WorldWideScience

Sample records for weathered rock

  1. Weathering of rock 'Ginger'

    Science.gov (United States)

    1997-01-01

    One of the more unusual rocks at the site is Ginger, located southeast of the lander. Parts of it have the reddest color of any material in view, whereas its rounded lobes are gray and relatively unweathered. These color differences are brought out in the inset, enhanced at the upper right. In the false color image at the lower right, the shape of the visible-wavelength spectrum (related to the abundance of weathered ferric iron minerals) is indicated by the hue of the rocks. Blue indicates relatively unweathered rocks. Typical soils and drift, which are heavily weathered, are shown in green and flesh tones. The very red color in the creases in the rock surface correspond to a crust of ferric minerals. The origin of the rock is uncertain; the ferric crust may have grown underneath the rock, or it may cement pebbles together into a conglomerate. Ginger will be a target of future super-resolution studies to better constrain its origin.Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator. JPL is an operating division of the California Institute of Technology (Caltech).

  2. Quantitative Chemical Indices of Weathered Igneous Rocks

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A study was conducted to compare the effectiveness of different weathering indices for characterising weathered igneous rocks of Hong Kong. Among eight chemical indices evaluated in this study, the Parker index has been found most suitable for a quantitative description of state of weathering. Based on geochemical results of 174 samples, the index decreases almost linearly with an increasing extent of weathering. The results enable a better understanding of the modification of geotechnical properties of igneous rocks associated with weathering processes.

  3. Characterizing and modelling 'ghost-rock' weathered limestones

    Science.gov (United States)

    Dubois, Caroline; Goderniaux, Pascal; Deceuster, John; Poulain, Angélique; Kaufmann, Olivier

    2016-04-01

    'Ghost-rock' karst aquifer has recently been highlighted. In this particular type of aquifer, the karst is not expressed as open conduits but consists in zones where the limestone is weathered. The in-situ weathering of limestone leaves a soft porous material called 'alterite'. The hydro-mechanical properties of this material differs significantly from those of the host rock: the weathering enhances the storage capacity and the conductivity of the rock. This type of weathered karst aquifer has never been studied from a hydrogeological point of view. In this study, we present the hydraulic characterization of such weathered zones. We also present a modelling approach derived from the common Equivalent Porous Medium (EPM) approach, but including the spatial distribution of hydrogeological properties through the weathered features, from the hard rock to the alterite, according to a weathering index. Unlike the Discrete Fracture Network (DFN) approaches, which enable to take into account a limited number of fractures, this new approach allows creating models including thousands of weathered features. As the properties of the alterite have to be considered at a centimeter scale, it is necessary to upscale these properties to carry out simulations over large areas. Therefore, an upscaling method was developed, taking into account the anisotropy of the weathered features. Synthetic models are built, upscaled and different hydrogeological simulations are run to validate the method. This methodology is finally tested on a real case study: the modelling of the dewatering drainage flow of an exploited quarry in a weathered karst aquifer in Belgium.

  4. Preliminary Study on weathering and pedogenesis of carbonate rock

    Institute of Scientific and Technical Information of China (English)

    王世杰; 季宏兵; 欧阳自远; 周德全; 郑乐平; 黎廷宇

    1999-01-01

    South China is the largest continuous distribution area of carbonate rock in the world. The origin of the soils over the bedrock carbonate rock has long been a controversial topic. Here further exploration is made by taking five soil profiles as examples, which are developed over the bedrock dolomitite and limestone and morphologically located in upland in karst terrain in the central, west and north Guizhou as well as west Hunan, and proved to be the weathering profiles of carbonate rock by the research results of acid-dissolved extraction experiment of bedrock, mineralogy and trace element geochemistry. Field, mineralogical and trace element geochemical characteristics of weathering and pedogenesis for carbonate rock are discussed in detail. It is pointed out that weathering and pedogenesis of carbonate rock are important pedogenetic mechanisms for soil resources in karst area, providing a basis for further researches on the origin of soils widely overlying bedrock carbonate rocks in South China.

  5. Physical and chemical weathering. [of Martian surface and rocks

    Science.gov (United States)

    Gooding, James L.; Arvidson, Raymond E.; Zolotov, Mikhail IU.

    1992-01-01

    Physical and chemical weathering processes that might be important on Mars are reviewed, and the limited observations, including relevant Viking results and laboratory simulations, are summarized. Physical weathering may have included rock splitting through growth of ice, salt or secondary silicate crystals in voids. Chemical weathering probably involved reactions of minerals with water, oxygen, and carbon dioxide, although predicted products vary sensitively with the abundance and physical form postulated for the water. On the basis of kinetics data for hydration of rock glass on earth, the fate of weathering-rind formation on glass-bearing Martian volcanic rocks is tentatively estimated to have been on the order of 0.1 to 4.5 cm/Gyr; lower rates would be expected for crystalline rocks.

  6. Heterogeneity of Parent Rocks and Its Constraints on Geochemical Criteria in Weathering Crusts of Carbonate Rocks

    Institute of Scientific and Technical Information of China (English)

    WANG Shijie; FENG Zhigang

    2004-01-01

    Owing to the low contents of their acid-insoluble components, carbonate rocks tend to decrease sharply in volume in association with the formation of weathering crust. The formation of a 1 m-thick weathering crust would usually consume more than ten meters to several tens of meters of thickness of parent rocks. The knowledge of how to identify the homogeneity of parent rocks is essential to understand the formation mechanism of weathering crust in karst regions,especially that of thick-layered red weathering crust. In this work the grain-size analyses have demonstrated that the three profiles studied are the residual weathering crust of carbonate rocks and further showed that there objectively exists the heterogeneity of parent rocks in the three studied weathering crusts. The heterogeneity of parent rocks can also be reflected in geochemical parameters of major elements, just as the characteristics of frequency plot of grain-size distribution.Conservative trace element ratios Zr/Hf and Nb/Ta are proven to be unsuitable for tracing the heterogeneity of parent rocks of weathering crust, but its geochemical mechanism is unclear. The authors strongly suggest in this paper that the identification of the homogeneity of parent rocks of weathering crust in karst regions is of prime necessity.

  7. Location-Related Differences in Weathering Behaviors and Populations of Culturable Rock-Weathering Bacteria Along a Hillside of a Rock Mountain.

    Science.gov (United States)

    Wang, Qi; Wang, Rongrong; He, Linyan; Sheng, Xiafang

    2016-12-21

    Bacteria play important roles in rock weathering, elemental cycling, and soil formation. However, little is known about the weathering potential and population of bacteria inhabiting surfaces of rocks. In this study, we isolated bacteria from the top, middle, and bottom rock samples along a hillside of a rock (trachyte) mountain as well as adjacent soils and characterized rock-weathering behaviors and populations of the bacteria. Per gram of rock or surface soil, 10(6)-10(7) colony forming units were obtained and total 192 bacteria were isolated. Laboratory rock dissolution experiments indicated that the proportions of the highly effective Fe (ranging from 67 to 92 %), Al (ranging from 40 to 48 %), and Cu (ranging from 54 to 81 %) solubilizers were significantly higher in the top rock and soil samples, while the proportion of the highly effective Si (56 %) solubilizers was significantly higher in the middle rock samples. Furthermore, 78, 96, and 6 % of bacteria from the top rocks, soils, and middle rocks, respectively, significantly acidified the culture medium (pH rock dissolution process. Most rock-weathering bacteria (79 %) from the rocks were different to those from the soils and most of them (species level) have not been previously reported. Furthermore, location-specific rock-weathering bacterial populations were found and Bacillus species were the most (66 %) frequently isolated rock-weathering bacteria in the rocks based on cultivation methods. Notably, the top rocks and soils had the highest and lowest diversity of rock-weathering bacterial populations, respectively. The results suggested location-related differences in element (Si, Al, Fe, and Cu) releasing effectiveness and communities of rock-weathering bacteria along the hillside of the rock mountain.

  8. CHEMICAL BEHAVIOR OF CERIUM ELEMENT IN ROCK WEATHERING SYSTEM

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    A study on existing valence state and chemical behavior of cerium element in two categories of rock weathering system in China has been carried out. In the granitoid weathering crust of Southern China,cerium as tetravalent hydroxide absorbed on clay minerals occupies 62.58 % of total amount of cerium and the cerium partitioning in the phase is 69.58 %. The depositing cerium stops its mobility downward, resulting in rare earth partitioning variation, the light rare earth partitioning is high at upper layer of weathering crust, the heavy rare earth partitioning is high at bottom layer of weathering crust, and the extracted product exists cerium lose effect. For Mn2+ as reducing agent existing in black weathering earth of Maoniuping rare earth ore,cerium is trivalent and absorbed on Mn-Fe oxide as colloid phase sediment. Colloid sediment phase can be divided into Mn-Fe combined phase and hydroxide sediment phase with cerium contents of 19.77% and 48.30%, and their cerium partitionings are 80.72% and 37.38% respectively. The Mn-Fe combined phase can selectively absorb cerium.

  9. Thermal stress weathering and the spalling of Antarctic rocks

    Science.gov (United States)

    Lamp, J. L.; Marchant, D. R.; Mackay, S. L.; Head, J. W.

    2017-01-01

    Using in situ field measurements, laboratory analyses, and numerical modeling, we test the potential efficacy of thermal stress weathering in the flaking of millimeter-thick alteration rinds observed on cobbles and boulders of Ferrar Dolerite on Mullins Glacier, McMurdo Dry Valleys (MDV). In particular, we examine whether low-magnitude stresses, arising from temperature variations over time, result in thermal fatigue weathering, yielding slow crack propagation along existing cracks and ultimate flake detachment. Our field results show that during summer months clasts of Ferrar Dolerite experience large-temperature gradients across partially detached alteration rinds (>4.7°C mm-1) and abrupt fluctuations in surface temperature (up to 12°C min-1); the latter are likely due to the combined effects of changing solar irradiation and cooling from episodic winds. The results of our thermal stress model, coupled with subcritical crack growth theory, suggest that thermal stresses induced at the base of thin alteration rinds 2 mm thick, common on rocks exposed for 105 years, may be sufficient to cause existing cracks to propagate under present-day meteorological forcing, eventually leading to rind detachment. The increase in porosity observed within alteration rinds relative to unaltered rock interiors, as well as predicted decreases in rind strength based on allied weathering studies, likely facilitates thermal stress crack propagation through a reduction of fracture toughness. We conclude that thermal stress weathering may be an active, though undervalued, weathering process in hyperarid, terrestrial polar deserts such as the stable upland region of the MDV.

