-central region of the NTS. While the Grouse Canyon Welded Tuff is not a potential repository medium, it has physical, thermal, and mechanical properties very similar to those tuffs currently under consideration and is accessible at depth (400 m below the surface) in an existing facility. Other goals of the experiment are to support computer-code and instrumentation development, and to measure in-situ thermal properties. The experimental array consists of a central electrical heater, 1.2 m long x 10.2 cm diameter, surrounded by three holes for measuring water-migration behavior, two holes for measuring temperature profiles, one hole for measuring thermally induced stress in the rock, and one hole perpendicular to the heater to measure displacement with a laser. This Experimental Plan describes the experimental objectives, the technical issues, the site, the experimental array, thermal and thermomechanical modeling results, the instrumentation, the data-acquisition system, posttest characterization, and the organizational details.

  18. Segment lengths influence hill walking strategies.

    Science.gov (United States)

    Sheehan, Riley C; Gottschall, Jinger S

    2014-08-22

    Segment lengths are known to influence walking kinematics and muscle activity patterns. During level walking at the same speed, taller individuals take longer, slower strides than shorter individuals. Based on this, we sought to determine if segment lengths also influenced hill walking strategies. We hypothesized that individuals with longer segments would display more joint flexion going uphill and more extension going downhill as well as greater lateral gastrocnemius and vastus lateralis activity in both directions. Twenty young adults of varying heights (below 155 cm to above 188 cm) walked at 1.25 m/s on a level treadmill as well as 6° and 12° up and downhill slopes while we collected kinematic and muscle activity data. Subsequently, we ran linear regressions for each of the variables with height, leg, thigh, and shank length. Despite our population having twice the anthropometric variability, the level and hill walking patterns matched closely with previous studies. While there were significant differences between level and hill walking, there were few hill walking variables that were correlated with segment length. In support of our hypothesis, taller individuals had greater knee and ankle flexion during uphill walking. However, the majority of the correlations were between tibialis anterior and lateral gastrocnemius activities and shank length. Contrary to our hypothesis, relative step length and muscle activity decreased with segment length, specifically shank length. In summary, it appears that individuals with shorter segments require greater propulsion and toe clearance during uphill walking as well as greater braking and stability during downhill walking.

  19. Ocean Hill-Brownsville, 40 Years Later

    Science.gov (United States)

    Kahlenberg, Richard D.

    2008-01-01

    Forty years ago--on May 9, 1968--the local school board in Brooklyn's black ghetto of Ocean Hill-Brownsville sent telegrams to 19 unionized educators, informing them that their employment in the district was terminated. Eighteen were white. One black teacher was mistakenly included on the list, but reinstated almost immediately after the error was…

  20. Ocean Hill-Brownsville, 40 Years Later

    Science.gov (United States)

    Kahlenberg, Richard D.

    2008-01-01

    Forty years ago--on May 9, 1968--the local school board in Brooklyn's black ghetto of Ocean Hill-Brownsville sent telegrams to 19 unionized educators, informing them that their employment in the district was terminated. Eighteen were white. One black teacher was mistakenly included on the list, but reinstated almost immediately after the error was…

  1. General Education at UNC-Chapel Hill

    Science.gov (United States)

    Schalin, Jay; Robinson, Jenna Ashley

    2013-01-01

    The general education program at UNC-Chapel Hill has abandoned the concept of a core curriculum. Instead, students choose their "required" classes from lists of thousands of courses that may be as narrow and idiosyncratic as Love, Sex and Marriage in Soviet Culture (RUSS 277) or The Gardens, Shrines and Temples of Japan (ASIA 586).…

  2. How to make a Hill Plot

    NARCIS (Netherlands)

    H. Drees (Holger); L.F.M. de Haan (Laurens); S. Resnick

    1998-01-01

    textabstractAn abundance of high quality data sets requiring heavy tailed models necessitates reliable methods of estimating the shape parameter governing the degree of tail heaviness. The Hill estimator is a popular method for doing this but its practical use is encumbered by several difficulties.

  3. Ostracoda from Vestfold Hill lake terraces, Antarctica

    Digital Repository Service at National Institute of Oceanography (India)

    Setty, M.G.A.P.

    Six species of ostracodes are recorded from two transects of terraces of Deep Lake, Vestfold Hills, Antarctica. Two species (@iXesteleberis@@ sp. and @iBradleya dictyon@@) range from Cretaceous to Recent, @iPoseidonamicus aff. P. major@@ ranges from...

  4. Surface water and groundwater interaction on a hill island

    DEFF Research Database (Denmark)

    Frederiksen, Rasmus Rumph; Rasmussen, Keld Rømer; Christensen, Steen

    – the hill islands – is relatively unknown. This study aims at providing new information about the rainfall-runoff processes in hill island landscapes where surface water and groundwater interaction is expected to have a dominant role and hill-slope processes not. Through stream flow measurements, field...

  5. Resonance tongues in Hill's equations : A geometric approach

    NARCIS (Netherlands)

    Broer, H; Simo, C

    2000-01-01

    The geometry of resonance tongues is considered in, mainly reversible, versions of Hill's equation, close to the classical Mathieu case. Hill's map assigns to each value of the multiparameter the corresponding Poincare matrix. Dy an averaging method, the geometry of Hill's map locally can be underst

  6. Diatreme evolution during the phreatomagmatic eruption of the Songaksan tuff ring, Jeju Island, Korea

    Science.gov (United States)

    Go, S. Y.; Kim, G. B.; Jeong, J. O.; Sohn, Y. K.

    2017-03-01

    The Songaksan tuff ring, Jeju Island, Korea, which erupted ca. 3.7 ka BP in a coastal setting, provides an unusual opportunity to study the processes of phreatomagmatic eruption and the formation of a diatreme because of the exceptionally well-preserved ejecta beds and well-known subsurface geology. The tuff sequence can be divided into four units (A to D), which have distinctly different accidental componentry (quartz-rich vs. quartz-poor), grain surface features (abraded and ash-coated vs. unabraded and uncoated), and chemical compositions of juvenile particles. The basal tephra bed of unit A, which probably erupted after the removal of the relatively hard shallow-level (120 m deep) accidental grains, suggesting that the early erupted tephra had not yet experienced recycling and pre-eruption mixing in the diatreme. On the other hand, the overlying tephra beds of units A, B, and D contain an abundance of abraded and ash-coated juvenile/accidental grains, suggesting that the tephra comprised significant proportions of "recycled" or "premixed" materials from previous eruptions or subsurface explosions, which participated in the explosion-driven mixing in the diatreme before eventual ejection from the diatreme. Unit C is unusual in that it comprises extremely rare accidental grains and ash-coated juvenile/accidental grains. We interpret that the supply of solid materials, either accidental or juvenile, to the diatreme was greatly reduced because of temporary stabilization of the diatreme and the reduction in magma flux to the diatreme. The diatreme is therefore envisaged to have been filled with a water-saturated slurry, in which particle abrasion and adhesion were inhibited. We also infer that the diatreme fill was temporarily removed by a powerful explosion before eruption of unit C on the basis of the near absence of the tephra grains from earlier eruptions throughout the tephra beds of unit C. The ratio of tachylite to sideromelane grains generally increases up

  7. The Hill Chart Calculation for Pelton Runner Models using the HydroHillChart - Pelton Module Software

    Directory of Open Access Journals (Sweden)

    Adelina Bostan

    2015-07-01

    Full Text Available The Pelton turbines industrial design is based on the hill chart characteristics obtained by measuring the models. Primary data measurements used to obtain the hill chart can be processed graphically, by hand or by using graphic programs respectively CAD programs; the HydroHillChart - Pelton module software is a specialized tool in achieving the hill chart, using interpolation cubic spline functions. Thereby, based on measurements of several models of Pelton turbines, a computerized library, used to design industrial Pelton turbines can be created. The paper presents the universal characteristics calculated by using the HydroHillChart - Pelton module software for a series of Pelton runners.

  8. Evidence to the Marley Hill Public Inquiry

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, G.K. (Council for the Protection of Rural England (UK). Durham and Teesdale Branch)

    1989-11-01

    George Kenneth Wilson, a retired power station enginer, and holder of such offices as Vice-Chairman of the CPRE Durham and Teesdale Branch, Secretary of the Derwent Valley Protection Society and an officer of the Opencast Mining Intelligence Group, presents reasons for dismissing the appeal for opencast mining at the Marley Hill site in the NE of England saying that the Mineral Planning Guidance Note, MPG3 seemed to be repeating mistakes inherent in the previous 'Plan for coal'. He considers that the application cannot be justified on the grounds of demand or forecast market trends. The type of coal is unsuitable for local power station boilers. The working of the site would destroy a large area of pleasant countryside. The standard of restoration of the 32 sites surrounding Marley Hill is in his opinion very poor.

  9. Uranium series dating of Allan Hills ice

    Science.gov (United States)

    Fireman, E. L.

    1986-03-01

    Uranium-238 decay series nuclides dissolved in Antarctic ice samples were measured in areas of both high and low concentrations of volcanic glass shards. Ice from the Allan Hills site (high shard content) had high Ra-226, Th-230 and U-234 activities but similarly low U-238 activities in comparison with Antarctic ice samples without shards. The Ra-226, Th-230 and U-234 excesses were found to be proportional to the shard content, while the U-238 decay series results were consistent with the assumption that alpha decay products recoiled into the ice from the shards. Through this method of uranium series dating, it was learned that the Allen Hills Cul de Sac ice is approximately 325,000 years old.

  10. Studies of the mobility of uranium and thorium in Nevada Test Site tuff

    Energy Technology Data Exchange (ETDEWEB)

    Wollenberg, H.A.; Flexser, S.; Smith, A.R. [Lawrence Berkeley Lab., CA (United States)

    1991-06-01

    Hydro-geochemical processes must be understood if the movement of radionuclides away from a breached radioactive waste canister is to be modeled and predicted. In this respect, occurrences of uranium and thorium in hydrothermal systems are under investigation in tuff and in rhyolitic tuff that was heated to simulate the effects of introduction of radioactive waste. In these studies, high-resolution gamma spectrometry and fission-track radiography are coupled with observations of alteration mineralogy and thermal history to deduce the evidence of, or potential for movement of, U and Th in response to the thermal environment. Observations to date suggest that U was mobile in the vicinity of the heater but that localized reducing environments provided by Fe-Ti-Mn-oxide minerals concentrated U and thus attenuated its migration.

  11. Diffusion of sodium, potassium, calcium, manganese, and radon in tuff and clinoptilolite under leaching

    Science.gov (United States)

    Dikii, N. P.; Dovbnya, A. N.; Lyashko, Yu. V.; Medvedev, D. V.; Medvedeva, E. P.; Uvarov, V. L.; Achkasov, K. V.

    2011-07-01

    Nuclear physics methods are used to determine the diffusion coefficients of Na, Ca, Mn, K, and 222Rn in clinoptilolite (Sokirnitsa occurrence, Ukraine) and in natural tuff (Yucca Mountain, Nevada, United States) and in tuff irradiated by γ-quanta ( E max = 23 MeV) to a dose of 107 Gy at a leaching temperature of 37°C. The diffusion coefficients of sodium and potassium in clinoptilolite are found to differ considerably: 4 × 10-17 and 2 × 10-20 m2/s, respectively. This indicates the influence of aquacomplexes on the cation transfer. The diffusion coefficient of radon in these materials is determined: in clinoptilolite it equals 2.5 × 10-12 m2/s.

  12. Sorption and desorption of remazol yellow by a Fe-zeolitic tuff

    Energy Technology Data Exchange (ETDEWEB)

    Solache R, M. J. [ININ, Departamento de Quimica, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Villalva C, R.; Diaz N, M. C., E-mail: marcos.solache@inin.gob.m [Instituto Tecnologico de Toluca, Division de Estudios del Posgrado, Av. Tecnologico s/n, Ex-Rancho La Virgen, 52140 Metepec, Estado de Mexico (Mexico)

    2010-07-01

    The adsorption of remazol yellow from aqueous solution was evaluated using a Fe-zeolitic tuff. The adsorbent was characterized by scanning electron microscopy, IR spectroscopy and X-ray diffraction. Sorption kinetic and isotherms were determined and the adsorption behavior was analyzed. Kinetic pseudo-second order and Langmuir-Freundlich models were successfully applied to the experimental results, indicating chemisorption on a heterogeneous material. The regeneration of the material was best accomplished by using a H{sub 2}O{sub 2} solution. The sorption capacity of the Fe-zeolitic tuff increased when the saturated samples were treated with a H{sub 2O2} or FeCl{sub 3} solution. (Author)

  13. Evaluating the paleomagnetic potential of single zircon crystals using the Bishop Tuff

    CERN Document Server

    Fu, Roger R; Lima, Eduardo A; Kehayias, Pauli; Araujo, Jefferson F D F; Glenn, David R; Gelb, Jeff; Einsle, Joshua F; Bauer, Ann M; Harrison, Richard J; Ali, Guleed A H; Walsworth, Ronald L

    2016-01-01

    Zircon crystals offer a unique combination of suitability for high-precision radiometric dating and high resistance to alteration. Paleomagnetic experiments on ancient zircons may potentially constrain the earliest geodynamo, which holds broad implications for the early Earth interior and atmosphere. However, the ability of zircons to record accurately the geomagnetic field has not been fully demonstrated. Here we conduct thermal and room temperature alternating field (AF) paleointensity experiments on 767.1 thousand year old (ka) zircons from the Bishop Tuff, California. The rapid emplacement of these zircons in a well-characterized magnetic field provides a high-fidelity test of the zircons intrinsic paleomagnetic recording accuracy. Successful dual heating experiments on nine zircons measured using a superconducting quantum interference device (SQUID) microscope yield a mean paleointensity of 46.2 +/- 18.8 microtesla (1sigma), which agrees closely with high-precision results from Bishop Tuff whole rock (43...

  14. An astronomical age for the Bishop Tuff and concordance with radioisotopic dates

    DEFF Research Database (Denmark)

    Rivera, Tiffany; Zeeden, Christian; Storey, Michael

    2014-01-01

    The Bishop Tuff forms a key stratigraphic horizon for synchronization of Quaternary sedimentary records in North America. The unit stratigraphically overlies the Matuyama-Brunhes geomagnetic polarity reversal by several thousand years; high-precision dating of this tuff may be valuable for regional...... and global correlation of records. The Quaternary time scale is anchored by 40Ar/39Ar ages on lava flows and ash layers where available, with stage boundaries and geomagnetic reversals including astronomically tuned records. However, astronomical dating has not yet validated the high-precision 238U/206Pb...... ages, including new single crystal 40Ar/39Ar sanidine fusion analyses presented here, which demonstrates that concordance through multiple dating techniques is achievable within the Quaternary...

  15. Magnetic links among lava flows, tuffs and the underground plumbing system in a monogenetic volcano, derived from magnetics and paleomagnetic studies

    Science.gov (United States)

    Urrutia-Fucugauchi, Jaime; Trigo-Huesca, Alfonso; Pérez-Cruz, Ligia

    2012-12-01

    A combined study using magnetics and paleomagnetism of the Toluquilla monogenetic volcano and associated lavas and tuffs from Valsequillo basin in Central Mexico provides evidence on a 'magnetic' link between the lavas, ash tuffs and the underground volcanic conduit system. Paleomagnetic analyses show that the lava and ash tuff carry reverse polarity magnetizations, which correlate with the inversely polarized dipolar magnetic anomaly over the volcano. The magnetizations in the lava and tuff show similar southward declinations and upward inclinations, supporting petrological inferences that the tuff was emplaced while still hot and indicating a temporal correlation for lava and tuff emplacement. Modeling of the dipolar anomaly gives a reverse polarity source magnetization associated with a vertical prismatic body with southward declination and upward inclination, which correlates with the reverse polarity magnetizations in the lava and tuff. The study documents a direct correlation of the paleomagnetic records with the underground magmatic conduit system of the monogenetic volcano. Time scale for cooling of the volcanic plumbing system involves a longer period than the one for the tuff and lava, suggesting that magnetization for the source of dipolar anomaly may represent a long time average as compared to the spot readings in the lava and tuff. The reverse polarity magnetizations in lava and tuff and in the underground source body for the magnetic anomaly are interpreted in terms of eruptive activity of Toluquilla volcano at about 1.3 Ma during the Matuyama reverse polarity C1r.2r chron.

  16. ARCPEP 2 Continuation Project (Seton Hill University)

    Science.gov (United States)

    2014-10-01

    Coaches uncover areas for possible goal development for Phase 2 participants • Supervised research hours of junior and senior dietetics students who...as website content and/or for training purposes for dietetics students The following tasks were completed at Seton Hill from 27 December 2013...assistants • Supervised student research hours for junior and senior dietetics majors • Scheduled and met with COSMED representative for annual BodPod

  17. Symbolism in Hills Like White Elephants

    Institute of Scientific and Technical Information of China (English)

    谢倩

    2014-01-01

    Hills Like White Elephants tells a story that happens in a small pub, where the protagonists are waiting for the train to Madrid in order to do the abortion.The thesis highlights the “iceberg theory”which is embodied everywhere in the text. By analyzing the the symbolism in the title, the names and the environment,the charm of the symbolism is well reflected.

  18. An SP-Hill layered broadcast cryptosystem

    Science.gov (United States)

    Spencer, M. E.; Tavares, S. E.

    A new type of cryptosystem with applications in broadcast communications and database systems is described. The scheme combines various elements of both SP-networks and Hill broadcast encryption systems. The theoretical basis for the encryption technique is described in a series of equations and the results of a preliminary production process complexity test are presented. The results of the test indicate that the scheme performs well cryptographically and that it represents a significant advance over conventional encryption systems.

  19. Zeolitic volcanic tuffs from Macicas (Cluj County, natural raw materials used for NH4+ removal from wastewaters

    Directory of Open Access Journals (Sweden)

    Horea Bedelean

    2006-04-01

    Full Text Available Volcanic tuffs out cropping in Măcicaş area (Cluj County have been investigated and tested for their ammonium removal capacity. The zeolitic volcanic tuffs from Măcicaş are mainly represented by vitric and vitric crystal tuffs. In this region, significant amounts of volcanic glass in the pyroclastic sequence have been replaced by zeolites (between 50-80 %. The main zeolite species identified in volcanic tuffs from Măcicaş is clinoptilolite and subordinately mordenite. The zeolitic tuff samples considered in zeolitic sodium form (labeled M1-Na and M2-Na are tested in ammonium removal experiments. The ammonium ions were completely removed from 0.0716g/dm3 NH4+ solution onto 10g of zeolitic material in static regime. In dynamic regime, the ammonium ions were completely removed after 250 ml and 500 ml solution passed on M1-Na and M2-Na sample respectively. Also the zeolite exhaustion takes place after more than 1500 ml solution is processed in both cases. The ionic exchange properties suggest that the zeolitic tuff of the Măcicaş region can be used as a final stage (following the biological process in wastewater treatment plants in order to assure compliance with environmental standards.

  20. Alteration history of Mount Epomeo Green Tuff and a related polymictic breccia, Ischia Island, Italy: evidence for debris avalanche

    Science.gov (United States)

    Altaner, S.; Demosthenous, C.; Pozzuoli, A.; Rolandi, G.

    2013-05-01

    This paper presents mineralogical, chemical, and textural data for the Mount Epomeo Green Tuff and an associated polymictic breccia on Ischia Island, Italy with the purpose of defining the alteration history of the two units and the emplacement origin of the polymictic breccia. Our results indicate that the Green Tuff trachytic ignimbrite experienced three alteration events that produced the following mineral assemblages: (1) phillipsite, randomly interstratified (R0) illite/smectite (I/S), Fe-illite, and smectite (in situ Green Tuff); (2) chabazite, phillipsite, R0 I/S, and Fe-illite (proximal facies Green Tuff at Scarrupata di Barano); and (3) analcime, authigenic K-feldspar, Fe-illite, R0 I/S, and smectite (clasts of Green Tuff in polymictic breccia). Phillipsite, chabazite, and R0 I/S within the in situ and proximal facies Green Tuff indicate low-temperature alteration ( T 70 °C) alteration within a mostly closed chemical system. These data suggest that the polymictic breccia represents a debris avalanche deposit created by a catastrophic volcanic collapse, which was associated with low-temperature hydrothermal alteration and thus structural weakening of the volcano. The debris avalanche that produced the polymictic breccia on Ischia may be related to nearby massive debris avalanche deposits recently discovered offshore of southern Ischia. The young age of the polymictic breccia (5.7-8.6 ka) and the possibility of its catastrophic emplacement indicate an additional volcanic hazard for Ischia Island.

  1. On the physics of unstable infiltration, seepage, and gravity drainage in partially saturated tuffs.

    Science.gov (United States)

    Faybishenko, B; Bodvarsson, G S; Salve, R

    2003-01-01

    To improve understanding of the physics of dynamic instabilities in unsaturated flow processes within the Paintbrush nonwelded unit (PTn) and the middle nonlithophysal portion of the Topopah Spring welded tuff unit (TSw) of Yucca Mountain, we analyzed data from a series of infiltration tests carried out at two sites (Alcove 4 and Alcove 6) in the Exploratory Studies Facility (ESF), using analytical and empirical functions. The analysis of infiltration rates measured at both sites showed three temporal scales of infiltration rate: (1) a macro-scale trend of overall decreasing flow, (2) a meso-scale trend of fast and slow motion exhibiting three-stage variations of the flow rate (decreasing, increasing, and [again] decreasing flow rate, as observed in soils in the presence of entrapped air), and (3) micro-scale (high frequency) fluctuations. Infiltration tests in the nonwelded unit at Alcove 4 indicate that this unit may effectively dampen episodic fast infiltration events; however, well-known Kostyakov, Horton, and Philip equations do not satisfactorily describe the observed trends of the infiltration rate. Instead, a Weibull distribution model can most accurately describe experimentally determined time trends of the infiltration rate. Infiltration tests in highly permeable, fractured, welded tuff at Alcove 6 indicate that the infiltration rate exhibits pulsation, which may have been caused by multiple threshold effects and water-air redistribution between fractures and matrix. The empirical relationships between the extrinsic seepage from fractures, matrix imbibition, and gravity drainage versus the infiltration rate, as well as scaling and self-similarity for the leading edge of the water front are the hallmark of the nonlinear dynamic processes in water flow under episodic infiltration through fractured tuff. Based on the analysis of experimental data, we propose a conceptual model of a dynamic fracture flow and fracture-matrix interaction in fractured tuff

  2. Bench-scale experimental determination of the thermal diffusivity of crushed tuff

    Energy Technology Data Exchange (ETDEWEB)

    Ryder, E.E.; Finley, R.E.; George, J.T.; Ho, C.K.; Longenbaugh, R.S. [Sandia National Labs., Albuquerque, NM (United States); Connolly, J.R. [New Mexico Univ., Albuquerque, NM (United States)

    1996-06-01

    A bench-scale experiment was designed and constructed to determine the effective thermal diffusivity of crushed tuff. Crushed tuff particles ranging from 12.5 mm to 37.5 mm (0.5 in. to 1.5 in.) were used to fill a cylindrical volume of 1.58 m{sup 3} at an effective porosity of 0.48. Two iterations of the experiment were completed; the first spanning approximately 502 hours and the second 237 hours. Temperatures near the axial heater reached 700 degrees C, with a significant volume of the test bed exceeding 100 degrees C. Three post-test analysis techniques were used to estimate the thermal diffusivity of the crushed tuff. The first approach used nonlinear parameter estimation linked to a one dimensional radial conduction model to estimate thermal diffusivity from the first 6 hours of test data. The second method used the multiphase TOUGH2 code in conjunction with the first 20 hours of test data not only to estimate the crushed tuffs thermal diffusivity, but also to explore convective behavior within the test bed. Finally, the nonlinear conduction code COYOTE-II was used to determine thermal properties based on 111 hours of cool-down data. The post-test thermal diffusivity estimates of 5.0 x 10-7 m{sup 2}/s to 6.6 x 10-7 m{sup 2}/s were converted to effective thermal conductivities and compared to estimates obtained from published porosity-based relationships. No obvious match between the experimental data and published relationships was found to exist; however, additional data for other particle sizes and porosities are needed.

  3. Reaction of the Topopah Spring Tuff with J-13 water at 120{sup 0}C

    Energy Technology Data Exchange (ETDEWEB)

    Oversby, V.M.

    1984-07-18

    This report describes a series of hydrothermal experiments using crushed tuff from the Topopah Spring Member and natural ground water from well J-13. The purpose of these experiments is to define the changes in water chemistry that would result from temperature changes caused by emplacing high-level nuclear waste in a repository in the Topopah Spring tuff. Experiments were conducted at 120{sup 0}C in Teflon-lined reaction vessels at four separate rock-to-water ratios and for reaction times up to 72 days. The composition of evaporite deposits contained in the pores of the surface-outcrop rock material used in these experiments is determined from solution compositions resulting from treatment of the rock before the start of the experiments. Results from the experiments at 120{sup 0}C are compared with previous experimental results from hydrothermal reaction of the Topopah Spring tuff with J-13 water at 90 and 150{sup 0}C. The main conclusion that can be drawn from this work is that changes in the water chemistry due to heating of the rock-water system can be expected to be very minor. There is no significant source of anions (F{sup -}, Cl{sup -}, NO{sub 3}{sup -}, or SO{sub 4}{sup 2-}) in the rock; solution anion compositions after reaction of pretreated rock with J-13 water differ very little from the starting compositions. The major changes in cations are an increase in silica to approximately the level of cristobalite solubility, supersaturation of aluminum followed by slow precipitation, and fairly rapid precipitation of calcium and magnesium due to the retrograde solubility of calcite. These results are in good agreement with those previously reported for reaction of the tuff with J-13 water at 90 and 150{sup 0}C. 7 references, 7 figures, 28 tables.

  4. On the physics of unstable infiltration, seepage, and gravity drainage in partially saturated tuffs

    Energy Technology Data Exchange (ETDEWEB)

    Faybishenko, B.; Bodvarsson, G.S.; Salve, R.

    2002-04-01

    To improve understanding of the physics of dynamic instabilities in unsaturated flow processes within the Paintbrush nonwelded unit (PTn) and the middle nonlithophysal portion of the Tonopah Spring welded tuff unit (TSw) of Yucca Mountain, we analyzed data from a series of infiltration tests carried out at two sites (Alcove 4 and Alcove 6) in the Exploratory Studies Facility, using analytical and empirical functions. The analysis of infiltration rates measured at both sites showed three temporal scales of infiltration rate: (1) a macro-scale trend of overall decreasing flow, (2) a meso-scale trend of fast and slow motion exhibiting three-stage variations of the flow rate (decreasing, increasing, and [again] decreasing flow rate, as observed in soils in the presence of entrapped air), and (3) micro-scale (high frequency) fluctuations. Infiltration tests in the nonwelded unit at Alcove 4 indicate that this unit may effectively dampen episodic fast infiltration events; however, well-known Kostyakov, Horton, and Philip equations do not satisfactorily describe the observed trends of the infiltration rate. Instead, a Weibull distribution model can most accurately describe experimentally determined time trends of the infiltration rate. Infiltration tests in highly permeable, fractured, welded tuff at Alcove 6 indicate that the infiltration rate exhibits pulsation, which may have been caused by multiple threshold effects and water-air redistribution between fractures and matrix. The empirical relationships between the extrinsic seepage from fractures, matrix imbibition, and gravity drainage versus the infiltration rate, as well as scaling and self-similarity for the leading edge of the water front are the hallmark of the nonlinear dynamic processes in water flow under episodic infiltration through fractured tuff. Based on the analysis of experimental data, we propose a conceptual model of a dynamic fracture flow and fracture-matrix interaction in fractured tuff

  5. Miocene cercopithecoidea from the Tugen Hills, Kenya.

    Science.gov (United States)

    Gilbert, Christopher C; Goble, Emily D; Hill, Andrew

    2010-11-01

    Miocene to Pleistocene fossiliferous sediments in the Tugen Hills span the time period from at least 15.5 Ma to 0.25 Ma, including time periods unknown or little known elsewhere in Africa. Consequently, the Tugen Hills deposits hold the potential to inform us about crucial phylogenetic events in African faunal evolution and about long-term environmental change. Among the specimens collected from this region are a number of discoveries already important to the understanding of primate evolution. Here, we describe additional cercopithecoid material from the Miocene deposits in the Tugen Hills sequence, including those from securely dated sites in the Muruyur Beds (16-13.4 Ma), the Mpesida Beds (7-6.2 Ma) and the Lukeino Formation (∼ 6.2-5.7 Ma). We also evaluate previously described material from the Ngorora Formation (13-8.8 Ma). Identified taxa include Victoriapithecidae gen. et sp. indet., cf. Parapapio lothagamensis, and at least two colobines. Specimens attributed to cf. Pp. lothagamensis would extend the species' geographic range beyond its type locality. In addition, we describe specimens sharing derived characters with modern African colobines (Tribe: Colobina), a finding that is congruent with previous molecular estimates of colobine divergence dates. These colobine specimens represent some of the earliest known members of the modern African colobine radiation and, in contrast to previous hypotheses, suggest that early African colobines were mainly arboreal and that semi-terrestrial Late Miocene and Plio-Pleistocene colobine taxa were secondarily derived in their locomotor adaptations.

  6. Preliminary hydrogeologic assessment of boreholes UE-25c #1, UE-25c #2, and UE-25c #3, Yucca Mountain, Nye County, Nevada

    Science.gov (United States)

    Geldon, A.L.

    1993-01-01

    Boreholes UE-25c #1, UE-25c #2, and UE-25c #3 (collectively called the C-holes) each were drilled to a depth of 914.4 meters at Yucca Mountain, on the Nevada Test Site, in 1983 and 1984 for the purpose of conducting aquifer and tracer tests. Each of the boreholes penetrated the Paintbrush Tuff and the tuffs and lavas of Calico Hills and bottomed in the Crater Flat Tuff. The geologic units penetrated consist of devitrified to vitrophyric, nonwelded to densely welded, ash-flow tuff, tuff breccia, ash-fall tuff, and bedded tuff. Below the water table, which is at an average depth of 401.6 meters below land surface, the rocks are argillic and zeolitic. The geologic units at the C-hole complex strike N. 2p W. and dip 15p to 21p NE. They are cut by several faults, including the Paintbrush Canyon Fault, a prominent normal fault oriented S. 9p W., 52.2p NW. The rocks at the C-hole complex are fractured extensively, with most fractures oriented approximately perpendicular to the direction of regional least horizontal principal stress. In the Crater Flat Tuff and the tuffs and lavas of Calico Hills, fractures strike predominantly between S. 20p E. and S. 20p W. and secondarily between S. 20p E. and S. 60p E. In the Topopah Spring Member of the Paintbrush Tuff, however, southeasterly striking fractures predominate. Most fractures are steeply dipping, although shallowly dipping fractures occur in nonwelded and reworked tuff intervals of the Crater Flat Tuff. Mineral-filled fractures are common in the tuff breccia zone of the Tram Member of the Crater Flat Tuff, and, also, in the welded tuff zone of the Bullfrog Member of the Crater Flat Tuff. The fracture density of geologic units in the C-holes was estimated to range from 1.3 to 7.6 fractures per cubic meter. Most of these estimates appear to be the correct order of magnitude when compared to transect measurements and core data from other boreholes 1.3 orders of magnitude too low. Geophysical data and laboratory analyses were

  7. Creep in Topopah Spring Member welded tuff. Yucca Mountain Site Characterization Project

    Energy Technology Data Exchange (ETDEWEB)

    Martin, R.J. III; Boyd, P.J.; Noel, J.S. [New England Research, Inc., White River Junction, VT (United States); Price, R.H. [Sandia National Labs., Albuquerque, NM (United States)

    1995-06-01

    A laboratory investigation has been carried out to determine the effects of elevated temperature and stress on the creep deformation of welded tuffs recovered from Busted Butte in the vicinity of Yucca Mountain, Nevada. Water saturated specimens of tuff from thermal/mechanical unit TSw2 were tested in creep at a confining pressure of 5.0 MPa, a pore pressure of 4.5 MPa, and temperatures of 25 and 250 C. At each stress level the load was held constant for a minimum of 2.5 {times} 10{sup 5} seconds and for as long as 1.8 {times} 10{sup 6} seconds. One specimen was tested at a single stress of 80 MPa and a temperature of 250 C. The sample failed after a short time. Subsequent experiments were initiated with an initial differential stress of 50 or 60 MPa; the stress was then increased in 10 MPa increments until failure. The data showed that creep deformation occurred in the form of time-dependent axial and radial strains, particularly beyond 90% of the unconfined, quasi-static fracture strength. There was little dilatancy associated with the deformation of the welded tuff at stresses below 90% of the fracture strength. Insufficient data have been collected in this preliminary study to determine the relationship between temperature, stress, creep deformation to failure, and total failure time at a fixed creep stress.

  8. Micromorphology of pedogenically derived fracture fills in Bandelier Tuff, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Davenport, D.W.; Wilcox, B.P. [Los Alamos National Lab., NM (United States); Allen, B.L. [Texas Tech Univ., Lubbock, TX (United States)

    1995-11-01

    Fractures in the Bandelier Tuff are potential paths for water movement and transport of contaminants from waste disposal sites and other contaminated areas at Los Alamos National Laboratory, Los Alamos, NM. Contaminants transported in this way could ultimately be found in Los Alamos drinking water or in the Rio Grande, which flows through heavily populated areas in both the USA and Mexico. We conducted this study to determine (i) the morphology and origin of soil-like material in the fractures, and (ii) the likelihood of significant water movement through the fractures. We examined thin sections of fracture fills, soils, and tuffs to obtain fabric and mineralogical data, and collected field data on soil horizons, color, texture, structure, clay films, and root abundance. Fracture fills consist of clay, CaCO{sub 3}, or combinations of the two with minor inclusions of tuff and sand grains. Clay consists of thick, highly oriented argillans aligned parallel to fracture walls, and of discrete books in fracture interiors. Carbonate consists of massive microcrystalline calcite, which completely fills some fractures, and laminae or infillings between clay laminae or books in clay-dominated fractures. The potential creation of new macropores by a variety of processes, however, including seismic activity and biological disturbance, could allow rapid water movement and contaminant transport. 44 refs., 8 figs., 4 tabs.

  9. Studies of ancient concrete as analogs of cementitious sealing materials for a repository in tuff

    Energy Technology Data Exchange (ETDEWEB)

    Roy, D.M.; Langton, C.A.

    1989-03-01

    The durability of ancient cementitious materials has been investigated to provide data applicable to determining the resistance to weathering of concrete materials for sealing a repository for storage of high-level radioactive waste. Because tuff and volcanic ash are used in the concretes in the vicinity of Rome, the results are especially applicable to a waste repository in tuff. Ancient mortars, plasters, and concretes collected from Rome, Ostia, and Cosa dating to the third century BC show remarkable durability. The aggregates used in the mortars, plasters, and concretes included basic volcanic and pyroclastic rocks (including tuff), terra-cotta, carbonates, sands, and volcanic ash. The matrices of ancient cementitious materials have been characterized and classified into four categories: (1) hydraulic hydrated lime and hydrated lime cements, (2) hydraulic aluminous and ferruginous hydrated lime cements ({plus_minus} siliceous components), (3) pozzolana/hydrated lime cements, and (4) gypsum cements. Most of the materials investigated are in category (3). The materials were characterized to elucidate aspects of the technology that produced them and their response to the environmental exposure throughout their centuries of existence. Their remarkable properties are the result of a combination of chemical, mineralogical, and microstructural factors. Their durability was found to be affected by the matrix mineralogy, particle size, and porosity; aggregate type, grading and proportioning; and the methodology of placement. 30 refs.

  10. Studies of ancient concrete as analogs of cementitious sealing materials for a repository in tuff

    Energy Technology Data Exchange (ETDEWEB)

    Roy, D.M.; Langton, C.A.

    1989-03-01

    The durability of ancient cementitious materials has been investigated to provide data applicable to determining the resistance to weathering of concrete materials for sealing a repository for storage of high-level radioactive waste. Because tuff and volcanic ash are used in the concretes in the vicinity of Rome, the results are especially applicable to a waste repository in tuff. Ancient mortars, plasters, and concretes collected from Rome, Ostia, and Cosa dating to the third century BC show remarkable durability. The aggregates used in the mortars, plasters, and concretes included basic volcanic and pyroclastic rocks (including tuff), terra-cotta, carbonates, sands, and volcanic ash. The matrices of ancient cementitious materials have been characterized and classified into four categories: (1) hydraulic hydrated lime and hydrated lime cements, (2) hydraulic aluminous and ferruginous hydrated lime cements ({plus_minus} siliceous components), (3) pozzolana/hydrated lime cements, and (4) gypsum cements. Most of the materials investigated are in category (3). The materials were characterized to elucidate aspects of the technology that produced them and their response to the environmental exposure throughout their centuries of existence. Their remarkable properties are the result of a combination of chemical, mineralogical, and microstructural factors. Their durability was found to be affected by the matrix mineralogy, particle size, and porosity; aggregate type, grading and proportioning; and the methodology of placement. 30 refs.

  11. Effects of Sabalan Tuff as a Natural Pozzolan on Properties of Plastic Concrete

    Science.gov (United States)

    Doodaran, R. Sadeghi; Khiavi, M. Pasbani

    One of the most common methods for watertighting in dams is to use cutoff or watertight walls. These types of walls should have high plasticity and low permeability [1]. Developing these walls with such qualities requires using plastic concrete with paneling method. In most cases, adding these materials to concrete improves some of its qualities such as consistency, viscosity of fresh concrete, decrease in permeability, increase in plasticity, long term increase in compressive strength, durability against sulphats and decrease in price. The main purpose of this project is using Sabalan natural tuff in plastic concrete for an access to a desirable modulus of elasticity without a decrease in compressive strength. In this paper, in addition to the impact of Sabalan natural pozzolan tuff on plastic concrete qualities, the impacts of pozzolan cement made of this kind of tuff (Ardebil pozzolan cement) on it has been considered. The results showed improvement on the qualities of plastic concrete such as decrease in permeability, decrease in modulus of elasticity and increase in durability against destructive factors with retaining compressive strength.

  12. Formation of a Hydrothermal Kaolinite Deposit from Rhyolitic Tuff in Jiangxi, China

    Institute of Scientific and Technical Information of China (English)

    Ye Yuan; Guanghai Shi; Mengchu Yang; Yinuo Wu; Zhaochong Zhang; Anjie Huang; Jiajing Zhang

    2014-01-01

    The Longmen kaolinite deposit is one of the largest hydrothermal clay deposits of Ganxi volcanic basin (northern Wuyi Mountain area, China). The pristine host rocks are rhyolitic crystal-vitric tuff and minor lapilli tuff from the Late Jurassic Ehuling Formation. The ore consists of kaolin-group minerals (kaolinite, dickite), pyrophyllite with minor quartz, sericite, pyrite, etc.. From the host rocks to the transition zones (altered rocks) then to the vein ores, contents of SiO2 and TFe2O3 decrease, whereas Al2O3 and LOI increase, consistent with the contents increase of kaolin minerals and pyrophyllite in the samples. The total REE abundances of the ores are much lower than that of the host and altered rocks, Rb, Nb, Nd, Zr, Ti and Y are significantly depleted. Apparent zoning features of bulk geochemistry and mineral component reflect that the kaolinite deposit occurred at the expense of the host rock by ascending hydrothermal fluids with distinct removal of SiO2, TFe2O3, Na2O, K2O. According to the mineral assemblage, the formation temperature of this deposit falls within the range of 270-350 ℃. With regard to the industrial applications, the kaolinized ores are suitable for use in ceramics and gemologic materials crafted for seal stones. Moreover, in mineralogical terms, this deposit is also proved to be an excellent example for studying channeled hydrothermal alterations of rhyolitic tuff.

  13. Magnetic fabric, welding texture and strain fabric in the Nuraxi Tuff, Sardinia, Italy

    Science.gov (United States)

    Pioli, L.; Lanza, R.; Ort, M.; Rosi, M.

    2008-09-01

    Anisotropy of magnetic susceptibility (AMS) has been used to interpret flow directions in ignimbrites, but no study has demonstrated that the AMS fabric corresponds to the flow fabric. In this paper, we show that the AMS and strain fabric coincide in a high-grade ignimbrite, the Nuraxi Tuff, a Miocene rhyolitic ignimbrite displaying a wide variability of rheomorphic features and a well-defined magnetic fabric. Natural remanent magnetization (NRM) data indicate that the magnetization of the tuff is homogeneous and was acquired at high temperatures by Ti-magnetite crystals. Comparison between the magnetic fabric and the deformation features along a representative section shows that AMS and anisotropy of isothermal remanent magnetization (AIRM) fabric are coaxial with and reproduce the shape of the strain ellipsoid. Magnetic tests and scanning electron microscopy observations indicate that the fabric is due to trails of micrometer-size, pseudo-single domain, magnetically interacting magnetite crystals. Microlites formed along discontinuities such as shard rims and vesicle walls mimicking the petrofabric of the tuff. The fabric was thus acquired after deposition, before late rheomorphic processes, and accurately mimics homogeneous deformation features of the shards during welding processes and mass flow.

  14. Leaching of solutes from ion-exchange resins buried in Bandelier Tuff

    Energy Technology Data Exchange (ETDEWEB)

    Essington, E.H.; Fuentes, H.R.; Polzer, W.L.; Lopez, E.A.; Stallings, E.A.

    1986-10-01

    Prediction of solute transport at shallow land burial facilities requires a knowledge of the rates of release of solutes (source term) from the buried wastes and of those processes affecting transport through the surrounding media. The leaching (removal) of lithium, strontium, and cesium from a resin/tuff mixture (Bandelier Tuff) was conducted under unsaturated steady and unsteady (drainage) flow conditions in both laboratory columns and large-scale field caissons to approximate the conditions of buried contaminated-waste resins. Lithium was leached most rapidly and strontium least rapidly. Stopping the flow for a period of 40 to 60 days to create drainage (unsteady flow) conditions had very little effect on the concentrations of solutes leached from the resin/tuff layer. Leaching of these solutes in laboratory columns simulated the large-scale (caisson) leaching very well. Thus, laboratory studies may be reasonable predictors of leaching under certain large-scale field conditions. Also, leaching appears to be a kinetics-controlled process that, for the experimental conditions of this study, may be represented by simple first-order kinetics. Further work should concentrate on understanding the effect of environmental factors such as solute mixtures, concentrations, and temperature, as well as those mechanisms that control leaching of solutes. Also, the evaluation and development of alternative mathematical models for describing the source term are needed.

  15. High-temperature, large-volume, lavalike ash-flow tuffs without calderas in southwestern Idaho

    Science.gov (United States)

    Ekren, E.B.; McIntyre, David H.; Bennett, Earl H.

    1984-01-01

    Rhyolitic rocks were erupted from vents in and adjacent to the Owyhee Mountains and Owyhee Plateau of southwestern Idaho from 16 m.y. ago to about 10 m.y. ago. They were deposited on a highly irregular surface developed on a variety of basement rocks that include granitic rocks of Cretaceous age, quartz latite and rhyodacite tuffs and lava flows of Eocene age, andesitic and basaltic lava flows of Oligocene age, and latitic and basaltic lava flows of early Miocene age. The rhyolitic rocks are principally welded tuffs that, regardless of their source, have one feature in common-namely internal characteristics indicating en-masse, viscous lavalike flowage. The flowage features commonly include considerable thicknesses of flow breccia at the bases of various cooling units. On the basis of the tabular nature of the rhyolitic deposits, their broad areal extents, and the local preservation of pyroclastic textures at the bases, tops, and distal ends of some of the deposits, we have concluded that the rocks were emplaced as ash flows at extremely high temperatures and that they coalesced to liquids before final emplacement and cooling. Temperatures of l090?C and higher are indicated by iron-titanium oxide compositions. Rhyolites that are about 16 m.y. old are preserved mostly in the downdropped eastern and western flanks of the Silver City Range and they are inferred to have been erupted from the Silver City Range. They rarely contain more than about 2 percent phenocrysts that consist of quartz and subequal amounts of plagioclase and alkali feldspar; commonly, they contain biotite, and they are the only rhyolitic rocks in the area to do so. The several rhyolitic units that are 14 m.y. to about 10 m.y. old contain only pyroxene-principally ferriferous and intermediate pigeonites-as mafic constituents. The rhyolites of the Silver City Range comprise many cooling units, none of which can be traced for great distances. Rocks erupted from the Owyhee Plateau include two sequences

  16. Hydrologic property alterations due to elevated temperatures at Yucca Mountain

    Energy Technology Data Exchange (ETDEWEB)

    Flint, A.L. [Geological Survey, Mercury, NV (United States); Nash, M.H.; Nash, M.S. [Foothill Engineering, Mercury (United States)

    1994-12-31

    Yucca Mountain is currently being evaluated as a potential site for a high level nuclear waste repository. The pre-emplacement hydrologic properties of the rock are important in determining the suitability of the site; however, post emplacement thermal loads and associated drying may permanently alter the character of the rock. A preliminary study was undertaken to determine the effects of elevated temperatures on hydrologic properties of the welded Topopah Spring member of the Paintbrush Tuff and a zeolitic, nonwelded tuff from the Tuffaceous Beds of Calico Hills. Rock outcrop samples were collected and dried in the laboratory at different temperatures (up to 400 degrees C). Hydrologic and physical properties -were tested before and after each of the drying cycles.

  17. Confidence Hills Mineralogy and Chemin Results from Base of Mt. Sharp, Pahrump Hills, Gale Crater, Mars

    Science.gov (United States)

    Cavanagh, P. D.; Bish, D. L.; Blake, D. F.; Vaniman, D. T.; Morris, R. V.; Ming, D. W.; Rampe, E. B.; Achilles, C. N.; Chipera, S. J.; Treiman, A. H.; hide

    2015-01-01

    The Mars Science Laboratory (MSL) rover Curiosity recently completed its fourth drill sampling of sediments on Mars. The Confidence Hills (CH) sample was drilled from a rock located in the Pahrump Hills region at the base of Mt. Sharp in Gale Crater. The CheMin X-ray diffractometer completed five nights of analysis on the sample, more than previously executed for a drill sample, and the data have been analyzed using Rietveld refinement and full-pattern fitting to determine quantitative mineralogy. Confidence Hills mineralogy has several important characteristics: 1) abundant hematite and lesser magnetite; 2) a 10 angstrom phyllosilicate; 3) multiple feldspars including plagioclase and alkali feldspar; 4) mafic silicates including forsterite, orthopyroxene, and two types of clinopyroxene (Ca-rich and Ca-poor), consistent with a basaltic source; and 5) minor contributions from sulfur-bearing species including jarosite.