  10. DEM investigation of weathered rocks using a novel bond contact model

    Institute of Scientific and Technical Information of China (English)

    Zhenming Shi; Tao Jiang; Mingjing Jiang; Fang Liu; Ning Zhang

    2015-01-01

    The distinct element method (DEM) incorporated with a novel bond contact model was applied in this paper to shed light on the microscopic physical origin of macroscopic behaviors of weathered rock, and to achieve the changing laws of microscopic parameters from observed decaying properties of rocks during weathering. The changing laws of macroscopic mechanical properties of typical rocks were summarized based on the existing research achievements. Parametric simulations were then conducted to analyze the relationships between macroscopic and microscopic parameters, and to derive the changing laws of microscopic parameters for the DEM model. Equipped with the microscopic weathering laws, a series of DEM simulations of basic laboratory tests on weathered rock samples was performed in comparison with analytical solutions. The results reveal that the relationships between macroscopic and microscopic parameters of rocks against the weathering period can be successfully attained by para-metric simulations. In addition, weathering has a significant impact on both stressestrain relationship and failure pattern of rocks.

  11. Plant-induced weathering of a basaltic rock: experimental evidence

    Science.gov (United States)

    Hinsinger, Philippe; Fernandes Barros, Omar Neto; Benedetti, Marc F.; Noack, Yves; Callot, Gabriel

    2001-01-01

    The active role of higher plants in the weathering of silicate minerals and rocks is still a question for debate. The present work aimed at providing experimental evidence of the important role of a range of crop plants in such processes. In order to quantitatively assess the possible effect of these diverse plant species on the weathering of a basaltic rock, two laboratory experiments were carried out at room temperature. These compared the amounts of elements released from basalt when leached with a dilute salt solution in the presence or absence of crop plants grown for up to 36 days. For Si, Ca, Mg, and Na, plants resulted in an increase in the release rate by a factor ranging from 1 to 5 in most cases. Ca and Na seemed to be preferentially released relative to other elements, suggesting that plagioclase dissolved faster than the other constituents of the studied basalt. Negligible amounts of Fe were released in the absence of plants as a consequence of the neutral pH and atmospheric pO 2 that were maintained in the leaching solution. However, the amounts of Fe released from basalt in the presence of plants were up to 100- to 500-fold larger than in the absence of plants, for banana and maize. The kinetics of dissolution of basalt in the absence of plants showed a constantly decreasing release rate over the whole duration of the experiment (36 days). No steady state value was reached both in the absence and presence of banana plants. However, in the latter case, the rates remained at a high initial level over a longer period of time (up to 15 days) before starting to decrease. For Fe, the maximum rate of release was reached beyond 4 days and this rate remained high up to 22 days of growth of banana. The possible mechanisms responsible for this enhanced release of elements from basalt in the presence of plants are discussed. Although these mechanisms need to be elucidated, the present results clearly show that higher plants can considerably affect the kinetics

  12. Tectonic constraints on a deep-seated rock slide in weathered crystalline rocks

    Science.gov (United States)

    Borrelli, Luigi; Gullà, Giovanni

    2017-08-01

    Deep-seated rock slides (DSRSs), recognised as one of the most important mass wasting processes worldwide, involve large areas and cause several consequences in terms of environmental and economic damage; they result from a complex of controlling features and processes. DSRSs are common in Calabria (southern Italy) where the complex geo-structural setting plays a key role in controlling the geometry of the failure surface and its development. This paper describes an integrated multi-disciplinary approach to investigate a DSRS in Palaeozoic high-grade metamorphic rocks of the Sila Massif; it focuses on the definition of the internal structure and the predisposing factors of the Serra di Buda landslide near the town of Acri, which is a paradigm for numerous landslides in this area. An integrated interdisciplinary study based on geological, structural, and geomorphological investigations-including field observations of weathering grade of rocks, minero-petrographic characterisations, geotechnical investigations and, in particular, fifteen years of displacement monitoring-is presented. Stereoscopic analysis of aerial photographs and field observations indicate that the Serra di Buda landslide consists of two distinct compounded bodies: (i) an older and dormant body ( 7 ha) and (ii) a more recent and active body ( 13 ha) that overlies the previous one. The active landslide shows movement linked to a deep-seated translational rock slide (block slide); the velocity scale ranges from slow (1.6 m/year during paroxysmal stages) to extremely slow (responsible for the formation of this landslide. In particular, the landslide shows a strongly tectonic constraint: the flanks are bounded by high-angle faults, and the main basal failure surface developed inside an E-W southward-dipping thrust fault zone. The entire active rock mass (total volume of approximately 6 Mm3) slid at one time on a failure surface that dipped < 27°, and the maximum depth, as determined by inclinometer

  13. Field Guide to Rock Weathering. Earth Science Curriculum Project Pamphlet Series PS-1.

    Science.gov (United States)

    Boyer, Robert E.

    Highlighted are the effects of weathering through field investigations of the environment, both natural rocks, and the urban environment's pavements, buildings, and cemeteries. Both physical weathering and chemical weathering are discussed. Questions are presented for post-field trip discussion. References and a glossary are provided. (Author/RE)

  14. The weathering of municipal solid waste incineration bottom ash evaluated by some weathering indices for natural rock.

    Science.gov (United States)

    Takahashi, Fumitake; Shimaoka, Takayuki

    2012-12-01

    The weathering of municipal solid waste incineration (MSWI) residues consists of complicated phenomena. This makes it difficult to describe leaching behaviors of major and trace elements in fresh/weathered MSWI bottom ash, which was relevant interactively to pH neutralization and formation of secondary minerals. In this study, mineralogical weathering indices for natural rock profiles were applied to fresh/landfilled MSWI bottom ash to investigate the relation of these weathering indices to landfill time and leaching concentrations of component elements. Tested mineralogical weathering indices were Weathering Potential Index (WPI), Ruxton ratio (R), Weathering Index of Parker (WIP), Vogt's Residual Index (V), Chemical Index of Alternation (CIA), Chemical Index of Weathering (CIW), Plagioclase Index of Alternation (PIA), Silica-Titania Index (STI), Weathering Index of Miura (Wm), and Weatherability index of Hodder (Ks). Welch's t-test accepted at 0.2% of significance level that all weathering indices could distinguish fresh and landfilled MSWI bottom ash. However, R and STI showed contrasted results for landfilled bottom ash to theoretical expectation. WPI, WIP, Wm, and Ks had good linearity with reclamation time of landfilled MSWI bottom ash. Therefore, these four indices might be applicable as an indicator to identify fresh/weathered MSWI bottom ash and to estimate weathering time. Although WPI had weak correlation with leachate pH, other weathering indices had no significant correlation. In addition, all weathering indices could not explain leaching concentration of Al, Ca, Cu, and Zn quantitatively. Large difficulty to modify weathering indices correctly suggests that geochemical simulation including surface sorption, complexation with DOM, and other mechanisms seems to be the only way to describe leaching behaviors of major and trace elements in fresh/weathered MSWI bottom ash. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Weathering of Carbonate Rocks by Biological Soil Crusts in Karst Areas

    Institute of Scientific and Technical Information of China (English)

    Ye Chen; Bin Lian; Zuoying Yin; Yuan Tang

    2014-01-01

    The weathering of carbonate rocks by biological soil crusts (BSC) in karst areas is very common. It is helpful to understand the weathering mechanisms and processes for avoiding karst rock-desertification. The weathering of carbonate rocks by BSC in karst areas, namely the expansion, contraction and curl resulting from environmental wetting-drying cycles, was investigated and ana-lyzed in this paper. The bulk density, area and thickness of BSC were determined and the weathering amount of limestone and dolomite per unit area of BSC was calculated as 3 700 and 3 400 g·m-2; the amount of biomass on the surface of limestone and dolomite was calculated as 1 146 and 1 301 g·m-2, respectively. Such an increased weathering amount was not only the result of chemical and physical weathering of BSC on carbonate rocks, but also the attachment and cementation of BSC to clay parti-cles, dust-fall, sand particles, solid particles brought by strong air currents, wind and other factors in the surrounding environment, which may also be related to the special environment and the special time period. Based on the results obtained, a weathering mode of BSC is studied, and the mechanisms of weathering by BSC are discussed. In conclusion, we suggest that the mechanical force exerted by the expansion and constriction of gelatinous and mucilaginous substances through wetting and drying of BSC play a significant role in the physical weathering process of the carbonate substrates.

  16. Metasomatic Mechanism of Weathering-Pedogenesis of Carbonate Rocks: I. Mineralogical and Micro-Textural Evidence

    Institute of Scientific and Technical Information of China (English)

    朱立军; 李景阳

    2002-01-01

    On the basis of mineralogical, geochemical and micro-textural studies of the typical sections of the red weathering crust of carbonate rocks in the subtropical karst areas of Guizhou Province and Guangxi Autonomous Region, we have found, either on a microscopic or on a macroscopical scale and in different positions of the sections, the most direct and most important mineralogical and micro-textural evidence for the development of metasomatism in the process of weathering-pedogenesis of numerous carbonate rocks. This paper also has expounded for the first time and systematically the mechanism of metasomatism involved in the process of weathering pedogenesis of carbonate rocks and proposed the sequence of mineral metasomatic evolution in the process of weathering-pedogenesis of carbonate rocks.

  17. Rock-weathering by lichens in Antarctic:patterns and mechanisms

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Saxicolous species of lichens are able to induce and accelerate weathering of their rocksubstrate, and effects of lichens on substrate can be attributed to both physical and chemical causes.This paper is focused on biotic weathering actions of epilithic and endolithic species on the differentrock types (sandstones and volcanogenic rocks) in Antarctica. The patterns, mechanisms, processes andneoformations of rock-weathering resulting from lichen colonization are expounded in detail.Furthermore, it is pointed out that, for a better understanding of the impacts of lichens onenvironments, the studies on the rate of biotic weathering and the comprehensive involvement of thelichen effects on weathering of natural rocks remain to be carried out in Antarctica.

  18. Rock weathering Tendency at Different Stages of Soil—Forming Processes in Fildes Peninsula,Antarctic

    Institute of Scientific and Technical Information of China (English)

    CHENJIE; GONGZITONG

    1996-01-01

    From the view of energy state of material,this paper introduces a concept a concept of weathering potential in carrying out quantitative calculation of the relevant products at different stages of rock-weathering and primary soil-forming processes,elaborates respectively on weathering degree in the bio-weathering layer of rocks and during the formation of soil material and clay,and evaluats the further tendency of weathering in the above-mentioned stages.The authors have discovered that the scales of weathering potential of the materials increase successively in the three stages,which indicates that the products in the above-mentioned three stages must have undergone stronger and stronger weathering in the primitive forming process of soil in Fildes Peninsula,Antarctic.But,Because of relatively weak chemical weathering,it is reasonable that there are much more skeleton grains and little clay in priamry soils in this region.Meanwhile the authors have also verified that the weathering potential of crde rock determines to some extent decrease in the products' weathering potential in the different stages in primary soil-forming,thereby plays an important role in the genesis and development of the primary soil in the studied area.

  19. An Examination of the Space Weathering Patina of Lunar Rock 76015

    Science.gov (United States)

    Noble, S.; Chrisoffersen, R.; Rahman, Z.

    2011-01-01

    Space weathering discussions have generally centered around soils but exposed rocks will also incur the effects of weathering. Rocks have much longer surface lifetimes than an individual soil grain and thus record a longer history of exposure. By studying the weathering products which have built up on a rock surface, we can gain a deeper perspective on the weathering process and better assess the relative importance of various weathering components. The weathered coating, or patina, of the lunar rock 76015 has been previously studied under SEM and also by TEM using ultramicrotome sample preparation methods. However, to really understand the products involved in creating these coatings, it is helpful to examine the patina in cross section, something which is now possible though the use of Focused Ion Beam (FIB) sample prep techniques, which allows us to preserve intact the delicate stratigraphy of the patina coating and provides a unique cross-sectional view of the space weathering process. Several samples have been prepared from the rock and the coatings are found to be quite variable in thickness and composition from one sample to the next.

  20. The effect of rock composition on cyanobacterial weathering of crystalline basalt and rhyolite.

    Science.gov (United States)

    Olsson-Francis, K; Simpson, A E; Wolff-Boenisch, D; Cockell, C S

    2012-09-01

    The weathering of volcanic rocks contributes significantly to the global silicate weathering budget, effecting carbon dioxide drawdown and long-term climate control. The rate of chemical weathering is influenced by the composition of the rock. Rock-dwelling micro-organisms are known to play a role in changing the rate of weathering reactions; however, the influence of rock composition on bio-weathering is unknown. Cyanobacteria are known to be a ubiquitous surface taxon in volcanic rocks. In this study, we used a selection of fast and slow growing cyanobacterial species to compare microbial-mediated weathering of bulk crystalline rocks of basaltic and rhyolitic composition, under batch conditions. Cyanobacterial growth caused an increase in the pH of the medium and an acceleration of rock dissolution compared to the abiotic controls. For example, Anabaena cylindrica increased the linear release rate (R(i)(l)) of Ca, Mg, Si and K from the basalt by more than fivefold (5.21-12.48) and increased the pH of the medium by 1.9 units. Although A. cylindrica enhanced rhyolite weathering, the increase in R(i)(l) was less than threefold (2.04-2.97) and the pH increase was only 0.83 units. The R(i)(l) values obtained with A. cylindrica were at least ninefold greater with the basalt than the rhyolite, whereas in the abiotic controls, the difference was less than fivefold. Factors accounting for the slower rate of rhyolite weathering and lower biomass achieved are likely to include the higher content of quartz, which has a low rate of weathering and lower concentrations of bio-essential elements, such as, Ca, Fe and Mg, which are known to be important in controlling cyanobacterial growth. We show that at conditions where weathering is favoured, biota can enhance the difference between low and high Si-rock weathering. Our data show that cyanobacteria can play a significant role in enhancing rock weathering and likely have done since they evolved on the early Earth.

  1. The relationship between geology and rock weathering on the rock instability along Mugling-Narayanghat road corridor, Central Nepal Himalaya

    OpenAIRE

    Regmi, Amar Deep; YOSHIDA, Kohki; Nagata, Hidehisa; Pradhan, Ananta Man Singh; Pradhan, Biswajeet; Pourghasemi, Hamid Reza

    2013-01-01

    The present study was conducted along the Mugling-Narayanghat road section and its surrounding region that is most affected by landslide and related mass-movement phenomena. The main rock types in the study area are limestone, dolomite, slate, phyllite, quartzite and amphibolites of Lesser Himalaya, sandstone, mudstone and conglomerates of Siwaliks and Holocene Deposits. Due to the important role of geology and rock weathering in the instabilities, an attempt has been made to understand the r...

  2. Dynamic Analysis of Tunnel in Weathered Rock Subjected to Internal Blast Loading

    Science.gov (United States)

    Tiwari, Rohit; Chakraborty, Tanusree; Matsagar, Vasant

    2016-11-01

    The present study deals with three-dimensional nonlinear finite element (FE) analyses of a tunnel in rock with reinforced concrete (RC) lining subjected to internal blast loading. The analyses have been performed using the coupled Eulerian-Lagrangian analysis tool available in FE software Abaqus/Explicit. Rock and RC lining are modeled using three-dimensional Lagrangian elements. Beam elements have been used to model reinforcement in RC lining. Three different rock types with different weathering conditions have been used to understand the response of rock when subjected to blast load. The trinitrotoluene (TNT) explosive and surrounding air have been modeled using the Eulerian elements. The Drucker-Prager plasticity model with strain rate-dependent material properties has been used to simulate the stress-strain response of rock. The concrete damaged plasticity model and Johnson-Cook plasticity model have been used for the simulation of stress-strain response of concrete and steel, respectively. The explosive (TNT) has been modeled using Jones-Wilkins-Lee (JWL) equation of state. The analysis results have been studied for stresses, deformation and damage of RC lining and the surrounding rock. It is observed that damage in RC lining results in higher stress in rock. Rocks with low modulus and high weathering conditions show higher attenuation of shock wave. Higher amount of ground shock wave propagation is observed in case of less weathered rock. Ground heave is observed under blast loading for tunnel close to ground surface.

  3. Rock weathering on the eastern mountains of southern Africa: Review and insights from case studies

    Science.gov (United States)

    Sumner, P. D.; Hall, K. J.; van Rooy, J. L.; Meiklejohn, K. I.

    2009-12-01

    The mountains in the eastern region of southern Africa are of significant regional importance, providing for a diverse range of land use including conservation, tourism and subsistence agriculture. The higher regions are comprised of flood basalts and are immediately underlain by predominantly aeolian-origin sandstones. Our understanding of the weathering of these basalts and sandstones is reviewed here, with particular focus on the insights gained from the Lesotho Highlands Water Project and an ongoing study into the deterioration of rock art. While the chemical weathering attributes of the basalts have been substantially investigated, it is evident that the environmental surface conditions of rock moisture and temperature, as affecting weathering processes, remain largely unknown. Within the sandstones, studies pertaining to rock art deterioration present insights into the potential surface weathering processes and highlight the need for detailed field monitoring. Outside of these site-specific studies, however, little is understood of how weathering impacts on landscape development; notably absent, are detail on weathering rates, and potential effects of biological weathering. Some palaeoenvironmental inferences have also been made from weathering products, both within the basalts and the sandstones, but aspects of these remain controversial and further detailed research can still be undertaken.

  4. On the dual nature of lichen-induced rock surface weathering in contrasting micro-environments.

    Science.gov (United States)

    Marques, Joana; Gonçalves, João; Oliveira, Cláudia; Favero-Longo, Sergio E; Paz-Bermúdez, Graciela; Almeida, Rubim; Prieto, Beatriz

    2016-10-01

    Contradictory evidence from biogeomorphological studies has increased the debate on the extent of lichen contribution to differential rock surface weathering in both natural and cultural settings. This study, undertaken in Côa Valley Archaeological Park, aimed at evaluating the effect of rock surface orientation on the weathering ability of dominant lichens. Hyphal penetration and oxalate formation at the lichen-rock interface were evaluated as proxies of physical and chemical weathering, respectively. A new protocol of pixel-based supervised image classification for the analysis of periodic acid-Schiff stained cross-sections of colonized schist revealed that hyphal spread of individual species was not influenced by surface orientation. However, hyphal spread was significantly higher in species dominant on northwest facing surfaces. An apparently opposite effect was noticed in terms of calcium oxalate accumulation at the lichen-rock interface; it was detected by Raman spectroscopy and complementary X-ray microdiffraction on southeast facing surfaces only. These results suggest that lichen-induced physical weathering may be most severe on northwest facing surfaces by means of an indirect effect of surface orientation on species abundance, and thus dependent on the species, whereas lichen-induced chemical weathering is apparently higher on southeast facing surfaces and dependent on micro-environmental conditions, giving only weak support to the hypothesis that lichens are responsible for the currently observed pattern of rock-art distribution in Côa Valley. Assumptions about the drivers of open-air rock-art distribution patterns elsewhere should also consider the micro-environmental controls of lichen-induced weathering, to avoid biased measures of lichen contribution to rock-art deterioration.