  18. A version of Hill's lemma for Cosserat continuum

    Institute of Scientific and Technical Information of China (English)

    Xikui Li; Qipeng Liu

    2009-01-01

    On the basis of Hill's lemma for classical Cauchy continuum, a version of Hill's lemma for micro-macro homogenization modeling of heterogeneous Cosserat continuum is presented in the frame of average-field theory. The admissible boundary conditions required to prescribe on the representative volume element for the modeling are extracted and discussed to ensure the satisfaction of HillMandel energy condition and the first-order average field theory.

  19. Correlates of simulated hill climb cycling performance.

    Science.gov (United States)

    Davison, R C; Swan, D; Coleman, D; Bird, S

    2000-02-01

    The aim of this study was to assess the relationship between several commonly used aerobic and anaerobic cycle ergometer tests and performance during a treadmill cycling hill climb. Eight competitive cyclists (age 27+/-7 years; body mass 73.2+/-5.2 kg; height 177+/-6 cm; mean +/- s) completed six tests in random order: a lactate minimum test; a Wingate anaerobic power test; and two 6-km climbs at 6% and two 1-km climbs at 12% gradient performed on a motorized treadmill. The mean times and power outputs for the 6-km and 1-km climbs were 16:30+/-1:08 min: s and 330+/-17.8 W, and 4:19+/-0:27 min: s and 411+/-24.4 W, respectively. The best individual predictor of 6-km and 1-km performance times was the time for the corresponding climb at the other distance (r = 0.97). The next strongest predictor of both hill climb performances was the average power produced during the Wingate test divided by body mass. Stepwise regression analysis showed that the two variables contributing most to the prediction equation for both climbs were the Wingate average power per unit of body mass and maximal aerobic power divided by total mass (rider + bike), which together accounted for 92 and 96% of the variability in the 6-km and 1-km climbs. In conclusion, among competitive cyclists, the Wingate average power per unit of body mass was the best single predictor of simulated cycling hill climb performance at the distance and gradient used.

  20. Black Hills State University Underground Campus.

    Science.gov (United States)

    Mount, Brianna J; Thomas, Keenan J; Oliver-Mallory, Kelsey C; Lesko, Kevin T; Schnee, Richard W; Henning, Reyco; MacLellan, Ryan F; Guerra, Marcelo B B; Busch, Matthew; Christofferson, Cabot-Ann D; Wilkerson, J F; Xu, Wenqin; Mei, Dongming

    2017-08-01

    The Black Hills State University Underground Campus (BHUC) houses a low background counting facility on the 4850' level of the Sanford Underground Research Facility. There are currently four ultra-low background, high-purity germanium detectors installed in the BHUC and it is anticipated four more detectors will be installed within a year. In total, the BHUC will be able to accommodate up to twelve detectors with space inside a class 1000 cleanroom, an automated liquid nitrogen fill system, on-site personnel assistance and other required utilities. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Proposed Schedule for Fenton Hill Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Albright, James N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Brown, Donald W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    1990-10-22

    To help in planning Fenton Hill experimental operations in concert with preparations for the Long-Term Flow Test (LTFT) next summer, the following schedule is proposed. This schedule fits some of the realities of the next few months, including the Laboratory closure during the Holidays, the seismic monitoring tests in Roswell, and the difficulties of operating during the winter months. Whenever possible, cyclic pumping operations during the colder months will be scheduled so that the pump will be on during the late evening and early morning hours to prevent freezeup.

  2. HydroHillChart – Francis module. Software used to Calculate the Hill Chart of the Francis Hydraulic Turbines

    Directory of Open Access Journals (Sweden)

    Dorian Nedelcu

    2015-07-01

    Full Text Available The paper presents the Hydro Hill Chart - Francis module application, used to calculate the hill chart of the Pelton, Francis and Kaplan hydraulic turbine models, by processing the data measured on the stand. After describing the interface and menu, the input data is graphically presented and the universal characteristic for measuring scenarios ao=const. and n11=const is calculated. Finally, the two calculated hill charts are compared through a graphical superimposition of the isolines.

  3. 试析蓝印花布制作工艺中蕴含的民间造物观念%Analyzing creation ideas implied Blue Calico production process

    Institute of Scientific and Technical Information of China (English)

    王兴业; 李焰

    2011-01-01

    以民间造物观念的视角切入,通过分析蓝印花布制作过程的原料选取、入染及防染技艺、纹饰设计、实用纺织品制作等工序,归纳其制作工艺的特点.认为它蕴含着朴素的生态自然观念、蓝白之色的素朴之美、节用致用为本的造物原则和寓意吉祥的纹饰设计方法等造物观念.这些民间造物观念根植于普通民众的物质、精神生活之中,对它们深入分析和研究,挖掘蕴含其中的积极意义,可以启发现代设计,为人们提供更健康、更环保、更人性化的生活方式.%To view from the perspective of popular creation ideas, the Blue Calico production process is addressed in terms of selection of raw materials, coloring, anti-staining, patterns designing and practical textiles production process. The production characteristics are summarized and it argues that the process contains eco-natural concept, concise beauty of white/blue colors, creation ideas of saving and practical, and implication of luckiness and happiness. These creation ideas are closely linked with people's lives, both material and spiritual lives of the people . Making use of these creation ideas in folk can inspire our modern art design, and provide services for the people to make our life more healthy, more eco-friendly and more humanized.

  4. Hill crossing during preheating after hilltop inflation

    CERN Document Server

    Antusch, Stefan; Orani, Stefano

    2015-01-01

    In 'hilltop inflation', inflation takes place when the inflaton field slowly rolls from close to a maximum of its potential (i.e. the 'hilltop') towards its minimum. When the inflaton potential is associated with a phase transition, possible topological defects produced during this phase transition, such as domain walls, are efficiently diluted during inflation. It is typically assumed that they also do not reform after inflation, i.e. that the inflaton field stays on its side of the 'hill', finally performing damped oscillations around the minimum of the potential. In this paper we study the linear and the non-linear phases of preheating after hilltop inflation. We find that the fluctuations of the inflaton field during the tachyonic oscillation phase grow strong enough to allow the inflaton field to form regions in position space where it crosses 'over the top of the hill' towards the 'wrong vacuum'. We investigate the formation and behaviour of these overshooting regions using lattice simulations: Rather t...

  5. New type of hill-top inflation

    Science.gov (United States)

    Barvinsky, A. O.; Kamenshchik, A. Yu.; Nesterov, D. V.

    2016-01-01

    We suggest a new type of hill-top inflation originating from the initial conditions in the form of the microcanonical density matrix for the cosmological model with a large number of quantum fields conformally coupled to gravity. Initial conditions for inflation are set up by cosmological instantons describing underbarrier oscillations in the vicinity of the inflaton potential maximum. These periodic oscillations of the inflaton field and cosmological scale factor are obtained within the approximation of two coupled oscillators subject to the slow roll regime in the Euclidean time. This regime is characterized by rapid oscillations of the scale factor on the background of a slowly varying inflaton, which guarantees smallness of slow roll parameters epsilon and η of the following inflation stage. A hill-like shape of the inflaton potential is shown to be generated by logarithmic loop corrections to the tree-level asymptotically shift-invariant potential in the non-minimal Higgs inflation model and R2-gravity. The solution to the problem of hierarchy between the Planckian scale and the inflation scale is discussed within the concept of conformal higher spin fields, which also suggests the mechanism bringing the model below the gravitational cutoff and, thus, protecting it from large graviton loop corrections.

  6. New type of hill-top inflation

    Energy Technology Data Exchange (ETDEWEB)

    Barvinsky, A.O. [Theory Department, Lebedev Physics Institute,Leninsky Prospect 53, Moscow 119991 (Russian Federation); Department of Physics, Tomsk State University,Lenin Ave. 36, Tomsk 634050 (Russian Federation); Department of Physics and Astronomy, Pacific Institue for Theoretical Physics,University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada); Kamenshchik, A.Yu. [Dipartimento di Fisica and INFN,via Irnerio 46, 40126 Bologna (Italy); L.D. Landau Institute for Theoretical Physcis,Kosygin str. 2, 119334 Moscow (Russian Federation); Nesterov, D.V. [Theory Department, Lebedev Physics Institute,Leninsky Prospect 53, Moscow 119991 (Russian Federation)

    2016-01-20

    We suggest a new type of hill-top inflation originating from the initial conditions in the form of the microcanonical density matrix for the cosmological model with a large number of quantum fields conformally coupled to gravity. Initial conditions for inflation are set up by cosmological instantons describing underbarrier oscillations in the vicinity of the inflaton potential maximum. These periodic oscillations of the inflaton field and cosmological scale factor are obtained within the approximation of two coupled oscillators subject to the slow roll regime in the Euclidean time. This regime is characterized by rapid oscillations of the scale factor on the background of a slowly varying inflaton, which guarantees smallness of slow roll parameters ϵ and η of the following inflation stage. A hill-like shape of the inflaton potential is shown to be generated by logarithmic loop corrections to the tree-level asymptotically shift-invariant potential in the non-minimal Higgs inflation model and R{sup 2}-gravity. The solution to the problem of hierarchy between the Planckian scale and the inflation scale is discussed within the concept of conformal higher spin fields, which also suggests the mechanism bringing the model below the gravitational cutoff and, thus, protecting it from large graviton loop corrections.

  7. The Goodwin model: behind the Hill function.

    Science.gov (United States)

    Gonze, Didier; Abou-Jaoudé, Wassim

    2013-01-01

    The Goodwin model is a 3-variable model demonstrating the emergence of oscillations in a delayed negative feedback-based system at the molecular level. This prototypical model and its variants have been commonly used to model circadian and other genetic oscillators in biology. The only source of non-linearity in this model is a Hill function, characterizing the repression process. It was mathematically shown that to obtain limit-cycle oscillations, the Hill coefficient must be larger than 8, a value often considered unrealistic. It is indeed difficult to explain such a high coefficient with simple cooperative dynamics. We present here molecular models of the standard Goodwin model, based on single or multisite phosphorylation/dephosphorylation processes of a transcription factor, which have been previously shown to generate switch-like responses. We show that when the phosphorylation/dephosphorylation processes are fast enough, the limit-cycle obtained with a multisite phosphorylation-based mechanism is in very good quantitative agreement with the oscillations observed in the Goodwin model. Conditions in which the detailed mechanism is well approximated by the Goodwin model are given. A variant of the Goodwin model which displays sharp thresholds and relaxation oscillations is also explained by a double phosphorylation/dephosphorylation-based mechanism through a bistable behavior. These results not only provide rational support for the Goodwin model but also highlight the crucial role of the speed of post-translational processes, whose response curve are usually established at a steady state, in biochemical oscillators.

  8. The Goodwin model: behind the Hill function.

    Directory of Open Access Journals (Sweden)

    Didier Gonze

    Full Text Available The Goodwin model is a 3-variable model demonstrating the emergence of oscillations in a delayed negative feedback-based system at the molecular level. This prototypical model and its variants have been commonly used to model circadian and other genetic oscillators in biology. The only source of non-linearity in this model is a Hill function, characterizing the repression process. It was mathematically shown that to obtain limit-cycle oscillations, the Hill coefficient must be larger than 8, a value often considered unrealistic. It is indeed difficult to explain such a high coefficient with simple cooperative dynamics. We present here molecular models of the standard Goodwin model, based on single or multisite phosphorylation/dephosphorylation processes of a transcription factor, which have been previously shown to generate switch-like responses. We show that when the phosphorylation/dephosphorylation processes are fast enough, the limit-cycle obtained with a multisite phosphorylation-based mechanism is in very good quantitative agreement with the oscillations observed in the Goodwin model. Conditions in which the detailed mechanism is well approximated by the Goodwin model are given. A variant of the Goodwin model which displays sharp thresholds and relaxation oscillations is also explained by a double phosphorylation/dephosphorylation-based mechanism through a bistable behavior. These results not only provide rational support for the Goodwin model but also highlight the crucial role of the speed of post-translational processes, whose response curve are usually established at a steady state, in biochemical oscillators.

  9. Magnesium oxide-impregnated tuff soil-derived ceramic: a novel cadmium(II) adsorbing media

    Science.gov (United States)

    Salim, Md; Bhakta, Jatindra N.; Maneesh, Namburath; Munekage, Yukihiro; Motomura, Kevin

    2017-07-01

    The contamination of cadmium (Cd) in the aquatic environment is one of the serious environmental and human health's risks. The present study attempted to develop the potential magnesium oxide (MgO)-impregnated tuff soil-derived ceramic (MITDC)-based novel adsorbent media for adsorbing higher rate of cadmium [Cd(II)] from water phase. A potential MITDC adsorbent media was developed using volcanic raw tuff soil and its Cd(II) adsorption capacity from water phase was evaluated comparing with the raw tuff soil. A series of studies were carried out in an agitated batch method at 20 ± 2 °C to characterize the adsorption capacity of MITDC under different conditions of factors, such as contact time (0-360 min), initial pH (3-11) of solution, dose of MITDC (2, 5, 7.5 and 10 g/L), and initial concentration of Cd(II) (5, 10, 20, 30, and 40 mg/L), influencing the adsorption mechanism. MITDC exhibited the equilibrium state of maximum Cd(II) adsorption at the contact time 120 min and pH 4.7 (removed 98.2 % Cd) when initial Cd(II) concentration was 10 mg/L in the present study. The dose of 7.5 g MITDC/L showed maximum removal of Cd(II) from water. Experimental data were described by the Freundlich and the Langmuir isotherms and equilibrium data fitted well with the Langmuir model ( R 2 = 0.996). The Cd(II) adsorption capacity of MITDC was 31.25 mg/g. The high Cd(II) adsorption capacity indicated that novel MITDC could be used as a potential ceramic adsorbent media to remove high rate of Cd(II) from aqueous phase.

  10. Estimation of possibilities of making euro pallets from reclaimed polyolefin’s with tuff

    Directory of Open Access Journals (Sweden)

    S. Kuciel

    2010-07-01

    Full Text Available Possibilities of reusing and developing of waste plastics are one of the main problems of waste management for municipal governmentespecially in the context of adapting Polish law to standards of EC [1]. During the last 10 years total amount of plastics waste increasedtwice, especially in communal agglomerations. Among communal waste plastics make up 7 to 14% of whole their mass and 30% of theirvolume [1,2]. Plastic products have been recycled to be used in a number of different products often different from their original use.Reclaimed plastics can’t be used as products which have contact with food or as high demands esthetic and hygienic products, they alsoshouldn’t be applied as short-time used products because they quickly come back to plastics store-place. Reclaimed plastics have lowerproperties than virgin plastics – mainly the strength falls with the simultaneous fall of modules and increase fragile especially for PP, PE,PS and PET [1]. One of the possibilities of reinforcement of polyolefines is adding diverse fillers like glass or carbon fibers (but they arerather expensive and natural fillers like mineral, wood and others [3]. It’s especially important for wasted of low density polyethylenewhich has low modulus. For the tests it was used waste polyethylene (LDPE and HDPE from industrial with 15% mineral fillers – tuff.For the tests it was prepared two kinds of composites materials with 15% of tuff powder. Besides for comparison it was tested recycledpolyethylene (HDPE and LDPE and next was tested specimens cut out from produced europallets (with 15% of tuff. It was testedmechanical properties all prepared composite materials like tensile strength, stress and bending e-modulus and processing properties likemelt flow, Vicat point and photos on SEM microscope.

  11. Magnesium oxide-impregnated tuff soil-derived ceramic: a novel cadmium(II) adsorbing media

    Science.gov (United States)

    Salim, Md; Bhakta, Jatindra N.; Maneesh, Namburath; Munekage, Yukihiro; Motomura, Kevin

    2015-07-01

    The contamination of cadmium (Cd) in the aquatic environment is one of the serious environmental and human health's risks. The present study attempted to develop the potential magnesium oxide (MgO)-impregnated tuff soil-derived ceramic (MITDC)-based novel adsorbent media for adsorbing higher rate of cadmium [Cd(II)] from water phase. A potential MITDC adsorbent media was developed using volcanic raw tuff soil and its Cd(II) adsorption capacity from water phase was evaluated comparing with the raw tuff soil. A series of studies were carried out in an agitated batch method at 20 ± 2 °C to characterize the adsorption capacity of MITDC under different conditions of factors, such as contact time (0-360 min), initial pH (3-11) of solution, dose of MITDC (2, 5, 7.5 and 10 g/L), and initial concentration of Cd(II) (5, 10, 20, 30, and 40 mg/L), influencing the adsorption mechanism. MITDC exhibited the equilibrium state of maximum Cd(II) adsorption at the contact time 120 min and pH 4.7 (removed 98.2 % Cd) when initial Cd(II) concentration was 10 mg/L in the present study. The dose of 7.5 g MITDC/L showed maximum removal of Cd(II) from water. Experimental data were described by the Freundlich and the Langmuir isotherms and equilibrium data fitted well with the Langmuir model (R 2 = 0.996). The Cd(II) adsorption capacity of MITDC was 31.25 mg/g. The high Cd(II) adsorption capacity indicated that novel MITDC could be used as a potential ceramic adsorbent media to remove high rate of Cd(II) from aqueous phase.

  12. Evaluating the paleomagnetic potential of single zircon crystals using the Bishop Tuff

    Science.gov (United States)

    Fu, Roger R.; Weiss, Benjamin P.; Lima, Eduardo A.; Kehayias, Pauli; Araujo, Jefferson F. D. F.; Glenn, David R.; Gelb, Jeff; Einsle, Joshua F.; Bauer, Ann M.; Harrison, Richard J.; Ali, Guleed A. H.; Walsworth, Ronald L.

    2017-01-01

    Zircon crystals offer a unique combination of suitability for high-precision radiometric dating and high resistance to alteration. Paleomagnetic experiments on ancient zircons may potentially constrain the history of the earliest geodynamo, which would hold broad implications for the early Earth's interior and atmosphere. However, the ability of zircons to record accurately the geomagnetic field has not been demonstrated. Here we conduct thermal and alternating field (AF) paleointensity experiments on 767.1 thousand year old (ka) zircons from the Bishop Tuff, California. The rapid emplacement of these zircons in a well-characterized magnetic field provides a high-fidelity test of the zircons' intrinsic paleomagnetic recording accuracy. Successful dual heating experiments on eleven zircons measured using a superconducting quantum interference device (SQUID) microscope yield a mean paleointensity of 54.1 ± 6.8μT (1σ; 42.6 ± 5.3μT after excluding possible maghemite-bearing zircons), which is consistent with high-precision results from Bishop Tuff whole rock (43.0 ± 3.2μT). High-resolution quantum diamond magnetic (QDM) mapping, electron microscopy, and X-ray tomography indicate that the bulk of the remanent magnetization in Bishop Tuff zircons is carried by Fe oxides associated with apatite inclusions, which may be susceptible to destruction via metamorphism and aqueous alteration in older zircons. As such, while zircons can reliably record the geomagnetic field, robust zircon-derived paleomagnetic results require careful characterization of the ferromagnetic carrier and demonstration of their occurrence in primary inclusions. We further conclude that a combination of quantum diamond magnetometry and high-resolution imaging can provide detailed, direct characterization of the ferromagnetic mineralogy of geological samples.

  13. Radionuclide Transport in Tuff and Carbonate Fractures from Yucca Flat, Nevada Test Site

    Energy Technology Data Exchange (ETDEWEB)

    Zavarin, M; Johnson, M R; Roberts, S K; Pletcher, R; Rose, T P; Kersting, A B; Eaton, G; Hu, Q; Ramon, E; Walensky, J; Zhao, P

    2006-02-01

    In the Yucca Flat basin of the Nevada Test Site (NTS), 747 shaft and tunnel nuclear detonations were conducted primarily within the tuff confining unit (TCU) or the overlying alluvium. The TCU in the Yucca Flat basin is hypothesized to reduce radionuclide migration to the regional carbonate aquifer (lower carbonate aquifer) due to its wide-spread aerial extent and chemical reactivity. However, shortcuts through the TCU by way of fractures may provide a migration path for radionuclides to the lower carbonate aquifer (LCA). It is, therefore, imperative to understand how radionuclides migrate or are retarded in TCU fractures. Furthermore, understanding the migration behavior of radionuclides once they reach the fractured LCA is important for predicting contaminant transport within the regional aquifer. The work presented in this report includes: (1) information on the radionuclide reactive transport through Yucca Flat TCU fractures (likely to be the primary conduit to the LCA), (2) information on the reactive transport of radionuclides through LCA fractures and (3) data needed to calibrate the fracture flow conceptualization of predictive models. The predictive models are used to define the extent of contamination for the Underground Test Area (UGTA) project. Because of the complex nature of reactive transport in fractures, a stepwise approach to identifying mechanisms controlling radionuclide transport was used. In the first set of TCU experiments, radionuclide transport through simple synthetic parallel-plate fractured tuff cores was examined. In the second, naturally fractured TCU cores were used. For the fractured LCA experiments, both parallel-plate and rough-walled fracture transport experiments were conducted to evaluate how fracture topography affects radionuclide transport. Tuff cores were prepared from archived UE-7az and UE-7ba core obtained from the USGS core library, Mercury, Nevada. Carbonate cores were prepared from archived ER-6-1 core, also obtained

  14. Experimental research on sealing of boreholes, shafts and ramps in welded tuff

    Energy Technology Data Exchange (ETDEWEB)

    Fuenkajorn, K. [Rock Engineering International, Tucson, AZ (United States)

    1996-04-01

    Laboratory and in-situ experiments have been conducted to determine the mechanical and hydraulic performance of cement borehole seals in densely welded Apache Leap tuff. Test results indicate that under saturated conditions, commercial expansive cement can provide good bond strength and adequate hydraulic performance for borehole seal under changing stress conditions. The cement seal should be installed at the intact portion of the opening, and should have a length-to-diameter ratio greater than four. Drying increases borehole plug permeability and decreases mechanical and hydraulic bonds at the plug-rock interface. In-situ testing indicates that installation procedure may significantly affect the cement plug performance.

  15. Fossil Fumarolic Pipes in the Tshirege Member of the Bandelier Tuff

    Science.gov (United States)

    Caporuscio, F. A.; Gardner, J. N.; Schultz-Fellenz, E. S.; Lewis, C. J.; Kelley, R. E.; Greene, M. K.

    2008-12-01

    The geology exposed on the walls (3000 m2) of a large pit in the Bandelier Tuff gives unparalled 3-D exposures of many structures that develop in thick deposits of pyroclastic flows. Subunits of the Tshirege Member of the Bandelier Tuff, erupted at 1.25 Ma, exhibit distinct rubble-filled fissures, or pipes, that range in width from centimeters to meters. The fissures exhibit zones of fines depletion, indurated wall structures, upward flaring geometry to the top of the host unit, and fissure-filling blocks of the host unit as well as rubble derived from overlying pyroclastic units. In the units directly overlying the fissures are intensely fractured in- place rubble zones. Additionally, the fissures appear to be regularly spaced at about 4.5 or 7.5 meters apart. All these field characteristics are indicative of fumarolic activity. Petrographic, XRD, and XRF studies of distinct pipes were done to investigate the physical changes imparted to the tuff by the fumarolic activity. Petrography indicates that the pipe wall and pipe centers are enriched in tridymite and potassium feldspar. These minerals fill the void spaces in pumice and groundmass void spaces of the pipe wall rocks, imparting the indurated nature. Other mineralogic indicators of late stage fumarolic gas phase deposition are optically continuous, feathery overgrowths on sanidine phenocrysts and scapolite in pipe centers. Also, clinopyroxenes in the overlying rubble zones have oxidized rims indicative of highly oxidizing gases emanating from the fumarolic pipes below. XRD analyses of rubble zones above the pipes show decreased cristobalite (4 wt. %) and feldspar (9 wt. %), and increased clay contents (12 to 26 wt. %). This change from feldspar and cristobalite to clay suggests an acidic nature of fumarolic gases. XRF analyses show trends in bulk chemistry consistent with fumarolic data from other tuffs. The data indicate that there have been systematic changes in the geochemistry of the fissures readily

  16. Geology of the USW SD-12 drill hole Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Rautman, C.A. [Sandia National Labs., Albuquerque, NM (United States); Engstrom, D.A. [Spectra Research Institute, Albuquerque, NM (United States)

    1996-11-01

    Drill hole USW SD-12 is one of several holes drilled under Site Characterization Plan Study 8.3.1.4.3.1, also known as the {open_quotes}Systematic Drilling Program,{close_quotes} as part of the U.S. Department of Energy characterization program at Yucca Mountain, Nevada, which has been proposed as the potential location of a repository for high-level nuclear waste. The SD-12 drill hole is located in the central part of the potential repository area, immediately to the west of the Main Test Level drift of the Exploratory Studies Facility and slightly south of midway between the North Ramp and planned South Ramp declines. Drill hole USW SD-12 is 2166.3 ft (660.26 m) deep, and the core recovered essentially complete sections of ash-flow tuffs belonging to the lower half of the Tiva Canyon Tuff, the Pah Canyon Tuff, and the Topopah Spring Tuff, all of which are part of the Miocene Paintbrush Group. A virtually complete section of the Calico Hills Formation was also recovered, as was core from the entire Prow Pass Tuff formation of the Crater Flat Group.

  17. 77 FR 22755 - Black Hills National Forest Advisory Board

    Science.gov (United States)

    2012-04-17

    ... approval of the Board's re-charter package submitted to the Secretary, U.S. Department of Agriculture...; ] DEPARTMENT OF AGRICULTURE Forest Service Black Hills National Forest Advisory Board AGENCY: USDA Forest Service. ACTION: Notice of cancellation of meetings of the Black Hills National Forest Advisory...

  18. Abyssal hills: Influence of topography on benthic foraminiferal assemblages

    Science.gov (United States)

    Stefanoudis, Paris V.; Bett, Brian J.; Gooday, Andrew J.

    2016-11-01

    Abyssal plains, often thought of as vast flat areas, encompass a variety of terrains including abyssal hills, features that constitute the single largest landscape type on Earth. The potential influence on deep-sea benthic faunas of mesoscale habitat complexity arising from the presence of abyssal hills is still poorly understood. To address this issue we focus on benthic foraminifera (testate protists) in the >150-μm fraction of Megacorer samples (0-1 cm layer) collected at five different sites in the area of the Porcupine Abyssal Plain Sustained Observatory (NE Atlantic, 4850 m water depth). Three sites are located on the tops of small abyssal hills (200-500 m elevation) and two on the adjacent abyssal plain. We examined benthic foraminiferal assemblage characteristics (standing stock, diversity, composition) in relation to seafloor topography (hills vs. plain). Density and rarefied diversity were not significantly different between the hills and the plain. Nevertheless, hills do support a higher species density (i.e. species per unit area), a distinct fauna, and act to increase the regional species pool. Topographically enhanced bottom-water flows that influence food availability and sediment type are suggested as the most likely mechanisms responsible for these differences. Our findings highlight the potential importance of mesoscale heterogeneity introduced by relatively modest topography in regulating abyssal foraminiferal diversity. Given the predominance of abyssal hill terrain in the global ocean, we suggest the need to include faunal data from abyssal hills in assessments of abyssal ecology.

  19. 78 FR 59337 - Black Hills National Forest Advisory Board; Meeting

    Science.gov (United States)

    2013-09-26

    ... Forest Service Black Hills National Forest Advisory Board; Meeting AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The Black Hills National Forest Advisory Board (Board) will meet in Rapid City, South Dakota. The Board is established consistent with the Federal Advisory Committee Act of...

  20. Pore-water extraction from unsaturated tuff by triaxial and one-dimensional compression methods, Nevada Test Site, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Mower, T.E. [PRC Environmental Management, Inc., Denver, CO (United States); Higgins, J.D. [Colorado School of Mines, Golden, CO (United States); Yang, In C.; Peters, C.A. [Geological Survey, Denver, CO (United States)

    1994-07-01

    The hydrologic system in the unsaturated tuff at Yucca Mountain, Nevada, is being evaluated for the US Department of Energy by the Yucca Mountain Project Branch of the US Geological Survey as a potential site for a high-level radioactive-waste repository. Part of this investigation includes a hydrochemical study that is being made to assess characteristics of the hydrologic system such as: traveltime, direction of flow, recharge and source relations, and types and magnitudes of chemical reactions in the unsaturated tuff. In addition, this hydrochemical information will be used in the study of the dispersive and corrosive effects of unsaturated-zone water on the radioactive-waste storage canisters. This report describes the design and validation of laboratory experimental procedures for extracting representative samples of uncontaminated pore water from welded and nonwelded, unsaturated tuffs from the Nevada Test Site.

  1. Petrographic and geochemical characteristics of a section through the Tiva Canyon Tuff at Antler Ridge, Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Singer, F.R.; Widmann, B.L.; Dickerson, R.P. [Science Applications International Corp., Golden, CO (United States); Byers, F.M. Jr. [Geological Survey, Denver, CO (United States)

    1994-12-31

    The Tiva Canyon Tuff of the Paintbrush Group of Miocene age caps much of Yucca Mountain, Nevada and is a compositionally zoned, compound cooling, pyroclastic flow that ranges from a dominantly high-silica rhyolitic base to a quartz-latitic caprock. Petrographic and geochemical studies have focused on rigorously defining the internal stratigraphy of this unit to support the detailed mapping of the Ghost Dance fault and other structures in the central fault block of Yucca Mountain. This study shows that devitrification textures and vapor phase mineralogy, in addition to other physical attributes such as pumice variability (flattening) and crystal content, can be used as distinguishing criteria to better define lithologic zones within the Tiva Canyon Tuff. In addition, the study also shows that the petrographic textures and chemistry of the groundmass vary systematically within recognizable lithologic zones and may be used to characterize and vertically divide litho-stratigraphic zones within the Tiva Canyon Tuff.

  2. Decay of isolated hills and saddles on Si(001)

    Science.gov (United States)

    Kirschbaum, Pierre; Brendel, Lothar; Roos, Kelly R.; Horn-von Hoegen, Michael; Heringdorf, Frank-J. Meyer zu

    2016-08-01

    We discuss the high temperature decay of isolated hills and saddle points on Si(001). Using in situ dark-field imaging in low energy electron microscopy, we track the movement of individual steps during high temperature annealing. We find different temperature dependent decay rates for the top of the hill compared to a saddle point with low step density that is present in the vicinity of the hill. The decay rate of the hill is always higher than the decay rate at the saddle. The two rates converge with increasing temperature and become equal at temperatures above 1060 °C. We also report an alternating fast and low decay rate for the layer-by-layer decay of the hills. This surprising finding is independent of temperature and is explained by macroscopic strain in the sample.

  3. HydroHillChart – Pelton module. Software used to Calculate the Hill Chart of the Pelton Hydraulic Turbines

    Directory of Open Access Journals (Sweden)

    Dorian Nedelcu

    2015-07-01

    Full Text Available The paper presents the HydroHillChart - Pelton module application, used to calculate the hill chart of the Pelton hydraulic turbine models, by processing the data measured on the stand. In addition, the tools offered by the application such as: interface, menu, input data, numerical and graphical results, etc. are described.

  4. Motivations of female Black Hills deer hunters

    Science.gov (United States)

    Gigliotti, Larry M.; Covelli Metcalf, Elizabeth

    2016-01-01

    State fish and wildlife agencies are particularly interested in attracting female participation because of the potential to offset declining participation in hunting. Understanding female hunters’ motivations will be critical for designing effective recruitment and retention programs for women hunters. Although female participation in hunting is increasing, males still outnumber females by about tenfold. Gender differences in deer hunters were explored by comparing ratings of eight motivations (social, nature, excitement, meat, challenge, trophy, extra hunting opportunity, and solitude). Hunter types were defined by hunters’ selection of the most important motivation for why they like Black Hills deer hunting. Overall, females and males were relatively similar in their ratings of the eight motivations, and we found 85% gender similarity in the selection of the most important motivation. Women were slightly more motivated by the food aspect of the hunt while men placed slightly more value on the hunt as a sporting activity.

  5. Uranium(VI adsorption on surfactant modified heulandite/clinoptilolite rich tuff

    Directory of Open Access Journals (Sweden)

    SRDJAN MATIJASEVIC

    2006-12-01

    Full Text Available The adsorption of uranium(VI on heulandite/clinoptilolite rich zeolitic tuff modified with diferent amounts (2, 5 and 10 meq/100 g of hexadecyltrimethyl ammonium (HDTMA ion was investigated. The organozeolites were prepared by ion exchange of inorganic cations at the zeolite surface with HDTMA ions, and the three prepared samples were denoted as OA-2, OA-5 and OA-10. The maximal amount of HDTMAin the organozeolite OA-10 (10 meq/100 g was equal to the external cation exchange capacity of the starting material. The results showed that uranium( VI adsorption on unmodified zeolitic tuff was low (0.34 mg uranium(VI/g adsorbent, while for the organozeolites, the adsorption increased with increasing amount of HDTMA at the zeolitic surface. The highest adsorption indexes were achieved for the organozeolite OA-10, in which all the surface inorganic cations had been replaced with HDTMA. An investigation of the adsorption of uranium(VI ions onto organozeolite OA-10 at different pH values (3, 6 and 8 showed that the adsorption index increased with increasing amount of adsorbent in the suspension. Since uranium(VI speciation is highly dependent on pH, from the adsorption isotherms, it can be seen that uranium(VI adsorption on organozeolite OA-10 at pH 6 and 8 is well described by a Langmuir type of isotherm, while at pH 3, it corresponds to a Type III isotherm.

  6. Clinoptilolite compositions in diagenetically-altered tuffs at a potential nuclear waste repository, Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Broxton, D.E.

    1987-12-31

    The compositions of Yucca Mountain clinoptilolites and their host tuffs are highly variable. Clinoptilolites and heulandites in fractures near the repository and in a thin, altered zone at the top of the Topopah Spring basal vitrophyre have consistent calcium-rich compositions. Below this level, clinoptilolites in thick zones of diagenetic alteration on the east side of Yucca Mountain have calcic-potassic compositions and become more calcium rich with depth. Clinoptilolites in stratigraphically equivalent tuffs to the west have sodic-potassic compositions and become more sodic with depth. Clinoptilolite properties important for repository performance assessment include thermal expansion/contraction behavior, hydration/dehydration behavior, and ion-exchange properties. These properties can be significantly affected by clinoptilolite compositions. The compositional variations for clinoptilolites found by this study suggest that the properties will vary vertically and laterally at Yucca Mountain. Used in conjunction with experimental data, the clinoptilolite compositions presented here can be used to model the behavior of clinoptilolites in the repository environment and along transport pathways.

  7. Biofilms on tuff stones at historical sites: identification and removal by nonthermal effects of radiofrequencies.

    Science.gov (United States)

    Cennamo, P; Caputo, P; Giorgio, A; Moretti, A; Pasquino, N

    2013-10-01

    A methodology aiming at identifying and removing biofilms from cultural heritage was applied to stones from tuff walls in historical sites. Identification of phototrophic encrusting microorganisms was carried out by optical and electron microscopy, as well as by molecular techniques (DNA analyses and denaturing gradient gel electrophoresis (DGGE)). In all sites, the examination of microbial components of biofilms resulted in the identification of 17 species belonging to Cyanobacteria, Rhodophyta, Bacillariophyta and Chlorophyta, with Cyanobacteria being the dominant components in all biofilms. In order to remove the biofilms, an innovative technique based on the use of nonthermal effects of radiofrequencies was adopted. The source of the electromagnetic fields was a signal generator connected to a horn antenna through an amplifier to provide the power boost required to generate the target field amplitude. Seven days after exposure to radiofrequency electromagnetic field, about 50 % reduction of biofilm was observed; after 14 days, biofilm extension was reduced by about 90 %. DGGE analyses performed after 14 days confirmed these visual inspections. Also, DGGE analyses carried out before and 14 days after treatments showed that 12 out of 17 identified species disappeared. A complete visual disappearance of biofilms was observed a month after the beginning of treatments. DGGE repeated at this time confirmed the total disappearance of biofilm-forming species. Treated stones, when transferred back to their original sites, did not show any microorganism re-growing after 6 months. No alteration in the color and structural consistency of tuff substrata was observed after radiofrequency treatments.

  8. Ash-flow tuffs of the Galiuro Volcanics in the northern Galiuro Mountains, Pinal County, Arizona

    Science.gov (United States)

    Krieger, Medora Louise Hooper

    1979-01-01

    The upper Oligocene and lower Miocene Galiuro Volcanics in the northern part of the Galiuro Mountains contains two distinctive major ash-flow tuff sheets, the Holy Joe and Aravaipa Members. These major ash-flows illustrate many features of ash-flow geology not generally exposed so completely. The Holy Joe Member, composed of a series of densely welded flows of quartz latite composition that make up a simple cooling unit. is a rare example of a cooling unit that has a vitrophyre at the top as well as at the base. The upper vitrophyre does not represent a cooling break. The Aravaipa Member. a rhyolite, is completely exposed in Aravaipa and other canyons and on Table Mountain. Remarkable exposures along Whitewash Canyon exhibit the complete change from a typical stacked-up interior zonation of an ash flow to a non welded distal margin. Vertical and horizontal changes in welding, crystallization, specific gravity, and lithology are exposed. The ash flow can be divided into six lithologic zones. The Holy Joe and Aravaipa Members of the Galiuro Volcanics are so well exposed and so clearly show characteristic features of ash-flow tuffs that they could be a valuable teaching aid and a source of theses for geology students.

  9. Wireline-rotary air coring of the Bandelier Tuff, Los Alamos, New Mexico

    Science.gov (United States)

    Teasdale, W.E.; Pemberton, R.R.

    1984-01-01

    This paper describes experiments using wireline-rotary air-coring techniques conducted in the Bandelier Tuff using a modified standard wireline core-barrel system. The modified equipment was used to collect uncontaminated cores of unconsolidated ash and indurated tuff at Los Alamos, New Mexico. Core recovery obtained from the 210-foot deep test hole was about 92 percent. A standard HQ-size, triple-tube wireline core barrel (designed for the passage of liquid drilling fluids) was modified for air coring as follows: (1) Air passages were milled in the latch body part of the head assembly; (2) the inside dimension of the outer core barrel tube was machined and honed to provide greater clearance between the inner and outer barrels; (3) oversized reaming devices were added to the outer core barrel and the coring bit to allow more clearance for air and cuttings return; (4) the eight discharge ports in the coring bit were enlarged. To control airborne-dust pollution, a dust-and-cuttings discharge subassembly, designed and built by project personnel, was used. (USGS)

  10. Analysis of Fracture in Cores from the Tuff Confining Unit beneath Yucca Flat, Nevada Test Site

    Energy Technology Data Exchange (ETDEWEB)

    Lance Prothro

    2008-03-01

    The role fractures play in the movement of groundwater through zeolitic tuffs that form the tuff confining unit (TCU) beneath Yucca Flat, Nevada Test Site, is poorly known. This is an important uncertainty, because beneath most of Yucca Flat the TCU lies between the sources of radionuclide contaminants produced by historic underground nuclear testing and the regional carbonate aquifer. To gain a better understanding of the role fractures play in the movement of groundwater and radionuclides through the TCU beneath Yucca Flat, a fracture analysis focusing on hydraulic properties was performed on conventional cores from four vertical exploratory holes in Area 7 of Yucca Flat that fully penetrate the TCU. The results of this study indicate that the TCU is poorly fractured. Fracture density for all fractures is 0.27 fractures per vertical meter of core. For open fractures, or those observed to have some aperture, the density is only 0.06 fractures per vertical meter of core. Open fractures are characterized by apertures ranging from 0.1 to 10 millimeter, and averaging 1.1 millimeter. Aperture typically occurs as small isolated openings along the fracture, accounting for only 10 percent of the fracture volume, the rest being completely healed by secondary minerals. Zeolite is the most common secondary mineral occurring in 48 percent of the fractures observed.

  11. Stable isotopes of authigenic minerals in variably-saturated fractured tuff

    Energy Technology Data Exchange (ETDEWEB)

    Weber, D.S.; Evans, D.D.

    1988-11-01

    Identifying stable isotope variation and mineralogical changes in fractured rock may help establish the history of climatic and geomorphological processes that might affect the isolation properties of a waste repository site. This study examines the use of the stable isotope ratios of oxygen ({sup 18}O/{sup 16}O) and carbon ({sup 13}C/{sup 12}C) in authigenic minerals as hydrogeochemical tools tracing low-temperature rock-water interaction in variably-saturated fractured stuff. Isotopic compositions of fracture-filling and rock matrix minerals in the Apache Leap tuff, near Superior, Arizona were concordant with geothermal temperatures and in equilibrium with water isotopically similar to present-day meteoric water and groundwater. Oxygen and carbon isotope ratios of fracture-filling, in unsaturated fractured tuff, displayed an isotopic gradient believed to result from near-surface isotopic enrichment due to evaporation rather than the effects of rock-water interaction. Oxygen isotope ratios of rock matrix opal samples exhibited an isotopic gradient believed to result from, leaching and reprecipitation of silica at depth. Methods and results can be used to further define primary flowpaths and the movement of water in variably-saturated fractured rock. 71 refs., 23 figs., 3 tabs.

  12. Inverse Dipolar Magnetic Anomaly Over the Volcanic Cone Linked to Reverse Polarity Magnetizations in Lavas and Tuffs - Implications for the Conduit System

    Science.gov (United States)

    Fucugauchi, J. U.; Perez-Cruz, L. L.; Trigo-Huesca, A.

    2012-12-01

    A combined magnetics and paleomagnetic study of Toluquilla monogenetic volcano and associated lavas and tuffs from Valsequillo basin in Central Mexico provides evidence on a magnetic link between lavas, ash tuffs and the underground volcanic conduit system. Paleomagnetic analyses show that lavas and ash tuffs carry reverse polarity magnetizations, which correlate with the inversely polarized dipolar magnetic anomaly over the volcano. The magnetizations in the lava and tuff show similar southward declinations and upward inclinations, supporting petrological inferences that the tuff was emplaced while still hot and indicating a temporal correlation for lava and tuff emplacement. Conduit geometry is one of the important controlling factors in eruptive dynamics of basaltic volcanoes. However volcanic conduits are often not, or only partly, exposed. Modeling of the dipolar anomaly gives a reverse polarity source magnetization associated with a vertical prismatic body with southward declination and upward inclination, which correlates with the reverse polarity magnetizations in the lava and tuff. The study documents a direct correlation of the paleomagnetic records with the underground magmatic conduit system of the monogenetic volcano. Time scale for cooling of the volcanic plumbing system involves a longer period than the one for the tuff and lava, suggesting that magnetization for the source of dipolar anomaly may represent a long time average as compared to the spot readings in the lava and tuff. The reverse polarity magnetizations in lava and tuff and in the underground source body for the magnetic anomaly are interpreted in terms of eruptive activity of Toluquilla volcano at about 1.3 Ma during the Matuyama reverse polarity C1r.2r chron.

  13. Melon chlorotic leaf curl virus: characterization and differential reassortment with closest relatives reveal adaptive virulence in the squash leaf curl virus clade and host shifting by the host-restricted bean calico mosaic virus.

    Science.gov (United States)

    Idris, A M; Mills-Lujan, K; Martin, K; Brown, J K

    2008-02-01

    The genome components of the Melon chlorotic leaf curl virus (MCLCuV) were cloned from symptomatic cantaloupe leaves collected in Guatemala during 2002. The MCLCuV DNA-A and DNA-B components shared their closest nucleotide identities among begomoviruses, at approximately 90 and 81%, respectively, with a papaya isolate of MCLCuV from Costa Rica. The closest relatives at the species level were other members of the Squash leaf curl virus (SLCV) clade, which is endemic in the southwestern United States and Mexico. Biolistic inoculation of cantaloupe seedlings with the MCLCuV DNA-A and -B components resulted in the development of characteristic disease symptoms, providing definitive evidence of causality. MCLCuV experimentally infected species within the Cucurbitaceae, Fabaceae, and Solanaceae. The potential for interspecific reassortment was examined for MCLCuV and its closest relatives, including the bean-restricted Bean calico mosaic virus (BCaMV), and three other cucurbit-infecting species, Cucurbit leaf crumple virus (CuLCrV), SLCV, and SMLCV. The cucurbit viruses have distinct but overlapping host ranges. All possible reassortants were established using heterologous combinations of the DNA-A or DNA-B components. Surprisingly, only certain reassortants arising from MCLCuV and BCaMV, or MCLCuV and CuLCrV, were viable in bean, even though it is a host of all of the "wild-type" (parent) viruses. The bean-restricted BCaMV was differentially assisted in systemically infecting the cucurbit test species by the components of the four cucurbit-adapted begomoviruses. In certain heterologous combinations, the BCaMV DNA-A or -B component was able to infect one or more cucurbit species. Generally, the reassortants were less virulent in the test hosts than the respective wild-type (parent) viruses, strongly implicating adaptive modulation of virulence. This is the first illustration of reassortment resulting in the host range expansion of a host-restricted begomovirus.

  14. Studying the sorption properties of a clinoptilolite-containing tuff with respect to europium(III) ions

    Science.gov (United States)

    Kozhevnikova, N. M.

    2014-03-01

    The kinetic laws of sorption of europium(III) ions from sulfate solutions by a clinoptilolite-containing tuff are studied. The kinetic parameters of sorption process are determined and absorption isotherms are constructed for europium ions. It is found that both external and internal diffusion are rate-limiting steps, and europium is completely extracted from dilute solutions (<0.0025 m).

  15. Zeolitic alteration and fracture fillings in silicic tuffs at a potential nuclear waste repository, Yucca Mountain, Nevada, USA

    Energy Technology Data Exchange (ETDEWEB)

    Broxton, D.E.; Carlos, B.A.

    1986-12-31

    This paper describes the distribution and chemistry of zeolites in tuffs and in fractures at Yucca Mountain. Samples used in this study were collected from continuously-cored exploratory drill holes. A variety of analytical techniques, including optical petrography, x-ray powder diffraction, electron microanalysis, and x-ray fluorescence, were used to characterize the distribution and chemistry of zeolites in these samples.

  16. Structure, stratigraphy, and eruption dynamics of a young tuff ring: Hanauma Bay, O'ahu, Hawai'i

    Science.gov (United States)

    Rottas, K. M.; Houghton, B. F.

    2012-09-01

    The Hanauma Bay-Koko Head complex is one of several young volcanic landforms along the Koko fissure, in southeastern O'ahu. The Hanauma Bay region of the complex comprises two nested tuff rings, inner and outer Hanauma Bay, and multiple smaller vents. The internal structure of the inner tuff ring, well exposed due to subsequent breaching by the ocean and wave erosion, indicates that it formed during a minimum of five distinct phases of deposition that produced five mappable units. Significant inward collapses generated major unconformities that separate the units exposed in the inner wall. The planes of failure are cut by narrow steep-walled, locally overhung channels and gullies, suggesting that the collapse events were each followed by short time breaks during which the deposits were eroded by rainfall runoff. Within each pyroclastic unit, there are many local slump scars and unconformities, suggesting that minor instability of the inner wall was a near-constant feature. From bedding sags and surge bed forms, it is apparent that the vent shifted at least twice during tuff ring growth. Ballistic blocks in the youngest unit indicate that the eruption overlapped in time with a separate eruption to the north, most likely to be that of the Kahauloa tuff ring 880 m away.