  5. Weathering-pedogenesis of Carbonate Rocks and Its Environmental Effects in Subtropical Region

    Institute of Scientific and Technical Information of China (English)

    ZHU Lijun; HE Shouyang; LI Jingyang

    2008-01-01

    We investigated the weathering-pedogenesis of carbonate rocks and its environmental effects in subtropical regions of China. The investigation demonstrated that the weathering-pedogenesis of carbonate rocks is the process of a joint action of corrosion and illuviation and metasomatism in subtropical region. It is characterized by multi-stage, multi-path and multi-style.With the persisting development of weathering-pedogenesis of carbonate rocks, metasomatic pedogenesis progressively became the main process of the weathering-pedogenesis and the dominant style of formation of minerals. And it proceeds through the whole process of evolution of theweathering-pedogenesis of carbonate rocks. The stage evolution of wcathering-pedogenesis ofcarbonate rocks and the fractionation evolution of newly produced minerals are characterized byobvious vertically zoning structures and the rules of gradation of elements geochemical characteristics in the carbonate rocks weathering profiles. The geochemical process of weathering-pedogenesis of carbonate rocks can be divided into three geochemical evolution stages, I.e., the Ca, Mg-depletion and Si, AI-enrichment stage; the Fe, Mn enrichment stage and the Si-depletion and Al-enrichment stage in the subtropical regions. Consistent with the three geochemical evolution stages, the sequence of formation and evolution of minerals can be divided into the clay mineral stage; the Fe, Mn oxide and the gibbsite stage. The influence of weathering-pedogenesis of carbonate rocks on the chemical forms of heavy elements is mainly affected via newly produced components and minerals in the process of weathering-pedogenesis, e.g., iron oxide minerals and organic matters. The important mechanism for the mobilization, transport and pollution of F and As is affected the selective adsorption and desorption of F and As on the surface of iron oxide minerals in the subtropical karst zones, I.e., the selective adsorption and desorption on mineral surfaces of

  6. Subcritical crack growth and mechanical weathering: a new consideration of how moisture influences rock erosion rates.

    Science.gov (United States)

    Eppes, Martha-Cary; Keanini, Russell; Hancock, Gregory S.

    2016-04-01

    The contributions of moisture to the mechanical aspects of rock weathering and regolith production are poorly quantified. In particular, geomorphologists have largely overlooked the role of subcritical crack growth processes in physical weathering and the fact that moisture strongly influences the rates of those processes. This influence is irrespective of the function that moisture plays in stress loading mechanisms like freezing or hydration. Here we present a simple numerical model that explores the efficacy of subcritical crack growth in granite rock subaerially exposed under a range of moisture conditions. Because most weathering-related stress loading for rocks found at, or near, Earth's surface (hereafter surface rocks) is cyclic, we modeled crack growth using a novel combination of Paris' Law and Charles' Law. This combination allowed us to apply existing empirically-derived data for the stress corrosion index of Charles' Law to fatigue cracking. For stress, we focused on the relatively straightforward case of intergranular stresses that arise during solar-induced thermal cycling by conductive heat transfer, making the assumption that such stresses represent a universal minimum weathering stress experienced by all surface rocks. Because all other tensile weathering-related stresses would be additive in the context of crack growth, however, our model can be adapted to include other stress loading mechanisms. We validated our calculations using recently published thermal-stress-induced cracking rates. Our results demonstrate that 1) weathering-induced stresses as modeled herein, and as published by others, are sufficient to propagate fractures subcritically over long timescales with or without the presence of water 2) fracture propagation rates increase exponentially with respect to moisture, specifically relative humidity 3) fracture propagation rates driven by thermal cycling are strongly dependent on the magnitude of diurnal temperature ranges and the

  7. Acid rock drainage and rock weathering in antarctica: Important sources for iron cycling in the southern ocean

    OpenAIRE

    Dold, B.; González-Toril, Elena; Aguilera, Ángeles; López Pamo, Enrique; M. E. Cisternas; Bucchi, F.; Amils, Ricardo

    2013-01-01

    Here we describe biogeochemical processes that lead to the generation of acid rock drainage (ARD) and rock weathering on the Antarctic landmass and describe why they are important sources of iron into the Antarctic Ocean. During three expeditions, 2009-2011, we examined three sites on the South Shetland Islands in Antarctica. Two of them displayed intensive sulfide mineralization and generated acidic (pH 3.2-4.5), iron-rich drainage waters (up to 1.78 mM Fe), which infiltrated as groundwater ...

  8. Acid rock drainage and rock weathering in Antarctica: important sources for iron cycling in the Southern Ocean.

    Science.gov (United States)

    Dold, B; Gonzalez-Toril, E; Aguilera, A; Lopez-Pamo, E; Cisternas, M E; Bucchi, F; Amils, R

    2013-06-18

    Here we describe biogeochemical processes that lead to the generation of acid rock drainage (ARD) and rock weathering on the Antarctic landmass and describe why they are important sources of iron into the Antarctic Ocean. During three expeditions, 2009-2011, we examined three sites on the South Shetland Islands in Antarctica. Two of them displayed intensive sulfide mineralization and generated acidic (pH 3.2-4.5), iron-rich drainage waters (up to 1.78 mM Fe), which infiltrated as groundwater (as Fe(2+)) and as superficial runoff (as Fe(3+)) into the sea, the latter with the formation of schwertmannite in the sea-ice. The formation of ARD in the Antarctic was catalyzed by acid mine drainage microorganisms found in cold climates, including Acidithiobacillus ferrivorans and Thiobacillus plumbophilus. The dissolved iron (DFe) flux from rock weathering (nonmineralized control site) was calculated to be 0.45 × 10(9) g DFe yr(-1) for the nowadays 5468 km of ice-free Antarctic rock coastline which is of the same order of magnitude as glacial or aeolian input to the Southern Ocean. Additionally, the two ARD sites alone liberate 0.026 and 0.057 × 10(9) g DFe yr(-1) as point sources to the sea. The increased iron input correlates with increased phytoplankton production close to the source. This might even be enhanced in the future by a global warming scenario, and could be a process counterbalancing global warming.

  9. Engineering-Geological Properties of Carbonate Rocks in Relation to Weathering Intensity

    Science.gov (United States)

    Pollak, Davor

    For most of the purposes engineering-geological explorations are done on the surface. Afterwards the surface data get correlated with other exploration results in order to produce rock mass quality model. The modelling of subsurface and deeper zones in karst areas in Croatia is usually a difficult task because of a complex geology. The evaluation of rock mass quality in those zones is even more demanding mainly because of the specific weathering processes of carbonate rocks. Since karstification significantly changes engineering-geological properties of carbonate rocks, it is of vital importance to determine the degree of weathering in surface and subsurface zones. Engineering-geological properties of carbonate rocks in the surface zone, subsurface and deeper zones are compared and discussed in the paper. Facts and examples are taken from recent highway projects in Croatia. From those data it has been recognized, that depending on the basic block size, two basic weathering models can be established. Each of the models has its specific engineering-geological properties.

  10. In-Situ and Experimental Evidence for Acidic Weathering of Rocks and Soils on Mars

    Science.gov (United States)

    Hurowitz, J. A.; McLennan, S. M.; Tosca, N. J.; Arvidson, R. E.; Michalski, J. R.; Ming, D.; Schroeder, C.; Squyres, S. W.

    2006-01-01

    Experimental data for alteration of synthetic Martian basalts at pH=0-1 indicate that chemical fractionations at low pH are vastly different from those observed during terrestrial weathering. Rock analyses from Gusev crater are well described by the relationships apparent from low pH experimental alteration data. A model for rock surface alteration is developed which indicates that a leached alteration zone is present on rock surfaces at Gusev. This zone is not chemically fractionated to a large degree from the underlying rock interior, indicating that the rock surface alteration process has occurred at low fluid-to-rock ratio. The geochemistry of natural rock surfaces analyzed by APXS is consistent with a mixture between adhering soil/dust and the leached alteration zone. The chemistry of rock surfaces analyzed after brushing with the RAT is largely representative of the leached alteration zone. The chemistry of rock surfaces analyzed after grinding with the RAT is largely representative of the interior of the rock, relatively unaffected by the alteration process occurring at the rock surface. Elemental measurements from the Spirit, Opportunity, Pathfinder and Viking 1 landing sites indicate that soil chemistry from widely separated locations is consistent with the low-pH, low fluid to rock ratio alteration relationships developed for Gusev rocks. Soils are affected principally by mobility of FeO and MgO, consistent with alteration of olivine-bearing basalt and subsequent precipitation of FeO and MgO bearing secondary minerals as the primary control on soil geochemistry.

  11. Effects of Space Weathering on Lunar Rocks: Scanning Electron Microscope Petrography

    Science.gov (United States)

    Wentworth, Susan J.; Keller, Lindsay P.; McKay, David S.

    1998-01-01

    Lunar rocks that have undergone direct exposure to the space weathering environment at the surface of the Moon commonly have patinas on their surfaces. Patinas are characterized by visible darkening and other changes in spectral properties of rocks. They form as a result of bombardment by micrometeorites, solar wind, and solar flares. Processes of space weathering and patina production have clearly been significant in the formation and history of the lunar regolith. It is very likely that other planetary bodies without atmospheres have undergone similar alteration processes; therefore, it is critical to determine the relationship between patinas and their host rocks in view of future robotic and remote-sensing missions to the Moon and other planetary bodies.

  12. Continental igneous rock composition: A major control of past global chemical weathering.

    Science.gov (United States)

    Bataille, Clément P; Willis, Amy; Yang, Xiao; Liu, Xiao-Ming

    2017-03-01

    The composition of igneous rocks in the continental crust has changed throughout Earth's history. However, the impact of these compositional variations on chemical weathering, and by extension on seawater and atmosphere evolution, is largely unknown. We use the strontium isotope ratio in seawater [((87)Sr/(86)Sr)seawater] as a proxy for chemical weathering, and we test the sensitivity of ((87)Sr/(86)Sr)seawater variations to the strontium isotopic composition ((87)Sr/(86)Sr) in igneous rocks generated through time. We demonstrate that the (87)Sr/(86)Sr ratio in igneous rocks is correlated to the epsilon hafnium (εHf) of their hosted zircon grains, and we use the detrital zircon record to reconstruct the evolution of the (87)Sr/(86)Sr ratio in zircon-bearing igneous rocks. The reconstructed (87)Sr/(86)Sr variations in igneous rocks are strongly correlated with the ((87)Sr/(86)Sr)seawater variations over the last 1000 million years, suggesting a direct control of the isotopic composition of silicic magmatism on ((87)Sr/(86)Sr)seawater variations. The correlation decreases during several time periods, likely reflecting changes in the chemical weathering rate associated with paleogeographic, climatic, or tectonic events. We argue that for most of the last 1000 million years, the ((87)Sr/(86)Sr)seawater variations are responding to changes in the isotopic composition of silicic magmatism rather than to changes in the global chemical weathering rate. We conclude that the ((87)Sr/(86)Sr)seawater variations are of limited utility to reconstruct changes in the global chemical weathering rate in deep times.

  13. Fission Track Dating of Authigenic Quartz in Red Weathering Crusts of Carbonate Rocks in Guizhou Province

    Institute of Scientific and Technical Information of China (English)

    LIU Xiuming; WANG Shijie; ZHANG Feng

    2004-01-01

    The Cenozoic evolution history of Guizhou Province, which is located on the southeastem flank of the Qinghai-Tibet Plateau, is unclear because of the lack of sedimentation records. The red weathering crusts widespread on the Yunnan-Guizhou Plateau may bear critical information about their evolution history. This work firstly determined the ages of four red weathering crusts in eastern, central and northern Guizhou. The material used in fission track dating is well-crystallized quartz occurring in many in-situ weathering crusts of carbonate rocks. The results showed that the fission track ages of quartz vary over a wide range from 1 to 25 Ma in the four profiles, significantly younger than the ages of the Triassic and Cambrian parent rocks. In combination with the evolution history of the regional geology during the period from 25 to 1 Ma, the ages of quartz can exclude the possibility that the origin of quartz has nothing to do with primary clastic minerals in parent rocks, authigenesis during diagenesis and hydrothermal precipitation or replacement by volcanic activities. It is deduced that the well-crystallized quartz was precipitated from Si-rich weathering fluids during the weathering process of carbonate rocks. The recorded ages of quartz from the four profiles are consistent with the episodes of the planation surfaces on the Qinghai-Tibet Plateau, the forming stages of red soil in the tropics of South China, the tectonically stable periods in Guizhou, and the ages of weathering in other parts of the world during the Cenozoic era. That is to say, the ages of authigenic quartz dated by the fission track method are well feasible and credible.

  14. Comparison of field and laboratory weathering rates in carbonate rocks from an Eastern Mediterranean drainage basin

    Science.gov (United States)

    Levenson, Yael; Ryb, Uri; Emmanuel, Simon

    2017-05-01

    The rates of carbonate rock weathering affect the global carbon cycle over timescales of hundreds to thousands of years. While field measurements show that the rate of carbonate denudation increases with rainfall, significant variability exists. To determine whether the mineralogical composition of the rocks causes this variability, we compare published long-term field denudation rates determined from cosmogenic isotopes (36Cl) with the weathering rates measured in laboratory experiments conducted on the same rock samples. The samples were collected from natural-rock outcrops across the Soreq drainage basin (Israel) that experience similar mean annual precipitation, but exhibit long-term denudation rates that vary from 6 mm ky-1 to 20 mm ky-1. In laboratory experiments, we found that the laboratory rates also varied, decreasing as the ratio of dolomite to calcite increased. However, no correlation was evident between the long-term denudation rates and mineral composition, suggesting that the variability in field rates was not controlled by the kinetics of dissolution. Other factors, such as rain intensity, biological activity, and mechanical erosion are likely to control the variability in the rates by inhibiting or accelerating the weathering of carbonate surfaces in natural settings.

  15. Defining the `negative emission' capacity of global agriculture deployed for enhanced rock weathering

    Science.gov (United States)

    Beerling, D. J.; Taylor, L.; Banwart, S. A.; Kantzas, E. P.; Lomas, M.; Mueller, C.; Ridgwell, A.; Quegan, S.

    2016-12-01

    Enhanced rock weathering involves application of crushed silicates (e.g. basalt) to the landscape to accelerate their chemical breakdown to release base cations and form bicarbonate that ultimate sequester CO2 in the oceans. Global croplands cover an area of 12 million km2 and might be deployed for long-term removal of anthropogenic CO2 through enhanced rock weathering with a number of co-benefits for food security. This presentation assesses the potential of this strategy to contribute to `negative emissions' as defined by a suite of simulations coupling a detailed model of rock grain weathering by crop root-microbial processes with a managed land dynamic global vegetation model driven by the `business as usual' future climate change scenarios. We calculate potential atmospheric CO2 drawdown over the next century by introducing a strengthened C-sink term into the global carbon cycle model within an intermediate complexity Earth system model. Our simulations indicate agricultural lands deployed in this way constitute a `low tech' biological negative emissions strategy. As part of a wider portfolio of options, this strategy might contribute to limiting future warming to 2oC, subject to economic costs and energy requirements.

  16. A landscape in three biospheres: biological rock weathering in a model ecosystem

    Science.gov (United States)

    Presler, J. K.

    2012-12-01

    Biological rock weathering is the process by which life breaks down minerals into forms that are readily available for creation of an ecosystem. In order to test how microbes, plants and mycorrhizal communities interact with bedrock to initiate a primary ecosystem that will eventually lead to soil formation, we developed a modular experiment in the desert biome of Biosphere-2. In this presentation we present selected phases in the development of the experimental setup. Briefly, we aimed to replicate a large-scale primordial landscape in a closed, mesocosm system involving six carefully designed, identical chambers, each containing 48 experimental columns, 30cm long. The rocks used, i.e. basalt, rhyolite, granite and schist, represent four prevalent rock types in the natural landscape. The biotic communities are represented by combinations of rock microbial communities, plants and their associated mycorrhizae. Bacterial inoculum was optimized for each rock type. Each model was created to remain completely separated from outside influence. We expect that this experiment will provide crucial knowledge about primary interactions between rock and biota on Earth. Experimental Modules

  17. Characterization of weathering profile in granites and volcanosedimentary rocks in West Africa under humid tropical climate conditions. Case of the Dimbokro Catchment (Ivory Coast)

    Science.gov (United States)

    Koita, M.; Jourde, H.; Koffi, K. J. P.; da Silveira, K. S.; Biaou, A.

    2013-06-01

    In granitic rocks, various models of weathering profile have been proposed, but never for the hard rocks of West Africa. Besides, in the literature there is no description of the weathering profile in volcanosedimentrary rocks. Therefore, we propose three models describing the weathering profiles in granites, metasediments, and volcanic rocks for hard rock formations located in West Africa. For each of these models proposed for granitic and volcanosedimentary rocks of the Dimbokro catchment, vertical layered weathering profiles are described, according to the various weathering and erosion cycles (specific to West Africa) that the geological formations of the Dimbokro catchment experienced from the Eocene to the recent Quaternary period. The characterization of weathering profiles is based on: i) bedrocks and weathering profile observations at outcrop, and ii) interpretation and synthesis of geophysical data and lithologs from different boreholes. For each of the geological formations (granites, metasediments, and volcanic rocks), their related weathering profile model depicted from top to bottom comprises four separate layers: alloterite, isalterite, fissured layer, and fractured fresh basement. These weathering profiles are systematically covered by a soil layer. Though granites, metasediments and volcanic rocks of the Dimbokro catchment experience the same weathering and erosion cycles during the palaeoclimatic fluctuations from Eocene to recent Quaternary period, they exhibit differences in thickness. In granites, the weathering profile is relatively thin due to the absence of iron crust which protects weathering products against dismantling. In metasediments and volcanic rocks iron crusts develop better than in granites; in these rocks the alterite are more resistant to dismantling.

  18. Characterization of weathering profile in granites and volcanosedimentary rocks in West Africa under humid tropical climate conditions. Case of the Dimbokro Catchment (Ivory Coast)

    Indian Academy of Sciences (India)

    M Koita; H Jourde; K J P Koffi; K S Da Silveira; A Biaou

    2013-06-01

    In granitic rocks, various models of weathering profile have been proposed, but never for the hard rocks of West Africa. Besides, in the literature there is no description of the weathering profile in volcanosedimentrary rocks. Therefore, we propose three models describing the weathering profiles in granites, metasediments, and volcanic rocks for hard rock formations located in West Africa. For each of these models proposed for granitic and volcano sedimentary rocks of the Dimbokro catchment, vertical layered weathering profiles are described, according to the various weathering and erosion cycles (specific to West Africa) that the geological formations of the Dimbokro catchment experienced from the Eocene to the recent Quaternary period. The characterization of weathering profiles is based on: i) bedrocks and weathering profile observations at outcrop, and ii) interpretation and synthesis of geophysical data and lithologs from different boreholes. For each of the geological formations (granites, metasediments, and volcanic rocks), their related weathering profile model depicted from top to bottom comprises four separate layers: alloterite, isalterite, fissured layer, and fractured fresh basement. These weathering profiles are systematically covered by a soil layer. Though granites, metasediments and volcanic rocks of the Dimbokro catchment experience the same weathering and erosion cycles during the palaeoclimatic fluctuations from Eocene to recent Quaternary period, they exhibit differences in thickness. In granites, the weathering profile is relatively thin due to the absence of iron crust which protects weathering products against dismantling. In metasediments and volcanic rocks iron crusts develop better than in granites; in these rocks the alterite are more resistant to dismantling.