  17. Characterization of liquid-water percolation in tuffs in the unsaturated zone, Yucca Mountain, Nye County, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Kume, J.; Rousseau, J.P.

    1989-12-31

    A surface-based borehole investigation currently (1989) is being done to characterize liquid-water percolation in tuffs of Miocene age in the unsaturated zone beneath Yucca Mountain, Nye County, Nevada Active in-situ testing and passive in-situ monitoring will be used in this investigation to estimate the present-day liquid-water percolation (flux). The unsaturated zone consists of a gently dipping sequence of fine-grained, densely fractured, and mostly welded ash-flow tuffs that are interbedded with fine-grained, slightly fractured, non-welded ash-flow and ash-fall tuffs that are partly vitric and zeolitized near the water table. Primary study objectives are to define the water potential field within the unsaturated zone and to determine the in-situ bulk permeability and bulk hydrologic properties of the unsaturated tuffs. Borehole testing will be done to determine the magnitude and spatial distribution of physical and hydrologic properties of the geohydrologic units, and of their water potential fields. The study area of this investigation is restricted to that part of Yucca Mountain that immediately overlies and is within the boundaries of the perimeter drift of a US Department of Energy proposed mined, geologic, high-level radioactive-waste repository. Vertically, the study area extends from near the surface of Yucca Mountain to the underlying water table, about 500 to 750 meters below the ground surface. The average distance between the proposed repository and the underlying water table is about 205 meters.

  18. Spectral Differences Between Palagonite Tuffs Formed in Sub-Glacial Versus Liquid Water Environments: Relevance to Mars

    Science.gov (United States)

    Farrand, W. H.; Lane, M. D.

    2002-01-01

    The reflectance and emissivity spectra of palagonite tuffs formed in sub-glacial environments are compared with those formed in liquid water environments. The relevance to palagonites produced by water-magma interactions on Mars is discussed. Additional information is contained in the original extended abstract.

  19. Status of understanding of the saturated-zone ground-water flow system at Yucca Mountain, Nevada, as of 1995

    Energy Technology Data Exchange (ETDEWEB)

    Luckey, R.R.; Tucci, P.; Faunt, C.C.; Ervin, E.M. [and others

    1996-12-31

    Yucca Mountain, which is being studied extensively because it is a potential site for a high-level radioactive-waste repository, consists of a thick sequence of volcanic rocks of Tertiary age that are underlain, at least to the southeast, by carbonate rocks of Paleozoic age. Stratigraphic units important to the hydrology of the area include the alluvium, pyroclastic rocks of Miocene age (the Timber Mountain Group; the Paintbrush Group; the Calico Hills Formation; the Crater Flat Group; the Lithic Ridge Tuff; and older tuffs, flows, and lavas beneath the Lithic Ridge Tuff), and sedimentary rocks of Paleozoic age. The saturated zone generally occurs in the Calico Hills Formation and stratigraphically lower units. The saturated zone is divided into three aquifers and two confining units. The flow system at Yucca Mountain is part of the Alkali Flat-Furnace Creek subbasin of the Death Valley groundwater basin. Variations in the gradients of the potentiometric surface provided the basis for subdividing the Yucca Mountain area into zones of: (1) large hydraulic gradient where potentiometric levels change at least 300 meters in a few kilometers; (2) moderate hydraulic gradient where potentiometric levels change about 45 meters in a few kilometers; and (3) small hydraulic gradient where potentiometric levels change only about 2 meters in several kilometers. Vertical hydraulic gradients were measured in only a few boreholes around Yucca Mountain; most boreholes had little change in potentiometric levels with depth. Limited hydraulic testing of boreholes in the Yucca Mountain area indicated that the range in transmissivity was more than 2 to 3 orders of magnitude in a particular hydrogeologic unit, and that the average values for the individual hydrogeologic units generally differed by about 1 order of magnitude. The upper volcanic aquifer seems to be the most permeable hydrogeologic unit, but this conclusion was based on exceedingly limited data.

  20. Evolution of the Puente Hills Thrust Fault

    Science.gov (United States)

    Bergen, K. J.; Shaw, J. H.; Dolan, J. F.

    2013-12-01

    This study aims to assess the evolution of the blind Puente Hills thrust fault system (PHT) by determining its age of initiation, lateral propagation history, and changes in slip rate over time. The PHT presents one of the largest seismic hazards in the United States, given its location beneath downtown Los Angeles. The PHT is comprised of three fault segments: the Los Angeles (LA), Santa Fe Springs (SFS), and Coyote Hills (CH). The LA and SFS segments are characterized by growth stratigraphy where folds formed by uplift on the fault segments have been continually buried by sediment from the Los Angeles and San Gabriel rivers. The CH segment has developed topography and is characterized by onlapping growth stratigraphy. This depositional setting gives us the unique opportunity to measure uplift on the LA and SFS fault segments, and minimum uplift on the CH fault segment, as the difference in sediment thicknesses across the buried folds. We utilize depth converted oil industry seismic reflection data to image the fold geometries. Identifying time-correlative stratigraphic markers for slip rate determination in the basin has been a problem for researchers in the past, however, as the faunal assemblages observed in wells are time-transgressive by nature. To overcome this, we utilize the sequence stratigraphic model and well picks of Ponti et al. (2007) as a basis for mapping time-correlative sequence boundaries throughout our industry seismic reflection data from the present to the Pleistocene. From the Pleistocene to Miocene we identify additional sequence boundaries in our seismic reflection data from imaged sequence geometries and by correlating industry well formation tops. The sequence and formation top picks are then used to build 3-dimensional surfaces in the modeling program Gocad. From these surfaces we measure the change in thicknesses across the folds to obtain uplift rates between each sequence boundary. Our results show three distinct phases of

  1. In defense of Magnetite-Ilmenite Thermometry in the Bishop Tuff and its implication for gradients in silicic magma reservoirs

    Science.gov (United States)

    Evans, Bernard W; Hildreth, Edward; Bachmann, Olivier; Scaillet, Bruno

    2016-01-01

    Despite claims to the contrary, the compositions of magnetite and ilmenite in the Bishop Tuff correctly record the changing conditions of T and fO2 in the magma reservoir. In relatively reduced (∆NNO 1, e.g., Fish Canyon Tuff, Pinatubo), and the d(aTiO2)/dT slope can be negative. Biotite, FeTi-oxides, liquid, and possibly plagioclase largely maintained equilibrium in the Bishop Tuff magma (unlike the pyroxenes, and cores of quartz, sanidine, and zircon) prior ro and during a mixing event triggered by a deeper recharge, which, based on elemental diffusion profiles in minerals, took place at least several decades before eruption. Equilibrating phases and pumice compositions show evolving chemical variations that correlate well with mutually consistent temperatures based on the FeTi-oxides, sanidine-plagioclase, and ∆18O quartz-magnetite pairs. Early Bishop Tuff (EBT) temperatures are lower (700 to ~780‎°C) than temperatures (780 to >820°C) registered in Late Bishop Tuff (LBT), the latter defined here not strictly stratigraphically, but by the presence of orthopyroxene and reverse-zoned rims on quartz and sanidine. The claimed similarity in compositions, Zr-saturation temperatures and thermodynamically calculated temperatures (730-740°C) between EBT and less evolved LBT reflect the use of glass inclusions in quartz cores in LBT that were inherited from the low temperature rhyolitic part of the reservoir characteristic of the EBT. LBT temperatures as high as 820°C, the preservation of orthopyroxene, and the presence of reverse-zoned minerals (quartz, sanidine, zircons) are consistent with magma recharge at the base of the zoned reservoir, heating the cooler rhyolitic melt, partly remelting cumulate mush, and introducing enough CO2 (0.4-1.4 wt%, mostly contained in the exsolved fluid phase) to significantly lower H2O-activity in the system.

  2. Stratigraphy, correlation, depositional setting, and geophysical characteristics of the Oligocene Snowshoe Mountain Tuff and Creede Formation in two cored boreholes

    Science.gov (United States)

    Larsen, Daniel; Nelson, Philip H.

    2000-01-01

    Core descriptions and geophysical logs from two boreholes (CCM-1 and CCM-2) in the Oligocene Snowshoe Mountain Tuff and Creede Formation, south-central Colorado, are used to interpret sedimentary and volcanic facies associations and their physical properties. The seven facies association include a mixed sequence of intracaldera ash-flow tuffs and breccias, alluvial and lake margin deposits, and tuffaceous lake beds. These deposits represent volcanic units related to caldera collapse and emplacement of the Snowshoe Mountain Tuff, and sediments and pyroclastic material deposited in the newly formed caldera basin, Early sedimentation is interpreted to have been rapid, and to have occurred in volcaniclastic fan environments at CCM-1 and in a variery of volcaniclastic fan, braided stream shallow lacustrine, and mudflat environments at CCM-2. After an initial period of lake-level rise, suspension settling, turbidite, and debris-flow sedimentation occurred in lacustrine slope and basin environments below wave base. Carbonate sedimentation was initially sporadic, but more continuous in the latter part of the recorded lake history (after the H fallout tuff). Sublacustrine-fan deposition occurred at CCM-1 after a pronounced lake-level fall and subsequent rise that preceded the H tuff. Variations in density, neutron, gamma-ray, sonic, and electrical properties of deposits penetrated oin the two holes reflect variations in lithology, porosity, and alteration. Trends in the geophysical properties of the lacustrine strata are linked to downhole changes in authigenic mineralology and a decrease in porosity interpreted to have resulted primarily from diagenesis. Lithological and geophysical characteristics provide a basis for correlation of the cores; however, mineralogical methods of correlation are hampered by the degree of diagenesis and alteration.

  3. Neogene fallout tuffs from the Yellowstone hotspot in the Columbia Plateau region, Oregon, Washington and Idaho, USA.

    Directory of Open Access Journals (Sweden)

    Barbara P Nash

    Full Text Available Sedimentary sequences in the Columbia Plateau region of the Pacific Northwest ranging in age from 16-4 Ma contain fallout tuffs whose origins lie in volcanic centers of the Yellowstone hotspot in northwestern Nevada, eastern Oregon and the Snake River Plain in Idaho. Silicic volcanism began in the region contemporaneously with early eruptions of the Columbia River Basalt Group (CRBG, and the abundance of widespread fallout tuffs provides the opportunity to establish a tephrostratigrahic framework for the region. Sedimentary basins with volcaniclastic deposits also contain diverse assemblages of fauna and flora that were preserved during the Mid-Miocene Climatic Optimum, including Sucker Creek, Mascall, Latah, Virgin Valley and Trout Creek. Correlation of ashfall units establish that the lower Bully Creek Formation in eastern Oregon is contemporaneous with the Virgin Valley Formation, the Sucker Creek Formation, Oregon and Idaho, Trout Creek Formation, Oregon, and the Latah Formation in the Clearwater Embayment in Washington and Idaho. In addition, it can be established that the Trout Creek flora are younger than the Mascall and Latah flora. A tentative correlation of a fallout tuff from the Clarkia fossil beds, Idaho, with a pumice bed in the Bully Creek Formation places the remarkably well preserved Clarkia flora assemblage between the Mascall and Trout Creek flora. Large-volume supereruptions that originated between 11.8 and 10.1 Ma from the Bruneau-Jarbidge and Twin Falls volcanic centers of the Yellowstone hotspot in the central Snake River Plain deposited voluminous fallout tuffs in the Ellensberg Formation which forms sedimentary interbeds in the CRBG. These occurrences extend the known distribution of these fallout tuffs 500 km to the northwest of their source in the Snake River Plain. Heretofore, the distal products of these large eruptions had only been recognized to the east of their sources in the High Plains of Nebraska and Kansas.

  4. Neogene fallout tuffs from the Yellowstone hotspot in the Columbia Plateau region, Oregon, Washington and Idaho, USA.

    Science.gov (United States)

    Nash, Barbara P; Perkins, Michael E

    2012-01-01

    Sedimentary sequences in the Columbia Plateau region of the Pacific Northwest ranging in age from 16-4 Ma contain fallout tuffs whose origins lie in volcanic centers of the Yellowstone hotspot in northwestern Nevada, eastern Oregon and the Snake River Plain in Idaho. Silicic volcanism began in the region contemporaneously with early eruptions of the Columbia River Basalt Group (CRBG), and the abundance of widespread fallout tuffs provides the opportunity to establish a tephrostratigrahic framework for the region. Sedimentary basins with volcaniclastic deposits also contain diverse assemblages of fauna and flora that were preserved during the Mid-Miocene Climatic Optimum, including Sucker Creek, Mascall, Latah, Virgin Valley and Trout Creek. Correlation of ashfall units establish that the lower Bully Creek Formation in eastern Oregon is contemporaneous with the Virgin Valley Formation, the Sucker Creek Formation, Oregon and Idaho, Trout Creek Formation, Oregon, and the Latah Formation in the Clearwater Embayment in Washington and Idaho. In addition, it can be established that the Trout Creek flora are younger than the Mascall and Latah flora. A tentative correlation of a fallout tuff from the Clarkia fossil beds, Idaho, with a pumice bed in the Bully Creek Formation places the remarkably well preserved Clarkia flora assemblage between the Mascall and Trout Creek flora. Large-volume supereruptions that originated between 11.8 and 10.1 Ma from the Bruneau-Jarbidge and Twin Falls volcanic centers of the Yellowstone hotspot in the central Snake River Plain deposited voluminous fallout tuffs in the Ellensberg Formation which forms sedimentary interbeds in the CRBG. These occurrences extend the known distribution of these fallout tuffs 500 km to the northwest of their source in the Snake River Plain. Heretofore, the distal products of these large eruptions had only been recognized to the east of their sources in the High Plains of Nebraska and Kansas.

  5. Performance predictions for mechanical excavators in Yucca Mountain tuffs; Yucca Mountain Site Characterization Project

    Energy Technology Data Exchange (ETDEWEB)

    Ozdemir, L.; Gertsch, L.; Neil, D.; Friant, J. [Colorado School of Mines, Golden, CO (United States). Earth Mechanics Inst.

    1992-09-01

    The performances of several mechanical excavators are predicted for use in the tuffs at Yucca Mountain: Tunnel boring machines, the Mobile Miner, a roadheader, a blind shaft borer, a vertical wheel shaft boring machine, raise drills, and V-Moles. Work summarized is comprised of three parts: Initial prediction using existing rock physical property information; Measurement of additional rock physical properties; and Revision of the initial predictions using the enhanced database. The performance predictions are based on theoretical and empirical relationships between rock properties and the forces-experienced by rock cutters and bits during excavation. Machine backup systems and excavation design aspects, such as curves and grades, are considered in determining excavator utilization factors. Instanteous penetration rate, advance rate, and cutter costs are the fundamental performance indicators.

  6. Long-term desorption behavior of uranium and neptunium in heterogeneous volcanic tuff materials /

    Energy Technology Data Exchange (ETDEWEB)

    Dean, Cynthia A.

    2010-05-01

    Uranium and neptunium desorption were studied in long-term laboratory experiments using four well-characterized volcanic tuff cores collected from southeast of Yucca Mountain, Nevada. The objectives of the experiments were to 1. Demonstrate a methodology aimed at characterizing distributions of sorption parameters (attributes of multiple sorption sites) that can be applied to moderately-sorbing species in heterogeneous systems to provide more realistic reactive transport parameters and a more realistic approach to modeling transport in heterogeneous systems. 2. Focus on uranium and neptunium because of their high solubility, relatively weak sorption, and high contributions to predicted dose in Yucca Mountain performance assessments. Also, uranium is a contaminant of concern at many DOE legacy sites and uranium mining sites.

  7. Hydration of tricalcium silicate in blended Cements manufactured with cuban tuffs

    Directory of Open Access Journals (Sweden)

    Duque Fernández, Gabriel Luis

    1989-03-01

    Full Text Available The tricalcium silicate (alite hydration velocity in cements with and without additives is studied in the presence of "Las Carolinas" quarry tuffs from Cienfuegos province, Cuba, the alite hydration velocity is enhanced reaching velocity constants 1.5 higher than in the standard cement.

    Se estudia la velocidad de hidratación del silicato tricálcico (alita presente en el cemento con y sin adiciones, demostrándose que en presencia de tobas del yacimiento "Las Carolinas" en la provincia de Cienfuegos, Cuba, se acelera la velocidad de hidratación de este componente, obteniéndose constantes de velocidad de reacción aproximadamente 1,5 veces mayores que en el cemento patrón.

  8. Stratigraphic relations and hydrologic properties of the Paintbrush Tuff (PTn) hydrologic unit, Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Moyer, T.C.; Geslin, J.K. [Science Applications International Corp., Golden, CO (United States); Flint, L.E. [U.S. Geological Survey, Yucca Mountain Project, Mercury, NV (United States)

    1996-08-01

    Yucca Mountain is being investigated as a potential site for a high- level nuclear waste repository. The intent of this study was to clarify stratigraphic relations within the Paintbrush Tuff (PTn) unit at Yucca Mountain in order to better understand vertical and lateral variations in hydrologic properties as they relate to the lithologic character of these rocks. This report defines informal stratigraphic units within the PTn interval, demonstrates their lateral continuity in the Yucca Mountain region, describes later and vertical variations within them, and characterizes their hydrologic properties and importance to numerical flow and transport models. We present tables summarizing the depth to stratigraphic contacts in cored borehole studies, and unit descriptions and correlations in 10 measured sections.

  9. Sullys Hill National Game Preserve Narrative Report : September - December 1942

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Sullys Hill National Game Reserve outlines Refuge accomplishments from September through December 1942. The report begins by summarizing...

  10. Quarterly Narrative Report for the Sullys Hill Wildlife Refuge : 1938

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains quarterly narrative reports for Sullys Hill Game Preserve for 1938 Reports summarizes activities and accomplishments, including hunting, weather...

  11. Quarterly Narrative Report for the Sullys Hill Wildlife Refuge : 1937

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains quarterly narrative reports for Sullys Hill Game Preserve for 1937 Reports summarizes activities and accomplishments, including hunting, weather...

  12. Quarterly Narrative Report for the Sullys Hill Wildlife Refuge : 1939

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains quarterly narrative reports for Sullys Hill Game Preserve for 1939 Reports summarizes activities and accomplishments, including hunting, weather...

  13. Bone Hill National Wildlife Refuge [Land Status Map

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This map was produced by the Division of Realty to depict landownership at Bone Hill National Wildlife Refuge. It was generated from rectified aerial photography,...

  14. "Beverly Hills 90210" : kes mida teeb / Tiina Lepiste

    Index Scriptorium Estoniae

    Lepiste, Tiina

    2003-01-01

    Aaron Spellingu produtseeritud ja 2000. aastal lõpetatud menuseriaalis "Beverly Hills 90210" osalenud näitlejate edaspidisest elust seoses plaaniga teha täispikk mängufilm "10 Year High School Reunion"

  15. [Sullys Hill National Game Preserve bison herd raw data, 2006

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Raw data from Texas A&M University on the Sullys Hill National Game Preserve federal bison herd. Data includes nuclear introgression markers and nuclear...

  16. Flint Hills National Wildlife Refuge: Comprehensive Conservation Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Comprehensive Conservation Plan (CCP) was written to guide management on Flint Hills NWR for the next 15 years. This plan outlines the Refuge vision and purpose...

  17. Background Contaminants Evaluation of Flint Hills National Wildlife Refuge - 1989

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This study was conducted to assess chlordane levels in sediments and fish of Flint Hills NWR. Chlordane is very persistent and highly toxic to aquatic organisms and...

  18. Refuge review report : Flint Hills National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is a review on Flint Hills NWR and summarizes refuge activities concerning staffing and employee development, budget, administration, planning,...

  19. EAARL Topography-Sagamore Hill National Historic Site

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Elevation maps (also known as Digital Elevation Models or DEMs) of the Sagamore Hill National Historic Site were produced from remotely-sensed,...

  20. Miscellaneous Reports for the Sullys Hill Wildlife Refuge : 1917 - 1932

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains data and yearly summaries for Sullys Hill Game Preserve since the time of its establishment in 1917 through 1932. Data reports covers deer,...

  1. USGS Hill Shade Base Map Service from The National Map

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — USGS Hill Shade (or Shaded Relief) is a tile cache base map created from the National Elevation Dataset (NED), a seamless dataset of best available raster elevation...

  2. Sullys Hill National Game Preservce Narrative Report : January - April 1953

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Sullys Hill National Game Reserve outlines Refuge accomplishments from January through April of 1953. The report begins by summarizing the...

  3. Saturated thickness of the Minnelusa aquifer, Black Hills, South Dakota.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set is a polygon coverage created in ARC/INFO that represents the saturated thickness of the Minnelusa aquifer, Black Hills area, South Dakota. The...

  4. Sullys Hill National Game Preservce Narrative Report : January - April 1948

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Sullys Hill National Game Reserve outlines Refuge accomplishments from January through April of 1948. The report begins by summarizing the...

  5. Sullys Hill National Game Preserve Narrative Report : September - December 1944

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Sullys Hill National Game Reserve outlines Refuge accomplishments from September through December 1944. The report begins by summarizing...

  6. Sullys Hill National Game Preserve Narrative Report : September - December 1943

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Sullys Hill National Game Reserve outlines Refuge accomplishments from September through December 1943. The report begins by summarizing...

  7. Sullys Hill National Game Preserve Narrative Report : September - December 1948

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Sullys Hill National Game Reserve outlines Refuge accomplishments from September through December 1948. The report begins by summarizing...

  8. Sullys Hill National Game Preserce : 1971 : Narrative Report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Sullys Hill National Game Preserve outlines Refuge accomplishments during the 1971 calendar year. The report begins by summarizing...

  9. Sullys Hill National Game Preserve Narrative Report : September - December 1954

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Sullys Hill National Game Reserve outlines Refuge accomplishments from September through December 1954. The report begins by summarizing...

  10. Sullys Hill National Game Preserve Narrative Report : September - December 1953

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Sullys Hill National Game Reserve outlines Refuge accomplishments from September through December 1953. The report begins by summarizing...

  11. Sullys Hill National Game Preserve Narrative Report : September - December 1946

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Sullys Hill National Game Reserve outlines Refuge accomplishments from September through December 1946. The report begins by summarizing...

  12. Sullys Hill National Game Preserce : 1970 : Narrative Report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Sullys Hill National Game Preserve outlines Refuge accomplishments during the 1970 calendar year. The report begins by summarizing...

  13. Sullys Hill National Game Preserve Narrative Report : September - December 1945

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Sullys Hill National Game Reserve outlines Refuge accomplishments from September through December 1945. The report begins by summarizing...

  14. Sullys Hill National Game Preserve Narrative Report : September - December 1952

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Sullys Hill National Game Reserve outlines Refuge accomplishments from September through December 1952. The report begins by summarizing...

  15. Sullys Hill National Game Preserve Narrative Report : September - December 1951

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Sullys Hill National Game Reserve outlines Refuge accomplishments from September through December 1951. The report begins by summarizing...

  16. Sullys Hill National Game Preserve Narrative Report : September - December 1949

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Sullys Hill National Game Reserve outlines Refuge accomplishments from September through December 1949. The report begins by summarizing...

  17. Sullys Hill National Game Preserve Narrative Report : September - December 1950

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Sullys Hill National Game Reserve outlines Refuge accomplishments from September through December 1950. The report begins by summarizing...

  18. EAARL Topography-Sagamore Hill National Historic Site

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Elevation maps (also known as Digital Elevation Models or DEMs) of the Sagamore Hill National Historic Site were produced from remotely-sensed,...

  19. Generalized thickness of the Minnelusa Formation, Black Hills, South Dakota.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set is a polygon coverage created in ARC/INFO that represents the generalized thickness of the Minnelusa Formation, Black Hills, South Dakota. The...

  20. Preserving genes: Sullys Hill bison gain national prominence

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Newspaper article on transferring bison from Sullys Hill National Game Preserve to Fort Niobrara National Wildlife Refuge to help maintain as genetically pure strain...

  1. Comprehensive Conservation Plan: Sullys Hill National Game Preserve

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Comprehensive Conservation Plan (CCP) was written to guide management on Sullys Hill National Game Preserve for the next 15 years. This plan outlines the...

  2. "Beverly Hills 90210" : kes mida teeb / Tiina Lepiste

    Index Scriptorium Estoniae

    Lepiste, Tiina

    2003-01-01

    Aaron Spellingu produtseeritud ja 2000. aastal lõpetatud menuseriaalis "Beverly Hills 90210" osalenud näitlejate edaspidisest elust seoses plaaniga teha täispikk mängufilm "10 Year High School Reunion"

  3. Pesticide evaluation for Flint Hills National Wildlife Refuge in Kansas

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Flint Hills National Wildlife Refuge is an overlay on the Corps of Engineers John Redmond Reservoir in east-central Kansas. The Refuge is managed to provide spring...

  4. Land Protection Plan: Flint Hills Legacy Conservation Area

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Land Protection Plan for Flint Hills Legacy Conservation Area provides a description of the project, a description of the area and its resources, threats to the...

  5. Quarterly Narrative Report for the Sullys Hill Wildlife Refuge : 1936

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains quarterly narrative reports for Sullys Hill Game Preserve for 1936 Reports summarizes activities and accomplishments, including hunting, weather...

  6. Sullys Hill National Game Preserve Narrative Report : September - December 1947

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Sullys Hill National Game Reserve outlines Refuge accomplishments from September through December 1947. The report begins by summarizing...

  7. On the Coleman-Hill theorem

    CERN Document Server

    Khare, A; Paranjape, M B; Khare, Avinash; MacKenzie, R; Paranjape, M B

    1994-01-01

    The Coleman-Hill theorem prohibits the appearance of radiative corrections to the topological mass (more precisely, to the parity-odd part of the vacuum polarization tensor at zero momentum) in a wide class of abelian gauge theories in 2+1 dimensions. We re-express the theorem in terms of the effective action rather than in terms of the vacuum polarization tensor. The theorem so restated becomes somewhat stronger: a known exception to the theorem, spontaneously broken scalar Chern-Simons electrodynamics, obeys the new non-renormalization theorem. Whereas the vacuum polarization {\\sl does} receive a one-loop, parity-odd correction, this does not translate to a radiative contribution to the Chern-Simons term in the effective action. We also point out a new situation, involving scalar fields and parity-odd couplings, which was overlooked in the original analysis, where the conditions of the theorem are satisfied and where the topological mass does, in fact, get a radiative correction.

  8. MOLECULAR CHARACTERIZATION OF ASSAM HILL GOAT

    Directory of Open Access Journals (Sweden)

    Galib Uz Zaman

    2013-01-01

    Full Text Available A total of 23 polymorphic microsatellite markers were used to evaluate genetic diversity and population structure in Assam Hill Goat (AHG. All the loci studied were polymorphic in nature. The number of observed alleles (Na detected ranged from 2 to 10 with an overall mean of 4.9±2.220. A total of 114 alleles were observed across all the loci. The effective number of alleles (Ne ranged from 1.035 to 7.127 with a mean of 2.68±1.590. The allele frequency ranged from 0.013 to 0.982. The overall mean observed (HO and expected (He heterozygosity were 0.43 and 0.48 respectively and this population was in Hardy-Weinberg equilibrium at most of the loci studied. The overall mean of within-population inbreeding estimate (FIS was 0.085. The population was stable with respect to size and was non-bottlenecked. The observed normal L-shaped curve indicated no mode shift in the population.

  9. Steamboat Hills exploratory slimhole: Drilling and testing

    Energy Technology Data Exchange (ETDEWEB)

    Finger, J.T.; Jacobson, F.D.; Hickox, C.E.; Eaton, R.R.

    1994-10-01

    During July-September, 1993, Sandia National Laboratories, in cooperation with Far West Capital, drilled a 4000 feet exploratory slimhole (3.9 inch diameter) in the Steamboat Hills geothermal field near Reno, Nevada. This well was part of Sandia`s program to evaluate slimholes as a geothermal exploration tool. During and after drilling the authors performed four series of production and injection tests while taking downhole (pressure-temperature-spinner) and surface (wellhead pressure and temperature, flow rate) data. In addition to these measurements, the well`s data set includes: continuous core (with detailed log); borehole televiewer images of the wellbore`s upper 500 feet; daily drilling reports from Sandia and from drilling contractor personnel; daily drilling fluid record; numerous temperature logs; and comparative data from production and injection wells in the same field. This report contains: (1) a narrative account of the drilling and testing, (2) a description of equipment used, (3) a brief geologic description of the formation drilled, (4) a summary and preliminary interpretation of the data, and (5) recommendations for future work.

  10. Stratigraphy, sedimentology and eruptive mechanisms in the tuff cone of El Golfo (Lanzarote, Canary Islands)

    Science.gov (United States)

    Pedrazzi, Dario; Martí, Joan; Geyer, Adelina

    2013-07-01

    The tuff cone of El Golfo on the western coast of Lanzarote (Canary Islands) is a typical hydrovolcanic edifice. Along with other edifices of the same age, it was constructed along a fracture oriented NEE-SWW that coincides with the main structural trend of recent volcanism in this part of the island. We conducted a detailed stratigraphic study of the succession of deposits present in this tuff cone and here interpret them in light of the depositional processes and eruptive dynamics that we were able to infer. The eruptive sequence is represented by a succession of pyroclastic deposits, most of which were emplaced by flow, plus a number of air-fall deposits and ballistic blocks and bombs. We distinguished five different eruptive/depositional stages on the basis of differences in inferred current flow regimes and fragmentation efficiencies represented by the resulting deposits; the different stages may be related to variations in the explosive energy. Eight lithofacies were identified based on sedimentary discontinuities, grain size, components, variations in primary laminations and bedforms. The volcanic edifice was constructed very rapidly around the vent, and this is inferred to have controlled the amount of water that was able to enter the eruption conduit. The sedimentological characteristics of the deposits and the nature and distribution of palagonitic alteration suggest that most of the pyroclastic succession in El Golfo was deposited in a subaerial environment. This type of hydrovolcanic explosive activity is common in the coastal zones of Lanzarote and the other Canary Islands and is one of the main potential hazards that could threaten the human population of this archipelago. Detailed studies of these hydrovolcanic eruptions such as the one we present here can help volcanologists understand the hazards that this type of eruption can generate and provide essential information for undertaking risk assessment in similar volcanic environments.

  11. Comenditic and pantelleritic ash-flow tuffs from Volcan Las Navajas, Nayarit, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, S.A.; Hebre, J.A.

    1985-01-01

    Two distinctive ash-flow tuffs occur around the base of Volcan Las Navajas, a Pleistocene trachyte - peralkaline rhyolite center located in the northwestern segment of the Mexican Volcanic belt. The lower ash-flow unit is locally up to 65 m thick, is lithic rich and contains pumice blocks of comenditic rhyolite. The unit is not extensively exposed, and thus its areal extent and volume cannot be determined. Its chemical characteristics and stratigraphic relationship to other products erupted from Las Navajas suggest that it is related to the formation of the older of the two calderas which occur on Las Navajas. Unconformably overlying this unwelded ash-flow is a pantelleritic airfall pumice unit which is locally welded. This airfall unit is conformably overlain by a welded as-flow tuff that contains fiamme of pantelleritic composition (72 %SiO/sub 2/, 8% FeO*, 900 ppm Zr, agpaitic index of 1.7) as well as pumice blocks that show evidence of various degrees of mixing between pantellerite and trachyte. This suggests eruption from a chemically zoned magma chamber. This unit is locally up to 20 m thick, although its top has been removed by erosion. It is found on all sides of Las Navajas except on the south where it may be covered by Volcan Sanganguey, a Pleistocene to Recent calc-alkaline volcano. The welded ash-flow has been dated by K - Ar at 0.2+/-0.1 m.y. Stratigraphically and chemically this ash-flow appears to be related to the formation of younger of the two calderas.

  12. Fitful and protracted magma assembly leading to a giant eruption, Youngest Toba Tuff, Indonesia

    Science.gov (United States)

    Reid, Mary R; Vazquez, Jorge A.

    2017-01-01

    The paroxysmal eruption of the 74 ka Youngest Toba Tuff (YTT) of northern Sumatra produced an extraordinary 2800 km3 of non-welded to densely welded ignimbrite and co-ignimbrite ash-fall. We report insights into the duration of YTT magma assembly obtained from ion microprobe U-Th and U-Pb dates, including continuous age spectra over >50% of final zircon growth, for pumices and a welded tuff spanning the compositional range of the YTT. A relatively large subpopulation of zircon crystals nucleated before the penultimate caldera-related eruption at 501 ka, but most zircons yielded interior dates 100-300 ka thereafter. Zircon nucleation and growth was likely episodic and from diverse conditions over protracted time intervals of >100 to >500 ka. Final zircon growth is evident as thin rim plateaus that are in Th/U chemical equilibrium with hosts, and that give crystallization ages within tens of ka of eruption. The longevity and chemical characteristics of the YTT zircons, as well as evidence for intermittent zircon isolation and remobilization associated with magma recharge, is especially favored at the cool and wet eutectoid conditions that characterize at least half of the YTT, wherein heat fluxes could dissolve major phases but have only a minor effect on larger zircon crystals. Repeated magma recharge may have contributed to the development of compositional zoning in the YTT but, considered together with limited allanite, quartz, and other mineral dating and geospeedometry, regular perturbations to the magma reservoir over >400 ka did not lead to eruption until 74 ka ago.

  13. Stormwater Management Plan for the Arden Hills Army Training Site, Arden Hills, Minnesota

    Energy Technology Data Exchange (ETDEWEB)

    Carr, Adrianne E. [Argonne National Lab. (ANL), Argonne, IL (United States); Wuthrich, Kelsey K. [Argonne National Lab. (ANL), Argonne, IL (United States); Ziech, Angela M. [Argonne National Lab. (ANL), Argonne, IL (United States); Bowen, Esther E. [Argonne National Lab. (ANL), Argonne, IL (United States); Quinn, John [Argonne National Lab. (ANL), Argonne, IL (United States)

    2013-03-01

    This stormwater management plan focuses on the cantonment and training areas of the Arden Hills Army Training Site (AHATS). The plan relates the site stormwater to the regulatory framework, and it summarizes best management practices to aide site managers in promoting clean site runoff. It includes documentation for a newly developed, detailed model of stormwater flow retention for the entire AHATS property and adjacent upgradient areas. The model relies on established modeling codes integrated in a U.S. Department of Defense-sponsored software tool, the Watershed Modeling System (WMS), and it can be updated with data on changes in land use or with monitoring data.

  14. Environmental Assessment: Proposed Training Facilities, Hill Air Force Base, Utah

    Science.gov (United States)

    2013-08-08

    8 Related to Hill AFB military personnel and civilian employees, the Bio-environmental Engineering Flight (75 AMDS /SGPB) is responsible for...area of Hill AFB to Pond 3, a wet detention pond that discharges to Kay’s Creek. Best management practices for Pond 3 are surface contaminant...to maintain construction opacity at less than 20 percent. Haul roads would be kept wet . Any soil that is deposited on nearby paved roads by

  15. Antiplane response of isosceles triangular hill to incident SH waves

    Institute of Scientific and Technical Information of China (English)

    Qiu Faqiang; Liu Diankui

    2005-01-01

    In this paper, antiplane response of an isosceles triangular hill to incident SH waves is studied based on the method of complex function and by using moving coordinate system. The standing wave function, which can satisfy the governing equation and boundary condition, is provided. Furthermore, numerical examples are presented; the influences of wave number and angle of the incident waves and the angle of the hill's peak on ground motion are discussed.

  16. The Nascent Development of Ecotourism in Lagong Hill

    OpenAIRE

    Ah-Choy Er

    2010-01-01

    Problem statement: The nascent development of ecotourism in Lagong Hill faces an interesting challenge. The aim of this research note is to evaluate the nascent development of ecotourism in Lagong Hill, Malaysia based on the common core precepts of ecotourism. Approach: The research methods comprise of secondary data collection and field survey via an in-depth interview with selected key informants. This is aided by on-field observation to verify and complement the re...

  17. The Bradford Hill considerations on causality: a counterfactual perspective

    Directory of Open Access Journals (Sweden)

    Höfler Michael

    2005-11-01

    Full Text Available Abstract Bradford Hill's considerations published in 1965 had an enormous influence on attempts to separate causal from non-causal explanations of observed associations. These considerations were often applied as a checklist of criteria, although they were by no means intended to be used in this way by Hill himself. Hill, however, avoided defining explicitly what he meant by "causal effect". This paper provides a fresh point of view on Hill's considerations from the perspective of counterfactual causality. I argue that counterfactual arguments strongly contribute to the question of when to apply the Hill considerations. Some of the considerations, however, involve many counterfactuals in a broader causal system, and their heuristic value decreases as the complexity of a system increases; the danger of misapplying them can be high. The impacts of these insights for study design and data analysis are discussed. The key analysis tool to assess the applicability of Hill's considerations is multiple bias modelling (Bayesian methods and Monte Carlo sensitivity analysis; these methods should be used much more frequently.

  18. Geologic and paleoecologic studies of the Nebraska Sand Hills

    Science.gov (United States)

    Ahlbrandt, Thomas S.; Fryberger, S.G.; Hanley, John H.; Bradbury, J. Platt

    1980-01-01

    PART A: The Nebraska Sand Hills are an inactive, late Quaternary, most probably Holocene, dune field (covering 57,000 km 2 ) that have been eroded along streams and in blowouts, resulting in excellent lateral and vertical exposures of the stratification of dune and interdune sediments. This paper presents new data on the geometry, primary sedimentary structures, modification of sedimentary structures, direction of sand movement, and petrography of these eolian deposits. Eolian deposits of the Sand Hills occur as relatively thin (9-24 m) 'blanket' sands, composed of a complex of dune and discontinuous, diachronous interdune deposits unconformably overlying fluviolacustrine sediments. The internal stratification of large dunes in the Sand Hills (as high as 100 m), is similar to the internal stratification of smaller dunes of the same type in the Sand Hills, differing only in scale. Studies of laminae orientation in the Sand Hills indicate that transverse, barchan, and blowout dunes can be differentiated in rocks of eolian origin using both the mean dip angle of laminae and the mean angular deviation of dip direction. A variety of secondary structures modify or replace primary eolian stratification in the Sand Hills, the more common of which are dissipation structures and bioturbation. Dissipation structures in the Sand Hills may develop when infiltrating water deposits clay adjacent to less permeable layers in the sand, or along the upper margins of frozen layers that form in the sands during winter. Cross-bed measurements from dunes of the Nebraska Sand Hills necessitate a new interpretation of the past sand transport directions. The data from these measurements indicate a general northwest-to-southeast drift of sand, with a more southerly drift in the southeast part of the Sand Hills. A large area of small dunes Sand Hills was interpreted by him on the basis of morphology only. We interpret these as transverse-ridge dunes that were generally moving to the south

  19. The Effects of Variable Welding and Devitrification on the Magnetic Fabric of Ash Flow Tuffs: An AMS and AARM Study of the Oligocene Carpenter Ridge Tuff, San Juan Mountains, Colorado

    Science.gov (United States)

    Mason, S. N.; Geissman, J. W.

    2011-12-01

    Anisotropy of magnetic susceptibility (AMS) data have been shown to be a powerful means of estimating the transport direction, and thus inferred source region, for several large volume, regionally extensive ash-flow tuffs (ignimbrites). Anisotropy of anhysteretic remanent magnetization (AARM) data have, on the other hand, corroborated inferred controls by different assemblages of magnetic particles on magnetic fabrics. For ash-flow tuffs, the effects of variable degrees of welding and subsequent devitrification on the magnetic fabric of these pyroclastic deposits are not well understood. We have collected magnetic fabric data from a continuously exposed sequence of outflow facies of the ca. 27.55 Ma Carpenter Ridge Tuff (CRT), one of the major large volume ash-flow tuffs of the Southern Rocky Mountain Volcanic Field, southwest Colorado, about 3 km east of Buffalo Pass on Colorado Highway 114. The CRT, a compound cooling unit, is of reverse polarity (although there is considerable internal variability in direction through the section) and was sourced from the Bachelor Caldera, southwest of the sample locality. Some 21 total independently oriented samples, as very large oriented blocks, were collected in traverse fashion through most of the lowermost cooling unit of the tuff, and an additional ten block samples were collected from the moderately welded and completely devitrified third cooling unit. At least ten and often 20 to 30 discrete specimens were prepared for analyses from each block. Orientation of AMS principal axes are internally consistent at the oriented sample level and, overall, throughout the section sampled, and imply a west to east transport orientation in this area, consistent with several other sampling sites in the CRT in the northeast part of the Southern Rocky Mountain Volcanic Field. AARM data at the block sample level are usually more dispersed. All of the samples have positive T values, implying strong foliations. The degree of anisotropy (P

  20. Mineralogy, origin and commercial value of the zeolite-rich tuffs in the Petrota-Pentalofos area, Evros County, Greece

    Directory of Open Access Journals (Sweden)

    Walsh, J. N.

    1998-04-01

    Full Text Available The zeolite-rich tuffs of the Petrota-Pentalofos area were deposited in the Arrestees Basin during the Eocene. They are up to 100 m thick and extend more than 15 Km in a long axis. Most of the outcrops consist of frequent alternations of very fine grained tuff with pumice and lapel tuffs, the latter containing detrital fragments of the Mesozoic substrate of the basin. X-ray Diffraction, Scanning Electron Microscopy and light microscopy analysis on quarry and borehole samples has shown that the tuffs are composed mainly of clinoptilolite and minor cristobalite, with a small proportion of detrital constituents (quartz, mica-schist and pyrogenic crystals (feldspars, quartz, biotite. Minor amounts of mordenite randomly occur in some of the northern outcrops, closer to the occurrences of lava. ICP-AES chemical analysis of the tuffs gives evidence that the original magmas were of quartz-latite composition. The tuffs rest on pre-Cenozoic metamorphic basement and pass gradationally upwards into sandstone and limestone. Evidence is given for deposition of the tuffs in a supra to infra-littoral environment. The zeolitic tuffs originated as epiclastic volcanic sediments, transported by water from the source of the eruption. The transformation of the volcanic glass of the tuffs to zeolite and cristobalite has taken place by meteoric waters in an open hydrological system existed during the Tertiary. The zeolitic rocks are currently being exploited as an animal feed supplement.Las tobas ricas en cebollitas del área de Petrota-Pentalofos se depositaron en la cuenca de Orejitas durante el Doceno. Alcanzan 100 m de potencia y superan los 15 km de extensión longitudinal. La mayoría de los afloramientos consisten en alternancias de toba de grano muy fino y toba de pómez y lapilli con fragmentos detritos del sustrato Mesozoico de la cuenca. Análisis por difamación de rayos X, microscopía electrónica de barrido y microscopía óptica en muestras de mano y de

  1. Geology of the USW SD-7 drill hole Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Rautman, C.A. [Sandia National Laboratories, Albuquerque, NM (United States); Engstrom, D.A. [Spectra Research Inst., Albuquerque, NM (United States)

    1996-09-01

    The USW SD-7 drill hole is one of several holes drilled under Site Characterization Plan Study 8.3.1.4.3.1, also known as the Systematic Drilling Program, as part of the U.S. Department of Energy characterization program at Yucca Mountain, Nevada. The Yucca Mountain site has been proposed as the potential location of a repository for high-level nuclear waste. The SD-7 drill hole is located near the southern end of the potential repository area and immediately to the west of the Main Test Level drift of the Exploratory Studies Facility. The hole is not far from the junction of the Main Test Level drift and the proposed South Ramp decline. Drill hole USW SD-7 is 2675.1 ft (815.3 m) deep, and the core recovered nearly complete sections of ash-flow tuffs belonging to the lower half of the Tiva Canyon Tuff, the Pah Canyon Tuff, and the Topopah Spring Tuff, all of which are part of the Miocene Paintbrush Group. Core was recovered from much of the underlying Calico Hills Formation, and core was virtually continuous in the Prow Pass Tuff and the Bullfrog Tuff. The SD-7 drill hole penetrated the top several tens of feet into the Tram Tuff, which underlies the Prow Pass and Bullfrog Tuffs. These latter three units are all formations of the Crater Flat Group, The drill hole was collared in welded materials assigned to the crystal-poor middle nonlithophysal zone of the Tiva Canyon Tuff; approximately 280 ft (85 m) of this ash-flow sheet was penetrated by the hole. The Yucca Mountain Tuff appears to be missing from the section at the USW SD-7 location, and the Pah Canyon Tuff is only 14.5 ft thick. The Pah Canyon Tuff was not recovered in core because of drilling difficulties, suggesting that the unit is entirely nonwelded. The presence of this unit is inferred through interpretation of down-hole geophysical logs.

  2. Geology of the USW SD-7 drill hole Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Rautman, C.A. [Sandia National Laboratories, Albuquerque, NM (United States); Engstrom, D.A. [Spectra Research Inst., Albuquerque, NM (United States)

    1996-09-01

    The USW SD-7 drill hole is one of several holes drilled under Site Characterization Plan Study 8.3.1.4.3.1, also known as the Systematic Drilling Program, as part of the U.S. Department of Energy characterization program at Yucca Mountain, Nevada. The Yucca Mountain site has been proposed as the potential location of a repository for high-level nuclear waste. The SD-7 drill hole is located near the southern end of the potential repository area and immediately to the west of the Main Test Level drift of the Exploratory Studies Facility. The hole is not far from the junction of the Main Test Level drift and the proposed South Ramp decline. Drill hole USW SD-7 is 2675.1 ft (815.3 m) deep, and the core recovered nearly complete sections of ash-flow tuffs belonging to the lower half of the Tiva Canyon Tuff, the Pah Canyon Tuff, and the Topopah Spring Tuff, all of which are part of the Miocene Paintbrush Group. Core was recovered from much of the underlying Calico Hills Formation, and core was virtually continuous in the Prow Pass Tuff and the Bullfrog Tuff. The SD-7 drill hole penetrated the top several tens of feet into the Tram Tuff, which underlies the Prow Pass and Bullfrog Tuffs. These latter three units are all formations of the Crater Flat Group, The drill hole was collared in welded materials assigned to the crystal-poor middle nonlithophysal zone of the Tiva Canyon Tuff; approximately 280 ft (85 m) of this ash-flow sheet was penetrated by the hole. The Yucca Mountain Tuff appears to be missing from the section at the USW SD-7 location, and the Pah Canyon Tuff is only 14.5 ft thick. The Pah Canyon Tuff was not recovered in core because of drilling difficulties, suggesting that the unit is entirely nonwelded. The presence of this unit is inferred through interpretation of down-hole geophysical logs.