  19. Geochemistry of Rare Earth Elements (REE) in the Weathered Crusts from the Granitic Rocks in Sulawesi Island, Indonesia

    Institute of Scientific and Technical Information of China (English)

    Adi Maulana; Kotaro Yonezu; Koichiro Watanabe

    2014-01-01

    We report for the first time the geochemistry of rare earth elements (REE) in the weath-ered crusts of I-type and calc-alkaline to high-K (shoshonitic) granitic rocks at Mamasa and Palu re-gion, Sulawesi Island, Indonesia. The weathered crusts can be divided into horizon A (lateritic profile) and B (weathered horizon). Quartz, albite, kaolinite, halloysite and montmorrilonite prevail in the weathered crust. Both weathered profiles show that the total REE increased from the parent rocks to the horizon B but significantly decrease toward the upper part (horizon A). LREE are enriched toward the upper part of the profile as shown by La/YbN value. However, HREE concentrations are high in horizon B1 in Palu profile. The total REE content of the weathered crust are relatively elevated com-pared to the parent rocks, particularly in the lower part of horizon B in Mamasa profile and in horizon B2 in Palu profile. This suggests that REE-bearing accessory minerals may be resistant against weath-ering and may remain as residual phase in the weathered crusts. The normalized isocon diagram shows that the mass balance of major and REE components between each horizon in Mamasa and Palu weathering profile are different. The positive Ce anomaly in the horizon A of Mamasa profile indicated that Ce is rapidly precipitated during weathering and retain at the upper soil horizon.

  20. Onset and ending of the late Palaeozoic ice age triggered by tectonically paced rock weathering

    Science.gov (United States)

    Goddéris, Yves; Donnadieu, Yannick; Carretier, Sébastien; Aretz, Markus; Dera, Guillaume; Macouin, Mélina; Regard, Vincent

    2017-04-01

    The onset of the late Palaeozoic ice age about 340 million years ago has been attributed to a decrease in atmospheric CO2 concentrations associated with expansion of land plants, as plants both enhance silicate rock weathering--which consumes CO2--and increase the storage of organic carbon on land. However, plant expansion and carbon uptake substantially predate glaciation. Here we use climate and carbon cycle simulations to investigate the potential effects of the uplift of the equatorial Hercynian mountains and the assembly of Pangaea on the late Palaeozoic carbon cycle. In our simulations, mountain uplift during the Late Carboniferous caused an increase in physical weathering that removed the thick soil cover that had inhibited silicate weathering. The resulting increase in chemical weathering was sufficient to cause atmospheric CO2 concentrations to fall below the levels required to initiate glaciation. During the Permian, the lowering of the mountains led to a re-establishment of thick soils, whilst the assembly of Pangaea promoted arid conditions in continental interiors that were unfavourable for silicate weathering. These changes allowed CO2 concentrations to rise to levels sufficient to terminate the glacial event. Based on our simulations, we suggest that tectonically influenced carbon cycle changes during the late Palaeozoic were sufficient to initiate and terminate the late Palaeozoic ice age.

  1. Hydrochemistry and rock weathering in a sub-tropical Lesser Himalayan river basin in Kumaun, India

    Science.gov (United States)

    Bartarya, S. K.

    1993-06-01

    Major ion chemistry of the water of the Gaula catchment — a medium-sized Lesser Himalayan basin in Kumaun, was measured in 1983 and 1984. The results show the influence of rock weathering on the concentration of major constituents in the ground water and surface water. The catchment lithology contributes a large part of the major constituents in the waters; Ca and Mg account for 40-73% of the cations and HCO 3 accounts for 48-98% of anions, and the equivalent ratio of Ca + Mg to Na + K is about nine. Cl + SO 4 accounts for 12-16% in the anion balance and does not represent a contribution from soil salt. The low Mg:Ca ratio (0.1-0.4) and high bicarbonate suggest the possibility of carbonate precipitation between the upper and the lower reaches. The excess Na over Cl, low Mg:Ca ratio and relatively high abundance of silica in the upper reaches indicate weathering of aluminosilicate minerals of crystalline rocks (granite, mica schist and quartz porphyry), and particularly of Na- and K-feldspar and quartz. Intense weathering of pyrite and or gypsum associated with the carbonate rocks is reflected by the substantially higher abundance of SO 4, low silica and the low Na:Cl ratio. In comparison with the Indian peninsular rivers, the low concentrations of the major constituents in the water of this Lesser Himalayan catchment indicate rapid infiltration and quick outflow of the rainwater and thus a short residence time for water, during which interaction with the rocks could occur, because of the steep slopes.

  2. USING ELASTIC WAVE VELOCITY ON CLASSIFICATION WEATHERING ROCK MATERIALS AND PREDICTION OF ENGINEERING PROPERTIES IN KURTUN GRANODIORITE

    Directory of Open Access Journals (Sweden)

    Şener CERYAN

    2007-02-01

    Full Text Available A great number of landslides occurred in weathered granites outcropped the area in which Kurtun Dams with reservoirs and Gümüshane-Giresun highways pass trough. For this, weathering effect on the rock materials of the Kurtun granodiorite was investigated. In this study, both physical and mineralogical changes on the granitic materials due to weathering are described separately using P- wave velocity in rocks materials. Mineralogical Change Parameter and Physical Parameter defined based on P- wave velocity in rocks materials are applied on the samples from the selected weathering profiles, for the estimation of the effects of weathering on the physicomechanical properties of rock materials. The relative variation of mechanical properties and these indices display a statistically significant correlation. Besides, it is shown that P wave velocity in the solid parts of the samples. and Quantitative Weathering index originally defined Ceryan (1999a as based on slake-durability index, Mineralogical Change Parameter and Physical Parameter can be used together to evaluate the effect of weathering on the mechanical behavior of rocks material from Kürtün granodiorite.

  3. Life on rock. Scaling down biological weathering in a new experimental design at Biosphere-2

    Science.gov (United States)

    Zaharescu, D. G.; Dontsova, K.; Burghelea, C. I.; Chorover, J.; Maier, R.; Perdrial, J. N.

    2012-12-01

    Biological colonization and weathering of bedrock on Earth is a major driver of landscape and ecosystem development, its effects reaching out into other major systems such climate and geochemical cycles of elements. In order to understand how microbe-plant-mycorrhizae communities interact with bedrock in the first phases of mineral weathering we developed a novel experimental design in the Desert Biome at Biosphere-2, University of Arizona (U.S.A). This presentation will focus on the development of the experimental setup. Briefly, six enclosed modules were designed to hold 288 experimental columns that will accommodate 4 rock types and 6 biological treatments. Each module is developed on 3 levels. A lower volume, able to withstand the weight of both, rock material and the rest of the structure, accommodates the sampling elements. A middle volume, houses the experimental columns in a dark chamber. A clear, upper section forms the habitat exposed to sunlight. This volume is completely sealed form exterior and it allows a complete control of its air and water parameters. All modules are connected in parallel with a double air purification system that delivers a permanent air flow. This setup is expected to provide a model experiment, able to test important processes in the interaction rock-life at grain-to- molecular scale.

  4. Rock weathering creates oases of life in a high Arctic desert.

    Science.gov (United States)

    Borin, Sara; Ventura, Stefano; Tambone, Fulvia; Mapelli, Francesca; Schubotz, Florence; Brusetti, Lorenzo; Scaglia, Barbara; D'Acqui, Luigi P; Solheim, Bjørn; Turicchia, Silvia; Marasco, Ramona; Hinrichs, Kai-Uwe; Baldi, Franco; Adani, Fabrizio; Daffonchio, Daniele

    2010-02-01

    During primary colonization of rock substrates by plants, mineral weathering is strongly accelerated under plant roots, but little is known on how it affects soil ecosystem development before plant establishment. Here we show that rock mineral weathering mediated by chemolithoautotrophic bacteria is associated to plant community formation in sites recently released by permanent glacier ice cover in the Midtre Lovénbreen glacier moraine (78 degrees 53'N), Svalbard. Increased soil fertility fosters growth of prokaryotes and plants at the boundary between sites of intense bacterial mediated chemolithotrophic iron-sulfur oxidation and pH decrease, and the common moraine substrate where carbon and nitrogen are fixed by cyanobacteria. Microbial iron oxidizing activity determines acidity and corresponding fertility gradients, where water retention, cation exchange capacity and nutrient availability are increased. This fertilization is enabled by abundant mineral nutrients and reduced forms of iron and sulfur in pyrite minerals within a conglomerate type of moraine rock. Such an interaction between microorganisms and moraine minerals determines a peculiar, not yet described model for soil genesis and plant ecosystem formation with potential past and present analogues in other harsh environments with similar geochemical settings.