  3. Green-tuff landslide areas are beneficial for rice nutrition in Japan

    Directory of Open Access Journals (Sweden)

    Kazue Tazaki

    2006-12-01

    Full Text Available Japanese Islands are covered with weathered volcanic rocks and soils. Terraced rice field are located in green-tuff areas which are very fertile but where landslides occur associated to strong earthquakes. The Xray diffraction and X-ray fluorescence analyses of the soils in landslide area identified predominant smectite and Mg, Al, Si, K, Ti, Mn and Fe are main components. The rice leaf showed that S, Cl, K and Ca play important roles for nutrients in the area. Drainpipe systems have set up in the green- tuff areas to reduce the risks of landslides. Reddish brown microbial mats inhabited bacteria and diatom in the drainpipe outlets. The microbial mats are rich in Fe and PO4(3-. The iron bacteria in the ground water have a high metabolic rate suggesting that the weathering materials were produced by not only physical and chemical influence but also by microorganism. Many microorganisms attach to mineral surfaces and show their high impact in the water mineral chemistry in the landslide area. Bacteria in the green-tuff over landslide area play important roles for sustainable agriculture including rice nutrition.As Ilhas Japonesas são cobertas de rochas e solos vulcânicos intemperizados. Terraços de campos de arroz estão comumente localizados em áreas de tufos verdes, as quais são férteis, mas estão geralmente sujeitas a trágicos deslizamentos de terra associados a grandes terremotos. As análises dos solos por difração e fluorescência de raios-X em áreas de deslizamento identificam a predominância de esmectitas, cujos componentes principais são Mg, Al, Si, K, Ca, Ti, Mn, e Fe como principais componentes. A palha de arroz mostrou que S, Cl, K, e Ca têm importantes papéis para a nutrição dos solos dessa área. Sistemas de tubos de deslizamento foram instalados nestas áreas detufos verdes de forma a reduzir os riscos de deslizamentos. Nas saídas dos tubos de descarga se formou uma esteira de algas microbianas marrom avermelhadas

  4. Confort 15 model of conduit dynamics: applications to Pantelleria Green Tuff and Etna 122 BC eruptions

    Science.gov (United States)

    Campagnola, S.; Romano, C.; Mastin, L. G.; Vona, A.

    2016-06-01

    Numerical simulations are useful tools to illustrate how flow parameters and physical processes may affect eruption dynamics of volcanoes. In this paper, we present an updated version of the Conflow model, an open-source numerical model for flow in eruptive conduits during steady-state pyroclastic eruptions (Mastin and Ghiorso in A numerical program for steady-state flow of magma-gas mixtures through vertical eruptive conduits. U.S. Geological Survey Open File Report 00-209, 2000). In the modified version, called Confort 15, the rheological constraints are improved, incorporating the most recent constitutive equations of both the liquid viscosity and crystal-bearing rheology. This allows all natural magma compositions, including the peralkaline melts excluded in the original version, to be investigated. The crystal-bearing rheology is improved by computing the effect of strain rate and crystal shape on the rheology of natural magmatic suspensions and expanding the crystal content range in which rheology can be modeled compared to the original version ( Conflow is applicable to magmatic mixtures with up to 30 vol% crystal content). Moreover, volcanological studies of the juvenile products (crystal and vesicle size distribution) of the investigated eruption are directly incorporated into the modeling procedure. Vesicle number densities derived from textural analyses are used to calculate, through Toramaru equations, maximum decompression rates experienced during ascent. Finally, both degassing under equilibrium and disequilibrium conditions are considered. This allows considerations on the effect of different fragmentation criteria on the conduit flow analyses, the maximum volume fraction criterion ("porosity criterion"), the brittle fragmentation criterion and the overpressure fragmentation criterion. Simulations of the pantelleritic and trachytic phases of the Green Tuff (Pantelleria) and of the Plinian Etna 122 BC eruptions are performed to test the upgrades in

  5. Influence of temperature on the adsorption of α-tocopherol from ethanol solutions on acid-activated clinoptilolite tuff

    Science.gov (United States)

    Kotova, D. L.; Vasilyeva, S. Yu.; Krysanova, T. A.

    2014-08-01

    Patterns in the adsorption of α-tocopherol on acid-activated clinoptilolite tuff at 283, 295, 305, and 333 K are established and explained. It is found that the selectivity of the sorbent toward the vitamin rises as the temperature of the process falls. The adsorption of α-tocopherol from dilute solutions is described in terms of the Langmuir adsorption theory. It is shown that the fixing of vitamin E monolayers in the structural matrix of clinoptilolite tuff is due to the formation of hydrogen bonds between isolated silanol groups of the adsorbent and oxygen atoms of the chromane ring and the phenol residue of α-tocopherol. The thermodynamic functions of monolayer adsorption of the vitamin are estimated. It is concluded that the formation of polymolecular layers in the form of associates is due to hydrophobic interactions between side substituents of α-tocopherol.

  6. The one-dimensional compression method for extraction of pore water from unsaturated tuff and effects on pore-water chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Higgins, J.D.; Burger, P.A. [Colorado School of Mines, Golden, CO (United States); Yang, L.C. [Geological Survey, Denver, CO (United States)

    1997-12-31

    Study of the hydrologic system at Yucca Mountain, Nevada, requires extraction of pore-water samples from unsaturated tuff bedrock. Two generations of compression cells have been designed and tested for extracting representative, unaltered pore-water samples from unsaturated tuff cores. The one-dimensional compression cell has a maximum compressive stress rating of 552 MPa. Results from 86 tests show that the minimum degree of saturation for successful extraction of pore water was about 14% for non welded tuff and about 61% for densely welded tuff. The high-pressure, one-dimensional compression cell has a maximum compressive stress rating of 827 MPa. Results from 109 tests show that the minimum degree of saturation for successful extraction of pore water was about 7.5% for non welded tuff and about 34% for densely welded tuff. Geochemical analyses show that, in general, there is a decrease in ion concentration of pore waters as extraction pressures increase. Only small changes in pore-water composition occur during the one-dimensional extraction test.

  7. Estimates of flow direction for calc-alkaline welded tuffs and paleomagnetic data reliability from anisotropy of magnetic susceptibility measurements: Central San Juan Mountains, southwest Colorado

    Science.gov (United States)

    Ellwood, Brooks B.

    1982-07-01

    Flow directions are estimated from the measurement of the magnetic fabric of 106 samples, collected at 18 sites in four welded tuff units in the central San Juan Mountains of southern Colorado. The estimates assume that the tuffs generally flowed directly away from the extrusive vents and that the lineations of magnetic grains within the tuffs represent the flow direction at individual sites. Errors in the estimation may arise from topographic variation, rheomorphism (post-emplacement mass flow) within the tuff, and other factors. Magnetic lineation is defined as the site mean anisotropy of magnetic susceptibility maximum azimuth. A test on the flow directions for individual units is based on the projection of lineation azimuths and their intersection within or near the known source caldera for the tuff. This test is positive for the four units examined. Paleomagnetic results for these tuffs are probably reliable indicators of the geomagnetic field direction in southwest Colorado, during the time (28.2-26.5 Ma) of emplacement.

  8. Permian plate margin volcanism and tuffs in adjacent basins of west Gondwana: Age constraints and common characteristics

    Science.gov (United States)

    López-Gamundí, Oscar

    2006-12-01

    Increasing evidence of Permian volcanic activity along the South American portion of the Gondwana proto-Pacific margin has directed attention to its potential presence in the stratigraphic record of adjacent basins. In recent years, tuffaceous horizons have been identified in late Early Permian-through Middle Permian (280-260 Ma) sections of the Paraná Basin (Brazil, Paraguay, and Uruguay). Farther south and closer to the magmatic tract developed along the continental margin, in the San Rafael and Sauce Grande basins of Argentina, tuffs are present in the Early to Middle Permian section. This tuff-rich interval can be correlated with the appearance of widespread tuffs in the Karoo Basin. Although magmatic activity along the proto-Pacific plate margin was continuous during the Late Paleozoic, Choiyoi silicic volcanism along the Andean Cordillera and its equivalent in Patagonia peaked between the late Early Permian and Middle Permian, when extensive rhyolitic ignimbrites and consanguineous airborne tuffaceous material erupted in the northern Patagonian region. The San Rafael orogenic phase (SROP) interrupted sedimentation along the southwestern segment of the Gondwana margin (i.e., Frontal Cordillera, San Rafael Basin), induced cratonward thrusting (i.e., Ventana and Cape foldbelts), and triggered accelerated subsidence in the adjacent basins (Sauce Grande and Karoo) located inboard of the deformation front. This accelerated subsidence favored the preservation of tuffaceous horizons in the syntectonic successions. The age constraints and similarities in composition between the volcanics along the continental margin and the tuffaceous horizons in the San Rafael, Sauce Grande, Paraná, and Karoo basins strongly suggest a genetic linkage between the two episodes. Radiometric ages from tuffs in the San Rafael, Paraná, and Karoo basins indicate an intensely tuffaceous interval between 280 and 260 Ma.

  9. Report on static hydrothermal alteration studies of Topopah Spring tuff waters in J-13 water at 150{sup 0}C

    Energy Technology Data Exchange (ETDEWEB)

    Knauss, K.G.; Beiriger, W.B.

    1984-08-31

    This report presents the results of preliminary experimental work done to define the package environment in a potential nuclear waste repository in the Topopah Spring Member of the Paintbrush Tuff. The work is supported by the Nevada Nuclear Waste Storage Investigations (NNWSI) Project as a part of the Waste Package task to design a package suitable for waste storage within volcanic units at the Nevada Test Site. Static hydrothermal alteration experiments were run for 4 months using polished wafers either fully submerged in an appropriate natural ground water or exposed to water-saturated air with enough excess water to allow refluxing. The aqueous results agreed favorably with similar experiments run using crushed tuff, and the use of solid polished wafers allowed us to directly evaluate the effects of reaction on the tuff. The results are preliminary in the sense that these experiments were run in Teflon-lined, static autoclaves, whereas subsequent experiments have been run in Dickson-type gold-cell rocking autoclaves. The results predict relatively minor changes in water chemistry, very minor alteration of the host rock, and the production of slight amounts of secondary minerals, when liquid water could return to the rock pores following the temperature maximum during the thermal period. 7 references, 16 figures, 10 tables.

  10. Stochastic Model of Fracture Frequency Heterogeneity in a Welded Tuff EGS reservoir, Snake River Plain, Idaho, USA

    Science.gov (United States)

    Moody, A.; Fairley, J. P., Jr.

    2014-12-01

    In light of recent advancements in reservoir enhancement and injection tests at active geothermal fields, there is interest in investigating the geothermal potential of widespread subsurface welded tuffs related to caldera collapse on the Snake River Plain (SRP). Before considering stimulation strategies, simulating heat extraction from the reservoir under in-situ fracture geometries will give a first-order estimation of extractable heat. With only limited deep boreholes drilled on the SRP, few analyses of the bulk hydrologic properties of the tuffs exist. Acknowledging the importance of the spatial heterogeneity of fractures to the permeability and injectivity of reservoirs hosted in impermeable volcanic units, we present fracture distributions from ICDP hole 5036-2A drilled as a part of Project HOTSPOT. The core documents more than 1200 m of largely homogeneous densely welded tuff hosting an isothermal warm-water reservoir at ~60˚ C. Multiple realizations of a hypothetical reservoir are created using sequential indicator algorithms that honor the observed vertical fracture frequency statistics. Results help form criteria for producing geothermal energy from the SRP.

  11. Testing the Consistency of Diffusion Modelling in Multiple Crystal Phases: A Case Study from the Bishop Tuff, California

    Science.gov (United States)

    Morgan, D. J.; Chamberlain, K. J.; Wilson, C. J. N.

    2014-12-01

    Diffusion modelling of elemental gradients across compositional zones within crystals is frequently used to investigate timescales of various magmatic processes. In most cases, however, only a single crystal phase is used for this modelling. The ~0.76 Ma Bishop Tuff (Long Valley, eastern California) in later parts of its eruptive sequence has zoned orthopyroxene, quartz and sanidine. It thus provides an unusual opportunity to compare the modelled timescales from each phase, and assess the limitations of single-phase diffusion modelling in lower-temperature, rhyolitic volcanic systems. The presence of a late-stage compositionally distinct melt (the 'bright-rim' melt) mixing into the lower parts of the Bishop magma chamber has been noted by many authors [e.g. Wark et al. 2007, Geology 35, 235; Roberge et al. 2013, CMP 165, 237; Chamberlain et al. 2014, J Petrol 55, 395] in later-erupted material discharged from vents along the northern ring fracture of the caldera. Here we present the results of 1D diffusion modelling of Ba and Sr in sanidine, Ti in quartz and Fe-Mg interdiffusion in orthopyroxene in samples from later-erupted ignimbrite packages in the tuff. Timescales from diffusion modelling of Fe-Mg interdiffusion in orthopyroxene are Bishop Tuff eruption. We highlight the importance of having a good understanding of the assumptions made and uncertainties in diffusion coefficients when undertaking such modelling, especially in examples where only one phase is available for diffusion modelling.

  12. Adsorption kinetic of arsenates as water pollutant on iron, manganese and iron-manganese-modified clinoptilolite-rich tuffs

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez-Cedillo, M.J. [Instituto Nacional de Investigaciones Nucleares, Departamento de Quimica, A.P. 18-1027, Col, Escandon, Del, Miguel Hidalgo, C.P. 11801 Mexico, D.F. (Mexico); Universidad Autonoma del Estado de Mexico, Facultad de Quimica, Paseo Colon y Paseo Tollocan s/n, Toluca (Mexico); Olguin, M.T. [Instituto Nacional de Investigaciones Nucleares, Departamento de Quimica, A.P. 18-1027, Col, Escandon, Del, Miguel Hidalgo, C.P. 11801 Mexico, D.F. (Mexico)], E-mail: mog@nuclear.inin.mx; Fall, Ch. [Centro Interamericano de Recursos del Agua, CIRA, km 14.5 de la Carretera Toluca - Ixtlahuaca, Unidad San Cayetano, Estado de Mexico (Mexico)

    2009-04-30

    Arsenate adsorption from aqueous solutions onto clinoptilolite-heulandite rich tuffs modified with iron or manganese or a mixture of both iron and manganese in this work was investigated. A kinetic model was considered to describe the arsenates adsorption on each zeolitic material. The modified clinoptilolite-heulandite rich tuffs were characterized by scanning electron microscopy and X-ray diffraction analysis. The elemental composition and the specific surface area of the zeolitic material were also determined. The arsenate adsorption by the modified zeolites was carried on in a batch system considering a contact time from 5 min to 24 h for the kinetic experimentation. The arsenic was detected by atomic absorption spectrometer using a hydride generator. The kinetics of the arsenate adsorption processes were described by the pseudo-second-order model and the obtained parameter k varies from 0.15 to 5.66 {mu}g/gh. In general, the results suggested that the kinetic adsorption of arsenates on the modified clinoptilolite-rich tuffs depend of the metallic specie that modified the surface characteristics of the zeolitic material, the chemical nature of the metal as well as the association between different metallic chemical species in the zeolitic surface.

  13. Removal and recovery of p-phenylenediamines developing compounds from photofinishing lab-washwater using clinoptilolite tuffs from Greece.

    Science.gov (United States)

    Vlessidis, A G; Triantafillidis, C S; Evmiridis, N P

    2001-04-01

    Clinoptilolite tuffs from areas in Thrace region of Greece are compared with synthetic zeolites NaY and NH4Y for the uptake of N4-ethyl-N4-(2-methansulphonamidoethyl)-2-methyl-1,4-phenylenediamin (sesquisulphate, monohydrate) with the trade name CD-3 for the purpose to be used for clean-up and recycling photo-finishing and photo-developing washwaters. The cation-exchange capacity is found to be 6.15-11.1 mg/g for zeoliferous tuffs at equilibrium concentration of 50 ppm CD-3 in aqueous solution compared to 65.0 mg/g of NaY and 48.2 mg/g for NH4Y synthetic zeolites corresponding to the removal of CD-3 from 120 to 2001 of 50 ppm aqueous solution per kg of natural zeoliferous tuff; this capacity is only 6-10 times lower than type-Y synthetic zeolite. Initial rates of uptake are 20.8 mg/l/min for natural and 38.5 mg/l/min for synthetic zeolites. Regeneration levels of 55, 23, 35, and 33% are obtained for MCH, SF, NaY, and NH4Y, respectively. The rapid and almost complete uptake of CD-3 from its aqueous solutions at low CD-3 concentrations by the natural zeolites is promising for such an application.

  14. Permeameter studies of water flow through cement and clay borehole seals in granite, basalt and tuff

    Energy Technology Data Exchange (ETDEWEB)

    South, D.L.; Daemen, J.J.K.

    1986-10-01

    Boreholes near a repository must be sealed to prevent rapid migration of radionuclide-contaminated water to the accessible environment. The objective of this research is to assess the performance of borehole seals under laboratory conditions, particularly with regard to varying stress fields. Flow through a sealed borehole is compared with flow through intact rock. Cement or bentonite seals have been tested in granite, basalt, and welded tuff. The main conclusion is that under laboratory conditions, existing commercial materials can form high quality seals. Triaxial stress changes about a borehole do not significantly affect seal performance if the rock is stiffer than the seal. Temperature but especially moisture variations (drying) significantly degrade the quality of cement seals. Performance partially recovers upon resaturation. A skillfully sealed borehole may be as impermeable as the host rock. Analysis of the influence of relative seal-rock permeabilities shows that a plug with permeability one order of magnitude greater than that of the rock results in a flow increase through the hole and surrounding rock of only 1-1/2 times compared to the undisturbed rock. Since a borehole is only a small part of the total rock mass, the total effect is even less pronounced. The simplest and most effective way to decrease flow through a rock-seal system is to increase the seal length, assuming it can be guaranteed that no dominant by-pass flowpath through the rock exists.

  15. Mineralogic Zonation Within the Tuff Confining Unit, Yucca Flat, Nevada Test Site

    Energy Technology Data Exchange (ETDEWEB)

    Lance Prothro

    2005-09-01

    Recently acquired mineralogic data from drill hole samples in Yucca Flat show that the tuff confining unit (TCU) can be subdivided into three mineralogic zones based on the relative abundances of primary and secondary mineral assemblages. These zones are (1) an upper zone characterized by the abundance of the zeolite mineral clinoptilolite with lesser amounts of felsic and clay minerals; (2) a middle zone with felsic minerals dominant over clinoptilolite and clay minerals; and (3) a basal argillic zone where clay minerals are dominant over felsic minerals and clinoptilolite. Interpretation of the mineralogic data, along with lithologic, stratigraphic, and geophysical data from approximately 500 drill holes, reveals a three-layer mineralogic model for the TCU that shows all three zones are extensive beneath Yucca Flat. The mineralogic model will be used to subdivide the TCU in the Yucca Flat hydrostratigraphic framework model, resulting in a more accurate and versatile framework model. In addition, the identification of the type, quantity, and distribution of minerals within each TCU layer will permit modelers to better predict the spatial distribution and extent of contaminant transport from underground tests in Yucca Flat, at both the level of the hydrologic source term and the corrective action unit.

  16. Properties of Vulcanized Polyisoprene Rubber Composites Filled with Opalized White Tuff and Precipitated Silica

    Directory of Open Access Journals (Sweden)

    Suzana Samaržija-Jovanović

    2014-01-01

    Full Text Available Opalized white tuff (OWT with 40 μm average particle size and 39.3 m2/g specific surface area has been introduced into polyisoprene rubber (NR. Their reinforcing effects were evaluated by comparisons with those from precipitated silica (PSi. The cure characteristic, apparent activation energy of cross-link (Eac and reversion (Ear, and mechanical properties of a variety of composites based on these rubbers were studied. This was done using vulcanization techniques, mechanical testing, and scanning electron microscopy (SEM. The results showed that OWT can greatly improve the vulcanizing process by shortening the time of optimum cure (tc90 and the scorch time (ts2 of cross-linked rubber composites, which improves production efficiency and operational security. The rubber composites filled with 50 phr of OWT were found to have good mechanical and elastomeric properties. The tensile strengths of the NR/OWT composites are close to those of NR/PSi composites, but the tear strength and modulus are not as good as the corresponding properties of those containing precipitated silica. Morphology results revealed that the OWT is poorly dispersed in the rubber matrix. According to that, the lower interactions between OWT and polyisoprene rubber macromolecules are obtained, but similar mechanical properties of NR/OWT (100/50 rubber composites compared with NR/PSi (100/50 rubber composites are resulted.

  17. Potential corrosion and degradation mechanisms of Zircaloy cladding on spent nuclear fuel in a tuff repository

    Energy Technology Data Exchange (ETDEWEB)

    Rothman, A.J.

    1984-09-01

    A literature review and analysis were made of corrosion and degradation processes applicable to Zircaloy cladding on spent nuclear fuel in a tuff repository. In particular, lifetime sought for the Zircaloy is 10,000 years. Among the potential failure mechanisms examined were: oxidation by steam, air, and water, including the effects of ions whose presence is anticipated in the water; mechanical overload; stress (creep) rupture; stress-corrosion cracking (SCC); and delayed failure due to hydride cracking. The conclusion is that failure due to oxidation is not credible, although a few experiments are suggested to confirm the effect of aqueous fluoride on the Zircaloy cladding. Mechanical overload is not a problem, and failure from stress-rupture does not appear likely based on a modified Larson-Miller analysis. Analysis shows that delayed hydride cracking is not anticipated for the bulk of spent fuel pins. However, for a minority of pins under high stress, there is some uncertainty in the analysis as a result of: (1) uncertainty about crack depths in spent fuel claddings and (2) the effect of slow cooling on the formation of radially oriented hydride precipitates. Experimental resolution is called for. Finally, insufficient information is currently available on stress-corrosion cracking. While evidence is presented that SCC failure is not likely to occur, it is difficult to demonstrate this conclusively because the process is not clearly understood and data are limited. Further experimental work on SCC susceptibility is especially needed.

  18. Testing for fullerenes in geologic materials: Oklo carbonaceous substances, Karelian shungites, Sudbury Black Tuff

    Science.gov (United States)

    Mossman, David; Eigendorf, Guenter; Tokaryk, Dennis; Gauthier-Lafaye, François; Guckert, Kristal D.; Melezhik, Victor; Farrow, Catharine E. G.

    2003-03-01

    Fullerenes have been reported from diverse geologic environments since their discovery in shungite from Karelian Russia. Our investigation is prompted by the presence of onionskin-like structures in some carbonaceous substances associated with the fossil nuclear fission reactors of Oklo, Gabon. The same series of extractions and the same instrumental techniques, laser desorption ionization and high-resolution mass spectroscopy (electron-impact mass spectroscopy), were employed to test for fullerenes in samples from three different localities: two sites containing putative fullerenes (Sudbury Basin and Russian Karelia) and one new location (Oklo, Gabon). We confirm the presence of fullerenes (C60 and C70) in the Black Tuff of the Onaping Formation impact breccia in the Sudbury Basin, but we find no evidence of fullerenes in shungite samples from various locations in Russian Karelia. Analysis of carbonaceous substances associated with the natural nuclear fission reactors of Oklo yields no definitive signals for fullerenes. If fullerenes were produced during sustained nuclear fission at Oklo, then they are present below the detection limit (˜100 fmol), or they have destabilized since formation. Contrary to some expectations, geologic occurrences of fullerenes are not commonplace.

  19. Correlation of the oldest Toba Tuff to sediments in the central Indian Ocean Basin

    Indian Academy of Sciences (India)

    J N Pattan; M Shyam Prasad; E V S S K Babu

    2010-08-01

    We have identified an ash layer in association with Australasian microtektites of ∼0.77Ma old in two sediment cores which are ∼450 km apart in the central Indian Ocean Basin (CIOB). Morphology and chemical composition of glass shards and associated microtektites have been used to trace their provenance. In ODP site 758 from Ninetyeast Ridge, ash layer-D (13 cm thick, 0.73–0.75 Ma) and layer-E (5 cm thick, 0.77–0.78 Ma) were previously correlated to the oldest Toba Tuff (OTT) eruptions of the Toba caldera, Sumatra. In this investigation, we found tephra ∼3100 km to the southwest of Toba caldera that is chemically identical to layer D of ODP site 758 and ash in the South China Sea correlated to the OTT. Layer E is not present in the CIOB or other ocean basins. The occurrence of tephra correlating to layer D suggests a widespread distribution of OTT tephra (∼3.6 × 107 km2), an ash volume of at least ∼1800 km3, a total OTT volume of 2300 km3, and classification of the OTT eruption as a super-eruption.

  20. Electromagnetic experiment to map in situ water in heated welded tuff: Preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez, A.L.; Daily, W.D.

    1987-03-16

    An experiment was conducted in Tunnel Complex G at the Nevada Test Site to evaluate geotomography as a possible candidate for in situ monitoring of hydrology in the near field of a heater placed in densely welded tuff. Alterant tomographs of 200 MHz electromagnetic permittivity were made for a vertical and a horizontal plane. After the 1 kilowatt heater was turned on, the tomographs indicated a rapid and strong drying adjacent to the heater. Moisture loss was not symmetric about the heater, but seemed to be strongly influenced by heterogeneity in the rock mass. The linear character of many tomographic features and their spatial correlation with fractures mapped in boreholes are evidence that drying was most rapid along some fractures. When the heater was turned off, an increase in moisture content occurred around the heater and along the dry fractures. However, this process is much slower and the magnitude of the moisture increase much smaller than the changes observed during heating of the rock. The interpretation of the tomographs is preliminary until they can be processed without the restrictive assumption of straight ray paths for the signals through the highly heterogeneous rock mass. 15 refs., 4 figs.

  1. Rapid estimate of solid volume in large tuff cores using a gas pycnometer

    Energy Technology Data Exchange (ETDEWEB)

    Thies, C. [ed.; Geddis, A.M.; Guzman, A.G. [and others

    1996-09-01

    A thermally insulated, rigid-volume gas pycnometer system has been developed. The pycnometer chambers have been machined from solid PVC cylinders. Two chambers confine dry high-purity helium at different pressures. A thick-walled design ensures minimal heat exchange with the surrounding environment and a constant volume system, while expansion takes place between the chambers. The internal energy of the gas is assumed constant over the expansion. The ideal gas law is used to estimate the volume of solid material sealed in one of the chambers. Temperature is monitored continuously and incorporated into the calculation of solid volume. Temperature variation between measurements is less than 0.1{degrees}C. The data are used to compute grain density for oven-dried Apache Leap tuff core samples. The measured volume of solid and the sample bulk volume are used to estimate porosity and bulk density. Intrinsic permeability was estimated from the porosity and measured pore surface area and is compared to in-situ measurements by the air permeability method. The gas pycnometer accommodates large core samples (0.25 m length x 0.11 m diameter) and can measure solid volume greater than 2.20 cm{sup 3} with less than 1% error.

  2. Experimental Analysis and Process Modeling of Carbon Dioxide Removal Using Tuff

    Directory of Open Access Journals (Sweden)

    Emanuele Bonamente

    2016-12-01

    Full Text Available Removal of carbon dioxide via selective adsorption is a key process to obtain consumer-grade natural gas from biogas and, more generally, CO2 capture and sequestration from gaseous mixtures. The aim of this work is the characterization and classification of a natural alternative to synthetic zeolites that could be used as a carbon dioxide adsorbent. Tuff particulate, easily available as a byproduct of the construction industry, was tested with different laboratory procedures to verify its suitability for CO2 removal applications. Relevant physical and adsorption properties were measured during an intensive experimental campaign. Porosity, pore size distribution, and specific surface area were obtained with mercury intrusion porosimetry. Adsorption isotherms and saturation curves were obtained using two custom experimental apparatuses. The selective adsorption was finally modeled using an original phenomenological parameterization, and a simplified simulation of the process was performed using a computational fluid dynamic approach, validated against observed data. Results show that natural zeolites represent a very promising and sustainable alternative to synthetic zeolites in pressure swing adsorption processes for CO2 removal.

  3. Hybrid fall deposits in the Bishop Tuff, California: A novel pyroclastic depositional mechanism

    Science.gov (United States)

    Wilson, C.J.N.; Hildreth, W.

    1998-01-01

    Hybrid fall deposits in the Bishop Tuff show features common to both archetypal fall and surge deposits. Like normal-fall deposits, they have an overall plane-parallel bedding and flat-lying pumice clasts but also, like surge deposits, they show variable development of cross-bedding, some crystal and pumice sorting, and some rounding of pumice clasts. All variations exist from normal-fall deposits, through streaky material with incipient development of cross-bedding, to the hybrid fall deposits with well-developed cross-bedding. The streaky and hybrid deposits are interpreted as fall material contemporaneously redeposited by strong (up to 40 m/s) swirling winds, comparable to firestorm whirlwinds, generated by air currents associated with coeval emplacement of pyroclastic flows. Recognition of hybrid fall deposits is important in interpreting the dynamics of explosive eruptions and correctly assessing volcanic hazards. However, although such deposits may be commonly produced by explosive eruptions, especially where pyroclastic flows accompany fall activity, they are likely to be overlooked, or wrongly interpreted as surge deposits or secondary, reworked material.

  4. 2013 strategic petroleum reserve big hill well integrity grading report.

    Energy Technology Data Exchange (ETDEWEB)

    Lord, David L.; Roberts, Barry L.; Lord, Anna C. Snider; Bettin, Giorgia; Sobolik, Steven Ronald; Park, Byoung Yoon; Rudeen, David Keith; Eldredge, Lisa; Wynn, Karen; Checkai, Dean; Perry, James Thomas

    2014-02-01

    This report summarizes the work performed in developing a framework for the prioritization of cavern access wells for remediation and monitoring at the Big Hill Strategic Petroleum Reserve site. This framework was then applied to all 28 wells at the Big Hill site with each well receiving a grade for remediation and monitoring. Numerous factors affecting well integrity were incorporated into the grading framework including casing survey results, cavern pressure history, results from geomechanical simulations, and site geologic factors. The framework was developed in a way as to be applicable to all four of the Strategic Petroleum Reserve sites.

  5. Comment: Comments on "How to repair the Hill cipher"

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A modification of the Hill cipher algorithm was recently proposed by Ismail et al.(2006), who claimed that their new scheme could offer more security than the original one due to an extra non-linearity layer introduced via an elaborated key generation mechanism. That mechanism produces one different encryption key for each one of the plaintext blocks. Nevertheless, we show in this paper that their method still has severe security flaws whose weaknesses are essentially the same as that already found in the original Hill cipher scheme.

  6. Analysis of Subsidence Data for the Big Hill Site, Texas

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, Stephen J.

    1999-06-01

    The elevation change data measured at the Big Hill SPR site over the last 10 years has been studied and a model utilized to project elevation changes into the future. The subsidence rate at Big Hill is low in comparison with other Strategic Petroleum Reserve sites and has decreased with time due to the maintenance of higher operating pressures and the normal decrease in creep closure rate of caverns with time. However, the subsidence at the site is projected to continue. A model was developed to project subsidence values 20 years into the future; no subsidence related issues are apparent from these projections.

  7. Application of the Plagioclase-Liquid Hygrometer to the Bishop Tuff: Consistency with Melt Inclusion H2O Contents

    Science.gov (United States)

    Jolles, J.; Lange, R. A.

    2015-12-01

    High-silica (74-77 wt% SiO2) rhyolites are the most evolved magmas on Earth and constitute some of the largest eruptions (1000s of km3). Of these, one classic example is the Bishop Tuff, a 760 ka eruption of >670 km3 of high-silica rhyolite erupted from Long Valley caldera, CA. Documenting dissolved H2O contents is crucial for understanding its origin and evolution. Analyses of water contents measured in quartz-hosted melt inclusions from the Bishop Tuff (Wallace et al. 1999; Anderson et al. 2000) show that the Early and Middle Bishop Tuff (Ig1Eb, Ig2Ea) have higher water contents (≤ 6.3 wt% H2O) than the Late Bishop Tuff (Ig2NWa; ≤ 5.2 wt%). Our work utilizes the revised plagioclase-liquid hygrometer (Waters & Lange, 2015), which is applicable to rhyolite, to evaluate internal consistency between Fe-Ti oxide temperatures, the plagioclase hygrometer, and melt inclusion H2O analyses. Two-oxide thermometry (Ghiorso & Evans, 2008), using all possible Fe-Ti oxide pairs (between 56 and 1500 pairs for individual samples), was carried out on 2-3 pumice clasts for each sampled eruptive unit. Resulting temperatures (°C ± 1σ) for individual clasts are: 705 ± 12, 728 ± 10 for unit Ig1Eb; 710 ± 12, 728 ± 11 for unit Ig2Ea; 752 ±10, 776 ± 8, 778 ± 7 for unit Ig2NWa; 791 ± 7, 795 ± 8 for unit Ig2Nb. The compositions of the most calcic plagioclase phenocrysts in the Early and Middle units are An17-19, whereas in the Late units they are An29-30. When the Fe-Ti oxide temperatures, whole rock analyses, and plagioclase compositions are incorporated into the plagioclase hygrometer, they give water contents at the onset of plagioclase crystallization of 6.6-6.9 wt% for the Early and Middle units and 4.8-4.9 wt % for the Late units. These results show internal consistency between melt inclusion analyses of water, Fe-Ti oxide thermometry, and the plagioclase-liquid hygrometer; they further support a temperature gradient across the Early, Middle, and Late Bishop Tuff units.

  8. Summary of Radionuclide Reactive Transport Experiments in Fractured Tuff and Carbonate Rocks from Yucca Flat, Nevada Test Site

    Energy Technology Data Exchange (ETDEWEB)

    Zavarin, M; Roberts, S; Reimus, P; Johnson, M

    2006-10-11

    In the Yucca Flat basin of the Nevada Test Site (NTS), 747 shaft and tunnel nuclear detonations were conducted primarily within the tuff confining unit (TCU) or the overlying alluvium. The TCU in the Yucca Flat basin is hypothesized to inhibit radionuclide migration to the highly transmissive and regionally extensive lower carbonate aquifer (LCA) due to its wide-spread aerial extent, low permeability, and chemical reactivity. However, fast transport pathways through the TCU by way of fractures may provide a migration path for radionuclides to the LCA. Radionuclide transport in both TCU and the LCA fractures is likely to determine the location of the contaminant boundary for the Yucca Flat/Climax Mine Corrective Action Unit (CAU). Radionuclide transport through the TCU may involve both matrix and fracture flow. However, radionuclide migration over significant distances is likely to be dominated by fracture transport. Transport through the LCA will almost certainly be dominated by fracture flow, as the LCA has a very dense, low porosity matrix with very low permeability. Because of the complex nature of reactive transport in fractures, a stepwise approach to identifying mechanisms controlling radionuclide transport was used. The simplest LLNL experiments included radionuclide transport through synthetic parallel-plate fractured tuff and carbonate cores. These simplified fracture transport experiments isolated matrix diffusion and sorption effects from all other fracture transport processes (fracture lining mineral sorption, heterogeneous flow, etc.). Additional fracture transport complexity was added by performing induced fractured LCA flowthrough experiments (effect of aperture heterogeneity) or iron oxide coated parallel plate TCU flowthrough experiments (effect of fracture lining minerals). Finally naturally fractured tuff and carbonate cores were examined at LLNL and LANL. All tuff and carbonate core used in the experiments was obtained from the USGS Core Library

  9. Eruptive history and petrogenesis of the mid-Miocene McDermitt tuff, northern NV and southern OR

    Science.gov (United States)

    Starkel, W. A.; Henry, C. D.; Ellis, B. S.; Wolff, J. A.

    2010-12-01

    The mid-Miocene McDermitt caldera on the northern NV - southern OR border is commonly considered to mark initial silicic volcanism associated with the Yellowstone hotspot track, proposed by Pierce and Morgan (1992). It was initially interpreted to consist of five, partly overlapping calderas. Our new work substantially revises this picture to show that silicic magmatism began at ~16.5 Ma, after emplacement of Steens basalts likely erupted from vents to the north, but consisted of a mix of metaluminous and peralkaline rhyolite lavas, and that a single, 30 x 40 km caldera formed during eruption of a zoned rhyolite-dacite ignimbrite, the McDermitt tuff (MDT), at ~16.2 Ma. This tuff is spectacularly exposed along the west side of the caldera where Basin and Range faulting has revealed pre-caldera lavas overlain by a complete section of MDT and megabreccia, locally strongly rheomorphic and mega-rheomorphic (Hargrove and Sheridan, 1984), capped by post-collapse icelandite lava. The MDT varies from aphyric, high-SiO2, peralkaline rhyolite to abundantly porphyritic, metaluminous dacite. Detailed sections through the 600m - thick MDT have revealed significant variations in the lithologic characteristics of the tuff. These variations include 1) fiamme content (eutaxitic to fiamme-absent), 2) degree of rheomorphism, 3) phenocryst abundance and 4) lithic contents: lithic-rich tuff (clast sizes on mm- to cm-scale), single lithic mesobreccias (up to m-scale), and multi-lithic mega-breccia (up to 10’s of m-scale). Similar lithologic horizons within the MDT are found in different lateral and stratigraphic locations that cannot be easily correlated. These observations indicate that the MDT has a rather complex depositional history involving multiple eruptive events. High-precision single crystal 40Ar / 39Ar dates are all within analytical error (16.18 Ma +/- 0.03 Ma; n = 4), which indicates that all events probably occurred over much less than 100 ka. The interdigitation of

  10. Economic Development Benefits of the Mars Hill Wind Farm, Wind Powering America Rural Economic Development, Case Study (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2009-06-01

    This case study summarizes the economic development benefits of the Mars Hill Wind Farm to the community of Mars Hill, Maine. The Mars Hill Wind Farm is New England's first utility-scale wind farm.

  11. 40Ar/39Ar dating of Pleistocene tuffs: an accurate age for the Matuyama-Brunhes geomagnetic reversal (MBGR)

    Science.gov (United States)

    Mark, D. F.; Renne, P. R.; Morgan, L. E.; Deino, A.; Smith, V. C.; Ellis, B. S.; Pearce, N. J.

    2012-12-01

    Recent recalibrations of the 40Ar/39Ar system [1,2] reveal inconsistencies with some previous ages inferred for the MBGR. An Ar/Ar age [3] for the Bishop Tuff (BT) (which post-dates the MBGR by at least 15.3 ± 2.2 ka [3]) recalculated [2] yields an age of 778.0 ± 3.8 ka (1σ, full systematic uncertainty). The age is c. 10 ka older than the BT zircon ID-TIMS U-Pb age [4] and places the MBGR at c. 793 ka, c. 13 and 20 ka older than astronomical ages for the MBGR of 780 ka [5] and 773 ka [6], respectively. To determine an accurate age for the MBGR, we have made a series of 40Ar/39Ar age determinations for Pleistocene tuffs from both Indonesia and North America that have direct relationships to the MBGR. Blind analyses were conducted at SUERC and BGC. We observed excellent inter-laboratory agreement and no systematic offset in data. Ar/Ar ages are reported relative to [2] (1σ, full systematic uncertainty). Drill cores from ODP Site 758 show the precise location of the MBGR. Below the MBGR are two distal tephra horizons that we have identified as products of two temporally distinct Old Toba Tuff (OTT) eruptions (layer d OTT1 and layer D OTT2). Continuous sedimentation between OTT1 (802.8 ± 0.7 ka, n = 100, MSWD 1.2) and OTT2 (796.2 ± 0.8 ka, n = 62, MSWD 1.3) allows for calculation of an accurate sedimentation rate and for extrapolation of an age from OTT2 to the MBGR. Data define an age for the MBGR of 795.2 ± 0.9 ka. Using tephra above the MBGR boundary, the Middle Toba Tuff (layer C) and Young Toba Tuff (layer A), extrapolation down core supports a MBGR age of c. 795 ka. Recent age data for BT sanidine reported relative to FCs at 28.172 Ma (767.4 ± 1.1 Ma) [7] oddly yielded an Ar/Ar age that was indistinguishable from the BT zircon U-Pb age [4], which is consistent with previous 40Ar/39Ar age measurements made relative to FCs at 28.02 Ma [3]. Thus we made a series of 40Ar/39Ar measurements on the exact same sample as used by Rivera et al. [7] and observed

  12. Preliminary analysis of thermal-infrared multispectral scanner data of the Iron Hill, Colorado carbonatite-alkalic rock complex

    Science.gov (United States)

    Rowan, Lawrence C.; Watson, Kenneth; Miller, Susanne H.

    1992-01-01

    The Iron Hill carbonatite-alkalic igneous rock complex is in the Powderhorn mining district, approximately 40 km south-southwest of Gunnison, Colorado. The complex, which occupies about 30 sq km, was emplaced in metasedimentay and metavolcanic rocks during the later Precambrian or early Cambrian. The main rock types in the complex, from oldest to youngest, are fenite, pyroxenite, uncompahgrite, ijolite, nepheline syenite, and dolomitic carbonatite. The carbonatite is limonitic and forms an elliptially shaped 4 sq km stock. Calcitic and dolomitic carbonatite dikes are also numerous throughout the complex and in the pre-existing rocks. Pyroxenite is the most widespread rock type within the complex, but pyroxene is extensively altered to biotite, phlogopite, and vermiculite. Fenite, which formed through Na, K-metasomatism of the country rocks, typically contains more feldspar and less quartz than the equivalent unaltered country rocks. The other alkalic rock types are less widespread and less well exposed. Parts of the complex are covered by Oligocene ash-flow tuff and alluvial, colluvial, and glacial deposits. Sagebrush and grass cover is moderately dense to very dense at low to intermediate elevations; coniferous tree cover is dense at high elevations and on some north-facing slopes at lower elevations. A new algorithm was used to compute spectral emissivity ratios, independent of any emissivity assumptions. This algorithm has the advantage that any of the possible emissivity ratios can be computed and, thus, a large variety of composite ratio images can be constructed, which permits examination of various geologic hypotheses based on the spectral properties of the surface materials.

  13. Petrography, mineralogy, and chemistry of calcite-silica deposits at Exile Hill, Nevada, compared with local spring deposits

    Energy Technology Data Exchange (ETDEWEB)

    Vaniman, D.T.; Chipera, S.J.; Bish, D.L.

    1995-12-01

    Chemical, mineralogic, and petrographic analyses of siliceous calcretes from Exile Hill east of Yucca Mountain, Nevada, indicate that pedogenic processes alone account for the formation of the calcretes. These calcretes have been interpreted by some observers as evidence of seismically triggered eruptions of deep water. Such an origin could have important consequences if Yucca Mountain is developed as an unsaturated site for the disposal of high-level nuclear waste. At odds with this hypothesis are the absence of features that should be present at fault-fed springs (e.g., fissure-ridge mounds with microterraces) and the preservation within root casts of delicate pedogenic microfossils, such as calcified filaments and needle-fiber calcites. Mineral-chemical evidence of pedogenic origin is found in heavy-mineral concentrations, reflected in Fe and Sc enrichments. These concentrations, which occur in the most massive of the vein calcretes, require derivation of detritus from a mixture of weathered and eolian materials that occur in the overlying B soil horizons, as opposed to direct incorporation of adjacent unweathered bedrock. Carbonate and silica abundances and accumulation rates are well within the scope of pedogenic processes. Calcium is derived from rainwater or eolian sources, whereas silica is derived in part by dissolution of local volcanic glasses or from dissolution of unstable silica minerals that are abundant in the local tuffs. In contrast with local deposits that are of spring or seep origin, the siliceous calcretes at Yucca Mountain are pedogenic in origin as well as evolution and provide no evidence in support of conjectured spring activity.

  14. 77 FR 6110 - Bishop Hill Interconnection LLC; Supplemental Notice that Initial Market-Based Rate Filing...

    Science.gov (United States)

    2012-02-07

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Bishop Hill Interconnection LLC; Supplemental Notice that Initial Market... in the above-referenced proceeding of Bishop Hill Interconnection LLC's application for...

  15. GHG PSD Permit: Cheyenne Light, Fuel & Power / Black Hills Power, Inc. – Cheyenne Prairie Generating Station

    Science.gov (United States)

    This page contains the final PSD permit for the Cheyenne Light, Fuel & Power / Black Hills Power, Inc. Cheyenne Prairie Generating Station, located in Laramie, Wyoming, and operated by Black Hills Service Company.

  16. Possible Late Quaternary faulting in the Benton Hills, southeastern Missouri

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, J.R.; Hoffman, D. (Missouri Geological Survey Program, Rolla, MO (United States). Dept. of Natural Resources)

    1993-03-01

    Geologic mapping in the 1930's by Dan Stewart and Lyle McManamy identified numerous faults in the Thebes Gap area of the Benton Hills, including two post-late Quaternary faults (max. of 10 m displacement) along the southeastern escarpment. Recent geologic mapping (Richard Harrison, pers. comm.) suggests dextral strike-slip displacement on most of these faults; some deformation post-dates the Pliocene-Pleistocene Mounds gravel. Small historical earthquake epicenters have been recorded in the Benton Hills area. Review of these data and analysis of the geologic and structural relationships to small- and large-scale drainage and alluvial features suggest tectonic control of the southeastern escarpment of the Benton Hills. The authors propose the coincidence of geologic structures and landforms resembles tectonically active alluvial basin margins, with the Benton Hills southeastern margin representing a fault block uplift escarpment. Future seismic reflection, drilling and trenching studies are planned to determine if the escarpment is fault controlled and of recent origin.

  17. Hills for the Head. Art across the Curriculum.

    Science.gov (United States)

    Sartorius, Tara Cady

    2000-01-01

    Provides information on Maltby Sykes, the painter, addressing issues such as his assignment during World War II, being an apprentice to Diego Rivera, and his relationship with George C. Miller. Discusses both the painting and the sketch titled "Hills." Includes activities in geography, visual art, history, and mathematics. (CMK)

  18. SummerHill Homes, San Francisco Bay Area, Fremont, California

    Energy Technology Data Exchange (ETDEWEB)

    None

    2006-10-01

    Building America fact sheet on SummerHill Homes of Northern California. The Villa Savona Homes in Fremont, California were built using 15% fly ash in concrete, engineered lumber for floors, high efficiency windows with Low-emissivity (Low-E) glass, and fi

  19. Correct thermodynamic forces in Tsallis thermodynamics: connection with Hill nanothermodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Morales, Vladimir [Departament de Termodinamica, Universitat de Valencia, C/Dr. Moliner 50, E-46100 Burjassot (Spain)]. E-mail: vladimir.garcia@uv.es; Cervera, Javier [Departament de Termodinamica, Universitat de Valencia, C/Dr. Moliner 50, E-46100 Burjassot (Spain); Pellicer, Julio [Departament de Termodinamica, Universitat de Valencia, C/Dr. Moliner 50, E-46100 Burjassot (Spain)

    2005-02-28

    The equivalence between Tsallis thermodynamics and Hill's nanothermodynamics is established. The correct thermodynamic forces in Tsallis thermodynamics are pointed out. Through this connection we also find a general expression for the entropic index q which we illustrate with two physical examples, allowing in both cases to relate q to the underlying dynamics of the Hamiltonian systems.

  20. 27 CFR 9.188 - Horse Heaven Hills.

    Science.gov (United States)

    2010-04-01

    ... Junction Quadrangle, Oregon—Washington, 1962, photo revised, 1970; (9) Wood Gulch Quadrangle, Washington...; and (28) Hat Rock Quadrangle, 1993. (c) Boundary. The Horse Heaven Hills viticultural area is located... miles to the junction of Pine Creek and the western boundary of section 16, T4N/R21E, on the Wood...

  1. Modified Hill Cipher with Key Dependent Permutation and Circular Rotation

    Directory of Open Access Journals (Sweden)

    V. U.K. Sastry

    2007-01-01

    Full Text Available In this study, we have modified the Hill cipher, by including a permutation and circular rotation into the cipher. Here both the permutation and the rotation depend upon the key. From the cryptanalysis and the avalanche effect, discussed in this study, we notice that the strength of the cipher is significant.

  2. Adjusting the Focus: Padua Hills Theatre and Latino History.

    Science.gov (United States)

    Garcia, Matt

    1996-01-01

    Reveals an interesting and overlooked chapter in Hispanic cultural history. The Claremont, California, Padua Hills Theater presented Spanish-language, Mexican-theme musicals to a mostly white audience from 1931 to 1974. Although it presented romantic, and occasionally stereotypical views of Mexican American life, the theater deserves recognition.…

  3. Hills for the Head. Art across the Curriculum.

    Science.gov (United States)

    Sartorius, Tara Cady

    2000-01-01

    Provides information on Maltby Sykes, the painter, addressing issues such as his assignment during World War II, being an apprentice to Diego Rivera, and his relationship with George C. Miller. Discusses both the painting and the sketch titled "Hills." Includes activities in geography, visual art, history, and mathematics. (CMK)

  4. Large scale radial stability density of Hill's equation

    NARCIS (Netherlands)

    Broer, Henk; Levi, Mark; Simo, Carles

    2013-01-01

    This paper deals with large scale aspects of Hill's equation (sic) + (a + bp(t)) x = 0, where p is periodic with a fixed period. In particular, the interest is the asymptotic radial density of the stability domain in the (a, b)-plane. It turns out that this density changes discontinuously in a certa

  5. Adjusting the Focus: Padua Hills Theatre and Latino History.

    Science.gov (United States)

    Garcia, Matt

    1996-01-01

    Reveals an interesting and overlooked chapter in Hispanic cultural history. The Claremont, California, Padua Hills Theater presented Spanish-language, Mexican-theme musicals to a mostly white audience from 1931 to 1974. Although it presented romantic, and occasionally stereotypical views of Mexican American life, the theater deserves recognition.…

  6. Developing Independent Learners: The Box Hill School Experience

    Science.gov (United States)

    Pavey, Sarah

    2010-01-01

    Box Hill School is an independent school in Surrey, England. In 2008 the English curriculum was abandoned in favour of the International Baccalaureate Diploma (IBD). A library is a statutory requirement of the International Baccalaureate Organisation (IBO) endorsement who also recommend this be managed by a qualified teacher-librarian. In May…

  7. Dynamics of liquefaction during the 1987 Superstition Hills, California, earthquake

    Science.gov (United States)

    Holzer, T.L.; Youd, T.L.; Hanks, T.C.

    1989-01-01

    Simultaneous measurements of seismically induced pore-water pressure changes and surface and subsurface accelerations at a site undergoing liquefaction caused by the Superstition Hills, California, earthquake (24 November 1987; M = 6.6) reveal that total pore pressures approached lithostatic conditions, but, unexpectedly, after most of the strong motion ceased. Excess pore pressures were generated once horizontal acceleration exceeded a threshold value.

  8. Project Hill-Climb: Drafting and Design in Motion

    Science.gov (United States)

    Crowl, William F.

    2008-01-01

    This article describes the Hill-Climb project of a second level Computer-Aided Drafting and Design (CADD) class. The author primarily designed the activity to increase student understanding of the assembly drawing process and its components. The emphasis on problem solving adds a dimension that can aid students in their other classes as well. By…

  9. Hille Palmi naised / Juta Kivimäe

    Index Scriptorium Estoniae

    Kivimäe, Juta, 1952-

    2008-01-01

    Kuni 14. V Vabaduse galeriis avatud Hille Palmi skulptuurinäitusest "Tardunud hetked". Lühidalt eelmistest väljapanekutest: Marje Üksise näitusest "Nõnda ma lähen" ja Malle Leisi maalinäitusest

  10. The Resonance Overlap and Hill Stability Criteria Revisited

    CERN Document Server

    Ramos, X S; Beaugé, C

    2015-01-01

    We review the orbital stability of the planar circular restricted three-body problem, in the case of massless particles initially located between both massive bodies. We present new estimates of the resonance overlap criterion and the Hill stability limit, and compare their predictions with detailed dynamical maps constructed with N-body simulations. We show that the boundary between (Hill) stable and unstable orbits is not smooth but characterized by a rich structure generated by the superposition of different mean-motion resonances which does not allow for a simple global expression for stability. We propose that, for a given perturbing mass $m_1$ and initial eccentricity $e$, there are actually two critical values of the semimajor axis. All values $a a_{\\rm unstable}$ are unstable in the Hill sense. The first limit is given by the Hill-stability criterion and is a function of the eccentricity. The second limit is virtually insensitive to the initial eccentricity, and closely resembles a new resonance over...

  11. Butterflies (Lepidoptera of Dibang Valley, Mishmi Hills, Arunachal Pradesh, India

    Directory of Open Access Journals (Sweden)

    M.J. Gogoi

    2012-10-01

    Full Text Available The present paper is the result of a butterfly diversity survey in the Mishmi Hills, Arunachal Pradesh including the Mehao Wildlife Sanctuary. The survey was conducted from March 7 to June 22, 2011. 294 butterfly species were recorded. The survey also resulted in the sighting of elusive butterflies like Meandrusa payeni evan, Meandrusa lachinus lachinus, Byasa polla and Spindasis rukmini.

  12. Geologic history of the Black Hills caves, South Dakota

    Science.gov (United States)

    Palmer, Arthur N.; Palmer, Margaret; Paces, James B.

    2016-01-01

    Cave development in the Madison aquifer of the Black Hills has taken place in several stages. Mississippian carbonates first underwent eogenetic (early diagenetic) reactions with interbedded sulfates to form breccias and solution voids. Later subaerial exposure allowed oxygenated meteoric water to replace sulfates with calcite and to form karst and small caves. All were later buried by ~2 km of Pennsylvanian–Cretaceous strata.

  13. The Fish Canyon Tuff: A new look at an old low-temperature thermochronology standard

    Science.gov (United States)

    Gleadow, Andrew; Harrison, Mark; Kohn, Barry; Lugo-Zazueta, Rául; Phillips, David

    2015-08-01

    The Fish Canyon Tuff (FCT) has served as an important source for geochronology standards, particularly for fission track, K-Ar and (40Ar/39Ar) dating, even though efforts to establish precise ages for its constituent minerals have proved to be unexpectedly complex. To evaluate the suitability of FCT apatite as a standard for apatite (U-Th-Sm)/He (AHe) thermochronometry, and to test underlying assumptions about its suitability for apatite fission track (AFT) thermochronometry, we analysed samples from a series of sites throughout the vertical and lateral extent of the host ignimbrite sheet. Samples were collected from the relatively lithic-rich, classic sampling location in the lower part of the thick proximal ignimbrite and a ∼ 330 m vertical section of FCT immediately above it. Average weighted mean AHe ages from multiple analyses at five sites in this profile range from 20.8 ± 0.4 Ma from the classic site at the base, to an average of 28.4 ± 0.2 Ma (all ± 1 σ) in the upper part of the section. The AHe age at the classic site is substantially reduced at 20.8 ± 0.4 Ma relative to a reference age for ignimbrite emplacement of 28.2 Ma. Corresponding zircon (U-Th)/He (ZHe) ages for these samples are all concordant at 28.3 ± 0.4 Ma. By contrast, apatite fission track (AFT) ages from the same vertical section are all concordant at 27.4 ± 0.7 Ma with the central age of 28.8 ± 0.8 Ma at the classic site, except for the uppermost sample (23.2 ± 1.7 Ma) for which clear evidence for local, probably fire, disturbance is seen in the track length distribution. The AHe data at the classic site thus provide evidence for substantial post-eruptive Early Miocene cooling of the tuff consistent with its position at the bottom of a deeply incised valley with ∼ 800 m of local relief and probably > 1000 m of removed section above it. The AFT age of the classic sampling site, however, is indistinguishable from ignimbrite emplacement and thus continues to be a useful standard

  14. 78 FR 48466 - Comcast Cable, West Division Customer Care, Morgan Hill, California; Notice of Negative...

    Science.gov (United States)

    2013-08-08

    ... Employment and Training Administration Comcast Cable, West Division Customer Care, Morgan Hill, California... workers of Comcast Cable, West Division Customer Care, Morgan Hill, California (subject firm). The... eligibility of Comcast Cable, West Division Customer Care, Morgan Hill, California, to apply for...

  15. The Hill equation: a review of its capabilities in pharmacological modelling.

    Science.gov (United States)

    Goutelle, Sylvain; Maurin, Michel; Rougier, Florent; Barbaut, Xavier; Bourguignon, Laurent; Ducher, Michel; Maire, Pascal

    2008-12-01

    The Hill equation was first introduced by A.V. Hill to describe the equilibrium relationship between oxygen tension and the saturation of haemoglobin. In pharmacology, the Hill equation has been extensively used to analyse quantitative drug-receptor relationships. Many pharmacokinetic-pharmacodynamic models have used the Hill equation to describe nonlinear drug dose-response relationships. Although the Hill equation is widely used, its many properties are not all well known. This article aims at reviewing the various properties of the Hill equation. The descriptive aspects of the Hill equation, in particular mathematical and graphical properties, are examined, and related to Hill's original work. The mechanistic aspect of the Hill equation, involving a strong connection with the Guldberg and Waage law of mass action, is also described. Finally, a probabilistic view of the Hill equation is examined. Here, we provide some new calculation results, such as Fisher information and Shannon entropy, and we introduce multivariate probabilistic Hill equations. The main features and potential applications of this probabilistic approach are also discussed. Thus, within the same formalism, the Hill equation has many different properties which can be of great interest for those interested in mathematical modelling in pharmacology and biosciences.

  16. Geology, geochemistry and geochronology of the Songwe Hill carbonatite, Malawi

    Science.gov (United States)

    Broom-Fendley, Sam; Brady, Aoife E.; Horstwood, Matthew S. A.; Woolley, Alan R.; Mtegha, James; Wall, Frances; Dawes, Will; Gunn, Gus

    2017-10-01

    Songwe Hill, Malawi, is one of the least studied carbonatites but has now become particularly important as it hosts a relatively large rare earth deposit. The results of new mapping, petrography, geochemistry and geochronology indicate that the 0.8 km diameter Songwe Hill is distinct from the other Chilwa Alkaline Province carbonatites in that it intruded the side of the much larger (4 × 6 km) and slightly older (134.6 ± 4.4 Ma) Mauze nepheline syenite and then evolved through three different carbonatite compositions (C1-C3). Early C1 carbonatite is scarce and is composed of medium-coarse-grained calcite carbonatite containing zircons with a U-Pb age of 132.9 ± 6.7 Ma. It is similar to magmatic carbonatite in other carbonatite complexes at Chilwa Island and Tundulu in the Chilwa Alkaline Province and others worldwide. The fine-grained calcite carbonatite (C2) is the most abundant stage at Songwe Hill, followed by a more REE- and Sr-rich ferroan calcite carbonatite (C3). Both stages C2 and C3 display evidence of extensive (carbo)-hydrothermal overprinting that has produced apatite enriched in HREE (<2000 ppm Y) and, in C3, synchysite-(Ce). The final stages comprise HREE-rich apatite fluorite veins and Mn-Fe-rich veins. Widespread brecciation and incorporation of fenite into carbonatite, brittle fracturing, rounded clasts and a fenite carapace at the top of the hill indicate a shallow level of emplacement into the crust. This shallow intrusion level acted as a reservoir for multiple stages of carbonatite-derived fluid and HREE-enriched apatite mineralisation as well as LREE-enriched synchysite-(Ce). The close proximity and similar age of the large Mauze nepheline syenite suggests it may have acted as a heat source driving a hydrothermal system that has differentiated Songwe Hill from other Chilwa carbonatites.

  17. Adsorption of Ba{sup 2+} by Ca-exchange clinoptilolite tuff and montmorillonite clay

    Energy Technology Data Exchange (ETDEWEB)

    Chavez, M.L., E-mail: marilu@servidor.unam.mx [Facultad de Quimica, Universidad Nacional Autonoma de Mexico, Cd. Universitaria, 04510 Mexico, D. F. (Mexico); Pablo, L. de, E-mail: liberto@servidor.unam.mx [Instituto de Geologia, Universidad Nacional Autonoma de Mexico, Cd. Universitaria, 04510 Mexico, D. F. (Mexico); Garcia, T.A., E-mail: nenaquim@hotmail.com [Facultad de Quimica, Universidad Nacional Autonoma de Mexico, Cd. Universitaria, 04510 Mexico, D. F. (Mexico)

    2010-03-15

    The adsorption of barium by Ca-exchanged clinoptilolite and montmorillonite is presented. The kinetics of adsorption of Ba{sup 2+} were evaluated contacting 1 g portion of each adsorber with 100 mL 0.1N BaCl{sub 2} for 200 h. Adsorption by Ca-clinoptilolite is defined by second-order kinetics of rate constant K{sub v} 8.232 x 10{sup -2} g mg{sup -1} h{sup -1} and maximum removal of 71.885 mg g{sup -1}. It is a two-stage process initiated by a rapid uptake of Ba{sup 2+} followed by more moderate kinetics. The adsorption isotherms were determined contacting 0.2 g of each adsorber with 10 mL 0.1-0.005N BaCl{sub 2} + CaCl{sub 2} solution, Ba{sup 2+}/Ca{sup 2+} ratio 1, for periods of 7 days for the tuff and 2 days for the clay. The equilibrium adsorption is described by the Langmuir model, of equilibrium constant K 0.0151 L mg{sup -1} and maximum adsorption of 15.29 mg g{sup -1}. The adsorption of Ba{sup 2+} by Ca-exchanged montmorillonite also follows a second-order reaction of rate constant K{sub v} 3.179 x 10{sup -2} g mg{sup -1} h{sup -1}, and calculated separation of 36.74 mg g{sup -1}; the Langmuir isotherm is defined by the constant K 0.034 L mg{sup -1} and maximum adsorption of 15.29 mg g{sup -1}. X-ray diffraction shows that the exchange of Ba{sup 2+} modifies the d{sub 001} of Ca-montmorillonite from 15.4 to 12.4 A.

  18. Potentiodynamic polarization studies on candidate container alloys for the Tuff Repository

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, N.G.; Beavers, J.A.; Durr, C.L. [Cortest Columbus Technologies, OH (United States)

    1992-01-01

    Cortest Columbus Technologies, Inc. (CC Technologies) is investigating the long-term performance of container materials used for high-level radioactive waste packages. This information is being developed for the Nuclear Regulatory Commission to aid in their assessment of the Department of Energy`s application to construct a geologic repository for disposal of high-level radioactive waste. This report summarizes the results of cyclic-potentiodynamic-polarization (CCP) studies performed on candidate container materials for the Tuff Repository. The CPP technique was used to provide an understanding of how specific variables such as environmental composition, temperature, alloy composition, and welding affect both the general- and localized-corrosion behavior of two copper-base and two Fe-Cr-Ni alloys in simulated repository environments. A statistically-designed test solution matrix was formulated, based on an extensive search of the literature, to evaluate the possible range of environmental species that may occur in the repository over the life of the canister. Forty-two CPP curves were performed with each alloy and the results indicated that several different types of corrosion were possible. The copper-base alloys exhibited unusual CCP behavior in that hysteresis was not always associated with pitting. The effects of temperature on the corrosions behavior were evaluated in two types of tests; isothermal tests at temperatures from 50{degrees}C to 90{degrees}C and heat-transfer tests where the solution was maintained at 50{degrees}C and the specimen was internally heated to 90{degrees}C. In the isothermal test, CPP curves were obtained with each alloy in simulated environments at 50{degrees}C, 75{degrees}C, and 90{degrees}C. The results of these CCP experiments indicated that no systematic trends were evident for the environments tested. Lastly, the effects of welding on the corrosion behavior of the alloys in simulated environments were examined.

  19. Influence of deterministic geologic trends on spatial variability of hydrologic properties in volcanic tuff

    Energy Technology Data Exchange (ETDEWEB)

    Rautman, C.A. [Sandia National Labs., Albuquerque, NM (United States); Flint, A.L. [Geological Survey, Mercury, NV (United States); Chornack, M.P. [Geological Survey, Denver, CO (United States); Istok, J.D. [Oregon State Univ., Corvallis, OR (United States). Dept. of Civil Engineering; Fling, L.E. [Raytheon Services Nevada, Mercury, NV (United States)

    1992-12-31

    Hydrologic properties have been measured on outcrop samples taken from a detailed, two-dimension grid covering a 1.4 km outcrop exposure of the 10-m thick non-welded-to-welded, shardy base microstratigraphic unit of the Tiva Canyon Member of the Miocene Paintbrush Tuff at Yucca Mountain, Nevada. These data allow quantification of spatial trends in rock matrix properties that exist in this important hydrologic unit. Geologic investigation, combined with statistical and geostatistical analyses of the numerical data, indicates that spatial variability of matrix properties is related to deterministic geologic processes that operated throughout the region. Linear vertical trends in hydrologic properties are strongly developed in the shardy base microstratigraphic unit, and they are more accurately modeled using the concept of a thickness-normalized stratigraphic elevation within the unit, rather than absolute elevation. Hydrologic properties appear to be correlated over distances of 0.25 to 0.3 of the unit thickness after removing the deterministic vertical trend. The use of stratigraphic elevation allows scaling of identified trends by unit thickness which may be of particular importance in a basal, topography-blanketing unit such as this one. Horizontal changes in hydrologic properties do not appear to form obvious trends within the limited lateral geographic extent of the ash-flow environment that was examined. Matrix properties appear to be correlated horizontally over distances between 100 and 400 m. The existence and quantitative description of these trends and patterns of vertical spatial continuity should increase confidence in models of hydrologic properties and groundwater flow in this area that may be constructed to support the design of a potential high-level nuclear waste repository at Yucca Mountain.

  20. Divergent late-stage crystal records in melt domains from the Youngest Toba Tuff, Sumatra, Indonesia

    Science.gov (United States)

    Tierney, C. R.; Reid, M. R.; Vazquez, J. A.; Chesner, C. A.

    2016-12-01

    The voluminous 74 ka Youngest Toba Tuff (YTT) ejected an enormous >1000 km3 of high-silica (>74 wt.% SiO2) rhyolite (HSR). Based on melt inclusion morphology, quartz crystallized at least several thousand years before eruption in the dominant HSR melt domain represented by moderately crystalline pumices (HSR-A; 12-25% crystals). Quartz crystallized within a couple thousand years of eruption in melts represented by rare crystal-poor pumices (HSR-B; 175 kyr before eruption for HSR-A zircon and allanite, and to 100 kyr (zircon) and 75 kyr (allanite) for the HSR-B. Additionally, HSR-B pumices have a higher proportion of crystals with detectable eruption-aged rim growth than HSR-A in zircon ( 60 vs 50%) and especially allanite ( 80 vs 40%). Rim compositions, except for HSR-B allanite, are heterogeneous, even in crystals that date to within error of eruption. Shallow depth profiles reveal that rim and near-rim growth may either be relatively continuous, or mantle distinctly older and different interior zones. The diversity in rim ages shows that individual crystals were not always at conditions suitable for detectable growth, either due to stagnation of magmatic conditions, or inclusion in other phases or crystal aggregates. Heterogeneity in rim ages and compositions of zircon and allanite within the same HSR pumice reveals a dynamic system involving migration and mixing of crystals with diverse histories. Coupled with the distinct differences in quartz crystallization, the relative youthfulness of rims and greater affinity of allanites to each other indicate the HSR-B may have experienced different conditions of magmatic storage than the HSR-A. In addition, there may have been less mixing of non-cognate crystals into the HSR-B domain. Although growth of individual crystals was sometimes interrupted, the diverse and continuous distribution of rim ages imply a sustained 175 ka history of melt residence and accumulation for the YTT overall.

  1. Laboratory study of fracture healing in Topopah Spring tuff: Implications for near field hydrology

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Wunan; Daily, W.D.

    1989-09-01

    Seven Topopah Spring tuff samples were studied to determine water permeability in this rock under pressure and temperature conditions similar to those expected in the near field of a nuclear waste package. Six of the seven samples were studied under isothermal condition; the other was subjected to a thermal gradient. Four of the six fractured samples contained a reopened, healed, natural fracture; one contained an induced tensile fracture and the other contained a saw-cut. The fracture surfaces were examined using scanning electron microscope (SEM) before and after the experiments and the water that flowed through the samples was sampled for chemical analysis. The experimental durations ranged from about 3 months to almost 6 months. Water permeability of the fractured samples was found to decrease by more than three orders of magnitude when the sample temperature increased to 150{degree}C. The sharpest decrease in permeability occurred when the temperature was increased above 90{degree}C. Permeability of the intact sample did not change significantly under the similar experimental conditions. When the temperature returned to room conditions, the water permeability did not recover. The mechanical strength of one healed sample was about half that of the intact rock. SEM studies of the fracture surfaces and water chemical analysis of the water suggested that both dissolution and deposition occurred on the fracture surfaces. Smoothing of fracture asperities because of dissolution and deposition was probably the main cause of the permeability decrease. Deposition of dissolved silica was probably the main cause of fracture healing. 12 refs., 6 figs., 1 tab.

  2. Stratigraphy, paleomagnetism, and magnetic fabric of the Toba Tuffs: Constraints on the sources and eruptive styles

    Science.gov (United States)

    Knight, Michael D.; Walker, George P. L.; Ellwood, Brooks B.; Diehl, Jimmy F.

    1986-09-01

    The Toba depression in north central Sumatra is a complex of several overlapping calderas resulting from three major ignimbrite-forming eruptions. Within the depression, the upland masses of Samosir and northern Uluan consist of welded ignimbrite capped by coarse breccia and lacustrine sediment, hitherto interpreted to be two parts of a single resurgent dome. This study has demonstrated that the welded tuffs of Samosir and Uluan have different magnetic polarities and therefore at least two different ignimbrites are present; the Samosir/Uluan massif may consist of parts of two resurgent domes. The first ignimbrite eruption occurred at 0.84 Ma and produced a very thick (>400 m), densely welded unit having a reversed polarity. Anisotropy of magnetic susceptibility (AMS) flow direction and lithic size data indicate that the source lies in the southern part of the Toba depression, and the thick deposit of Uluan is thought to have ponded in a 40-km-wide caldera. The second ignimbrite is normally magnetized. AMS flow direction data indicate two separate source vents, one to the north in the Haranggaol caldera, and another to the south. The thick deposit at Samosir is thought to have ponded in the southern caldera. Coarse sediments then accumulated over Samosir and northern Uluan and were capped by lacustrine deposits. A renewed episode of resurgence then uplifted Samosir Island and possibly the northern part of Uluan. At approximately 0.075 Ma the last and apparently largest ignimbrite eruption occurred from calderas in the north and south parts of the Toba depression. This ignimbrite is mostly nonwelded and normally magnetized. Part of the Uluan dome was destroyed by collapse of the Sibandung caldera and Latung graben and concomitant with renewed subsidence of the Haranggaol and Porsea calderas.

  3. Regional and local correlations of feldspar geochemistry of the Peach Spring Tuff, Alvord Mountain, California

    Science.gov (United States)

    Buesch, David C.

    2016-01-01

    The chemical composition of feldspar grains in an ignimbrite from the Spanish Canyon Formation in the Alvord Mountain area, California, have been used to confirm similarities in three measured sections locally, and they are similar to exposures of the Peach Spring Tuff (PST) regionally. Feldspar grains were identified on the basis of texture (zoning, as mantled feldspars, or in crystal clusters), whether the grains were attached to glass or were in pumice clasts, or were simply crystal fragments with no textural context. Chemistry was determined by electron microprobe analysis, and each analysis is calculated in terms of the percent endmember and plotted on orthoclase (Or) versus anorthite (An) plots. In general, the PST has sanidine and plagioclase compositions that are consistent with having formed in high-silica rhyolite and trachyte within a zoned magma chamber. Feldspars from the PST in Spanish Canyon area cluster along the rhyolitic trend with no grains along the trachytic trend. Similar clustering of feldspars along the rhyolitic trend with no grains along the trachytic trend also occur in the PST from Granite Spring and Providence Mountains to the east of the Alvord Mountain area, and the ranges in compositions are also similar in these locations. In contrast, the PST in the Kane Wash area of the Newberry Mountains has feldspars only from the rhyolitic trend in the basal deposits, but some grains from the trachytic trend are in the upper part of the deposit, and the range in compositions are greater than in the Spanish Canyon area. The variations in vertical compositional zoning and compositional range in these different deposits suggests there were probably different flow paths (or timing of the delivery) during the eruption and runout of the pyroclastic flow(s) generated from the climactic eruption of the PST magma chamber.

  4. Zircon crystallization and recycling in the magma chamber of the rhyolitic Kos Plateau Tuff (Aegean arc)

    Science.gov (United States)

    Bachman, O.; Charlier, B.L.A.; Lowenstern, J. B.

    2007-01-01

    In contrast to most large-volume silicic magmas in continental arcs, which are thought to evolve as open systems with significant assimilation of preexisting crust, the Kos Plateau Tuff magma formed dominantly by crystal fractionation of mafic parents. Deposits from this ~60 km3 pyroclastic eruption (the largest known in the Aegean arc) lack xenocrystic zircons [secondary ion mass spectrometry (SIMS) U-Pb ages on zircon cores never older than 500 ka] and display Sr-Nd whole-rock isotopic ratios within the range of European mantle in an area with exposed Paleozoic and Tertiary continental crust; this evidence implies a nearly closed-system chemical differentiation. Consequently, the age range provided by zircon SIMS U-Th-Pb dating is a reliable indicator of the duration of assembly and longevity of the silicic magma body above its solidus. The age distribution from 160 ka (age of eruption by sanidine 40Ar/39Ar dating; Smith et al., 1996) to ca. 500 ka combined with textural characteristics (high crystal content, corrosion of most anhydrous phenocrysts, but stability of hydrous phases) suggest (1) a protracted residence in the crust as a crystal mush and (2) rejuvenation (reduced crystallization and even partial resorption of minerals) prior to eruption probably induced by new influx of heat (and volatiles). This extended evolution chemically isolated from the surrounding crust is a likely consequence of the regional geodynamics because the thinned Aegean microplate acts as a refractory container for magmas in the dying Aegean subduction zone (continent-continent subduction).

  5. The magnitude and impact of the Youngest Toba Tuff super-eruption

    Directory of Open Access Journals (Sweden)

    Antonio eCosta

    2014-08-01

    Full Text Available Super-eruptions, orders of magnitude larger than eruptions experienced in historic times, have devastated wide areas by pyroclastic flows, covered continent-size areas by ash fallout, and injected large quantities of aerosols into the stratosphere affecting global climate. The Youngest Toba Tuff (YTT is the largest known super-eruption in the Quaternary. Here we reconstructed the ultra-distal volcanic ash dispersal during this super-eruption using a computational ash dispersal model, which provides insights into the eruption dynamics and the impact of the event. The method uses a 3D time-dependent tephra dispersion model, a set of wind fields, and several tens of thickness measurements of the YTT tephra deposit. Results reveal that the YTT eruption dispersed ~8600 km3 (~3800 km3 dense rock equivalent, DRE of ash, covering ~40 million km2 with more than 5 mm of ash. These new fallout volume estimations indicate that the total volume of the material erupted (including the massive pyroclastic density current, 1500 km3 DRE, deposits on Sumatra was ~5300 km3 DRE. Simulation results indicate that the eruption had a very large mass flow rate and that the umbrella cloud, associated with the eruption plume, spread as an enormous gravity current around the neutral buoyancy level. The YTT tephra forms a key chronostratigraphic marker in the sedimentary sequences, and is particularly useful for constraining the age of the palaeoenvironmental and archaeological records, and synchronizing these archives to investigate temporal relationships. These new constraints on the extent of the YTT deposit are therefore particularly useful for cryptotephra studies that aim to find non-visible tephra layers for these chronological purposes. This method used to constrain volcanological parameters of eruptions in the past provides insights into the dispersal processes, and allows the amount of volatiles released to be estimated which is crucial to assessing the impact of

  6. Busted Butte Phase 2: of Post-Test Mineback and Overcore Rock Samples

    Energy Technology Data Exchange (ETDEWEB)

    H.J. Turin; M.A. McGraw; C.L. Jones; C.D. Scism; W.E. Soll

    2002-10-07

    A complex tracer mixture was injected continuously for over two years into a 10 x 10 x 7 m block of tuff as part of the unsaturated-zone (UZ) tracer test at Busted Butte. The test was designed to address uncertainties associated with flow and transport models within the Topopah Springs and Calico Hills tuffs. The tracer mixture included nonreactive (Br, I, and FBAs) and reactive tracers (Li, Ce, Sm, Ni, Coy and Mn) and synthetic colloids. Once injection was completed, samples from the block were collected in two ways. Overcores were taken from around and below injection holes. Then, the entire block was excavated via mineback--during which progressive vertical planes of the block were exposed. Samples from the overcores and mineback were analyzed to determine the distribution of tracers on different spatial scales than available from collection borehole data. Rock analyses confirmed collection pad results that the nonreactive tracers, Br and FBAs, moved several meters. Furthermore, Br and FBAs are observed above and lateral to the injector planes suggesting that capillarity was an important process for tracer movement. Lithium, the most mobile of the metals, was transported on a scale of meters. This is consistent with laboratory sorption measurements and observed breakthrough on the collection pads. Co and Ni show transport distances of tens of cm, while Sm and Ce moved far less, possibly due to precipitation and sorption effects. Colloid transport was assessed using 1 ft3 blocks extracted from the BB Phase 2 block. In the Calico Hills material, after 15 L of water was injected over 3.5 months, less than 1% of the colloids injected were recovered. Flow patterns in the block indicate that water injected at the center imbibed outward from the injection point. In a block taken from a boundary of the Calico Hills ashfall layer, breakthrough was observed only due to fractures formed during drying of the block. The colloid transport module for FEHM was tested against

  7. The Menengai Tuff: A 36 ka widespread tephra and its chronological relevance to Late Pleistocene human evolution in East Africa

    Science.gov (United States)

    Blegen, Nick; Brown, Francis H.; Jicha, Brian R.; Binetti, Katie M.; Faith, J. Tyler; Ferraro, Joseph V.; Gathogo, Patrick N.; Richardson, Jonathan L.; Tryon, Christian A.

    2016-11-01

    The East African Rift preserves the world's richest Middle and Late Pleistocene (∼780-12 ka) geological, archaeological and paleontological archives relevant to the emergence of Homo sapiens. This region also provides unparalleled chronological control for many important sites through tephrochronology, the dating and correlation of volcanic ashes as widespread isochronous markers in the geological record. There are many well-characterized Pliocene-Early Pleistocene tephras that are widespread across East Africa. A comparable framework is lacking for the Middle and Late Pleistocene; a period characterized by spatially and temporally complex patterns of climate change, as well as the emergence of modern Homo sapiens and the dispersal of this species across and out of Africa. Unraveling relationships among these spatial and temporally complex phenomena requires a precise chronology. To this end we report the Menengai Tuff, a widespread volcanic ash produced by the large-scale caldera-forming eruption in Kenya and 40Ar/39Ar dated to 35.62 ± 0.26 ka. Geochemical characterization of 565 glass shards from 36 samples by wavelength-dispersive electron probe microanalysis show the Menengai Tuff was deposited over >115,000 km2 and is found in the Baringo, Chalbi, Elmenteita, Nakuru, Olorgesailie, Turkana, and Victoria basins, all of which preserve rich Late Pleistocene paleoenvironmental and archaeological archives. Correlation and dating of the Menengai Tuff demonstrate that it is the most widespread tephra and largest eruption currently known from the Late Pleistocene of East Africa. As such, it is a valuable marker in establishing a Late Pleistocene chronology for paleoclimatic, archeological, and paleontological records relevant to the study of human evolution.

  8. Petrologic and geochemical characterization of the Topopah Spring Member of the Paintbrush Tuff: outcrop samples used in waste package experiments

    Energy Technology Data Exchange (ETDEWEB)

    Knauss, K.G.

    1984-06-01

    This report summarizes characterization studies conducted with outcrop samples of Topopah Spring Member of the Paintbrush Tuff (Tpt). In support of the Waste Package Task within the Nevada Nuclear Waste Storage Investigation (NNWSI), Tpt is being studied both as a primary object and as a constituent used to condition water that will be reacted with waste form, canister, or packing material. These studies directly or indirectly support NNWSI subtasks concerned with waste package design and geochemical modeling. To interpret the results of subtask experiments, it is necessary to know the exact nature of the starting material in terms of the intial bulk composition, mineralogy, and individual phase geochemistry. 31 figures, 5 tables.

  9. Sorption Kinetics Of Selected Heavy Metals Adsorption To Natural And Fe(III Modified Zeolite Tuff Containing Clinoptilolite Mineral

    Directory of Open Access Journals (Sweden)

    Sirotiak Maroš

    2015-06-01

    Full Text Available In the research described in this paper, studied was sorption capacity of natural and ferric modification of zeolite tuff containing mineral clinoptilolite from the Nižný Hrabovec deposit to remove potentially toxic metals (ionic forms of chromium, nickel, copper and aluminium from their water solutions. We reported that the Fe (III zeolite has an enhanced ability to sorption of Cu (II, and a slight improvement occurs in the case of Cr (VI and Ni (II. On the other hand, the deterioration was observed in the case of Al (III adsorption.

  10. Sorption Kinetics Of Selected Heavy Metals Adsorption To Natural And Fe(III) Modified Zeolite Tuff Containing Clinoptilolite Mineral

    Science.gov (United States)

    Sirotiak, Maroš; Lipovský, Marek; Bartošová, Alica

    2015-06-01

    In the research described in this paper, studied was sorption capacity of natural and ferric modification of zeolite tuff containing mineral clinoptilolite from the Nižný Hrabovec deposit to remove potentially toxic metals (ionic forms of chromium, nickel, copper and aluminium) from their water solutions. We reported that the Fe (III) zeolite has an enhanced ability to sorption of Cu (II), and a slight improvement occurs in the case of Cr (VI) and Ni (II). On the other hand, the deterioration was observed in the case of Al (III) adsorption.

  11. Primary and redeposited facies from a large-magnitude, rhyolitic, phreatomagmatic eruption: Cana Creek Tuff, Late Carboniferous, Australia

    Science.gov (United States)

    McPhie, J.

    1986-07-01

    The Cana Creek Tuff is one of four rhyolitic ignimbrite members of the Late Carboniferous Currabubula Formation, a volcanogenic conglomeratic braidplain sequence exposed along the western margin of the New England Orogen in northeastern New South Wales. The source is not exposed but was probably located tens of kilometres to the west of existing outcrops. The medial to distal parts of the tuff average about 70 m in thickness, are widespread (minimum present area ˜ 1400 km 2), and comprise a primary pyroclastic facies (ignimbrite, ash-fall tuff) and a redeposited volcaniclastic facies (sandstone, conglomerate). Both facies are composed of differing proportions of crystal fragments (quartz, plagioclase, K-feldspar), pumiceous clasts (pumice, shards, fine ash), and accidental lithics. The eruption responsible for this unit was explosive and of large magnitude (dense rock equivalent volume about 100 km 3). That it was also phreatomagmatic in character is proposed on the basis of: the intimate association of primary and redeposited facies; the presence of accretionary lapilli both in ignimbrite and in ash-fall tuff; the fine grain size of juvenile pyroclasts; the low grade of the ignimbrite; and the close similarity in facies, composition and magnitude to the deposits from the 20,000y. B.P. phreatomagmatic eruption at Taupo, New Zealand (the Wairakei and parts of the Hinuera Formations). The eruption began and ended from a vent with excess water available, possibly submersed in a caldera lake, and generated volcaniclastic sheet floods and debris flows. The emplacement of the primary pyroclastic facies is correlated with an intervening stage when the water:magma mass ratio was lower. The deposits from a large-magnitude, phreatomagmatic eruption are predicted to show systematic lateral variations in facies. Primary pyroclastic facies predominate near the source although the preserved stratigraphy is an incomplete record because of widespread contemporaneous erosion

  12. EMG activities and plantar pressures during ski jumping take-off on three different sized hills.

    Science.gov (United States)

    Virmavirta, M; Perttunen, J; Komi, P V

    2001-04-01

    Different profiles of ski jumping hills have been assumed to make the initiation of take-off difficult especially when moving from one hill to another. Neuromuscular adaptation of ski jumpers to the different jumping hills was examined by measuring muscle activation and plantar pressure of the primary take-off muscles on three different sized hills. Two young ski jumpers volunteered as subjects and they performed several trials from each hill (K-35 m, K-65 m and K-90 m) with the same electromyographic (EMG) electrode and insole pressure transducer set-up. The results showed that the differences in plantar pressure and EMGs between the jumping hills were smaller than expected for both jumpers. The small changes in EMG amplitudes between the hills support the assumption that the take-off was performed with the same intensity on different jumping hills and the timing of the gluteus EMG demonstrates well the similarity of the muscle activation on different hills. On the basis of the results obtained it seems that ski jumping training on small hills does not disturb the movement patterns for bigger hills and can also be helpful for special take-off training with low speed.

  13. Sorption-desorption studies on tuff. II. Continuation of studies with samples from Jackass Flats, Nevada and initial studies with samples from Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Vine, E.N.; Aguilar, R.D.; Bayhurst, B.P.

    1980-01-01

    Distruibution coefficients were determined by a static (batch) technique for sorption-desorption of radionuclides between tuffs from drill holes UE25a No. 1 and J-13 at the Nevada Test Site and water from well J-13. Measurements were performed under atmospheric and controlled atmosphere conditions. Under atmospheric conditions tuffs high in zeolite minerals had sorption ratios of {similar_to}10{sup 3} to 10{sup 4} ml/g with Sr, Cs, Ba, Ce, Eu, Am, and Pu. For tuffs similar mineralogically to a microgranite the sorption ratios were {similar_to}10{sup 2} to 10{sup 3} ml/g. Values for U and Tc were obtained under controlled atmosphere (< 0.2 ppM 0{sub 2}) conditions. Studies were also begun to measure distribution ratios by a dynamic (column) technique. The ratios obtained for the elements studied, Sr, Cs, and Ba, were similar to, although lower than, those obtained by batch methods.

  14. Comagmatic granophyric granite in the Fish Canyon Tuff, Colorado: Implications for magma-chamber processes during a large ash-flow eruption

    Science.gov (United States)

    Lipman, P.; Dungan, M.; Bachmann, Olivier

    1997-01-01

    The 27.8 Ma Fish Canyon Tuff, a vast ash-flow sheet (??5000 km3) of uniform phenocryst-rich dacite, is representative of "monotonous intermediate" eruptions from a magma chamber that lacked compositional gradients. Sparse small fragments of comagmatic granophyre in late-erupted tuff and postcaldera lava, having mineral compositions indistinguishable from phenocrysts in the tuff and precaldera lava-like rocks, record complex events in the Fish Canyon chamber just prior to eruption. Sanidine phenocrysts in the granophyre preserve zoning evidence of mingling with andesitic magma, then shattering by decompression and volatile loss accompanying early Fish Canyon eruptions before overgrowth by granophyre. The textural and chemical disequilibria indicate that the eruption resulted from batholith-scale remobilization of a shallow subvolcanic chamber, contrary to previous interpretations of magma storage and phenocryst growth in the lower crust.

  15. Diversity and biogeography of land snails (Mollusca, Gastropoda) in the limestone hills of Perak, Peninsular Malaysia.

    Science.gov (United States)

    Foon, Junn Kitt; Clements, Gopalasamy Reuben; Liew, Thor-Seng

    2017-01-01

    Limestone hills are now gaining global conservation attention as hotspots for short-range endemic species. Levels of land snail endemism can be high at limestone hills, especially at hill clusters that are geographically isolated. In the State of Perak, Peninsular Malaysia, limestone hills have been opportunistically surveyed for land snails in the past, but the majority have yet to be surveyed. To address this knowledge gap, we systematically surveyed the terrestrial malacofauna of 12 limestone hills that, based on our opinion, are a representation of the limestone land snail assemblages within the State. Our inventory yielded high sampling completeness (>85%). We found 122 species of land snails, of which 34 species were unique to one of the surveyed hills. We identified 30 species that are potentially new to science. The number of land snail species recorded at each hill ranged between 39 and 63 species. Four of the sampled limestone hills namely, Prk 01 G. Tempurung, Prk 55 G. Pondok, Prk 47 Kanthan, and Prk 64 Bt Kepala Gajah, have high levels of species richness and unique species, representing 91% of the total species recorded in this study. We identified two clusters of limestone hills in central Perak with distinct differences in land snail species composition - a northern hill cluster on elevated granite bedrock and southern hill cluster in a low-lying valley surrounded by alluvial soils. As limestone hills continue to be quarried to meet the cement demand, the four identified limestone hills, along with other hills from the two clusters, warrant urgent conservation attention in order to maintain high species diversity within Perak's terrestrial malacofauna.

  16. OBSERVATION AND ANALYSIS OF A PRONOUNCED PERMEABILITY AND POROSITY SCALE-EFFECT IN UNSATURATED FRACTURED TUFF

    Energy Technology Data Exchange (ETDEWEB)

    V. VESSELINOV; ET AL

    2001-01-01

    Over 270 single-hole (Guzman et al., 1996) and 44 cross-hole pneumatic injection tests (Illman et al., 1998; Illman, 1999) have been conducted at the Apache Leap Research Site (ALRS) near Superior, Arizona. They have shown that the pneumatic pressure behavior of fractured tuff at the site is amenable to analysis by methods which treat the rock as a continuum on scales ranging from meters to tens of meters, and that this continuum is representative primarily of interconnected fractures. Both the single-hole and cross-hole test results are free of skin effect. Single-hole tests have yielded estimates of air permeability at various locations throughout the tested rock volume, on a nominal support scale of about 1 m. The corresponding log permeability data exhibit spatial behavior characteristic of a random fractal and yield a kriged estimate of how these 1-m scale log permeabilities vary in three-dimensional space (Chen et al., 2000). Cross-hole tests have been analyzed by means of a three-dimensional inverse model (Vesselinov et al., 2000) in two ways: (a) by interpreting pressure records from individual borehole monitoring intervals, one at a time, while treating the rock as if it was spatially uniform; and (b) by using the inverse model to interpret pressure records from multiple tests and borehole monitoring intervals simultaneously, while treating the rock as a random fractal characterized by a power variogram. The first approach has yielded equivalent air permeabilities and air-filled porosities for a rock volume characterized by a length-scale of several tens of meters. Comparable results have been obtained by means of type-curves (Illman and Neuman, 2001). The second approach amounts to three-dimensional pneumatic tomography, or stochastic imaging, of the rock. It has yielded a high-resolution geostatistical estimate of how air permeability and air-filled porosity, defined over grid blocks having a length-scale of 1 m, vary throughout the modeled rock volume

  17. Anion exchange selectivity of surfactant modified clinoptilolite-rich tuff for environmental remediation.

    Science.gov (United States)

    de Gennaro, Bruno; Catalanotti, Lilia; Bowman, Robert S; Mercurio, Mariano

    2014-09-15

    Lately, the functionalization of industrial minerals with high technological properties, such as natural zeolites, is shaping as a promising approach in environmental sphere. In fact, under the specific conditions, the surface functionalization via adsorption of cationic surfactants reverses the surface charge of the mineral, enabling zeolites to simultaneously interact either with organic contaminants or inorganic anions. This aspect allows zeolites to be used in the remediation of contaminated fluids. The present research shed new light on some still not fully understood aspects concerning exchange kinetics such as anion-exchange mechanisms and selectivity of surface modified minerals. For this purpose the mineralogical characterization and the surface properties evaluation (X Ray Powder Diffraction, chemical analysis, thermal analysis, ECEC and AEC) of a clinoptilolite-rich tuff were performed, and the anion exchange isotherms of the sample, modified with hexadecyltrimethylammonium chloride or bromide (HDTMA-Cl/-Br), were determined. Ion-exchange equilibrium data of uni-uni valent reaction were obtained by solutions containing Br(-), Cl(-), NO3(-) or ClO4(-). Liquid phase was analysed via high performance liquid chromatography. Thermodynamic quantities (Ka and ΔG(0)) were determined and compared with the Hofmeister series. The value of the ECEC, calculated in batch conditions, was about 137 mmol/kg, in good agreement with that evaluated in dynamic conditions, while the AEC data were different for the SMNZ-Br and -Cl samples, amounting to 137 and 106 mmol/kg, respectively, thus indicating a different compactness of the bilayer formed in the two cases. Moreover, the anion isotherm results and the mathematical evaluation of the thermodynamic parameters, demonstrated the good affinity of SMNZ-Br towards chloride, nitrate and perchlorate, and of SMNZ-Cl for nitrate and perchlorate, also endorsing the possibility of using the same thermodynamic approach developed to

  18. Observation and analysis of a pronounced permeability and porosity scale-effect in unsaturated fractured tuff

    Energy Technology Data Exchange (ETDEWEB)

    Illman, W. A. (Walter A.); Hyun, Y. (Yunjung); Neuman, S. P.; Di Federico, V. (Vittorio); Tartakovsky, D. M. (Daniel M.); Vesselinov, V. V. (Velimir V.)