  5. Uranium and thorium in weathering and pedogenetic profiles developed on granitic rocks from NW Spain

    Energy Technology Data Exchange (ETDEWEB)

    Taboada, Teresa [Departamento de Edafoloxia e Quimica Agricola, Facultade de Bioloxia, University of Santiago de Compostela, E-15782, Santiago de Compostela (Spain)]. E-mail: edteresa@usc.es; Martinez Cortizas, Antonio [Departamento de Edafoloxia e Quimica Agricola, Facultade de Bioloxia, University of Santiago de Compostela, E-15782, Santiago de Compostela (Spain); Garcia, Carlota [Departamento de Edafoloxia e Quimica Agricola, Facultade de Bioloxia, University of Santiago de Compostela, E-15782, Santiago de Compostela (Spain); Garcia-Rodeja, Eduardo [Departamento de Edafoloxia e Quimica Agricola, Facultade de Bioloxia, University of Santiago de Compostela, E-15782, Santiago de Compostela (Spain)

    2006-03-01

    Uranium and thorium were analyzed in seven weathering and pedogenetic soil profiles developed on granitic rocks from NW Spain. Concentrations were measured by X-ray fluorescence spectrometry (XRF) and the U- and Th-bearing minerals were studied by scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDS). Both elements were determined in rock, bulk soil and in different grain-size fractions (sand: 2000-50 {mu}m, silt: 50-2 {mu}m, and clay: < 2 {mu}m). U concentrations in the rock varied between 5.3 and 27.7 mg kg{sup -1} and Th concentrations from 5.5 to 50.7 mg kg{sup -1}. The most alkalic rocks can be considered as U-rich granites. Bulk soil U and Th concentrations are similar to those of the rocks (4.8-29.2 and 7.4-56.7 mg kg{sup -1}, respectively), but in the grain-size fractions both elements show the lowest concentrations in the sand and the highest in the clay. In the latter, concentrations are always higher than those of the rocks, particularly in the C horizons with enrichments up to 4 times for U and 5 times for Th. The concentration profiles and the ratios to the parent rock suggest that U and Th are leached from the surface soil and accumulate in the deeper horizons. Mass balance calculations, using Ti as a reference immobile element, also support U and Th leaching in the solum and supergene enrichment in bottom horizons. Leaching seems to be more intense on horizons with gravel content higher than 20%. The leaching of U and Th in the topmost horizons and the accumulation in the bottom soil horizons can be considered as a natural attenuation of the impact of these radiogenic elements in the environment. But their enrichment in the potentially airborne fraction poses some risk of redistribution in the ecosystems.

  6. Decay patterns of brick wall in atmospheric environment: a possible analogue to rock weathering?

    Science.gov (United States)

    Prikryl, Richard; Weishauptová, Zuzana; Přikrylová, Jiřina; Jablonský, Jakub

    2015-04-01

    This study is focused on the decay of bricks exposed in enclosing wall of the Regional maternal hospital in Prague city centre (Czech Republic). The hospital, listed as a Czech architectural monument, has been constructed from locally produced bricks in neo-Gothic style in the period of 1867-1875. The bricks of the enclosing wall show sequence of decay patterns that resemble weathering forms observable on monuments built of natural stone. This study aims to study the observed decay patterns by means of in situ mapping and by analyses of decayed material (optical microscopy, SEM/EDS, X-ray diffraction, Hg-porosimetry, water soluble salts analysis) and to interpret them based on the phase composition and other properties of bricks. Finally, the decay patterns of studied brick wall are compared to known weathering sequences on porous rocks (both on natural outcrops and on artistic monuments).

  7. Using Resistivity Measurements to Determine Anisotropy in Soil and Weathered Rock

    Directory of Open Access Journals (Sweden)

    S. Soto-Caban

    2013-08-01

    Full Text Available This study uses electrical resistivity measurements of soils and weathered rock to perform a fast and reliable evaluation of field anisotropy. Two test sites at New Concord, Ohio were used for the study. These sites are characterized by different landform and slightly east dipping limestone and siltstone formations of Pennsylvanian age. The measured resistivity ranged from 19 Ω∙m to 100 ��∙m, and varied with depth, landform, and season. The anisotropy was determined by a comparison of resistance values along the directions of strike and the dip. Measurements showed that the orientation of electrical anisotropy in the shallow ground may vary due to fluid connection, which is determined by the pore geometry in soil and rock, as well as by the direction of fluid movement. Results from this study indicated that a portable electrical resistivity meter is sensitive and reliable enough to be used for shallow ground fluid monitoring.

  8. Lead isotopes tracing the life cycle of a catchment: From source rock via weathering to human impact

    Science.gov (United States)

    Negrel, P. J.; Petelet-Giraud, E.; Guerrot, C.; Millot, R.

    2015-12-01

    Chemical weathering of rocks involves consumption of CO2, a greenhouse gas with a strong influence on climate. Among rocks exposed to weathering, basalt plays a major role in the carbon cycle as it is more easily weathered than other crystalline silicate rocks. This means that basalt weathering acts as a major atmospheric CO2 sink. The present study investigated the lead isotopes in rock, soil and sediment for constraining the life cycle of a catchment, covering source rocks, erosion processes and products, and anthropogenic activities. For this, we investigated the Allanche river drainage basin in the Massif Central, the largest volcanic areas in France, that offers opportunities for selected geochemical studies since it drains a single type of virtually unpolluted volcanic rock, with agricultural activity increasing downstream. Soil and sediment are derived exclusively from basalt weathering, and their chemistry, coupled to isotope tracing, should shed light on the behavior of chemical species during weathering from parental bedrock. Bedrock samples of the basin, compared to regional bedrock of the volcanic province, resulted from a complex history and multiple mantle reservoir sources and mixing. Regarding soils and sediments, comparison of Pb and Zr normalized to mobile K shows a linear evolution of weathering processes, whereby lead enrichment from atmospheric deposition is the other major contributor. Lead-isotope ratios showed that most of the lead budget in sediment and soil results from bedrock weathering with an influence of past mining and mineral processing of ores in the Massif Central, and deposition of lead-rich particles from gasoline combustion, but no lead input from agricultural activity. A classic box model was used to investigate the dynamics of sediment transfer at the catchment scale, the lead behavior in the continuum bedrock-soil-sediment and the historical evolution of anthropogenic aerosol emissions.

  9. Variability of erodibility in rock-floored channels produced by differential weathering

    Science.gov (United States)

    Sparacino, M. S.; Hancock, G. S.; Small, E. E.; Lamp, L.

    2011-12-01

    The erosion of bedrock-floored channels is a critical process governing the rate of landscape evolution in many settings. Field and modeling studies suggest that bedrock channels evolve toward equilibrium through adjustment of geometry and slope to the imposed discharge, sediment supply, and substrate erodibility conditions. Recent numerical modeling of rock-floored channel cross-sections suggests that equilibrium channel geometry and slope are sensitive to variation in rock erodibility along the channel perimeter. However, few field studies have focused on systematic measurement of rock erodibility across rock-floored channels. We hypothesize variations in weathering intensity and duration across some channels results in variable erodibility. To determine if erodibility varies in some channels, we used a Type N Schmidt hammer to measure in situ compressive strength in channels floored by sandstone (3 sites, Utah), basalt (2 sites, Hawaii), granite (3 sites, Virginia) and limestone (2 sites, Virginia). Rock compressive strength is assumed to be an adequate proxy for erodibility (Sklar et al., 2001). At each site, we collected compressive strength measurements along transects oriented perpendicular to flow direction. We surveyed the transects to determine the position of measurements within cross-sections and to estimate width/depth ratios. Of 19 transects measured in sandstone channels, 10 show significant decreases in compressive strength (up to 60%) with increasing height above the channel thalweg. Five sandstone transects collected from a rapidly eroding slot canyon show no significant change in compressive strength with height. Transects on basalt and 2 of 3 transects on granite show significant compressive strength decreases with increasing height. Transects on limestone, however, reveal compressive strength increases with height above the thalweg. The width-depth ratios in the granite channels are ~10 times greater than the limestone channels, despite similar

  10. Neutron activation analysis for the demonstration of amphibolite rock-weathering activity of a yeast.

    Science.gov (United States)

    Rades-Rohkohl, E; Hirsch, P; Fränzle, O

    1979-12-01

    Neutron activation analysis was employed in a survey of weathering abilities of rock surface microorganisms. A yeast isolated from an amphibolite of a megalithic grave was found actively to concentrate, in media and in or on cells, iron and other elements when grown in the presence of ground rock. This was demonstrated by comparing a spectrum of neutron-activated amphibolite powder (particle size, 50 to 100 mum) with the spectra of neutron-activated, lyophilized yeast cells which had grown with or without amphibolite powder added to different media. The most active yeast (IFAM 1171) did not only solubilize Fe from the rock powder, but significant amounts of Co, Eu, Yb, Ca, Ba, Sc, Lu, Cr, Th, and U were also mobilized. The latter two elements occurred as natural radioactive isotopes in this amphibolite. When the yeast cells were grown with neutron-activated amphibolite, the cells contained the same elements. Furthermore, the growth medium contained Fe, Co, and Eu which had been solubilized from the amphibolite. This indicates the presence, in this yeast strain, of active rockweathering abilities as well as of uptake mechanisms for solubilized rock components.

  11. Solar-induced weathering of rocks: integrating instrumental and numerical studies

    Science.gov (United States)

    Hallet, B.; Eppes, M. C.; Mackenzie-Helnwein, P.; Warren, K.; McFadden, L.; Gillespie, A.; Putkonen, J.; Swami, S.; Shi, J.