    2001-01-01

    Over 270 single-hole (Guzman et d., 1996) and 44 cross-hole pneumatic injection tests (Illman et al., 1998; Illman, 1999) have been conducted at the Apache Leap Research Site (ALRS) near Superior, Arizona. They have shown that the pneumatic pressure behavior of fractured tuff at the site is amenable to analysis by methods which treat the rock as a continuum on scales ranging from meters to tens of meters, and that this continuum is representative primarily of interconnected fractures. Both the single-hole and cross-hole test results are free of skin effect. Single-Role tests have yielded estimates of air permeability at various locations throughout the tested rock volume, on a nonind support scale of about 1 m. The corresponding log permeability data exhibit. spatial behavior characteristic of a random fractal and yield a kriged estimate (Fig. 1) of how these 1-m scale log permeabilities vary in three-dimemional space (Chen et al., 2000). Cross-hole tests have been analyzed by means of a thee-dimensional inverse model (Vesselinov et al., 2000) in two ways: (a) by interpreting pressure 1n:ccirds from individual borehole monitoring intervals, one at a time, while treating the rock as if it was spatially uniform; and (b) by using the inverse model to interpret pressure records from multiple tests and borehole monitoring intervals simultaneously, while treating the rock as a random fractal characterized by a power variogram. The first approach has yielded equivalent air permeabilities and air-filled porosities for a rock volume characterized by a length-scale of several tens of meters. Comparable results have been obtained by means of type-curves (Illman and Neuman, 2001). The second approach mounts to three-tlimensional pneumatic tomography, or stochastic imaging, of the rock. It has yielded a high-resolution geostatistical estimate of how air permeability and air-filled porosity, defined over grid blocks having a length-scale of 1 m, vary throughout the modeled rock

  19. Analysis of Hydrogen Isotopic Exchange: Lava Creek Tuff Ash and Isotopically Labeled Water

    Science.gov (United States)

    Ross, A. M.; Seligman, A. N.; Bindeman, I. N.; Nolan, G. S.

    2015-12-01

    Nolan and Bindeman (2013) placed secondarily hydrated ash from the 7.7 ka eruption of Mt. Mazama (δD=-149‰, 2.3wt% H2Ot) in isotopically labeled water (+650 ‰ δD, +56 ‰ δ18O) and observed that the H2Ot and δ18O values remained constant, but the δD values of ash increased with the surrounding water at 20, 40 and 70 °C. We expand on this work by conducting a similar experiment with ash from the 640 ka Lava Creek Tuff (LCT, δD of -128 ‰; 2.1 wt.% H2Ot) eruption of Yellowstone to see if significantly older glass (with a hypothesized gel layer on the surface shielding the interior from alteration) produces the same results. We have experiments running at 70, 24, and 5 °C, and periodically remove ~1.5 mg of glass to measure the δD (‰) and H2Ot (wt.%) of water extracted from the glass on a TC/EA MAT 253 continuous flow system. After 600 hours, the δD of the samples left at 5 and 24 °C remains at -128 ‰, but increased 8‰ for the 70 °C run series. However, there is no measurable change in wt.% of H2Ot, indicating that hydrogen exchange is not dictated by the addition of water. We are measuring and will report further progress of isotope exchange. We also plan to analyze the water in the LCT glass for δ18O (‰) to see if, as is the case for the Mt. Mazama glass, the δ18O (‰) remains constant. We also analyzed Mt. Mazama glass from the Nolan and Bindeman (2013) experiments that have now been sitting in isotopically labeled water at room temperature for ~5 years. The water concentration is still unchanged (2.3 wt.% H2Ot), and the δD of the water in the glass is now -111 ‰, causing an increase of 38 ‰. Our preliminary results show that exchange of hydrogen isotopes of hydrated glass is not limited by the age of the glass, and that the testing of hydrogen isotopes of secondarily hydrated glass, regardless of age, may not be a reliable paleoclimate indicator.

  20. Distribution and significance of crystalline, perlitic and vesicular textures in the Ordovician Garth Tuff (Wales)

    Science.gov (United States)

    McArthur, A. N.; Cas, R. A. F.; Orton, G. J.

    Diverse spherulitic and granular crystalline fabrics, perlitic textures and fabrics related to the growth and migration of vesicles occur in the Garth Tuff, a largely welded Ordovician ignimbrite. Defining the distribution of such textures helps to constrain the ignimbrite's cooling and degassing history. Suites of spherulitic and perlitic textures closely reflect variation in cooling rates. Seven facies are defined based on the style and intensity of crystallisation: (1) a medium to coarsely crystalline, equigranular facies; (2) an intensely spherulitic facies; (3) a sparsely spherulitic facies; (4) a pectinate facies; (5) a microcrystalline to cryptocrystalline, equigranular facies; (6) a lithophysal facies; and (7) a transitional perlite-pectinate facies. Textural changes from facies 1 to 5 reflect progressively higher cooling rates. Facies 1 occurs in proximal settings in the ignimbrite's core. Facies 2 to 5 successively envelop facies 1, with facies 2 becoming the dominant fabric in the ignimbrite's core in medial settings. Facies 5 is typically developed in the originally glassy perlitic zones at the ignimbrite's welded margins. Crystallisation under hydrous conditions is reflected by second-boiling textures in the sporadically developed lithophysal facies. The seventh facies reflects a subtle interplay between cooling, hydration and crystallisation which locally prevented perlitic fracturing. The distribution of amygdales reflects patterns of volatile migration and entrapment. In the lower levels of the ignimbrite, amygdales occur in irregular concentrations or rare subvertical pipe-like structures. Pipe-like structures attest to fumarolic activity while the ignimbrite was in a rheomorphic state. Amygdales are widespread and evenly distributed in the upper levels of the ignimbrite. However, the top of the welding profile is characterised by a thin, poorly vesiculated, originally vitrophyric horizon that abruptly caps an intense concentration of amygdales

  1. Magnetism and magnetic mineralogy of ash flow tuffs from Yucca Mountain, Nevada

    Science.gov (United States)

    Schlinger, Charles M.; Veblen, David R.; Rosenbaum, Joseph G.

    1991-04-01

    The magnetic susceptibility (χ) and remanent magnetization of an ash flow sheet are profoundly influenced by cooling history after emplacement. Spatial variations in these properties, therefore, provide a potentially useful tool for geological studies. Maxima and minima in χ measured along profiles at Yucca Mountain, Nevada, identify persistent magnetic marker horizons within vitric portions of the Tiva Canyon and underlying Topopah Spring Members of the Paintbrush Tuff. The correlatable variations of χ with vertical position in these units exist over the 8 km of strike examined. The observed stratigraphic changes in magnetic properties reflect variations in amounts and mineralogy of Fe-Ti oxide phenocrysts, and the presence, shape, size, and mineralogy of magnetic Fe-oxide microcrystals that precipitated at high temperature after emplacement of each sheet. Vitrophyre near the top of the Topopah Spring Member has a distinctive maximum in χ, due to titanomagnetite phenocrysts. Susceptibility in the lower portion of the overlying Tiva Canyon Member reaches maximum values of about 1.3×10-2 (SI) near the base of the member, beneath the columnarly jointed vitrophyre, due to the presence of abundant superparamagnetic cubic Fe-oxide. These elongate microcrystals are several tens of nm long, and are typically deformed and tapered. Up section in the Tiva Canyon Member, the susceptibility decreases, going to a minimum within the columnar vitrophyre. At this stratigraphic level the precipitated Fe-oxides are larger and carry intense NRM of up to 30 A/m; χ is only 3×10-3. The whisker-like microcrystals of Fe-oxide, which typically nucleated on what appears to be chain silicate, grew as needles up to 25 μm in length. The size variations of the precipitated Fe-oxides, which were established using transmission electron microscopy (TEM) and petrographic observation, are consistent both with variations in magnetic susceptibility measured at the outcrop and with variations

  2. Influence of Lithophysal Geometry on the Uniaxial Compression of Tuff-Like Rock

    Energy Technology Data Exchange (ETDEWEB)

    Rigby, Douglas B.

    2007-06-13

    A large portion of the rock of the high-level nuclear waste repository at Yucca Mountain contains lithophysae or voids. These voids have a significant detrimental effect on the engineering properties of the rock mass and its performance. The lithophysae were formed at the time of volcanic deposition by pockets of gas trapped within the compressing and cooling pyroclastic flow material. Lithophysae vary by size, shape, and spatial frequency of occurrence. Due to the difficulties of testing actual lithophysal rock, the current mechanical property data set is limited and the numerical models of lithophysal rock are not well validated. The purpose of this task was to experimentally quantify the effect of void geometry in the mechanical compression of cubes of analog lithophysal-like rock. In this research the mechanical properties of the analog rock were systematically studied by examining various patterns of voids based on variables consisting of hole shape, size, and geometrical distribution. Each specified hole pattern was cast into 6 by 6 by 6-in. Hydro-StoneTB® specimens (produced in triplicate) and then tested under uniaxial compression. Solid Hydro-StoneTB® specimens exhibited similar mechanical properties to those estimated for rock mass solid specimens of Topopah Spring tuff. The results indicated that the compressive strength and Young’s Modulus values decrease with increasing specimen void porosity. The modulus and strength with void porosity relationships are essentially linear over the 5 to 20 percent void porosity range. When zero void porosity (solid specimen) results are added, exponential functions do not provide a good fit to the data due to a significant sensitivity of strength and modulus to the presence of macro-sized voids. From solid specimens there is roughly a 60 percent drop in strength with about 7 percent void porosity, increasing to an 80 percent drop at about 20 percent void porosity. The percent change in modulus from the solid

  3. Steepest Ascent Hill Climbing For A Mathematical Problem

    CERN Document Server

    Abraham, Siby; Sanyal, Sugata; Sanglikar, Mukund

    2010-01-01

    The paper proposes artificial intelligence technique called hill climbing to find numerical solutions of Diophantine Equations. Such equations are important as they have many applications in fields like public key cryptography, integer factorization, algebraic curves, projective curves and data dependency in super computers. Importantly, it has been proved that there is no general method to find solutions of such equations. This paper is an attempt to find numerical solutions of Diophantine equations using steepest ascent version of Hill Climbing. The method, which uses tree representation to depict possible solutions of Diophantine equations, adopts a novel methodology to generate successors. The heuristic function used help to make the process of finding solution as a minimization process. The work illustrates the effectiveness of the proposed methodology using a class of Diophantine equations given by a1. x1 p1 + a2. x2 p2 + ...... + an . xn pn = N where ai and N are integers. The experimental results vali...

  4. Meteorological observations in support of a hill cap cloud experiment

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Morten

    1998-06-01

    Humid air flows form a hill cap cloud over the Agana mountain ridge in the north-east of Tenerife. The HILLCLOUD project utilised this cloud formation to investigate the chemical and physical properties of cloud aerosols by land based observations. The project was part of the second Aerosol characterisation Experiment (ACE-2) of the International Global Atmospheric chemistry project (IGAC). The present report describes meteorological observations in support of the hill cap cloud experiment. Time-series of wind speed, wind direction, temperature and humidity were collected at ground-based meteorological stations during a period starting one year in advance of the main campaign. A series of radiosonde detecting the upstream stability and wind profile were launched during the main campaign. (au) 5 tabs., 32 ills., 6 refs.

  5. Linear Stability of Hill's Vortex to Axisymmetric Perturbations

    CERN Document Server

    Protas, Bartosz

    2015-01-01

    We consider the linear stability of Hill's vortex with respect to axisymmetric perturbations. Given that Hill's vortex is a solution of a free-boundary problem, this stability analysis is performed by applying methods of shape differentiation to the contour dynamics formulation of the problem in a 3D axisymmetric geometry. This approach allows us to systematically account for the effect of boundary deformations on the linearized evolution of the vortex under the constraint of constant circulation. The resulting singular integro-differential operator defined on the vortex boundary is discretized with a highly accurate spectral approach. This operator has two unstable and two stable eigenvalues complemented by a continuous spectrum of neutrally-stable eigenvalues. By considering a family of suitably regularized (smoothed) eigenvalue problems solved with a range of numerical resolutions we demonstrate that the corresponding eigenfunctions are in fact singular objects in the form of infinitely sharp peaks localiz...

  6. New type of hill-top inflation: CFT driven cosmology

    CERN Document Server

    Barvinsky, A O

    2015-01-01

    We suggest a new type of hill-top inflation originating from the initial conditions in the form of the microcanonical density matrix for the cosmological model driven by conformal field theory (CFT) with a large number of quantum fields. Initial conditions for inflation are set up by cosmological instantons describing underbarrier oscillations in the vicinity of the inflaton potential maximum. These periodic oscillations of the inflaton field and cosmological scale factor are obtained within the approximation of two coupled oscillators subject to the slow roll regime in Euclidean time. This regime is characterized by rapid oscillations of the scale factor on the background of a slowly varying inflaton, which justifies smallness of slow roll parameters $\\epsilon$ and $\\eta$ of inflation in real Lorentzian time. The hill-like shape of the inflaton potential is shown to be generated by logarithmic loop corrections to the tree-level asymptotically shift-invariant potential in the non-minimal Higgs inflation model...

  7. Flow characteristics above a very low and gently sloping hill

    Science.gov (United States)

    Smedman, Ann-Sofi; Bergström, Hans

    1984-05-01

    Tower measurements of wind and turbulence in near neutral conditions at the top of a very low and gently sloping hill (height ~ 20 m, with a length scale ~ 1000 m) are analysed in terms of current flow-over-hill theory. Measurements of wind maximum height and the change of the variances of the three wind components from the inner to the outer region are found to be in agreement with predictions from the theory. Spectra of the longitudinal and vertical wind components in the inner region, scaled according to Panofsky et al. (1982), come close to the corresponding Kansas curves in the high frequency range. They have higher energy in the low frequency region, probably a spectral lag effect caused by rougher upwind terrain. In the outer region, the spectra coincide with the corresponding Kansas curves if normalized by their respective variances and plotted against f/f m.

  8. Great Western Savings Center - Beverly Hills, California (EE.UU.

    Directory of Open Access Journals (Sweden)

    William L. Pereira Asociados, Arquitectos

    1974-09-01

    Full Text Available This building which has an original elliptic plan form and is enclosed by curtain walls is situated on a strategic ground-site in Beverly Hills and is the savings center for the densely populated area of Los Angeles. The building consists of: four basements for parking; ground floor with entrances, halls and savings-bank; mezzanine floor and first floor with coffee-shop, four dining halls and auditorium, seven storeys with offices; the tenth floor is reserved for the financial department and the management section. The top part is occupied by the machine rooms of the six elevators. Tre structure consists of high tensile steel reinforced concrete and bronzed coloured glass enclosures. This is the highet building in Beverly Hills.Este edificio, de original planta elíptica y cerramiento a base de muros cortina, ocupa un solar estratégico en Beverly Hills y sirve como central de ahorro a toda la zona densamente poblada de Los Angeles. Consta de: cuatro sótanos para estacionamiento de vehículos, y planta baja con accesos, vestíbulos y caja de ahorros; entreplanta y planta primera con cafetería, cuatro comedores y auditorio; siete plantas de oficinas y planta décima destinada a albergar los despachos de dirección y departamento financiero, además del cuerpo superior, ocupado por los cuartos de máquinas de los seis aparatos elevadores. La estructura es de hormigón armado con acero de alta resistencia y cerramientos de vidrio color bronce. Es el edificio más alto de Beverly Hills.

  9. Susceptibility of Shallow Landslide in Fraser Hill Catchment, Pahang Malaysia

    Directory of Open Access Journals (Sweden)

    Wan Nor Azmin Sulaiman

    2010-01-01

    Full Text Available In tropical areas especially during monsoon seasons intense precipitation is the main caused that trigger the natural shallow landslide phenomena. This phenomenon can be disastrous and widespread in occurrence even in undisturbed forested catchment. In this paper, an attempt has been made to evaluate the susceptibility of natural hill slopes to failure for a popular hill resort area, the Fraser Hill Catchment under different rainfall regimes and soil thickness. A Digital Elevation Model (DEM was prepared for the 8.2 km2 catchment. A GIS based deterministic model was then applied to predict the spatial landslide occurrence within catchment. Model input parameters include bulk density, friction angle, cohesion and hydraulic conductivity were gathered through in situ and lab analysis as well as from previous soil analysis records. Landslides locations were recorded using GPS as well as previous air photos and satellite imagery to establish landslide source areas inventory. The landslide susceptibility map was produced under different precipitation event’s simulation to see the effects of precipitation to stability of the hill slopes of the catchment. The results were categorized into naturally unstable (Defended, Upper Threshold, Lower Threshold, marginal instability (Quasi Stable and stable area (Moderately Stable and Stable. Results of the simulation indicated notable change in precipitation effect on Defended area is between 10mm to 40mm range in a single storm event. However, when storm event is exceeded 120mm, the result on Defended area produced by the model tends to be constant further on. For area categorized as naturally unstable (Factor of Safety, SF<1, with 110 mm of precipitation in a single storm event and soil depth at 2 meters and 4 meters could affect 69.51% and 69.88% respectively of the catchment area fall under that class. In addition, the model was able to detect 4% more of the landslide inventory under shallower soil depth of

  10. Prof. Nanopoulos visits Hill Primary School in Greece

    CERN Multimedia

    2014-01-01

    This video is an extract of a reportage broadcasted by SKAI TV in Greece about the visit of Prof. Dimitri Nanopoulos to Hill Primary School, the oldest operating school in Greece. The video describes a breakthrough education programme aimed at introducing big ideas in physics, particle physics and cosmology to K-6 students through a pedagogical approach that promotes inquiry, creativity and hands-on experimentation with the use everyday materials.

  11. Indirect Solar Drier for Drying of Hill Products

    Directory of Open Access Journals (Sweden)

    R. K. Aggarwal

    2012-06-01

    Full Text Available An indirect solar drier of 25 kg capacity has been developed fitted with solar cell for running the fan. The bulbs are provided in the solar collector for air heating during clouds and evening & morning for faster drying reducing drying time. 15 such solar driers have been installed in the state. Various hill agricultural crops have been dried in solar drier by the farmers andcollected. The market value of dried products has also been compared.

  12. Stochastic modeling of a lava-flow aquifer system

    Science.gov (United States)

    Cronkite-Ratcliff, Collin; Phelps, Geoffrey A.

    2014-01-01

    This report describes preliminary three-dimensional geostatistical modeling of a lava-flow aquifer system using a multiple-point geostatistical model. The purpose of this study is to provide a proof-of-concept for this modeling approach. An example of the method is demonstrated using a subset of borehole geologic data and aquifer test data from a portion of the Calico Hills Formation, a lava-flow aquifer system that partially underlies Pahute Mesa, Nevada. Groundwater movement in this aquifer system is assumed to be controlled by the spatial distribution of two geologic units—rhyolite lava flows and zeolitized tuffs. The configuration of subsurface lava flows and tuffs is largely unknown because of limited data. The spatial configuration of the lava flows and tuffs is modeled by using a multiple-point geostatistical simulation algorithm that generates a large number of alternative realizations, each honoring the available geologic data and drawn from a geologic conceptual model of the lava-flow aquifer system as represented by a training image. In order to demonstrate how results from the geostatistical model could be analyzed in terms of available hydrologic data, a numerical simulation of part of an aquifer test was applied to the realizations of the geostatistical model.

  13. Geomechanical properties of Topopah Spring Tuff at the 0.5-m scale: preliminary results of compression tests at elevated temperature

    Energy Technology Data Exchange (ETDEWEB)

    Blair, S. C., LLNL

    1997-08-25

    This report presents preliminary results of laboratory testing of a small block sample of Topopah Spring Tuff. This is the first in a series of tests on small block samples. The purpose of these tests is to investigate the thermal-mechanical, thermal-hydrological, and thermal-chemical response of the rock to conditions similar to the near-field environment (NFE) of a potential nuclear waste repository. This report presents preliminary results of deformation and elastic- wave velocity measurements on a 0.5-m scale block of Topopah Spring tuff tested in uniaxial compression and at temperatures to 85{degrees}C.

  14. Does Zika Virus Cause Microcephaly - Applying the Bradford Hill Viewpoints

    Science.gov (United States)

    Awadh, Asma; Chughtai, Abrar Ahmad; Dyda, Amalie; Sheikh, Mohamud; Heslop, David J.; MacIntyre, Chandini Raina

    2017-01-01

    Introduction: Zika virus has been documented since 1952, but been associated with mild, self-limiting disease. Zika virus is classified as an arbovirus from a family of Flaviviridae and primarily spread by Aedes Aegypti mosquitos. However, in a large outbreak in Brazil in 2015, Zika virus has been associated with microcephaly. Methods: In this review we applied the Bradford-Hill viewpoints  to investigate the association between Zika virus and microcephaly. We examined historical studies, available data and also compared historical rates of microcephaly prior to the Zika virus outbreak. The available evidence was reviewed against the Bradford Hill viewpoints. Results: All  the nine criteria were met to varying degrees: strength of association, consistency of the association, specificity, temporality, plausibility, coherence, experimental evidence, biological gradient and analogy. Conclusion: Using the Bradford Hill Viewpoints as an evaluation framework for causation is highly suggestive that the association between Zika virus and microcephaly is causal. Further studies using animal models on the viewpoints which were not as strongly fulfilled would be helpful. PMID:28357156

  15. Surface ozone characterization at Larsemann Hills and Maitri, Antarctica.

    Science.gov (United States)

    Ali, Kaushar; Trivedi, D K; Sahu, S K

    2017-04-15

    Data are analyzed in terms of daily average ozone, its diurnal variation and its relation with meteorological parameters like dry bulb temperature (T), wet bulb temperature (Tw), atmospheric pressure and wind speed based on measurement of these parameters at two Indian Antarctic stations (Larsemann Hills, and Maitri) during 28th Indian Scientific Expedition of Antarctica (ISEA) organized during Antarctic summer of the year 2008-09. The work has been carried out to investigate summer time ozone level and its day-to-day and diurnal variability at these coastal locations and to highlight possible mechanism of ozone production and destruction. The result of the analysis indicates that daily average ozone concentration at Larsemann Hills varied from ~13 and ~20ppb with overall average value of ~16ppb and at Maitri, it varied from ~16 and ~21ppb with overall average value of ~18ppb. Photochemistry is found to partially contribute occasionally to the surface layer ozone at both the stations. Lower concentration of ozone at Maitri during beginning of the observational days may be due to destruction of ozone through activated halogens, whereas higher ozone on latter days may be due to photochemistry and advective transport from east to south-east areas. Ozone concentration during blizzard episodes at both the stations is reduced due to slow photochemical production of ozone, its photochemical removal and removal through deposition of ozone molecules on precipitation particles. Diurnal variation of ozone at Larsemann Hills and Maitri has been found to be absent.

  16. Three dimensional simulation for Big Hill Strategic Petroleum Reserve (SPR).

    Energy Technology Data Exchange (ETDEWEB)

    Ehgartner, Brian L. (Sandia National Laboratories, Albuquerque, NM); Park, Byoung Yoon; Sobolik, Steven Ronald (Sandia National Laboratories, Albuquerque, NM); Lee, Moo Yul (Sandia National Laboratories, Albuquerque, NM)

    2005-07-01

    3-D finite element analyses were performed to evaluate the structural integrity of caverns located at the Strategic Petroleum Reserve's Big Hill site. State-of-art analyses simulated the current site configuration and considered additional caverns. The addition of 5 caverns to account for a full site and a full dome containing 31 caverns were modeled. Operations including both normal and cavern workover pressures and cavern enlargement due to leaching were modeled to account for as many as 5 future oil drawdowns. Under the modeled conditions, caverns were placed very close to the edge of the salt dome. The web of salt separating the caverns and the web of salt between the caverns and edge of the salt dome were reduced due to leaching. The impacts on cavern stability, underground creep closure, surface subsidence and infrastructure, and well integrity were quantified. The analyses included recently derived damage criterion obtained from testing of Big Hill salt cores. The results show that from a structural view point, many additional caverns can be safely added to Big Hill.

  17. The Nascent Development of Ecotourism in Lagong Hill

    Directory of Open Access Journals (Sweden)

    Ah-Choy Er

    2010-01-01

    Full Text Available Problem statement: The nascent development of ecotourism in Lagong Hill faces an interesting challenge. The aim of this research note is to evaluate the nascent development of ecotourism in Lagong Hill, Malaysia based on the common core precepts of ecotourism. Approach: The research methods comprise of secondary data collection and field survey via an in-depth interview with selected key informants. This is aided by on-field observation to verify and complement the research findings. Results and Discussion: The ecotourism park management has exhibited environmentally responsible behavior. Nature conservation, tourism management, solid waste management and water utilization adopt the core precepts of ecosystem protection, minimal environmental impact and environmental education. However, there is a lack of outreach towards the indigenous people who are residing within this forest reserve. The Orang Asli, the indigenous people of this area, have profound and in-depth knowledge of the forest and its terrains. This local knowledge and cultural heritage has yet to be tapped as part of community-based ecotourism. In addition, there is a lack of scientific research on the impact of quarrying and timber production on ecotourism. Conclusion: The ecotourism venture in Lagong Hill fulfills the core precepts of ecotourism with the exception of the participation of indigenous people. There is a need to inculcate community-based ecotourism rather than primarily focusing on environmental or economic impacts. More scientific research is required to determine carrying capacity, and the impact of quarrying and timber production on ecotourism.

  18. Mycorrhizal interactions of orchids colonizing Estonian mine tailings hills.

    Science.gov (United States)

    Shefferson, Richard P; Kull, Tiiu; Tali, Kadri

    2008-02-01

    Northeastern Estonia is home to extensive oil shale mines. Associated with these are desolate and environmentally damaging hills of ash and semicoke tailings. Interestingly, some of the first plants to colonize these hills are rare orchids. Here, we assess the identities of the mycorrhizal fungi associated with these orchids, in particular Epipactis atrorubens, Orchis militaris, and Dactylorhiza baltica, and compare them with mycorrhizal fungi from orchids from pristine habitat. Epipactis atrorubens associated with the widest breadth of fungi, including unnamed members of the basidiomycete family Tulasnellaceae and the potentially ectomycorrhizal ascomycetes Trichophaea woolhopeia and Geopora cooperi. Orchis militaris also associated with unnamed members of the Tulasnellaceae. Dactylorhiza baltica associated with Ceratobasidium albasitensis. In Epipactis and Orchis, the same fungi associated with plants in the pristine habitat as with those on ash hills. The tulasnelloid and ceratobasidioid fungi mycorrhizal with these orchids appear closely related to common orchid mycorrhizal fungi, while one of the ascomycetes mycorrhizal with E. atrorubens is closely related to a mycorrhizal fungus with E. microphylla. Our results suggest that these orchids and their fungi are not limited to pristine habitats and that environmentally polluted sites may present novel habitats that may be exploited for endangered plant conservation.

  19. Evolution of optimal Hill coefficients in nonlinear public goods games.

    Science.gov (United States)

    Archetti, Marco; Scheuring, István

    2016-10-07

    In evolutionary game theory, the effect of public goods like diffusible molecules has been modelled using linear, concave, sigmoid and step functions. The observation that biological systems are often sigmoid input-output functions, as described by the Hill equation, suggests that a sigmoid function is more realistic. The Michaelis-Menten model of enzyme kinetics, however, predicts a concave function, and while mechanistic explanations of sigmoid kinetics exist, we lack an adaptive explanation: what is the evolutionary advantage of a sigmoid benefit function? We analyse public goods games in which the shape of the benefit function can evolve, in order to determine the optimal and evolutionarily stable Hill coefficients. We find that, while the dynamics depends on whether output is controlled at the level of the individual or the population, intermediate or high Hill coefficients often evolve, leading to sigmoid input-output functions that for some parameters are so steep to resemble a step function (an on-off switch). Our results suggest that, even when the shape of the benefit function is unknown, biological public goods should be modelled using a sigmoid or step function rather than a linear or concave function.

  20. ACCOMMODATION INFRASTRUCTURE AND TOURISM FLOWS ON FELEACU HILL (CLUJ COUNTY

    Directory of Open Access Journals (Sweden)

    DANIELA-LIVIA GHEORGHIEȘ

    2016-06-01

    Full Text Available Accommodation Infrastructure and Tourism Flows on Feleacu Hill (Cluj County. Feleacu Hill experienced tourism development between 2001 and 2015. The INS data indicates that the number of accommodation units increased from one (2001 to four (2015 and there are a few more which are not registered in the INS database. The accommodation capacity increases, as many guesthouses are expanding their premises to receive more tourists and new accommodation units emerge, such as Hotel Premier in Vâlcele (Feleacu commune. Tourism flows also registered a highly positive trend. The number of arrivals increased from 95 tourists in 2002 to 7791 tourists in 2015. However, there was a downturn between 2009 and 2012, due to the economic crisis and the opening of the Turda – Gilău motorway (A3, which redirected transit routes outside the region and led to the closure of Paradis Hotel in 2012. Since 2012, the number of arrivals and overnight stays increased steadily due to the development of new forms of tourism – rural tourism, agrotourism, extreme tourism and complex tourism, materialized in growing numbers of tourists at the two guesthouses in Ciurila commune (“La Mesteceni” and “Domeniul Regilor”. Tourism brings obvious benefits to the rural communities on Feleacu Hill, even if the average duration of stay is still low.

  1. Petrochemical variation of Topopah Spring tuff matrix with depth (stratigraphic level), drill hole USW G-4, Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Byers, F.M. Jr.

    1985-12-01

    This study describes and interprets petrochemical variation of the matrix (excluding fractures and large gas cavities) of the Topopah Spring Member of the Paintbrush Tuff. This tuff includes the candidate host rock for a high-level nuclear waste repository at Yucca Mountain on the Nevada Test Site. Cored hole USW G-4, near the site of a potential exploratory shaft at Yucca Mountain, penetrated 359.4 m (1179 ft) of the member within the unsaturated zone. This study shows that petrographic textures and chemistry of the matrix vary systematically within recognizable lithologic subunits related to crystallization (cooling) zones, welding (compaction) zones, and compositional zones (rhyolite versus quartz latite). The methods used for this study include petrographic modal thin section analysis using an automated counter and electron microprobe analysis of the groundmass. Distinctive textural categories are defined, and they can be ranked from finest to coarsest as vitrophyre (glass), cryptocrystalline groundmass, spherulites, granophyre, lithic fragments, and phenocrysts. The two main groundmass compositions are also defined: rhyolite high silica) and quartz latite. The value of these petrochemical studies lies in providing microscopic criteria for recognizing the zonal subunits where they may have greatly limited exposure, as in mined drifts and in core from horizontal drill holes. For example, the lower nonlithophysal zone can be distinguished microscopically from the middle nonlithophysal zone by (1) degree of compaction, (2) amount of quartz, and (3) amount of lithic fragments. The variability between these textural categories should also be considered in designing physical and chemical tests of the Topopah Spring.

  2. Magnetic properties in an ash flow tuff with continuous grain size variation: a natural reference for magnetic particle granulometry

    Science.gov (United States)

    Till, J.L.; Jackson, M.J.; Rosenbaum, J.G.; Solheid, P.

    2011-01-01

    The Tiva Canyon Tuff contains dispersed nanoscale Fe-Ti-oxide grains with a narrow magnetic grain size distribution, making it an ideal material in which to identify and study grain-size-sensitive magnetic behavior in rocks. A detailed magnetic characterization was performed on samples from the basal 5 m of the tuff. The magnetic materials in this basal section consist primarily of (low-impurity) magnetite in the form of elongated submicron grains exsolved from volcanic glass. Magnetic properties studied include bulk magnetic susceptibility, frequency-dependent and temperature-dependent magnetic susceptibility, anhysteretic remanence acquisition, and hysteresis properties. The combined data constitute a distinct magnetic signature at each stratigraphic level in the section corresponding to different grain size distributions. The inferred magnetic domain state changes progressively upward from superparamagnetic grains near the base to particles with pseudo-single-domain or metastable single-domain characteristics near the top of the sampled section. Direct observations of magnetic grain size confirm that distinct transitions in room temperature magnetic susceptibility and remanence probably denote the limits of stable single-domain behavior in the section. These results provide a unique example of grain-size-dependent magnetic properties in noninteracting particle assemblages over three decades of grain size, including close approximations of ideal Stoner-Wohlfarth assemblages, and may be considered a useful reference for future rock magnetic studies involving grain-size-sensitive properties.

  3. Sedimentary-volcanic tuffs formed during the early Middle Triassic volcanic event in Guizhou Province and their stratigraphic significance

    Institute of Scientific and Technical Information of China (English)

    XIAO Jiafei; HU Ruizhong

    2005-01-01

    The sedimentary-volcanic tuff (locally called "green-bean rock") formed during the early Middle Triassic volcanic event in Guizhou Province is characterized as being thin, stable, widespread, short in forming time and predominantly green in color. The green-bean rock is a perfect indicator for stratigraphic division. Its petrographic and geochemical features are unique, and it is composed mainly of glassy fragments and subordinately of crystal fragments and volcanic ash balls. Analysis of the major and trace elements and rare-earth elements (REE), as well as the related diagrams, permits us to believe that the green-bean rock is acidic volcanic material of the calc-alkaline series formed in the Indosinian orogenic belt on the Sino-Vietnam border, which was atmospherically transported to the tectonically stable areas and then deposited as sedimentary-volcanic rocks there. According to the age of green-bean rock, it is deduced that the boundary age of the Middle-Lower Triassic overlain by the sedimentary-volcanic tuff is about 247 Ma.

  4. Geochemical and Mineralogical Analyses of Palagonitic Tuffs and Altered Rinds of Pillow Lavas on Iceland and Applications to Mars

    Science.gov (United States)

    Bishop, Janice; Schiffman, P.; Southard, R.; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    Samples of altered pillow lavas and hyalotuffs were collected from a volcanic Tuya and hyaloclastite ridge in western Iceland. Altered basaltic material from regions such as Hloudufell Tuya and Thorolfsfell Ridge may be similar to the surface fines on Mars, which are thought to contain altered basaltic components as well. Geochemical and mineralogical analyses have been performed on the Icelandic samples in order to characterize the properties that distinguish palagonitization from other forms of low temperature alteration in this environment. Major elements were measured using an electron microprobe and mineralogy was determined through X-ray diffraction and visible- infrared reflectance spectroscopy. The primary focus in this study was on the less than 2 microns size fractions of the Hloudufell altered pillow and Thorolfsfell palagonitic tuff samples. The palagonitic tuff contained more crystalline clay minerals and has a higher Al/Fe ratio. The altered pillow lava contained higher abundances of nanophase iron oxides/oxyhydroxides. The extended visible region spectra of the less than 2 microns fractions of both Icelandic samples are similar to bright Martian soils measured by Pathfinder.

  5. Interaction between organic vapors and clinoptilolite-mordenite rich tuffs in parent, decationized, and lead exchanged forms.

    Science.gov (United States)

    Elizalde-González, M P; Pérez-Cruz, M A

    2007-08-15

    Scientific interest in adsorption phenomena of organic vapors has concentrated on synthetic zeolites. Solid-vapor systems containing natural zeolites deserve special attention due to their abundance and environmental applications. Adsorption thermodynamic characteristics for benzene, toluene, n-hexane, and CCl(4) were measured on clinoptilolite-rich zeolitic tuffs from Mexico (ZE) and Hungary (ZH) on parent, decationized, dealuminated, and lead-exchanged samples. The clinoptilolite structure released Na(+) and Ca(2+) by acid treatment and this was accompanied by dealumination to a greater extent on ZE than on ZH. The exchange isotherm of Pb(2+) on ZE exhibited a concave type "a" form and accomplished 95% exchange and the tuff was selective at X(i(s))toluene>n-hexane>carbon tetrachloride. The -DeltaH values were higher for toluene than for the other adsorbates. Curves of q(isost) vs coverage decreased with the increment of the adsorbed amount in practically all studied systems. The contributions to the solid-vapor interaction potential were examined using inverse gas chromatography. The specific interaction energy G(sp) was primarily due to adsorbate-framework and adsorbate-cation interactions at low adsorbate pressures producing low surface coverage.

  6. The palaeogeographic setting and the local environmental impact of the 130 ka Falconiera tuff-cone eruption (Ustica island, Italy)

    Science.gov (United States)

    de Vita, Sandro; Foresta Martin, Franco

    2017-04-01

    This research focuses on the effects of the last eruption at Ustica (Suthern Tyrrhenian Sea, Italy), which formed the Falconiera tuff-cone at around 130 ka BP in the north-eastern tip of the island. This eruption was mainly explosive and phreatomagmatic, and emplaced a series of pyroclastic surge beds that formed an asymmetric tuff cone. This is the most easily recognizable volcanic edifice on Ustica, although its north-eastern sector has been partially eroded. A section of the feeding conduit is exposed northward, and is composed of lavas that fed the last stages of the eruption characterized by an intracrateric lava lake and a Strombolian scoria-fallout deposit. The eruption occurred during Upper Pleistocene Marine Isotopic Substage 5.5, a warm period characterized by a high sea-level stand (6±3 m above the present sea level in stable areas) and the diffusion of subtropical flora and fauna across the Mediterranean sea. This eruption slightly modified the morphology of Ustica, but impacted both marine and terrestrial environments, burying beach deposits rich in mollusk shells (i.e. Strombus bubonius, Conus testudinarius, Brachidontes puniceus), colonies of corals (Cladocora caespitosa) and subaerial plants (Chamaerops humilis). These organisms, found in some cases in their life position, along with other lines of evidence, provide information on the palaeogeography of this sector of the island at the time of the eruption, and on the local impact of this event on the environment.

  7. Petroleum exploration of shallow marine deposit Carboniferous volcanic tuff reservoir in the western margin of Junggar Basin

    Institute of Scientific and Technical Information of China (English)

    Wang Jianyong; Wang Xuezhong; Ma Liqun

    2013-01-01

    In 2011,petroleum exploration of shallow marine deposits Carboniferous and volcanic tuff reservoir re-alized breakthroughs at Chepaizi slope in the western margin of Junggar Basin. Pai 61 well ,with 855.7 ~949.6 m section,in the conventional test oil obtained 6 t/d industrial oil flow. The surface viscosity is 390 mPa· s (50℃). The marine deposit of Carboniferous are deep oil source rocks and high-quality reservoir. Magma volcanic activity provides the basis for volcanic reservoir development and distribution. The weathering crust and secondary cracks developed volcanic tuff by strong rock weathering and dissolution of organic acids which has become top quality reservoir. Deep Permian oil-gas migrated and accumulated to high parts along Hong-Che fault belt and stratigraphic unconformity stripping. Permian and Triassic volcanic rocks or dense mudstone sedimentary cover as a regional seal for the late Carboniferous oil-gas to save critically. The seismic pre-stack time migration processing technologies for the problem of poor inner structures of Carboniferous were developed. Response of volcanic rock seismic and logging are obvious. The application imaging logging and nuclear magnetic technology achieved the qualitative identification and quantification of fracture description.

  8. Combining Experimental Petrology and 3D Imaging to Gain Insight into Syn-eruptive Conditions of the Bishop Tuff, California

    Science.gov (United States)

    Chattin, Archer; Pamukcu, Ayla; Gardner, James; Gualda, Guilherme

    2015-04-01

    The Bishop tuff is a rhyolitic ignimbrite deposited by a supereruption 0.76 million years ago that formed the Long Valley Caldera in California, USA. Pamukcu et. al (2012) identifies two distinct crystal populations present in the Bishop Tuff, the first being a long-lived, large phenocryst population that records storage conditions, and the second a rapidly nucleated, quickly staunched microlite population thought to result from eruptive decompression. Laboratory experiments to reproduce this quickly grown population may help constrain the conditions and rates under which decompression took place. Rapid nucleation of microlites is accompanied by just as rapid bubble nucleation when volatiles exsolve during decompression; the size distribution of vesicles in eruptive products may thus provide important information on syn-eruptive processes. In this study we combine information from vesicle size distributions on natural pumice with data on experimentally produced microlite crystals with the goal of better understanding the syn-eruptive evolution of a supereruption-forming magma body. Decompression experiments are run using a natural Bishop tuff pumice clast ground and melted in the presence of water to obtain a melt representative of late-erupted Bishop Tuff (LBT) magmas. Experimental charges were subjected to decompression at varying rates and initial temperatures. At this time five experiments have been completed. All decompression experiments start at 130MPa, consistent with water concentration in LBT glass inclusions, and end at 10 MPa. Initial temperatures are either 710°C or 785°C, while decompression rates are 20 MPa/hr, 5.5MPa/hr, or 1.7MPa/hr Experimental products were compared to natural products using Scanning Electron Microscopy to document eventual crystal rims and microlites. We have been successful in causing limited feldspar crystallization, but have yet to generate quartz microlites. Bubble size distributions are obtained by analyzing x

  9. Fifty Shades of Grey: Zircon Perspectives on the Timing and Chemistry of Magma Interactions Reflected in the Bishop Tuff

    Science.gov (United States)

    Chamberlain, K. J.; Wilson, C. J.; Wooden, J. L.; Baker, J. A.; Charlier, B. L.

    2012-12-01

    The ~0.76 Ma Bishop Tuff eruption in eastern California is an archetypal example of the products of a compositionally stratified magma chamber. Key issues regarding the melt-dominant magma body that have arisen from recent studies include the role of horizontal variability versus vertical stratification, and the nature and timing of a late-stage ingress of compositionally contrasting melt. The latter is reflected in, for example, CL-bright rims on quartz, and Sr- and Ba-rich rims on sanidines, both of which are reported in samples from ignimbrite erupted from vents along the northern caldera rim. Various studies have placed contrasting temporal constraints on assembly and evacuation of the Bishop Tuff magma body and the processes occurring within it from one or two mineral phases. Although the overall crystal specific record is more complex, it has the potential to distinguish between mixing, in-situ crystallisation and other magmatic processes, and resolve the associated timings of these events. Zircon has been widely utilised in the Bishop Tuff and other silicic systems because of its unique records of information about the ages and P-T-X environments of growth. Here we present SHRIMP-RG ion probe data from Bishop Tuff zircons, collected from samples spanning the full eruptive sequence. A combination of age data, textural analysis and trace element analysis is used to yield insights into magma chamber development and the pre-eruptive state of the melt-dominant magma body, as evidenced in material erupted from different vent areas around what became the Long Valley caldera. U-Pb dating of 307 spots from all zones in crystals from all samples yields a strongly unimodal age spectrum, with a mean age of 794+/-3 ka (10 spots rejected, MSWD = 2.0). CL images of the dated zircon suites show the appearance of bright-rimmed zircons in later-erupted ignimbrite packages (accompanied generally by bright-rimmed sanidine and quartz crystals), but with diversity in the

  10. URANIUM-SERIES DISEQUILIBRIUM IN TUFF AND GRANITE:HYDROGEOLOGICAL IMPLICATIONS

    Energy Technology Data Exchange (ETDEWEB)

    M. Gasscoyne; N.H. Miller

    2000-10-27

    -life of the radionuclide involved. Depending on the analytical precision obtained, the observation of a {sup 234}U/{sup 238}U activity ratio that is less than or greater than 1.000 clearly shows that an isotope of uranium has migrated within the rock in the last 1-2 million years. Other daughter/parent activity ratios can be used to detect radionuclide migration over shorter time-scales, such as {sup 230}Th/{sup 234}U (300,000 years) and {sup 226}Ra/{sup 230}Th (8,000 years). Uranium-series disequilibrium is, therefore, a useful technique for application to site evaluation for nuclear fuel waste disposal because it can be used to: (1) show that so-called ''intact rock'' is indeed intact (i.e. radionuclides are in secular equilibrium and are immobile), (2) determine the principal flow regimes in a rock mass by analysis of rock matrix, fracture material, etc., (3) estimate the time period of recent radionuclide migration in the rock, and (4) proxy as a natural analogue for the potential mobility of uranium at the site. Several examples of these applications have been reported. This paper describes the use of uranium-series disequilibrium in the comparison of two North American sites: the water-saturated Lac du Bonnet granite batholith on the Canadian Shield and the unsaturated tuffs from the Exploratory Studies Facility (ESF) and Cross-Drift Tunnels at Yucca Mountain, Nevada. In particular, the fact that unfractured rock should be at secular equilibrium is applied to both sites to determine if the rock matrix is a significant flow path for groundwater.

  11. Scoria Cone and Tuff Ring Stratigraphy Interpreted from Ground Penetrating Radar, Rattlesnake Crater, Arizona

    Science.gov (United States)

    Kruse, S. E.; McNiff, C. M.; Marshall, A. M.; Courtland, L. M.; Connor, C.; Charbonnier, S. J.; Abdollahzadeh, M.; Connor, L.; Farrell, A. K.; Harburger, A.; Kiflu, H. G.; Malservisi, R.; Njoroge, M.; Nushart, N.; Richardson, J. A.; Rookey, K.

    2013-12-01

    Numerous recent studies have demonstrated that detailed investigation of scoria cone and maar morphology can reveal rich details the eruptive and erosion histories of these volcanoes. A suite of geophysical surveys were conducted to images Rattlesnake Crater in the San Francisco Volcanic Field, AZ, US. We report here the results of ~3.4 km of ground penetrating radar (GPR) surveys that target the processes of deposition and erosion on the pair of cinder cones that overprint the southeast edge of Rattlesnake crater and on the tuff ring that forms the crater rim. Data were collected with 500, 250, 100, and 50 MHz antennas. The profiles were run in a radial direction down the northeast flanks of the cones (~1 km diameter, ~120 meters height) , and on the inner and outer margins of the oblong maar rim (~20-80 meters height). A maximum depth of penetration of GPR signal of ~15m was achieved high on the flanks of scoria cones. A minimum depth of essentially zero penetration occurred in the central crater. We speculate that maximum penetration occurs near the peaks of the cones and crater rim because ongoing erosion limits new soil formation. Soil formation would tend to increase surface conductivity and hence decrease GPR penetration. Soil is probably better developed within the crater, precluding significant radar penetration there. On the northeast side of the gently flattened rim of the easternmost scoria cone, the GPR profile shows internal layering that dips ~20 degrees northeast relative to the current ground surface. This clearly indicates that the current gently dipping surface is not a stratigraphic horizon, but reflects instead an erosive surface into cone strata that formed close to the angle of repose. Along much of the cone flanks GPR profiles show strata dipping ~4-5 degrees more steeply than the current surface, suggesting erosion has occurred over most of the height of the cone. An abrupt change in strata attitude is observed at the gradual slope

  12. Correlation of the KHS Tuff of the Kibish Formation to volcanic ash layers at other sites, and the age of early Homo sapiens (Omo I and Omo II).

    Science.gov (United States)

    Brown, Francis H; McDougall, Ian; Fleagle, John G

    2012-10-01

    Hominin specimens Omo I and Omo II from Member I of the Kibish Formation, Ethiopia are attributed to early Homo sapiens, and an age near 196 ka has been suggested for them. The KHS Tuff, within Member II of the Kibish Formation has not been directly dated at the site, but it is believed to have been deposited at or near the time of formation of sapropel S6 in the Mediterranean Sea. Electron microprobe analyses suggest that the KHS Tuff correlates with the WAVT (Waidedo Vitric Tuff) at Herto, Gona, and Konso (sample TA-55), and with Unit D at Kulkuletti in the Ethiopian Rift Valley. Konso sample TA-55 is older than 154 ka, and Unit D at Kulkuletti is dated at 183 ka. These correlations and ages provide strong support for the age originally suggested for the hominin remains Omo I and Omo II, and for correlation of times of deposition in the Kibish region with formation of sapropels in the Mediterranean Sea. The Aliyo Tuff in Member III of the Kibish Formation is dated at 104 ka, and correlates with Gademotta Unit 15 in the Ethiopian Rift Valley. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Spatial distribution of damage around faults in the Joe Lott Tuff Member of the Mount Belknap Volcanics, Utah: A mechanical analog for faulting in pyroclastic deposits on Mars

    Science.gov (United States)

    Okubo, Chris H.

    2012-01-01

    Volcanic ash is thought to comprise a large fraction of the Martian equatorial layered deposits and much new insight into the process of faulting and related fluid flow in these deposits can be gained through the study of analogous terrestrial tuffs. This study identifies a set of fault-related processes that are pertinent to understanding the evolution of fault systems in fine-grained, poorly indurated volcanic ash by investigating exposures of faults in the Miocene-aged Joe Lott Tuff Member of the Mount Belknap Volcanics, Utah. The porosity and granularity of the host rock are found to control the style of localized strain that occurs prior to and contemporaneous with faulting. Deformation bands occur in tuff that was porous and granular at the time of deformation, while fractures formed where the tuff lost its porous and granular nature due to silicic alteration. Non-localized deformation of the host rock is also prominent and occurs through compaction of void space, including crushing of pumice clasts. Significant off-fault damage of the host rock, resembling fault pulverization, is recognized adjacent to one analog fault and may reflect the strain rate dependence of the resulting fault zone architecture. These findings provide important new guidelines for future structural analyses and numerical modeling of faulting and subsurface fluid flow through volcanic ash deposits on Mars.

  14. Geochemistry and zircon U-Pb geochronology of the rhyolitic tuff on Port Island, Hong Kong: Implications for early Cretaceous tectonic setting

    Directory of Open Access Journals (Sweden)

    Longlong Zhao

    2017-05-01

    Full Text Available Early Cretaceous rhyolitic tuffs, widely distributed on Port Island, provide insights into the volcanism and tectonic setting of Hong Kong. In this paper we present petrological, geochronological and geochemical data of the rhyolitic tuff to constrain the diagenesis age and petrogenesis of the rocks, tectonic setting and early Cretaceous volcanism of Hong Kong. The first geochronological data show that the zircons in the volcanic rocks have U-Pb age of 141.1–139.5 Ma, which reveals that the rhyolitic tuff on Port Island was formed in the early Cretaceous (K1. Geochemically, these acid rocks, which are enriched in large ion lithophile elements (LILEs and light rare earth elements (LREEs, and depleted in high field strength elements (HFSEs, belong to the high K calc-alkaline to shoshonite series with strongly-peraluminous characteristic. The geochemical analyses suggest that the volcanic rocks were derived from deep melting in the continental crust caused by basaltic magma underplating. Based on the geochemical analysis and previous studies, we concluded that the rhyolitic tuffs on Port Island were formed in a back-arc extension setting in response to the subduction of the Paleo-Pacific Plate beneath the Eurasian Plate.

  15. Evaluation of Pleistocene groundwater flow through fractured tuffs using a U-series disequilibrium approach, Pahute Mesa, Nevada, USA

    Science.gov (United States)

    Paces, James B.; Nichols, Paul J.; Neymark, Leonid A.; Rajaram, Harihar

    2013-01-01

    Groundwater flow through fractured felsic tuffs and lavas at the Nevada National Security Site represents the most likely mechanism for transport of radionuclides away from underground nuclear tests at Pahute Mesa. To help evaluate fracture flow and matrix–water exchange, we have determined U-series isotopic compositions on more than 40 drill core samples from 5 boreholes that represent discrete fracture surfaces, breccia zones, and interiors of unfractured core. The U-series approach relies on the disruption of radioactive secular equilibrium between isotopes in the uranium-series decay chain due to preferential mobilization of 234U relative to 238U, and U relative to Th. Samples from discrete fractures were obtained by milling fracture surfaces containing thin secondary mineral coatings of clays, silica, Fe–Mn oxyhydroxides, and zeolite. Intact core interiors and breccia fragments were sampled in bulk. In addition, profiles of rock matrix extending 15 to 44 mm away from several fractures that show evidence of recent flow were analyzed to investigate the extent of fracture/matrix water exchange. Samples of rock matrix have 234U/238U and 230Th/238U activity ratios (AR) closest to radioactive secular equilibrium indicating only small amounts of groundwater penetrated unfractured matrix. Greater U mobility was observed in welded-tuff matrix with elevated porosity and in zeolitized bedded tuff. Samples of brecciated core were also in secular equilibrium implying a lack of long-range hydraulic connectivity in these cases. Samples of discrete fracture surfaces typically, but not always, were in radioactive disequilibrium. Many fractures had isotopic compositions plotting near the 230Th-234U 1:1 line indicating a steady-state balance between U input and removal along with radioactive decay. Numerical simulations of U-series isotope evolution indicate that 0.5 to 1 million years are required to reach steady-state compositions. Once attained, disequilibrium 234U/238U

  16. A high-pyrite semianthracite of Late Permian age in the Songzao Coalfield, southwestern China: Mineralogical and geochemical relations with underlying mafic tuffs

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Shifeng; Wang, Xibo; Chen, Wenmei [State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology, Beijing 100083, (China); Li, Dahua [Research Center of State Key Laboratory of Coal Resources and Safe Mining, Chongqing 400042, (China); Chou, Chen-Lin [Illinois State Geological Survey (Emeritus), 615 East Peabody Drive, Champaign, IL 61820, (United States); Zhou, Yiping [Yunnan Institute of Coal Geology Prospection, Kunming 650218, (China); Zhu, Changsheng; Li, Hang [Research Center of State Key Laboratory of Coal Resources and Safe Mining, Chongqing 400042, (China); Zhu, Xingwei; Xing, Yunwei; Zhang, Weiguo; Zou, Jianhua [State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology, Beijing 100083, (China)

    2010-09-01

    The No. 12 Coal (Late Permian) in the Songzao Coalfield, Chongqing, southwestern China, is characteristically high in pyrite and some trace elements. It is uniquely deposited directly above mafic tuff beds. Samples of coal and tuffs have been studied for their mineralogy and geochemistry using inductively coupled plasma-mass spectrometry, X-ray fluorescence, plasma low-temperature ashing plus powder X-ray diffraction, and scanning electron microscopy equipped with energy-dispersive X-ray analysis. The results show that the minerals of the No. 12 Coal are mainly composed of pyrite, clay minerals (kaolinite, chamosite, and illite), ankerite, calcite, and trace amounts of quartz and boehmite. Kaolinite and boehmite were mainly derived from sediment source region of mafic tuffs. Chamosite was formed by the reaction of kaolinite with Fe-Mg-rich fluids during early diagenesis. The high pyrite (S{sub p,d} 8.83%) in the coal was related to marine transgression over peat deposits and abundant Fe derived from the underlying mafic tuff bed. Ankerite and calcite were precipitated from epigenetic fluids. Chemical compositions of incompatible elements indicate that the tuffs were derived from enriched mantle and the source magmas had an alkali-basalt character. Compared to other coals from the Songzao Coalfield and common Chinese coals, the No. 12 Coal has a lower SiO{sub 2}/Al{sub 2}O{sub 3} (1.13) but a higher Al{sub 2}O{sub 3}/Na{sub 2}O (80.1) value and is significantly enriched in trace elements including Sc (13.5 {mu}g/g), V (121 {mu}g/g), Cr (33.6 {mu}g/g), Co (27.2 {mu}g/g), Ni (83.5 {mu}g/g), Cu (48.5 {mu}g/g), Ga (17.3 {mu}g/g), Y (68.3 {mu}g/g), Zr (444 {mu}g/g), Nb (23.8 {mu}g/g), and REE (392 {mu}g/g on average). Above mineralogical compositions, as well as similar ratios of selected elements (e.g., SiO{sub 2}/Al{sub 2}O{sub 3} and Al{sub 2}O{sub 3}/Na{sub 2}O) and similar distribution patterns of incompatible elements (e.g., the mantle-normalized diagram for

  17. Major element and oxygen isotope geochemistry of vapour-phase garnet from the Topopah Spring Tuff at Yucca Mountain, Nevada, USA

    Science.gov (United States)

    Moscati, Richard J.; Johnson, Craig A.

    2014-01-01

    Twenty vapour-phase garnets were studied in two samples of the Topopah Spring Tuff of the Paintbrush Group from Yucca Mountain, in southern Nevada. The Miocene-age Topopah Spring Tuff is a 350 m thick, devitrified, moderately to densely welded ash-flow tuff that is zoned compositionally from high-silica rhyolite to latite. During cooling of the tuff, escaping vapour produced lithophysae (former gas cavities) lined with an assemblage of tridymite (commonly inverted to cristobalite or quartz), sanidine and locally, hematite and/or garnet. Vapour-phase topaz and economic deposits associated commonly with topaz-bearing rhyolites (characteristically enriched in F) were not found in the Topopah Spring Tuff at Yucca Mountain. Based on their occurrence only in lithophysae, the garnets are not primary igneous phenocrysts, but rather crystals that grew from a F-poor magma-derived vapour trapped during and after emplacement of the tuff. The garnets are euhedral, vitreous, reddish brown, trapezohedral, as large as 2 mm in diameter and fractured. The garnets also contain inclusions of tridymite. Electron microprobe analyses of the garnets reveal that they are almandine-spessartine (48.0 and 47.9 mol.%, respectively), have an average composition of (Fe1.46Mn1.45Mg0.03Ca0.10)(Al1.93Ti0.02)Si3.01O12 and are comparatively homogeneous in Fe and Mn concentrations from core to rim. Composited garnets from each sample site have δ18O values of 7.2 and 7.4‰. The associated quartz (after tridymite) has δ18O values of 17.4 and 17.6‰, values indicative of reaction with later, low-temperature water. Unaltered tridymite from higher in the stratigraphic section has a δ18O of 11.1‰ which, when coupled with the garnet δ18O values in a quartz-garnet fractionation equation, indicates isotopic equilibration (vapour-phase crystallization) at temperatures of ~600°C. This high-temperature mineralization, formed during cooling of the tuffs, is distinct from the later and commonly recognized

  18. A high-pyrite semianthracite of Late Permian age in the Songzao Coalfield, southwestern China: Mineralogical and geochemical relations with underlying mafic tuffs

    Science.gov (United States)

    Dai, S.; Wang, X.; Chen, W.; Li, D.; Chou, C.-L.; Zhou, Y.; Zhu, Chen; Li, H.; Zhu, Xudong; Xing, Y.; Zhang, W.; Zou, J.

    2010-01-01

    The No. 12 Coal (Late Permian) in the Songzao Coalfield, Chongqing, southwestern China, is characteristically high in pyrite and some trace elements. It is uniquely deposited directly above mafic tuff beds. Samples of coal and tuffs have been studied for their mineralogy and geochemistry using inductively coupled plasma-mass spectrometry, X-ray fluorescence, plasma low-temperature ashing plus powder X-ray diffraction, and scanning electron microscopy equipped with energy-dispersive X-ray analysis.The results show that the minerals of the No. 12 Coal are mainly composed of pyrite, clay minerals (kaolinite, chamosite, and illite), ankerite, calcite, and trace amounts of quartz and boehmite. Kaolinite and boehmite were mainly derived from sediment source region of mafic tuffs. Chamosite was formed by the reaction of kaolinite with Fe-Mg-rich fluids during early diagenesis. The high pyrite (Sp,d=8.83%) in the coal was related to marine transgression over peat deposits and abundant Fe derived from the underlying mafic tuff bed. Ankerite and calcite were precipitated from epigenetic fluids.Chemical compositions of incompatible elements indicate that the tuffs were derived from enriched mantle and the source magmas had an alkali-basalt character. Compared to other coals from the Songzao Coalfield and common Chinese coals, the No. 12 Coal has a lower SiO2/Al2O3 (1.13) but a higher Al2O3/Na2O (80.1) value and is significantly enriched in trace elements including Sc (13.5??g/g), V (121??g/g), Cr (33.6??g/g), Co (27.2??g/g), Ni (83.5??g/g), Cu (48.5??g/g), Ga (17.3??g/g), Y (68.3??g/g), Zr (444??g/g), Nb (23.8??g/g), and REE (392??g/g on average). Above mineralogical compositions, as well as similar ratios of selected elements (e.g., SiO2/Al2O3 and Al2O3/Na2O) and similar distribution patterns of incompatible elements (e.g., the mantle-normalized diagram for incompatible elements and chondrite-normalized diagram for rare earth elements) of coal and tuff, indicated that

  19. On the covering of a Hill's region by solutions in the restricted three-body problem

    Science.gov (United States)

    Kozlov, Valery; Polekhin, Ivan

    2017-03-01

    We consider two classical celestial-mechanical systems: the planar restricted circular three-body problem and its simplification, the Hill's problem. Numerical and analytical analyses of the covering of a Hill's region by solutions starting with zero velocity at its boundary are presented. We show that, in all considered cases, there always exists an area inside a Hill's region that is uncovered by the solutions.

  20. Wine Industry Competitiveness: A survey of the Shawnee Hills American Viticultural Area

    Directory of Open Access Journals (Sweden)

    C. Matthew Rendleman

    2016-06-01

    Shawnee Hill׳s AVA winery owner/operators regard increases in regional tourism, growth in the US wine market continuous innovation, unique services and processes, and flow of information from customers to have the most enhancing effects on their businesses, and that confidence/trust in Illinois state political systems, tax systems, and administrative/bureaucratic regulations were the most constraining factors. Furthermore the Shawnee Hills AVA has growing competition, yet consists of innovative winery owners. It may currently lack external financial support, but with a community focus on product differentiation, the Shawnee Hills AVA has a chance, owners believe, to capture a portion of the growing market for regional products.

  1. Considerations on seismic microzonation in areas with two-dimensional hills

    Indian Academy of Sciences (India)

    Mohsen Kamalian; Abdollah Sohrabi-Bidar; Arash Razmkhah; Amirata Taghavi; Iraj Rahmani

    2008-11-01

    This paper presents the results of an extensive numerical parametric study on seismic behavior of 2D homogenous hills subjected to vertically propagating incident SV waves. It is shown that the amplification potential of these hills is strongly influenced by the wavelength, by the shape ratio, by the shape of the hill and in a less order of importance, by the Poisson ratio of the media. The 2D topography effect could be ignored, only if the hill has a shape ratio of less than 0.1 or if it is subjected to incident waves with predominant dimensionless periods of greater than 13 times the shape ratio. In incidence of waves with wavelengths longer than the width of the hill, the amplification curve usually finds its maximum at the crest and decreases towards the base of the hill. Else, some de-amplification zones would occur along the hill. Among hills with similar shape ratios, those with intermediate cross section areas show intermediate seismic behavior, too. Estimated seismic site coefficients for the crest of a 2D rocky hill depend on its shape ratio and could reach even 1.7, which encourages one to classify it according to standard site categorization procedures as soil profile types SC or SD instead of the conventional SB type.

  2. Audio-magnetotelluric (AMT) study to investigate the genesis of Mujil hill

    Science.gov (United States)

    Rahmania, Suryanto, Wiwit

    2017-07-01

    Gunung Mujil is an isolated hill located near Pondoworejo village, Kalibawang sub-district, Kulon Progo district, and Special Province of Yogyakarta. The hill is part of the eastern Kulon Progo mountain range extended relatively in the North-South direction. The lithology of the hill consists of andesite breccia and it's similar with the Old Andesite Formation that built the Kulon Progo Mountains. There are at least two hypothesis about the genesis and the formation mechanism of this hill, (1) it was formed by debris mass from Kulon Progo Mountains, and (2) ) it was formed by an intrusion. Our study intended to determine the subsurface resistivity below the hill and to relating those results to with the scenario of the genesis of the Mujil hill. We conducted Audio-magnetotellurics (AMT) measurements along two lines survey crossing the Mujil hill consisting of 20 measurements. Since the measurements are located near the villages, most of the data has a fair to bad quality and only one station yielded an excellent data. A 1D Forward modeling was then applied to find best-fit model of the AMT data. The results shows that the Mujil hill was built by debris mass of the Old Andesite Formation from Kulon Progo mountain which is represented by a lower resistivity value under the Mujil hill.

  3. Environmental Assessment: Proposed Photovoltaic Array, Hill Air Force Base, Utah

    Science.gov (United States)

    2008-08-28

    AFB tree removal and replacement plan (Hill 2006). The tree replacement policy is based on each tree’s diameter at breast height ( DBH ). For example...if a tree with a DBH of 10 inches was removed, it would be replaced with 10 trees each with a one-inch DBH , or any combination of trees equivalent...would not create solid or hazardous waste. Biological No effects Attempts to preserve trees could be unsuccessfuL Up to 62 trees could be Resources

  4. Andean terraced hills (a use of satellite imagery)

    CERN Document Server

    Sparavigna, Amelia Carolina

    2010-01-01

    The aim of this paper is in stimulating the use of satellite imagery, in particular the free service of Google Maps, to investigate the distribution of the agricultural technique of terraced hills in Andean countries, near Titicaca Lake. In fact, satellite maps can give a clear view of the overall surface modified by human work, being then a precious help for on-site archaeological researches and for historical analysis. Satellite imagery is also able to give the distribution of burial and worship places. The paper discusses some examples near the Titicaca Lake.

  5. Iowa Hill Pumped Storage Project Investigations - Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, David [Sacramento Municipal Unitlity District, Sacramento, CA (United States)

    2016-07-01

    This Final Technical Report is a summary of the activities and outcome of the Department of Energy (DOE) Assistance Agreement DE-EE0005414 with the Sacramento Municipal Utility District (SMUD). The Assistance Agreement was created in 2012 to support investigations into the Iowa Hill Pumped-storage Project (Project), a new development that would add an additional 400 MW of capacity to SMUD’s existing 688MW Upper American River Hydroelectric Project (UARP) in the Sierra Nevada mountains east of Sacramento, California.

  6. Stream piracy in the Black Hills: A geomorphology lab exercise

    Science.gov (United States)

    Zaprowski, B.J.; Evenson, E.B.; Epstein, J.B.

    2002-01-01

    The Black Hills of South Dakota exhibits many fine examples of stream piracy that are very suitable for teaching geomorphology lab exercises. This lab goes beyond standard topographic map interpretation by using geologic maps, well logs, gravel provenance and other types of data to teach students about stream piracy. Using a step-by-step method in which the lab exercises ramp up in difficulty, students hone their skills in deductive reasoning and data assimilation. The first exercises deal with the identification of stream piracy at a variety of spatial scales and the lab culminates with an exercise on landscape evolution and drainage rearrangement.

  7. The origin of an unusual tuff ring of perlitic rhyolite pyroclasts: The last explosive phase of the Ramadas Volcanic Centre, Andean Puna, Salta, NW Argentina

    Science.gov (United States)

    Tait, M. A.; Cas, R. A. F.; Viramonte, J. G.

    2009-05-01

    A thick sequence of bedded pyroclastic deposits, comprised largely of crystal poor, partially flow-banded perlite fragments defines the remains of a tuff ring around the eastern margin of the Miocene Ramadas Volcanic Centre (RVC), Central Andes, NW Argentina. In numerous quarry exposures, planar bed-forms dominate, but low-angle cross-stratification, lensoidal truncations and lateral pinching and swelling of cm-dm scale bed-forms occur, consistent with pyroclastic surge as the dominant transport and depositional mechanism. Intercalated are mantling, very fine grained, well-sorted, mm-cm scale planar ash layers that represent deposition from pyroclastic fall out and are most likely the products of co-surge ash clouds. Also observed are thick m-scale, laterally continuous, poorly-sorted horizons that are interpreted as pyroclastic flow deposits. Grainsize variations within the > 70 m thick succession range from fine ash to coarse lapilli, with occasional large blocks reaching 20 cm. Clast vesicularities are typically very low. The sequence constitutes a rhyolitic tuff ring around the proximal margins of the RVC. Stratigraphic relationships indicate that the tuff ring was developed following cessation of the major plinian eruption phase of the RVC. A series of pyroclastic density currents and associated ash clouds is inferred to have resulted in the construction of the rhyolitic tuff ring, with deposition focussed on the eastern and southern margins of the central vent. The fine-grained nature of the deposits and low clast vesicularity are consistent with some degree of magma:water interaction during fragmentation. Pervasive perlitic fracturing of clasts found within the tuff deposits also indicates hydration and an extended, post-depositional hydration of the pyroclastic sequence, due to the influence of meteoric water, is likely to have occurred, with deposit permeability, clast specific surface and climate influential in facilitating additional textural

  8. Vegetation during UMBI and deposition of Tuff IF at Olduvai Gorge, Tanzania (ca. 1.8 Ma) based on phytoliths and plant remains.

    Science.gov (United States)

    Albert, Rosa Maria; Bamford, Marion K

    2012-08-01

    As part of ongoing research at Olduvai Gorge, Tanzania, to determine the detailed paleoenvironmental setting during Bed I and Bed II times and occupation of the basin by early hominins, we present the results of phytolith analyses of Tuff IF which is the uppermost unit of Bed I. Phytoliths were identified in most of the levels and localities on the eastern paleolake margin, but there are not always sufficient numbers of identifiable morphologies to infer the specific type of vegetation due to dissolution. Some surge surfaces and reworked tuff surfaces were vegetated between successive ash falls, as indicated by root-markings and the presence of a variety of phytolith morphotypes. Dicotyledonous wood/bark types were dominant except at the FLK N site just above Tuff IF when monocots are dominant and for the palm-dominated sample from the reworked channel cutting down into Tuff IF at FLK N. The area between the two fault scarps bounding the HWK Compartment, approximately 1 km wide, was vegetated at various time intervals between some of the surges and during the reworking of the Tuff. By lowermost Bed II times the eastern margin was fully vegetated again. Climate and tectonic activity probably controlled the fluctuating lake levels but locally the paleorelief and drainage were probably the controlling factors for the vegetation changes. These data support a scenario of small groups of hominins making brief visits to the paleolake during uppermost Bed I times, followed by a more desirable vegetative environment during lowermost Bed II times. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Sorption of indigo carmine by a Fe-zeolitic tuff and carbonaceous material from pyrolyzed sewage sludge

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez-Segura, E. [Facultad de Quimica, Universidad Autonoma del Estado de Mexico, Paseo Colon y Tollocan s/n., C.P. 50000 Toluca (Mexico); Departamento de Quimica, Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, Col. Escandon, Delegacion Miguel Hidalgo, C.P. 11801 Mexico, D.F. (Mexico); Solache-Rios, M., E-mail: marcos.solache@inin.gob.mx [Departamento de Quimica, Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, Col. Escandon, Delegacion Miguel Hidalgo, C.P. 11801 Mexico, D.F. (Mexico); Colin-Cruz, A. [Facultad de Quimica, Universidad Autonoma del Estado de Mexico, Paseo Colon y Tollocan s/n., C.P. 50000 Toluca (Mexico)

    2009-10-30

    Indigo carmine removal from aqueous solution has been evaluated using Fe-zeolitic tuff and carbonaceous material from pyrolyzed sewage sludge treated with HCl (CM). The adsorbents were characterized by scanning electron microscopy, BET surface area and X-ray diffraction. Sorption kinetics and isotherms were determined and the adsorption behaviors analyzed. Kinetic pseudo-second order and Langmuir-Freundlich models were successfully applied to the experimental results obtained with the Fe-zeolitic material, while kinetic first order and Langmuir-Freundlich models were applied to the results from the carbonaceous materials. This indicates mechanisms of chemisorption and physic sorption, respectively, on the heterogeneous materials. The results indicate that the carbonaceous material from the pyrolysis of sewage sludge (sorption capacity 92.83 mg/g) is a better adsorbent of indigo carmine than the zeolitic material (sorption capacity 32.83 mg/g).

  10. Deformation and velocity measurements at elevated temperature in a fractured 0.5 M block of tuff

    Energy Technology Data Exchange (ETDEWEB)

    Blair, S.C.; Berge, P.A.

    1996-02-01

    This paper presents preliminary results of laboratory tests conducted on small block samples of Topopah Spring tuff, in support of the Yucca Mountain Site Characterization Project. The overall objective of these tests is to investigate the thermal-mechanical, thermal-hydrological, and thermal-chemical response of the rock to conditions similar to the near-field environment (NFE) of a potential nuclear waste repository. We present preliminary results of deformation and elastic wave velocity measurements on a 0.5-m-scale block of Topopah Spring tuff tested in uniaxial compression to 8.5 MPa and at temperatures to 85{degree}C. The Young`s modulus was found to be about 7 to 31 GPa for vertical measurements parallel to the stress direction across parts of the block containing no fractures or a few fractures, and 0.5 to 0.9 GPA for measurements across individual fractures, at ambient temperature and 8.5 MPa maximum stress. During stress cycles between 5 and 8.5 MPa, the deformation modulus values for the matrix with fractures were near 15-20 GPa at ambient temperature but dropped to about 10 GPa at 85{degree}C. Compressional wave velocities were found to be about 3.6 to 4.7 km/s at ambient temperature and stress. After the stress was cycled, velocities dropped to values as low as 2.6 km/s in the south end of the block where vertical cracks developed. Heating the block to about 85{degree}C raised velocities to as much as 5.6 km/s in the upper third of the block.

  11. Estimates of the hydrologic impact of drilling water on core samples taken from partially saturated densely welded tuff

    Energy Technology Data Exchange (ETDEWEB)

    Buscheck, T.A.; Nitao, J.J.

    1987-09-01

    The purpose of this work is to determine the extent to which drill water might be expected to be imbibed by core samples taken from densely welded tuff. In a related experimental study conducted in G-Tunnel, drill water imbibition by the core samples was observed to be minimal. Calculations were carried out with the TOUGH code with the intent of corroborating the imbibition observations. Due to the absence of hydrologic data pertaining directly to G-Tunnel welded tuff, it was necessary to apply data from a similar formation. Because the moisture retention curve was not available for imbibition conditions, the drainage curve was applied to the model. The poor agreement between the observed and calculated imbibition data is attributed primarily to the inappropriateness of the drainage curve. Also significant is the value of absolute permeability (k) assumed in the model. Provided that the semi-log plot of the drainage and imbibition moisture retention curves are parallel within the saturation range of interest, a simple relationship exists between the moisture retention curve, k, and porosity ({phi}) which are assumed in the model and their actual values. If k and {phi} are known, we define the hysteresis factor {lambda} to be the ratio of the imbibition and drainage suction pressures for any saturation within the range of interest. If k and {phi} are unknown, {lambda} also accounts for the uncertainties in their values. Both the experimental and modeling studies show that drill water imbibition by the core has a minimal effect on its saturation state. 22 refs., 6 figs., 2 tabs.

  12. Reactive transport modeling of plug-flow reactor experiments: quartz and tuff dissolution at 240°C

    Science.gov (United States)

    Johnson, James W.; Knauss, Kevin G.; Glassley, William E.; DeLoach, Laura D.; Tompson, Andrew F. B.

    1998-08-01

    Extension of reactive transport modeling to predict the coupled thermal, hydrological, and chemical evolution of complex geological systems is predicated on successful application of the approach to simulate well-constrained physical experiments. In this study, steady-state effluent concentrations and dissolution/precipitation features associated with crushed quartz and tuff dissolution at 240°C have been determined experimentally using a plug-flow reactor (PFR) and scanning electron microscopy (SEM) techniques, then modeled with the reactive transport simulator GIMRT ( Steefel and Yabusaki, 1996) using a linear rate law from transition state theory (TST) . For quartz dissolution, interdependence of the specific surface area ( Am) and reaction rate constant ( km) predicted from the modeling agrees closely with that obtained from an analytical solution to the reaction-transport equation without diffusion/dispersion, verifying the advection-dominant nature of the PFR experiments. Independently-determined Aqtz and kqtz from the literature are shown to be internally consistent with respect to the model and analytical interdependence, implying appropriateness of the linear TST rate law and adequacy of BET-determined Am for use in modeling PFR experiments. Applications of this integrated approach for monomineralic dissolution include assessment of internal consistency among independent Am and km data, estimation of km from BET-determined Am, and rapid evaluation of alternative rate laws. For tuff dissolution, accurate simulation of the experimental steady-state effluent concentrations (to within 3% for Na, Al and K; to within 15% for Si and Ca) and dearth of alteration phases (complex systems for which development of experimental analogs is impractical or impossible.

  13. Impact craters as biospheric microenvironments, Lawn Hill Structure, Northern Australia.

    Science.gov (United States)

    Lindsay, John; Brasier, Martin

    2006-04-01

    Impact craters on Mars act as traps for eolian sediment and in the past may have provided suitable microenvironments that could have supported and preserved a stressed biosphere. If this is so, terrestrial impact structures such as the 18-km-diameter Lawn Hill Structure, in northern Australia, may prove useful as martian analogs. We sampled outcrop and drill core from the carbonate fill of the Lawn Hill Structure and recorded its gamma-log signature. Facies data along with whole rock geochemistry and stable isotope signatures show that the crater fill is an outlier of the Georgina Basin and was formed by impact at, or shortly before, approximately 509-506 million years ago. Subsequently, it was rapidly engulfed by the Middle Cambrian marine transgression, which filled it with shallow marine carbonates and evaporites. The crater formed a protected but restricted microenvironment in which sediments four times the thickness of the nearby basinal succession accumulated. Similar structures, common on the martian surface, may well have acted as biospheric refuges as the planet's water resources declined. Low-pH aqueous environments on Earth similar to those on Mars, while extreme, support diverse ecologies. The architecture of the eolian crater fill would have been defined by long-term ground water cycles resulting from intermittent precipitation in an extremely arid climate. Nutrient recycling, critical to a closed lacustrine sub-ice biosphere, could be provided by eolian transport onto the frozen water surface.

  14. Woods and Russell, Hill, and the emergence of medical statistics

    Science.gov (United States)

    Farewell, Vern; Johnson, Tony

    2010-01-01

    In 1937, Austin Bradford Hill wrote Principles of Medical Statistics (Lancet: London, 1937) that became renowned throughout the world and is widely associated with the birth of modern medical statistics. Some 6 years earlier Hilda Mary Woods and William Thomas Russell, colleagues of Hill at the London School of Hygiene and Tropical Medicine, wrote a similar book An Introduction to Medical Statistics (PS King and Son: London, 1931) that is little known today. We trace the origins of these two books from the foundations of early demography and vital statistics, and make a detailed examination of some of their chapters. It is clear that these texts mark a watershed in the history of medical statistics that demarcates the vital statistics of the nineteenth and early twentieth centuries from the modern discipline. Moreover, we consider that the book by Woods and Russell is of some importance in the development of medical statistics and we describe and acknowledge their place in the history of this discipline. Copyright © 2010 John Wiley & Sons, Ltd. PMID:20535761

  15. Population structure and sexual maturity of the calico box crab Hepatus epheliticus Linnaeus (Brachyura, Hepatidae from Yucatan Peninsula, Mexico Estructura poblacional y madurez sexual en el cangrejo caja moteado Hepatus epheliticus Linnaeus (Brachyura, Hepatidae procedente de la Península del Yucatán, México

    Directory of Open Access Journals (Sweden)

    Patricio Hernáez

    2012-07-01

    Full Text Available The calico box crab Hepatus epheliticus is an abundant species from shallow and continental shelf waters of the Atlantic coast of USA and Mexico. Information about population structure and sexual maturity is absent, even though this crab is caught to be used as bait for the octopus fishery in the Campeche Bank, Mexico. In order to achieve such information, a total of 768 individuals were collected from January to March 2010 through baited traps installed in the Yucatan Peninsula, Mexico. Our results showed that sex ratio is biased towards more males than females (1:0.55, contradicting to that reported in other brachyuran crabs. The absence of ovigerous females suggests that they did not enter into the traps during embryogenesis. Males reached a larger maximum size than females (64.0 ± 6.15 and 58.4 ± 5.60 mm carapace width, respectively. The general scheme of growth being positive allometric throughout ontogeny of both sexes. Males presented a transition phase from juveniles to adult corresponding to the puberty moult. The estimation of the onset of functional sexual maturity revealed a steady situation for the population, with 21.5 and 13.8% of males and females, respectively, morphologically immature at the time of catch. This study constitutes the first report on population structure and sexual maturity in a population of the calico box crab H. epheliticus.El cangrejo caja moteado Hepatus epheliticus es un abundante braquiuro perteneciente a la familia Hepatidae, distribuido desde aguas someras hasta la plataforma continental en la costa atlántica de Estados Unidos y México. La información sobre su demografía poblacional y madurez sexual es actualmente inexistente, aun cuando esta especie es intensamente capturada como carnada en la pesquería del pulpo del estado de Campeche, México. Entre enero y marzo de 2010, se colectaron 768 especímenes usando trampas instaladas en la Península de Yucatán, México. Los resultados mostraron una

  16. Studies on termite hill and lime as partial replacement for cement in plastering

    Energy Technology Data Exchange (ETDEWEB)

    Olusola, K.O.; Olanipekun, E.A.; Ata, O.; Olateju, O.T. [Obafemi Awolowo University, Ile-Ife, Osun State (Nigeria). Department of Building

    2006-03-15

    This study investigated the compressive strength and water absorption capacity of 50x50x50mm mortar cubes made from mixes containing lime, termite hill and cement and sand. Two mix ratios (1:4 and 1:6) and varying binder replacements of cement with lime or termite hill amounting to 0%, 10%, 20%, 30%, 40% and 50% were used. Test results showed that the compressive strength of the mortar cubes increases with age and decreases with increasing percentage replacement of cement with lime and termite hill. However, for mix ratio 1:6, up to 20% replacement of cement with either lime or termite hill, all the mortar cubes had the same strength; subsequently, the termite hill exhibited a higher compressive strength. For mix ratio 1:4, mortar cubes made from lime/cement and termite hill/cement mixtures had the same strength at 50% replacement. Generally, water absorption is higher in mixtures containing lime (18.10% and 14.20% for mix ratios 1:6 and 1:4, respectively, both at 50% replacement level) than those containing termite hill (16.10% and 13.02% for mix ratios 1:6 and 1:4, respectively, both at 50% replacement level). Termite hills seem to be promising as a suitable, locally available housing material for plastering. (author)

  17. Five New Records of Terrestrial and Lithophytic Orchids (Orchidaceae) from Penang Hill, Malaysia.

    Science.gov (United States)

    Yeu, Nga Shi; Nordin, Farah Alia; Othman, Ahmad Sofiman

    2016-08-01

    Five new records of terrestrial and lithophytic orchid species were gathered from Penang Hill, Pulau Pinang, Malaysia namely Bulbophyllum depressum, Goodyera pusilla, Peristylus monticola, Podochilus microphyllus, and Zeuxine gracilis. Checklist of each species is provided and their distribution in Penang Hill is discussed.

  18. Sharing the Gift of Jazz: An Interview with Willie L. Hill Jr.

    Science.gov (United States)

    Howe, Brad

    2011-01-01

    This article presents an interview with Willie L. Hill Jr., founder and director of the Society for Jazz Education. Currently a professor of music education at the University of Massachusetts-Amherst and the director of the UMass Fine Arts Center, Hill has served as director of education for the Thelonious Monk Institute of Jazz. He is a past…

  19. Characteristics of successful puma kill sites of elk in the Black Hills, South Dakota

    Science.gov (United States)

    Chadwick P. Lehman; Christopher T. Rota; Mark A. Rumble; Joshua J. Millspaugh

    2017-01-01

    Elk Cervus canadensis nelsoni in the Black Hills, South Dakota, have been declining since 2006 and there is concern by resource managers and hunters that puma Puma concolor predation may be contributing to declining herds. We evaluated characteristics at sites where puma successfully killed elk in the Black Hills of South Dakota. We evaluated characteristics at coarse...

  20. 76 FR 60815 - Final Legislative Environmental Impact Statement (LEIS) for the Limestone Hills Training Area...

    Science.gov (United States)

    2011-09-30

    ... Department of the Army Final Legislative Environmental Impact Statement (LEIS) for the Limestone Hills... land within the Limestone Hills Training Area (LHTA) from BLM administration. The LEIS proposes that..., mining, recreation, transportation, utility right-of-ways, and wildlife management. A limestone mine...

  1. Sharing the Gift of Jazz: An Interview with Willie L. Hill Jr.

    Science.gov (United States)

    Howe, Brad

    2011-01-01

    This article presents an interview with Willie L. Hill Jr., founder and director of the Society for Jazz Education. Currently a professor of music education at the University of Massachusetts-Amherst and the director of the UMass Fine Arts Center, Hill has served as director of education for the Thelonious Monk Institute of Jazz. He is a past…

  2. Rare Plants and Animals of the Texas Hill Country: Educator's Guide.

    Science.gov (United States)

    Texas State Dept. of Parks and Wildlife, Austin.

    Texas Hill Country is a land of fresh water springs, stony hills, and steep canyons and home to many rare plants and animals. Six activities for grades 3-5 and six activities for grades 6-12 are contained in this guide. Elementary activity highlights include using "The Lorax" by Dr. Seuss to stimulate critical thinking about environmental problems…

  3. 75 FR 20774 - Establishment of Class E Airspace; Fort A.P. Hill, VA

    Science.gov (United States)

    2010-04-21

    ... Federal Aviation Administration 14 CFR Part 71 Establishment of Class E Airspace; Fort A.P. Hill, VA... Register December 7, 2009 that establishes Class E airspace at Fort A.P. Hill, VA. DATES: Effective Date..., Eastern Service Center, Federal Aviation Administration, P.O. Box 20636, Atlanta, Georgia 30320;...

  4. Hume, Mill, Hill, and the sui generis epidemiologic approach to causal inference.

    Science.gov (United States)

    Morabia, Alfredo

    2013-11-15

    The epidemiologic approach to causal inference (i.e., Hill's viewpoints) consists of evaluating potential causes from the following 2, noncumulative angles: 1) established results from comparative, observational, or experimental epidemiologic studies; and 2) reviews of nonepidemiologic evidence. It does not involve statements of statistical significance. The philosophical roots of Hill's viewpoints are unknown. Superficially, they seem to descend from the ideas of Hume and Mill. Hill's viewpoints, however, use a different kind of evidence and have different purposes than do Hume's rules or Mill's system of logic. In a nutshell, Hume ignores comparative evidence central to Hill's viewpoints. Mill's logic disqualifies as invalid nonexperimental evidence, which forms the bulk of epidemiologic findings reviewed from Hill's viewpoints. The approaches by Hume and Mill cannot corroborate successful implementations of Hill's viewpoints. Besides Hume and Mill, the epidemiologic literature is clueless about a plausible, pre-1965 philosophical origin of Hill's viewpoints. Thus, Hill's viewpoints may be philosophically novel, sui generis, still waiting to be validated and justified.

  5. Anita Hill/Clarence Thomas Revisited: Emotionality as a Necessary Component of Credibility

    Science.gov (United States)

    Sigal, Janet; And Others

    In the years since the Anita Hill/Clarence Thomas Senate Confirmation hearings, it is apparent that this event has had some far-reaching consequences. Although the immediate outcome of the Senate hearings was not positive for Professor Hill, the effect of her testimony seems to have been to encourage more discussion of sexual harassment. The…

  6. The Sou Hills: A barrier to faulting in the central Nevada Seismic Belt

    Science.gov (United States)

    Fonseca, Julia

    1988-01-01

    Bedrock zones transverse to regional structures may indicate barriers at depth that inhibit the propagation of fault ruptures in the Basin and Range Province. The Tertiary bedrock of the Sou Hills separates Dixie and Pleasant valleys and is transverse to the trends of physiography and historic surface faulting in central Nevada. Four lines of evidence indicate that the Sou Hills are a barrier to faulting in the seismic belt. First, total late Cenozoic vertical displacement on range-bounding faults decreases toward the Sou Hills. Second, analyses of landforms that reflect rates of relative uplift show that Quaternary uplift decreases where range-bounding faults meet the Sou Hills. Third, the most recent prehistoric faulting south of the transverse zone is several thousand years younger than faulting to the north. Fourth, patterns of late Quaternary fault scarps in the Sou Hills are similar to rupture patterns observed at the termination of faults elsewhere.

  7. Late Devonian spermatophyte diversity and paleoecology at Red Hill, north-central Pennsylvania, USA

    Energy Technology Data Exchange (ETDEWEB)

    Cressler, Walter L. III. [Francis Harvey Green Library, 29 West Rosedale Avenue, West Chester University, West Chester, PA, 19383 (United States); Prestianni, Cyrille [Universite de Liege, Boulevard du Rectorat B18, Liege 4000 (Belgium); LePage, Ben A. [The Academy of Natural Sciences, 1900 Benjamin Franklin Parkway, Philadelphia, PA, 19103 and PECO Energy Company, 2301 Market Avenue, S9-1, Philadelphia, PA 19103 (United States)

    2010-08-01

    Early spermatophytes have been discovered at Red Hill, a Late Devonian (Famennian) fossil locality in north-central Pennsylvania, USA. The Red Hill locality contains an Archaeopteris-dominated flora within an outcrop of the Duncannon Member of the Catskill Formation. Palynological analyses of the plant fossil-bearing horizons within the Red Hill outcrop indicate deposition within the VCo palynozone. This is the earliest time horizon known to contain evidence for spermatophytes, and is contemporaneous with well-known spermatophyte-bearing deposits in West Virginia and Belgium. Some of the spermatophyte material from Red Hill compares well with Aglosperma sp., previously known as isolated ovules from the latest Devonian of South Wales and England, thus extending its geographic and stratigraphic range. Red Hill specimens of Aglosperma sp. occur both as isolated ovules and attached to dichotomously forking axes. Additional spermatophyte cupules discovered at Red Hill are morphologically similar to those of the previously described Late Devonian spermatophytes Elkinsia Rothwell, Scheckler, et Gillespie, Moresnetia Stockmans, and Xenotheca Arber et Goode. Some of the Red Hill cupule complexes are distinct from the aforementioned taxa in consisting of slender dichotomously forking axes terminating in paired cupules with highly fused and symmetric cupule quadrant lobes. The distinctive nature of these Red Hill specimens warrants the creation of Duodimidia pfefferkornii Cressler, Prestianni, et LePage gen. et sp. nov. Plant fossil remains with sphenopteroid foliage are also present at Red Hill, possibly attributable to the spermatophytes. Previous systematic sampling of the rich plant-fossil bearing layer at Red Hill and analysis of its floristic diversity and abundance as well as the presence and absence of charcoal suggests a pattern of floral turnover from a local-scale Rhacophyton-dominated community to spermatophyte colonization following disturbance by wildfires

  8. A new Lower Triassic ichthyopterygian assemblage from Fossil Hill, Nevada

    Directory of Open Access Journals (Sweden)

    Neil P. Kelley

    2016-01-01

    Full Text Available We report a new ichthyopterygian assemblage from Lower Triassic horizons of the Prida Formation at Fossil Hill in central Nevada. Although fragmentary, the specimens collected so far document a diverse fauna. One partial jaw exhibits isodont dentition with blunt tipped, mesiodistally compressed crowns and striated enamel. These features are shared with the Early Triassic genus Utatsusaurus known from coeval deposits in Japan and British Columbia. An additional specimen exhibits a different dentition characterized by relatively small, rounded posterior teeth resembling other Early Triassic ichthyopterygians, particularly Grippia. This Nevada assemblage marks a southward latitudinal extension for Early Triassic ichthyopterygians along the eastern margin of Panthalassa and indicates repeated trans-hemispheric dispersal events in Early Triassic ichthyopterygians.

  9. A Pragmatic Analysis of Hemingway's "Hills Like White Elephant"

    Institute of Scientific and Technical Information of China (English)

    李贺

    2008-01-01

    Hemingway's short story Hills Like White Elephant serves as a best illustration of the TiP of an Iceberg Theory.His deliberate omission of information concerning the background of the protagonists and purposeful avoidance of maklog authorial comments makes it possble to understand the text in totally differeot ways and leaves readers to struggle for the undersatnding of the potential meaning of the text all by themselves.By applying the Cooperative Principie and the Pragmatic Theory of Politeness to the conversation in the text,the essay here tries to recover the information hidden bonesth the surface of the text and to recoilstruct the text as a whole.The cooclusion is that proper application of relevant pragmatic theory can help readers have a relatively rationsl and reasonable understanding of the text.

  10. [Vasculitis: New nomenclature of the Chapel Hill consensus conference 2012].

    Science.gov (United States)

    Holl-Ulrich, K

    2014-11-01

    Within the last years, many advances have been made in the understanding of the etiopathology of vasculitis as well as of different disease courses. The revised 2012 Chapel Hill consensus conference (CHCC) nomenclature reflects current knowledge on the etiopathology in addition to the descriptive principles of vessel size and types of inflammation. The anti-neutrophil cytoplasmic antibody (ANCA)-associated forms of vasculitis have been separated as a group, as opposed to immune complex small vessel vasculitis. When consensus was achieved eponyms have been replaced by systematic names, such as granulomatosis with polyangiitis (Wegener's granulomatosis) or eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome). Moreover, clinically important but less well-known types of vasculitis have now been included in the CHCC nomenclature. This article presents the changes and summarizes the results of important new articles on the clinical picture and morphology of vasculitis.

  11. [Vasculitis. New nomenclature of the Chapel Hill consensus conference 2012].

    Science.gov (United States)

    Holl-Ulrich, K

    2013-11-01

    In recent years, many advances have been made in our understanding of vasculitis etiopathology as well as of different disease courses. The revised Chapel Hill Consensus Conference (CHCC) 2012 nomenclature reflects current knowledge about etiopathology, in addition to the descriptive principles of vessel size and type of inflammation. Anti-neutrophil cyptoplasmic antibody (ANCA)-associated vasculitides have been classified as a separate group, as opposed to immune complex small vessel vasculitis. In cases where consensus was achieved, eponyms have been replaced by systematic names, such as granulomatosis with polyangiitis (Wegener's) or eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome). Moreover, clinically important but less well-known types of vasculitis have now been included in the CHCC nomenclature. This article presents the changes, focussing on those types that are relevant to the histopathologist, and summarizes the results of important new articles on morphology and clinical picture of vasculitis.

  12. A database on endemic plants at Tirumala hills in India

    Science.gov (United States)

    Latheef, Shaik Abdul; Prasad, Beerkam; Bavaji, Middi; Subramanyam, Gangapatnam

    2008-01-01

    Medicinal plants play an important role in health care. The use of medicinal plants for treatment is growing in view of cost and non-compliance of modern medicine as in case of non-communicable diseases. Plants such as Boswellia, ovalifoliolata, Cycas beddomei, Pimpinella tirupatiensis, Pterocarpus santalinus, Shorea thumbuggaia, Syzygium alternifolium, Terminalia pallida are endemic to Tirumala hills of seshachalam range falling under the Eastern Ghats of India. These plants species have medicinal properties such as anti-tumorogenic, anti-microbial, purgative, hypoglycemic, abortificient, analgesic, anti-septic, anti-pyretic and anti-inflammatory. We created a database named DEPTH in an attempt to communicate data of these plants to the scientific community. DEPTH contains data on scientific name, vernacular name, family name, morphological description, economic importance, known medicinal compounds and medicinal importance. Availability http://svimstpt.ap.nic.in/MedicinalPlants/mainpage.htm PMID:18317578

  13. Modelling Fine Scale Movement Corridors for the Tricarinate Hill Turtle

    Science.gov (United States)

    Mondal, I.; Kumar, R. S.; Habib, B.; Talukdar, G.

    2016-06-01

    Habitat loss and the destruction of habitat connectivity can lead to species extinction by isolation of population. Identifying important habitat corridors to enhance habitat connectivity is imperative for species conservation by preserving dispersal pattern to maintain genetic diversity. Circuit theory is a novel tool to model habitat connectivity as it considers habitat as an electronic circuit board and species movement as a certain amount of current moving around through different resistors in the circuit. Most studies involving circuit theory have been carried out at small scales on large ranging animals like wolves or pumas, and more recently on tigers. This calls for a study that tests circuit theory at a large scale to model micro-scale habitat connectivity. The present study on a small South-Asian geoemydid, the Tricarinate Hill-turtle (Melanochelys tricarinata), focuses on habitat connectivity at a very fine scale. The Tricarinate has a small body size (carapace length: 127-175 mm) and home range (8000-15000 m2), with very specific habitat requirements and movement patterns. We used very high resolution Worldview satellite data and extensive field observations to derive a model of landscape permeability at 1 : 2,000 scale to suit the target species. Circuit theory was applied to model potential corridors between core habitat patches for the Tricarinate Hill-turtle. The modelled corridors were validated by extensive ground tracking data collected using thread spool technique and found to be functional. Therefore, circuit theory is a promising tool for accurately identifying corridors, to aid in habitat studies of small species.

  14. The History of Allan Hills 84001 Revised: Multiple Shock Events

    Science.gov (United States)

    Treiman, Allan H.

    1998-01-01

    The geologic history of Martian meteorite Allan Hills (ALH) 84001 is more complex than previously recognized, with evidence for four or five crater-forming impacts onto Mars. This history of repeated deformation and shock metamorphism appears to weaken some arguments that have been offered for and against the hypothesis of ancient Martian life in ALH 84001. Allan Hills 84001 formed originally from basaltic magma. Its first impact event (I1) is inferred from the deformation (D1) that produced the granular-textured bands ("crush zones") that transect the original igneous fabric. Deformation D1 is characterized by intense shear and may represent excavation or rebound flow of rock beneath a large impact crater. An intense thermal metamorphism followed D1 and may be related to it. The next impact (I2) produced fractures, (Fr2) in which carbonate "pancakes" were deposited and produced feldspathic glass from some of the igneous feldspars and silica. After I2, carbonate pancakes and globules were deposited in Fr2 fractures and replaced feldspathic glass and possibly crystalline silicates. Next, feldspars, feldspathic glass, and possibly some carbonates were mobilized and melted in the third impact (I3). Microfaulting, intense fracturing, and shear are also associated with 13. In the fourth impact (I4), the rock was fractured and deformed without significant heating, which permitted remnant magnetization directions to vary across fracture surfaces. Finally, ALH 84001 was ejected from Mars in event I5, which could be identical to I4. This history of multiple impacts is consistent with the photogeology of the Martian highlands and may help resolve some apparent contradictions among recent results on ALH 84001. For example, the submicron rounded magnetite grains in the carbonate globules could be contemporaneous with carbonate deposition, whereas the elongate magnetite grains, epitaxial on carbonates, could be ascribed to vapor-phase deposition during I3.

  15. Draft tube flow phenomena across the bulb turbine hill chart

    Science.gov (United States)

    Duquesne, P.; Fraser, R.; Maciel, Y.; Aeschlimann, V.; Deschênes, C.

    2014-03-01

    In the framework of the BulbT project launched by the Consortium on Hydraulic Machines and the LAMH (Hydraulic Machine Laboratory of Laval University) in 2011, an intensive campaign to identify flow phenomena in the draft tube of a model bulb turbine has been done. A special focus was put on the draft tube component since it has a particular importance for recuperation in low head turbines. Particular operating points were chosen to analyse flow phenomena in this component. For each of these operating points, power, efficiency and pressure were measured following the IEC 60193 standard. Visualizations, unsteady wall pressure and efficiency measurements were performed in this component. The unsteady wall pressure was monitored at seven locations in the draft tube. The frequency content of each pressure signal was analyzed in order to characterize the flow phenomena across the efficiency hill chart. Visualizations were recorded with a high speed camera using tufts and cavitation bubbles as markers. The predominant detected phenomena were mapped and categorized in relation to the efficiency hill charts obtained for three runner blade openings. At partial load, the vortex rope was detected and characterized. An inflection in the partial load efficiency curves was found to be related to complex vortex rope instabilities. For overload conditions, the efficiency curves present a sharp drop after the best efficiency point, corresponding to an inflection on the power curves. This break off is more severe towards the highest blade openings. It is correlated to a flow separation at the wall of the draft tube. Also, due to the separation occurring in these conditions, a hysteresis effect was observed on the efficiency curves.

  16. 77 FR 60458 - Public Land Order No. 7803; Withdrawal of Public Lands for the Limestone Hills Training Area; MT

    Science.gov (United States)

    2012-10-03

    ... Bureau of Land Management Public Land Order No. 7803; Withdrawal of Public Lands for the Limestone Hills... laws, for a period of 5 years. This withdrawal will protect the Limestone Hills Training Area in... hours. SUPPLEMENTARY INFORMATION: The Limestone Hills Training Area withdrawal will maintain the...

  17. Analysis of Conservative Tracer Tests in the Bullfrog, Tram, and Prow Pass Tuffs, 1996 to 1998, Yucca Mountain, Nye County, Nevada

    Science.gov (United States)

    Umari, Amjad; Fahy, Michael F.; Earle, John D.; Tucci, Patrick

    2008-01-01

    To evaluate the potential for transport of radionuclides in ground water from the proposed high-level nuclear-waste repository at Yucca Mountain, Nevada, conservative (nonsorbing) tracer tests were conducted among three boreholes, known as the C-hole Complex, and values for transport (or flow) porosity, storage (or matrix) porosity, longitudinal dispersivity, and the extent of matrix diffusion were obtained. The C-holes are completed in a sequence of Miocene tuffaceous rock, consisting of nonwelded to densely welded ash-flow tuff with intervals of ash-fall tuff and volcaniclastic rocks, covered by Quaternary alluvium. The lower part of the tuffaceous-rock sequence includes the Prow Pass, Bullfrog, and Tram Tuffs of the Crater Flat Group. The rocks are pervaded by tectonic and cooling fractures. Paleozoic limestone and dolomite underlie the tuffaceous rocks. Four radially convergent and one partially recirculating conservative (nonsorbing) tracer tests were conducted at the C-hole Complex from 1996 to 1998 to establish values for flow porosity, storage porosity, longitudinal dispersivity, and extent of matrix diffusion in the Bullfrog and Tram Tuffs and the Prow Pass Tuff. Tracer tests included (1) injection of iodide into the combined Bullfrog-Tram interval; (2) injection of 2,6 difluorobenzoic acid into the Lower Bullfrog interval; (3) injection of 3-carbamoyl-2-pyridone into the Lower Bullfrog interval; and (4) injection of iodide and 2,4,5 trifluorobenzoic acid, followed by 2,3,4,5 tetrafluorobenzoic acid, into the Prow Pass Tuff. All tracer tests were analyzed by the Moench single- and dual-porosity analytical solutions to the advection-dispersion equation or by superposition of these solutions. Nonlinear regression techniques were used to corroborate tracer solution results, to obtain optimal parameter values from the solutions, and to quantify parameter uncertainty resulting from analyzing two of the three radially convergent conservative tracer tests

  18. Antibacterial behavior of silver-modified clinoptilolite-heulandite rich tuff on coliform microorganisms from wastewater in a column system.

    Science.gov (United States)

    De la Rosa-Gómez, I; Olguín, M T; Alcántara, D

    2008-09-01

    The water disinfecting behavior of silver-modified clinoptilolite-heulandite rich tuff (ZSAg) as an antibacterial agent against coliform microorganisms from water in a continuous mode was investigated. Silver recovery from the disinfected effluents by the sodium-modified clinoptilolite-heulandite rich tuff (ZSNa) was also considered. Escherichia coli (ATCC 8739) and total coliform microorganisms, as indicators of microbiological contamination of water, were chosen to achieve the disinfection of synthetic wastewater or municipal wastewater. Ammonium (NH(4)(+)) and chloride (Cl(-)) ions were added to the synthetic wastewater as an interfering chemical species on the disinfection processes. The antibacterial activity of the ZSAg as a bactericide was measured by the coliform concentration as evaluated by the APHA method. The amount of silver in the disinfected effluents was determined using atomic absorption spectroscopy. The inactivation of the ZSAg was calculated from the breakthrough curves based on the model reported by Gupta et al. It was found that when the silver concentration in the effluent is less than 0.6 microg/mL, the bacterial survival percentage increased and the volume of disinfected water diminished. The total silver amounts found in the effluent at the end of the disinfection processes varied depending on the water treated (synthetic or municipal wastewater). The presence of NH(4)(+) ions in synthetic wastewater influent notably improved the disinfected water volume (zero NVC/100mL), in comparison to the disinfection of the same influent without NH(4)(+) ions. A contrary water disinfection behavior was observed in the presence of Cl(-) ions. The silver recovery does not depend on the mass of the sodium zeolitic bed according with the wastewater to be treated (synthetic or municipal wastewater) and the presence of NH(4)(+) or Cl(-) ions in the influent also influenced the silver recovery from wastewater. The ZSNa did not have antibacterial activity

  19. Numerical simulation of air- and water-flow experiments in a block of variably saturated, fractured tuff from Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Kwicklis, E.M.; Healy, R.W. [Geological Survey, Denver, CO (United States); Thamir, F. [AMX International, Inc., Denver, CO (United States); Hampson, D. [EQE International, Evergreen, CO (United States)

    1998-11-01

    Numerical models of water movement through variably saturated, fractured tuff have undergone little testing against experimental data collected from relatively well-controlled and characterized experiments. This report used the results of a multistage experiment on a block of variably saturated, fractured, welded tuff and associated core samples to investigate if those results could be explained using models and concepts currently used to simulate water movement in variably saturated, fractured tuff at Yucca Mountain, Nevada, the potential location of a high-level nuclear-waste repository. Aspects of the experiment were modeled with varying degrees of success. Imbibition experiments performed on cores of various lengths and diameters were adequately described by models using independently measured permeabilities and moisture-characteristic curves, provided that permeability reductions resulting from the presence of entrapped air were considered. Entrapped gas limited maximum water saturations during imbibition to approximately 0.70 to 0,80 of the fillable porosity values determined by vacuum saturation. A numerical simulator developed for application to fluid flow problems in fracture networks was used to analyze the results of air-injection tests conducted within the tuff block through 1.25-cm-diameter boreholes. These analyses produced estimates of transmissivity for selected fractures within the block. Transmissivities of other fractures were assigned on the basis of visual similarity to one of the tested fractures. The calibrated model explained 53% of the observed pressure variance at the monitoring boreholes (with the results for six outliers omitted) and 97% of the overall pressure variance (including monitoring and injection boreholes) in the subset of air-injection tests examined.

  20. Review of the thermal stability and cation exchange properties of the zeolite minerals clinoptilolite, mordenite, and analcime; applications to radioactive waste isolation in silicic tuff

    Energy Technology Data Exchange (ETDEWEB)

    Smyth, J.R.; Caporuscio, F.A.

    1981-06-01

    Silicic tuffs of the southern Great Basin and basalts of the Columbia River Plateau are under investigation as potential host rocks for high- and intermediate-level radioactive wastes. Nonwelded and partially welded tuffs may contain major amounts (> 50%) of the zeolite minerals clinoptilolite, mordenite, and analcime. Densely welded tuffs and some basalt flows may contain clinoptilolite as fracture filling that limits the permeability of these rocks. The cation exchange properties of these zeolite minerals allow them to pose a formidable natural barrier to the migration of cationic species of various radionuclides in aqueous solutions. However, these minerals are unstable at elevated temperatures and at low water-vapor pressures and may break down either by reversible dehydration or by irreversible mineralogical reactions. All the breakdown reactions occurring at increased temperature involve a net volume reduction and evolution of fluids. Thus, they may provide a pathway (shrinkage fractures) and a driving force (fluid pressure) for release of radionuclides to the biosphere. These reactions may be avoided by keeping zeolite-bearing horizons saturated with water and below about 85{sup 0}C. This may restrict allowable gross thermal loadings in waste repositories in volcanic rocks.

  1. Using 40Ar/39Ar ages of intercalated silicic tuffs to date flood basalts: Precise ages for Steens Basalt Member of the Columbia River Basalt Group

    Science.gov (United States)

    Mahood, Gail A.; Benson, Thomas R.

    2017-02-01

    To establish causality between flood basalt eruptions and extinction events and global environmental effects recorded by isotopic excursions in marine sediments, highly accurate and precise ages for the flood basalts are required. But flood basalts are intrinsically difficult to date. We illustrate how 40Ar/39Ar feldspar ages for silicic tuffs intercalated with and overlying sections of Steens Basalt, the earliest lavas of the Middle Miocene Columbia River Basalt Group in the northwestern United States, provide high-precision ages that, for the first time, make it possible to resolve age differences with stratigraphic position within a section of these flood lavas. The stratigraphically lowest rhyolitic tuff, a fall deposit, yielded an age of 16.592 ± ± 0.028 Ma (FCs = 28.02 Ma), and the uppermost, the alkali rhyolite ignimbrite Tuff of Oregon Canyon, is 16.468 ± ± 0.014 Ma. The argon and stratigraphic data indicate that Steens Basalt eruptions occurred from ∼16.64 to 16.43 Ma in the southern end of its distribution. We estimate that the Steens Mountain geomagnetic reversal occurred at 16.496 ± ± 0.028 Ma (±0.18 Ma total error). Our estimates of the timing for initiation of volcanism and volumetric eruptive rates do not seem to support volcanic forcing by the initial stages of Columbia River Basalt Group eruptions as an explanation for the abrupt warming and carbonate dissolution at the beginning of the Miocene Climatic Optimum.

  2. Research concerning the influence of several factors on Pb2+, Cu2+ and Zn2+ ions adsorption by natural zeolite tuff from Maramureş county, Northern Romania

    Directory of Open Access Journals (Sweden)

    Dan Costin

    2010-11-01

    Full Text Available The purpose of this research is to highlight the influence that certain parameters have on theremoval efficiency of Pb2+, Cu2+ and Zn2+ ions from industrial wastewater using natural zeolite tuff.Environmental and human health damage arising due to heavy metal content in surface water andgroundwater have been challenging for researchers to find the most effective treatment methods with ahigh yield and relatively low cost (Carland & Aplan 1995; Curkovic et al 1997; Inglezakis et al 2003;Inglezakis et al 2005. They may well be achieved by using natural zeolites whose properties such as:molecular sieves, adsorption, hydration-dehydration without modifying their structural network, whichgive them an important role in the removal of heavy metal ions from wastewater (Alvarez-Ayuso et al2003; Peric et al 2004. For this experiment the zeolite tuff sample was taken from a perimeter withvolcanic tuffs located in the Bârsana area, Maramures County, Romania. During the batch experiment theinfluence of certain factors on the ion exchange process was observed, like: particle diameter of zeolitetuff and the pH of the contact solution. After processing the data it was found that the highest levels ofspecific adsorption for all studied heavy metal ions has been obtained for the lowest average diameters(d = 0.037 mm of the ground natural zeolite used in the experiment and the best adsorption has beendone at the highest pH used in the experiment (pH = 4.

  3. Hill's Equation with Small Fluctuations: Cycle to Cycle Variations and Stochastic Processes

    CERN Document Server

    Adams, Fred C

    2013-01-01

    Hill's equations arise in a wide variety of physical problems, and are specified by a natural frequency, a periodic forcing function, and a forcing strength parameter. This classic problem is generalized here in two ways: [A] to Random Hill's equations which allow the forcing strength q_k, the oscillation frequency \\lambda_k, and the period \\tau_k of the forcing function to vary from cycle to cycle, and [B] to Stochastic Hill's equations which contain (at least) one additional term that is a stochastic process \\xi. This paper considers both random and stochastic Hill's equations with small parameter variations, so that p_k=q_k-, \\ell_k=\\lambda_k-, and \\xi are all O(\\epsilon), where \\epsilon<<1. We show that random Hill's equations and stochastic Hill's equations have the same growth rates when the parameter variations p_k and \\ell_k obey certain constraints given in terms of the moments of \\xi. For random Hill's equations, the growth rates for the solutions are given by the growth rates of a matrix tran...

  4. Method development and strategy for the characterization of complexly faulted and fractured rhyolitic tuffs, Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Karasaki, K. [Lawrence Berkeley Lab., CA (United States); Galloway, D. [Geological Survey, Sacramento, CA (United States)

    1991-06-01

    The planned high-level nuclear waste repository at Yucca Mountain, Nevada, would exist in unsaturated, fractured welded tuff. One possible contaminant pathway to the accessible environment is transport by groundwater infiltrating to the water table and flowing through the saturated zone. Therefore, an effort to characterize the hydrology of the saturated zone is being undertaken in parallel with that of the unsaturated zone. As a part of the saturated zone investigation, there wells-UE-25c{number_sign}1, UE-25c{number_sign}2, and UE-25c{number_sign}3 (hereafter called the c-holes)-were drilled to study hydraulic and transport properties of rock formations underlying the planned waste repository. The location of the c-holes is such that the formations penetrated in the unsaturated zone occur at similar depths and with similar thicknesses as at the planned repository site. In characterizing a highly heterogeneous flow system, several issues emerge. (1) The characterization strategy should allow for the virtual impossibility to enumerate and characterize all heterogeneities. (2) The methodology to characterize the heterogeneous flow system at the scale of the well tests needs to be established. (3) Tools need to be developed for scaling up the information obtained at the well-test scale to the larger scale of the site. In the present paper, the characterization strategy and the methods under development are discussed with the focus on the design and analysis of the field experiments at the c-holes.

  5. Wastewater from wood and pulp industry treated by combination of coagulation, adsorption on modified clinoptilolite tuff and membrane processes.

    Science.gov (United States)

    Bennani, Yasmina; Kosutić, Kresimir; Drazević, Emil; Rozeć, Mirela

    2012-06-01

    Wastewater from the wood and pulp industry is of environmental concern. It contains high concentrations of organic and inorganic matter. In this work a combined method of coagulation, adsorption and nanofiltration/reverse osmosis (NF/RO) was investigated in the purification of biologically treated wastewater from wood processing. Coagulation with 0.8 g dm(-3) AlCl3 x 6H2O and adsorption on 2.5 g m(-3) modified clinoptilolite tuff resulted in removal efficiencies of total carbon (TC), total organic carbon (TOC) and inorganic carbon (IC) up to 67.1%, 77.4% and 49.5%, respectively. Almost complete removal of solutes was achieved after NF/RO treatment. The TOC removal efficiency with RO membrane (CPA-3, LFC-1, XLE) and tight NF membrane (NF90) was 98% and with highly porous NF membrane (DK), 88%. After the proposed treatment the purified water stream can be recycled into the process or safely disposed to the river.

  6. Paleomagnetism in the Determination of the Emplacement Temperature of Cerro Colorado Tuff Cone, El Pinacate Volcanic Field, Sonora, Mexico.

    Science.gov (United States)

    Rodriguez Trejo, A.; Alva-Valdivia, L. M.; Vidal Solano, J. R.; Garcia Amador, B.; Gonzalez-Rangel, J. A.

    2014-12-01

    Cerro Colorado Maar is located at the World Heritage Site, biosphere reserve El Pinacate and Gran Desierto del Altar, at the NNW region of Sonora, Mexico (in El Pinacate Volcanic Field). It is a tuff cone, about 1 km diameter, result of several phreatomagmatic episodes during the late Quaternary. We report paleomagnetic and rock magnetic properties from fusiform volcanic bombs obtained from the borders of Cerro Colorado. This study is based in the thermoremanent magnetization TRM normally acquired by volcanic rocks, which can be used to estimate the emplacement temperature range. We performed the experiments on 20 lithic fragments (10 cm to 20 cm approximately), taking 6-8 paleomagnetic cores from each. Rock magnetic experiments (magnetic susceptibility vs. temperature (k-T), hysteresis curves and FORC analysis, shows that the main magnetic mineral carriers of magnetization are titanomagnetite and titanohematite in different levels of intergrowth. The k-T curves suggest in many cases, only one magnetic phase, but also in other cases a second magnetic phase. Thermal demagnetization was used to demagnetize the specimens in detailed short steps and make a well-defined emplacement temperature determination ranges. We found that temperature emplacement determination range for these two magnetic phases is between 350-450 °C, and 550-580 °C, respectively. These results are consistent with those expected in an eruption of Surtsey type, showing a distinct volcanic activity compared to the other craters from El Pinacate volcanic field.

  7. Closure development for high-level nuclear waste containers for the tuff repository; Phase 1, Final report

    Energy Technology Data Exchange (ETDEWEB)

    Robitz, E.S. Jr.; McAninch, M.D. Jr.; Edmonds, D.P. [Babcock and Wilcox Co., Lynchburg, VA (USA). Nuclear Power Div.]|[Babcock and Wilcox Co., Alliance, OH (USA). Research and Development Div.

    1990-09-01

    This report summarizes Phase 1 activities for closure development of the high-level nuclear waste package task for the tuff repository. Work was conducted under U.S. Department of Energy (DOE) Contract 9172105, administered through the Lawrence Livermore National Laboratory (LLNL), as part of the Yucca Mountain Project (YMP), funded through the DOE Office of Civilian Radioactive Waste Management (OCRWM). The goal of this phase was to select five closure processes for further evaluation in later phases of the program. A decision tree methodology was utilized to perform an objective evaluation of 15 potential closure processes. Information was gathered via a literature survey, industrial contacts, and discussions with project team members, other experts in the field, and the LLNL waste package task staff. The five processes selected were friction welding, electron beam welding, laser beam welding, gas tungsten arc welding, and plasma arc welding. These are felt to represent the best combination of weldment material properties and process performance in a remote, radioactive environment. Conceptual designs have been generated for these processes to illustrate how they would be implemented in practice. Homopolar resistance welding was included in the Phase 1 analysis, and developments in this process will be monitored via literature in Phases 2 and 3. Work was conducted in accordance with the YMP Quality Assurance Program. 223 refs., 20 figs., 9 tabs.

  8. Laboratory analysis of fluid flow and solute transport through a variably saturated fracture embedded in porous tuff

    Energy Technology Data Exchange (ETDEWEB)

    Chuang, Y.; Haldeman, W.R.; Rasmussen, T.C.; Evans, D.D. [Arizona Univ., Tucson, AZ (USA). Dept. of Hydrology and Water Resources

    1990-02-01

    Laboratory techniques are developed that allow concurrent measurement of unsaturated matrix hydraulic conductivity and fracture transmissivity of fractured rock blocks. Two Apache Leap tuff blocks with natural fractures were removed from near Superior, Arizona, shaped into rectangular prisms, and instrumented in the laboratory. Porous ceramic plates provided solution to block tops at regulated pressures. Infiltration tests were performed on both test blocks. Steady flow testing of the saturated first block provided estimates of matrix hydraulic conductivity and fracture transmissivity. Fifteen centimeters of suction applied to the second block top showed that fracture flow was minimal and matrix hydraulic conductivity was an order of magnitude less than the first block saturated matrix conductivity. Coated-wire ion-selective electrodes monitored aqueous chlorided breakthrough concentrations. Minute samples of tracer solution were collected with filter paper. The techniques worked well for studying transport behavior at near-saturated flow conditions and also appear to be promising for unsaturated conditions. Breakthrough curves in the fracture and matrix, and a concentration map of chloride concentrations within the fracture, suggest preferential flows paths in the fracture and substantial diffusion into the matrix. Average travel velocity, dispersion coefficient and longitudinal dispersivity in the fracture are obtained. 67 refs., 54 figs., 23 tabs.

  9. Employing volcanic tuff minerals in interior architecture design to reduce microbial contaminants and airborne fungal carcinogens of indoor environments.

    Science.gov (United States)

    Gedikoglu, Yaman; Gedikoglu, Gunduz; Berkin, Genco; Ceyhan, Taskin; Altinoz, Meric A

    2012-09-01

    Indoor volatile organic compounds (VOCs) have posed significant risks to human health since people have both shifted to a life spent, for the most part, indoors. Further, changes in materials used in the construction of buildings, furnishings, and tools either leak or encourage the production of VOCs. Whether these enclosed areas are residences, hospitals or workplaces (specifically composting facilities or closed farm buildings for raising livestock), VOCs can rise to levels that threaten people's health. VOCs can either originate from phenolic and benzene-like compounds in building materials and office furniture or from molds (fungi) growing inside improperly ventilated or sealed buildings. Regardless of the source, exposure to VOCs could lead to significant health concerns from sick-building syndrome, 'leukemia houses,' in-hospital fungemia cases or occupation-associated cancer epidemics due to aflatoxicosis. Innovative 21st-century building materials could offer solutions to these challenges. We propose that volcanic materials, clays and minerals (volcanic tuff, modified clay montmorillonite and mineral clinoptilolite), in their original or chemically modified form, could act like synthetic lungs in building walls, breathing and filtering VOCs, and thus limiting human exposure to disease.

  10. FY 1985 status report on feasibility assessment of copper-base waste package container materials in a tuff repository

    Energy Technology Data Exchange (ETDEWEB)

    McCright, R.D.

    1985-09-30

    This report discusses progress made during the first year of a two-year study on the feasibility of using copper or a copper-base alloy as a container material for a waste package in a potential repository in tuff rock at the Yucca Mountain site in Nevada. The expected corrosion and oxidation performances of oxygen-free copper, aluminum bronze, and 70% copper-30% nickel are presented; a test plan for determining whether copper or one of the alloys can meet the containment requirements is outlined. Some preliminary corrosion test data are presented and discussed. Fabrication and joining techniques for forming waste package containers are descibed. Preliminary test data and analyses indicate that copper and copper-base alloys have several attractive features as waste package container materials, but additional work is needed before definitive conclusions can be made on the feasibility of using copper or a copper-base alloy for containers. Plans for work to be undertaken in the second year are indicated.

  11. SCATTERING OF PLANE SH-WAVE BY A CYLINDRICAL HILL OF ARBITRARY SHAPE

    Institute of Scientific and Technical Information of China (English)

    曹欣荣; 宋天舒; 刘殿魁

    2001-01-01

    The problems of scattering of plane SH-wave by a cylindrical hill of arbitrary shape is studied based on the methods of conjunction and division of solution zone. The scattering wave function is given by using the complex variable and conformal mapping methods. The conjunction boundary conditions are satisfied. Furthermore appling orthogonal function expanding technique, the problems can finally be summarized into the solution of a series of infinite algebraic equations. At last, numerical results of surface displacements of a cylindrical arc hill and of a semi-ellipse hill are obtained. And those computational results are compared with the results of finite element method (FEM).

  12. Subsurface structure of a maar-diatreme and associated tuff ring from a high-resolution geophysical survey, Rattlesnake Crater, Arizona

    Science.gov (United States)

    Marshall, Anita; Connor, Charles; Kruse, Sarah; Malservisi, Rocco; Richardson, Jacob; Courtland, Leah; Connor, Laura; Wilson, James; Karegar, Makan A.

    2015-10-01

    Geophysical survey techniques including gravity, magnetics, and ground penetrating radar were utilized to study the diatreme and tuff ring at Rattlesnake Crater, a maar in the San Francisco Volcanic Field of northern Arizona. Significant magnetic anomalies (+ 1600 nT) and a positive gravity anomaly (+ 1.4 mGal) are associated with the maar. Joint modeling of magnetic and gravity data indicate that the diatreme that underlies Rattlesnake Crater has volume of 0.8-1 km3, and extends to at least 800 m depth. The modeled diatreme comprises at least two zones of variable density and magnetization, including a low density, highly magnetized unit near the center of the diatreme, interpreted to be a pyroclastic unit emplaced at sufficiently high temperature and containing sufficient juvenile fraction to acquire thermal remanent magnetization. Magnetic anomalies and ground penetrating radar (GPR) imaging demonstrate that the bedded pyroclastic deposits of the tuff ring also carry high magnetization, likely produced by energetic emplacement of hot pyroclastic density currents. GPR profiles on the tuff ring reveal long ( 100 m) wavelength undulations in bedding planes. Elsewhere, comparable bedforms have been interpreted as base surge deposits inflated by air entrainment from eruption column collapse. Interpretation of these geophysical data suggests that Rattlesnake Crater produced highly energetic phreatomagmatic activity that gave way to less explosive activity as the eruption progressed. The positive gravity anomaly associated with the maar crater is interpreted to be caused by coherent bodies within the diatreme and possibly lava ponding on the crater floor. These dense magnetized bodies have excess mass of 2-4 × 1010 kg, and occupy approximately 5% of the diatreme by volume. Magnetic anomalies on the crater floor are elongate NW-SE, suggesting that the eruption may have been triggered by the interaction of ascending magma with water in fractures of this orientation. GPR

  13. Interseismic Strain Accumulation Across Metropolitan Los Angeles: Puente Hills Thrust

    Science.gov (United States)

    Argus, D.; Liu, Z.; Heflin, M. B.; Moore, A. W.; Owen, S. E.; Lundgren, P.; Drake, V. G.; Rodriguez, I. I.

    2012-12-01

    Twelve years of observation of the Southern California Integrated GPS Network (SCIGN) are tightly constraining the distribution of shortening across metropolitan Los Angeles, providing information on strain accumulation across blind thrust faults. Synthetic Aperture Radar Interferometry (InSAR) and water well records are allowing the effects of water and oil management to be distinguished. The Mojave segment of the San Andreas fault is at a 25° angle to Pacific-North America plate motion. GPS shows that NNE-SSW shortening due to this big restraining bend is fastest not immediately south of the San Andreas fault across the San Gabriel mountains, but rather 50 km south of the fault in northern metropolitan Los Angeles. The GPS results we quote next are for a NNE profile through downtown Los Angeles. Just 2 mm/yr of shortening is being taken up across the San Gabriel mountains, 40 km wide (0.05 micro strain/yr); 4 mm/yr of shortening is being taken up between the Sierra Madre fault, at the southern front of the San Gabriel mountains, and South Central Los Angeles, also 40 km wide (0.10 micro strain/yr). We find shortening to be more evenly distributed across metropolitan Los Angeles than we found before [Argus et al. 2005], though within the 95% confidence limits. An elastic models of interseismic strain accumulation is fit to the GPS observations using the Back Slip model of Savage [1983]. Rheology differences between crystalline basement and sedimentary basin rocks are incorporated using the EDGRN/EDCMP algorithm of Wang et al. [2003]. We attempt to place the Back Slip model into the context of the Elastic Subducting Plate Model of Kanda and Simons [2010]. We find, along the NNE profile through downtown, that: (1) The deep Sierra Madre Thrust cannot be slipping faster than 2 mm/yr, and (2) The Puente Hills Thrust and nearby thrust faults (such as the upper Elysian Park Thrust) are slipping at 9 ±2 mm/yr beneath a locking depth of 12 ±5 km (95% confidence limits

  14. NORTH HILL CREEK 3-D SEISMIC EXPLORATION PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    Marc T. Eckels; David H. Suek; Denise H. Harrison; Paul J. Harrison

    2004-05-06

    Wind River Resources Corporation (WRRC) received a DOE grant in support of its proposal to acquire, process and interpret fifteen square miles of high-quality 3-D seismic data on non-allotted trust lands of the Uintah and Ouray (Ute) Indian Reservation, northeastern Utah, in 2000. Subsequent to receiving notice that its proposal would be funded, WRRC was able to add ten square miles of adjacent state and federal mineral acreage underlying tribal surface lands by arrangement with the operator of the Flat Rock Field. The twenty-five square mile 3-D seismic survey was conducted during the fall of 2000. The data were processed through the winter of 2000-2001, and initial interpretation took place during the spring of 2001. The initial interpretation identified multiple attractive drilling prospects, two of which were staked and permitted during the summer of 2001. The two initial wells were drilled in September and October of 2001. A deeper test was drilled in June of 2002. Subsequently a ten-well deep drilling evaluation program was conducted from October of 2002 through March 2004. The present report discusses the background of the project; design and execution of the 3-D seismic survey; processing and interpretation of the data; and drilling, completion and production results of a sample of the wells drilled on the basis of the interpreted survey. Fifteen wells have been drilled to test targets identified on the North Hill Creek 3-D Seismic Survey. None of these wildcat exploratory wells has been a dry hole, and several are among the best gas producers in Utah. The quality of the data produced by this first significant exploratory 3-D survey in the Uinta Basin has encouraged other operators to employ this technology. At least two additional 3-D seismic surveys have been completed in the vicinity of the North Hill Creek Survey, and five additional surveys are being planned for the 2004 field season. This project was successful in finding commercial oil, natural gas

  15. Geologic map of the Paintbrush Canyon Area, Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Dickerson, R.P. [Geological Survey, Denver, CO (United States); Drake, R.M. II [Pacific Western Technologies, Ltd., Lakewood, CO (United States)

    1998-11-01

    This geologic map is produced to support site characterization studies of Yucca Mountain, Nevada, site of a potential nuclear waste storage facility. The area encompassed by this map lies between Yucca Wash and Fortymile Canyon, northeast of Yucca Mountain. It is on the southern flank of the Timber Mountain caldera complex within the southwest Nevada volcanic field. Miocene tuffs and lavas of the Calico Hills Formation, the Paintbrush Group, and the Timber Mountain Group crop out in the area of this map. The source vents of the tuff cones and lava domes commonly are located beneath the thickest deposits of pyroclastic ejecta and lava flows. The rocks within the mapped area have been deformed by north- and northwest-striking, dominantly west-dipping normal faults and a few east-dipping normal faults. Faults commonly are characterized by well developed fault scarps, thick breccia zones, and hanging-wall grabens. Latest movement as preserved by slickensides on west-dipping fault scarps is oblique down towards the southwest. Two of these faults, the Paintbrush Canyon fault and the Bow Ridge fault, are major block-bounding faults here and to the south at Yucca Mountain. Offset of stratigraphic units across faults indicates that faulting occurred throughout the time these volcanic units were deposited.

  16. The Analysis of Characters'Speech Acts in Hills Like White Elephants%The Analysis of Characters' Speech Acts in Hills Like White Elephants

    Institute of Scientific and Technical Information of China (English)

    任佳宏

    2016-01-01

    This article will analyze Hemingway's short novel Hills Like White Elephants from speech act theory perspective. Thus we will have a better understanding about the characters' relationship in the novel and the author's purposes in writing this novel. And the author's writing features will be reproduced, as well as the topic of the novel, the way of the language expressions and the relation of the significance. The analysis of the speech acts of the characters in Hills Like White Elephants can not only help people understand this novel but also provide materials to study this classical novel in new field. It is also hoped that the analysis of Hills Like White Elephants will arouse an important way to the appreciation of other classical novels.

  17. Generalized thickness of the Madison Limestone and Englewood Formation, Black Hills, South Dakota.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set is a polygon coverage created in ARC/INFO that represents the generalized thickness of the Madison Limestone and Englewood Formation, Black Hills,...

  18. Sullys Hill National Game Preservce Narrative Report for January - April 1959

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Sullys Hill National Game Reserve outlines Refuge accomplishments from January through April of 1959. The report begins by summarizing the...

  19. Sullys Hill National Game Preservce Narrative Report for May - August 1952

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Sullys Hill National Game Reserve outlines Refuge accomplishments from May through August 1952. The report begins by summarizing the...

  20. Flint Hills National Wildlife Refuge Annual narrative report: Calendar year 1986

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Flint Hills NWR outlines Refuge accomplishments during the 1986 calendar year. The report begins with an introduction to the Refuge and...

  1. Digital Geologic Map of the Butcher Hill quadrangle, South Dakota (NPS, GRD, GRE, WICA)

    Data.gov (United States)

    National Park Service, Department of the Interior — The Digital Geologic Map of the Butcher Hill quadrangle, South Dakota is composed of GIS data layers, two ancillary GIS tables, a Windows Help File with ancillary...

  2. Flint Hills National Wildlife Refuge : Annual Narrative Report : Calendar Year 1993

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Flint Hills National Wildlife Refuge summarizes refuge activities during the 1993 calendar year. The report begins with a summary of...

  3. Flint Hills National Wildlife Refuge: Annual narrative report: Calendar year 1977

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Flint Hills NWR outlines Refuge accomplishments during the 1977 calendar year. The report begins with an introduction to the Refuge and...

  4. Unioned layer of coal resource calculation in the Danforth Hills coal field, Colorado (dan*fing)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Final unioned polygon coverages and shapefiles used to calculate coal resources of the A through G coal zones, Danforth Hills coal field, northwestern Colorado....

  5. Flint Hills National Wildlife Refuge : Annual Narrative Report : Calendar Year 1992

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Flint Hills National Wildlife Refuge summarizes refuge activities during the 1992 calendar year. The report begins with a summary of...

  6. Flint Hills National Wildlife Refuge Annual narrative report: Calendar year 1982

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Flint Hills National Wildlife Refuge outlines Refuge accomplishments during the 1982 calendar year. The report begins with an introduction...

  7. Altitude of the top of the Fox Hills aquifer in the Williston structural basin

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These data represent the altitude, in feet above North American Vertical Datum of 1988 (NAVD88), of the Fox Hills aquifer in the Williston structural basin. The...

  8. Final Amendment to the Comprehensive Conservation Plan & Environmental Assessment: Flint Hills National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is an amendment, accompanied by an Environmental Assessment (EA), to the current 2000 Comprehensive Conservation Plan (CCP) for Flint Hills NWR. The purpose of...

  9. Preliminary report on diatoms from the deep lake terraces, Vestfold Hills, Antarctica

    Digital Repository Service at National Institute of Oceanography (India)

    Setty, M.G.A.P.; Kellogg, D.E.; Kellogg, T.B.

    with fragments of pyroxenite, quartzite, permatite, gneiss, and glacial debris. Halite and mirabilite crystals are common. A general study of foraminifera of the lake sediments of the Vestfold Hills was made and the results are presented here...

  10. [Flint Hills National Wildlife Refuge: Annual narrative report: Calendar year 1972

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Flint Hills NWR outlines Refuge accomplishments during the 1972 calendar year. The report begins by summarizing the weather...

  11. Flint Hills National Wildlife Refuge: Annual narrative report: Calendar year 1978

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Flint Hills NWR outlines Refuge accomplishments during the 1978 calendar year. The report begins with an introduction to the Refuge and...

  12. Flint Hills National Wildlife Refuge Annual narrative report: Calendar year 1984

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Flint Hills NWR outlines Refuge accomplishments during the 1984 calendar year. The report begins with an introduction to the Refuge and...

  13. Color Infrared Orthorectified Photomosaic Leaf-off for Sagamore Hill National Historic Site Vegetation Mapping Project

    Data.gov (United States)

    National Park Service, Department of the Interior — Orthorectified color infrared ERDAS IMAGINE image of Sagamore Hill National Historic Site (sahi_final.img). Produced from 3 color infrared photos taken April 28,...

  14. Flint Hills National Wildlife Refuge : Annual habitat work plan (calendar year 2009)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Annual habitat management work plan for the calendar year of 2009 at Flint Hills National Wildlife Refuge. Management plans for each habitat type is included as well...

  15. Flint Hills National Wildlife Refuge Annual narrative report: Calendar year 1987

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Flint Hills NWR outlines Refuge accomplishments during the 1987 calendar year. The report begins with an introduction to the Refuge and...

  16. Atlas of water resources in the Black Hills area, South Dakota

    Science.gov (United States)

    Carter, Janet M.; Driscoll, Daniel G.; Williamson, Joyce E.; Lindquist, Van A.

    2002-01-01

    The Black Hills area is an important resource center that provides an economic base for western South Dakota through tourism, agriculture, the timber industry, and mineral resources. In addition, water originating from the area is used for municipal, industrial, agricultural, and recreational purposes throughout much of western South Dakota. The Black Hills area also is an important recharge area for aquifers in the northern Great Plains.Population growth, resource development, and periodic droughts have the potential to affect the quantity, quality, and availability of water within the Black Hills area. Growth has resulted in competing interests for available water supplies. The Black Hills Hydrology Study was initiated in 1990 to address these concerns. This long-term study is a cooperative effort between the U.S. Geological Survey (USGS), the South Dakota Department of Environment and Natural Resources, and the West Dakota Water Development District, which represents various local and county cooperators.

  17. Flint Hills National Wildlife Refuge: Annual narrative report: Calendar year 1989

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Flint Hills National Wildlife Refuge outlines Refuge accomplishments during the 1989 calendar year. The report begins with an introduction...

  18. Sullys Hill National Game Preservce Narrative Report for January - April 1957

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Sullys Hill National Game Reserve outlines Refuge accomplishments from January through April of 1957. The report begins by summarizing the...

  19. Flint Hills National Wildlife Refuge Annual narrative report: Calendar year 1983

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Flint Hills NWR outlines Refuge accomplishments during the 1983 calendar year. The report begins with an introduction to the Refuge and...

  20. Flint Hills National Wildlife Refuge Annual narrative report calendar year 1969

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Flint Hills National Wildlife Refuge outlines Refuge accomplishments during the 1969 calendar year. The report begins by summarizing...

  1. Flint Hills National Wildlife Refuge Annual narrative report calendar year 1968

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Flint Hills National Wildlife Refuge outlines Refuge accomplishments during the 1968 calendar year. The report begins by summarizing...

  2. Flint Hills National Wildlife Refuge Annual narrative report calendar year 1970

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Flint Hills National Wildlife Refuge outlines Refuge accomplishments during the 1970 calendar year. The report begins by summarizing...

  3. Flint Hills National Wildlife Refuge : Annual Narrative Report : Calendar Year 1991

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Flint Hills National Wildlife Refuge summarizes refuge activities during the1991 calendar year. The report begins with a summary of...

  4. Systematic studies of Bornean Zingiberaceae V. Zingiberoideae of Lambir Hills, Sarawak

    NARCIS (Netherlands)

    Sakai, S.; Nagamasu, H.

    2006-01-01

    This paper reports the subfamily Zingiberoideae (Zingiberaceae) of Lambir Hills National Park, Sarawak, Malaysia. Twelve species representing Boesenbergia, Globba, and Zingiber are recorded. Systematic and ecological notes are provided, and the key to the Bornean species of Boesenbergia is updated.

  5. Flint Hills National Wildlife Refuge: Annual narrative report: Calendar year 1980

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Flint Hills NWR outlines Refuge accomplishments during the 1980 calendar year. The report begins with an introduction to the Refuge and...

  6. Mida teha, et lapsed koolist ei puuduks? / Triin Tomingas, Hille Hinsberg, Sirje Ess...[jt

    Index Scriptorium Estoniae

    2011-01-01

    Küsimusele vastavad lapsevanemad Triin Tomingas ja Hille Hinsberg, Saaremaa ühisgümnaasiumi algklasside õppealajuhataja Sirje Ess, Tallinna Pelgulinna gümnaasiumi direktor Tõnu Piibur, MTÜ Ellu psühholoog-koolitaja Tiia Lister

  7. Flint Hills National Wildlife Refuge Annual narrative report: Calendar year 1988

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Flint Hills NWR outlines Refuge accomplishments during the 1988 calendar year. The report begins with an introduction to the Refuge and...

  8. Sullys Hill National Game Preserve Narrative Report for September - December 1960

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Sullys Hill National Game Reserve outlines Refuge accomplishments from September through December 1960. The report begins by summarizing...

  9. Sullys Hill National Game Preserve Narrative Report for September - December 1955

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Sullys Hill National Game Reserve outlines Refuge accomplishments from September through December 1955. The report begins by summarizing...

  10. Sullys Hill National Game Preserve Narrative Report for May - August 1962

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Sullys Hill National Game Reserve outlines Refuge accomplishments from May through August 1962. The report begins by summarizing the...

  11. Sullys Hill National Game Preserve Narrative Report for September - December 1958

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Sullys Hill National Game Reserve outlines Refuge accomplishments from September through December 1958. The report begins by summarizing...

  12. Sullys Hill National Game Preserve Narrative Report for September - December 1962

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Sullys Hill National Game Reserve outlines Refuge accomplishments from September through December 1962. The report begins by summarizing...

  13. Sullys Hill National Game Preserve Narrative Report for May - August 1961

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Sullys Hill National Game Reserve outlines Refuge accomplishments from May through August 1961. The report begins by summarizing the...

  14. Sullys Hill National Game Preserve Narrative Report for September - December 1957

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Sullys Hill National Game Reserve outlines Refuge accomplishments from September through December 1957. The report begins by summarizing...

  15. Sullys Hill National Game Preserve Narrative Report for May - August 1960

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Sullys Hill National Game Reserve outlines Refuge accomplishments from May through August 1960. The report begins by summarizing the...

  16. Sullys Hill National Game Preserve Narrative Report for September - December 1956

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Sullys Hill National Game Reserve outlines Refuge accomplishments from September through December 1956. The report begins by summarizing...

  17. Sullys Hill National Game Preserve Narrative Report for September - December 1959

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Sullys Hill National Game Reserve outlines Refuge accomplishments from September through December 1959. The report begins by summarizing...

  18. 78 FR 28892 - Hazardous Fire Risk Reduction, East Bay Hills, CA

    Science.gov (United States)

    2013-05-16

    ... SECURITY Federal Emergency Management Agency Hazardous Fire Risk Reduction, East Bay Hills, CA AGENCY: Federal Emergency Management Agency, DHS. ACTION: Notice of availability of draft environmental impact.... Fish and Wildlife Service, the California Emergency Management Agency, the University of California...

  19. Sullys Hill National Game Preservce Narrative Report for May - August 1951

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Sullys Hill National Game Reserve outlines Refuge accomplishments from May through August 1951. The report begins by summarizing the...

  20. Sullys Hill National Game Preservce Narrative Report for May - August 1956

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Sullys Hill National Game Reserve outlines Refuge accomplishments from May through August 1956. The report begins by summarizing the...