    2011-12-01

    The contribution of solar-driven thermal cycling to the progressive breakdown of surface rocks on the Earth and other planets is controversial. We introduce a current study of the physical state in boulders that integrates modern instrumental and numerical approaches to quantify the surface temperature, stresses, strains, and microfracture activity in exposed boulders, and to shed light on the processes underlying this form of mechanical weathering. We are monitoring the surface and environmental conditions of two ~30 cm dia. granite boulders (one in North Carolina, one in New Mexico) in the field for ~1 yr each. Each rock is instrumented with 8 thermocouples, 8 strain gauges, a surface moisture sensor and 6 Acoustic Emission (AE) sensors to monitor microfracture activity continuously. These sensors and a full meteorological station, including soil-moisture probes, are combined into a single, remotely accessible system. AE events can be located to within 2.5 cm. We are able 1) to spatially and temporally correlate microcrack growth (AE events) with the rock surface and environmental conditions experienced by the rock, and 2) to validate modeling results. The modeling work addresses two coupled problems: 1) the time-varying thermal regime of rocks exposed to diurnal variations in solar radiation as dictated by latitude, and time of the year, as well as the surface emissivity and thermal properties of the rock and soil, and size and shape of the rock, and 2) the corresponding time-varying stress and strain fields in the rocks using representative elastic properties and realistic rock shape and orientation. AE events tend to occur shortly after sunset (6-9 pm) in the upper portion of the boulder. Most of the events occur in summer and winter months for the NC boulder. The majority occur in bursts of tens to hundreds over periods of a few minutes, and are often associated with environmental factors other than simple diurnal warming and cooling, such as wind gusts, that

  12. Visible and infrared properties of unaltered to weathered rocks from Precambrian granite-greenstone terrains of the West African Craton

    Science.gov (United States)

    Metelka, Václav; Baratoux, Lenka; Jessell, Mark W.; Naba, Séta

    2015-12-01

    In situ and laboratory 0.35 μm-2.5 μm spectra of rocks from a Paleoproterozoic granite-greenstone terrain along with its Neoproterozoic sedimentary cover and derived regolith materials were examined in western Burkina Faso. The reflectance spectra show the influence of typical arid to semi-arid weathering with the formation of desert varnish, iron films, and dust coatings. Fe and Mg-OH absorption features related to chlorite, amphibole, pyroxene, epidote, and biotite are observable in the mafic and intermediate meta-volcanic rocks as well as in the granodiorites and tonalites. Al-OH absorption caused by kaolinite, smectite, illite/muscovite are typical for meta-volcano-sedimentary schists, Tarkwaian-type detrital meta-sediments, sandstones of the Taoudeni basin, all of the weathered surfaces and regolith materials. Ferric and ferrous iron absorptions related to both primary rock-forming minerals and secondary weathering minerals (goethite, hematite) were observed in most of the sampled materials. The results show that although weathering alters the spectral signature of the fresh rock, indicative absorption features located in the short wave infrared region remain detectable. In addition, spectra of soils partially reflect the mineral composition of the weathered rock surfaces. The analysis of the hyperspectral data shows the potential of differentiating between the sampled surfaces. The library presents a primary database for the geological and regolith analysis of remote sensing data in West Africa.

  13. Enrichment and Release of Rare Earth Elements during Weathering of Sedimentary Rocks in Wujiang Catchments, Southwest China

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Thirteen weathering profiles of sedimentary rocks such as limestone, dolomitic limestone, dolomite, sillicalite, black shale and purple sandrock from Wujiang catchments were selected for study on enrichment and release behavior of rare earth elements (REE) during weathering, and its impact on plant growth and riverine REE distribution in the catchments with methods of hierachical cluster analysis and mass balance calculation in order to set a basis for riverine material source research and agricultural production. The results show that the enrichment degree of REE in calcareous soils from the Wujiang catchments is much higher than that of limestone, yellow soil, upper continental crust (UCC), China soil (CS) and world soil (WS). The ability of enrichment and release of REE is partly controlled by distribution of REE in bedrocks, contents and adsorption ability of organic matters, clay minerals and Fe-oxides/hydroxides in weathering profiles. The REE released from weathering of carbonate rocks and clastic rocks can be absorbed and utilized by local plants. The results also reveal that release of REE and Fe mainly from weathering of carbonate rocks and partly from clastic rocks exerts an important control on riverine REE distribution.

  14. The role of forest trees and their mycorrhizal fungi in carbonate rock weathering and its significance for global carbon cycling.

    Science.gov (United States)

    Thorley, Rachel M S; Taylor, Lyla L; Banwart, Steve A; Leake, Jonathan R; Beerling, David J

    2015-09-01

    On million-year timescales, carbonate rock weathering exerts no net effect on atmospheric CO2 concentration. However, on timescales of decades-to-centuries, it can contribute to sequestration of anthropogenic CO2 and increase land-ocean alkalinity flux, counteracting ocean acidification. Historical evidence indicates this flux is sensitive to land use change, and recent experimental evidence suggests that trees and their associated soil microbial communities are major drivers of continental mineral weathering. Here, we review key physical and chemical mechanisms by which the symbiotic mycorrhizal fungi of forest tree roots potentially enhance carbonate rock weathering. Evidence from our ongoing field study at the UK's national pinetum confirms increased weathering of carbonate rocks by a wide range of gymnosperm and angiosperm tree species that form arbuscular (AM) or ectomycorrhizal (EM) fungal partnerships. We demonstrate that calcite-containing rock grains under EM tree species weather significantly faster than those under AM trees, an effect linked to greater soil acidification by EM trees. Weathering and corresponding alkalinity export are likely to increase with rising atmospheric CO2 and associated climate change. Our analyses suggest that strategic planting of fast-growing EM angiosperm taxa on calcite- and dolomite-rich terrain might accelerate the transient sink for atmospheric CO2 and slow rates of ocean acidification.

  15. K-Ar age constrains on chemically weathered granitic basement rocks (saprolites) in Scandinavia

    Science.gov (United States)

    Margreth, Annina; Fredin, Ola; Viola, Giulio; Knies, Jochen; Sørlie, Ronald; Lie, Jan-Erik; Margrethe Grandal, Else; Zwingmann, Horst; Vogt, Christoph

    2017-04-01

    Remnants of in-situ weathered bedrock, saprolite, are found in several locations in Scandinavia. Saprolites contain important information about past climate conditions and landscape evolution, although their age and genesis are commonly difficult to constrain. It is generally thought that clay-poor, coarse-grained (arêne) saprolites, mostly occurring as thin regolith blankets or in larger outcrops, formed in temperate climate during the Cenozoic, whereas clay-rich (argillic) saprolites, commonly restricted to small, fracture-bounded outcrops, formed in (sub-)tropical climate during the Mesozoic. Recent methodological and conceptual advances in K-Ar dating of illite-bearing fault rocks have been applied to date clay-rich saprolites. To test the K-Ar dating technique for saprolites, we first selected an offshore site in the Viking Graben of the North Sea, where weathered and fractured granitic basement highs have been drilled during petroleum exploration, and an abandoned kaolin mine in Southern Sweden. Both targets provide independent age control through the presence of overlying Mesozoic sedimentary rocks. Clay-rich saprolites occurring in fractured basement rocks were additionally sampled in a joint valley landscape on the southwestern coast of Norway, which can be regarded as the possible onland correlative to the offshore basement high. In order to offer a sound interpretation of the obtained K-Ar ages, the mineralogical and chemical composition of the saprolites requires a thorough characterization. Scanning electron microscopy of thin sections, integrated by XRD and XRF analysis, reveals the progressive transformation of primary granitic rock minerals into secondary clay minerals. The authigenesis of illite is particularly important to understand, since it is the only K-bearing clay mineral that can be dated by the K-Ar method. K-feldspars and mica are the common primary K-bearing minerals, from which illite can be formed. While progressive leaching of

  16. Methods applied in determining the variations of strength and srtucture of plutonic rock material exposed to artificial weathering treatment

    Directory of Open Access Journals (Sweden)

    Ihalainen, P.

    1993-12-01

    Full Text Available In this study the most significant factors determining the weathering of natural rock material proved to be the water saturation of the samples and the chemical composition of the pore water. The action of hydrolysis caused by the acidity of the pore water, combined with repeated freezing and thawing in 100% relative humidity proved to be the most significant factor in the alteration of the strength and structure of the studied material, the Inari anorthosite. The action of these methods disintegrated the rock material more than any other weathering treatment or any other combination of the treatments used in this study. The changes in the strength of the rock material were most reliably illustrated by the changes in tensile strength, measured by the changes in the modulus of rupture and the point load index. In several cases the standard deviations of the results exceeded the absolute changes of the corresponding parameter value. By progressing weathering, the porosity of the Inari anorthosite changed in such a way that both the frost and salt weathering increased primarily the proportion of the large pores while the hydrolysis increased the proportion of the small pores of the total porosity. It is rather difficult to simulate in the laboratory the changes in strength and structure of building stone caused by natural weathering, since the effectiveness of the climatic and environmental factors affecting the rock surface in real conditions varies from case to case and according to the duration of the weathering action. An unweathered firm silicate rock with low porosity, such as the Inari anorthosite, has such a resistance against weathering that the necessary series of laboratory experiments to determine the changes in strength inevitably take several months.

  17. The relationship between weathering and welding degree of pyroclastic rocks in the Kilistra ancient city, Konya (Central Anatolia, Turkey)

    Science.gov (United States)

    Bozdaǧ, Ali; Bayram, A. Ferat; İnce, İsmail; Asan, Kürşad

    2016-11-01

    Pyroclastic rocks used in both historical and modern structures are inevitably exposed to various weathering processes, leading to damage and destruction of them. To reduce the effects of weathering caused by various atmospheric effects, geologists need to know what processes are more effective and how they affect rock bodies. In this study, our aim is to show the relationship between the weathering and welding degree of pyroclastic rocks, sampled around the Ancient City of Kilistra in Konya (Central Anatolia, Turkey). For this purpose, we conducted field trips, and used petrographic and laboratory techniques such as, physico-mechanical tests and accelerated weathering tests (i.e., Freeze-Thaw, F-T; Wetting-Drying, W-D and Salt Crystallization, SC). Pyroclastic rocks around Kilistra ancient city comprise two different sub-units: the unwelded, lower pyroclastic unit (LPU) and the welded, upper pyroclastic unit (UPU). Following cycles of F-T and SC tests, we observed an increase in porosity values, but a decrease in uniaxial compressive strength values, which was more evident in unwelded-LPU samples. Also, the significant macroscopic textural changes occurred in LPU samples, linked to their unwelded nature. However, physico-mechanical features of both LPU and UPU samples were not significantly changed after W-D tests. Altogether, our findings show that welding degree is one of the main factors controlling weathering and physico-mechanical properties of pyroclastic rocks, and also F-T and SC are more effective processes than W-D on weathering. Accordingly, our approach here could be used to protect the endangered historical structures carved into pyroclastic rocks around the world.

  18. Chemical weathering on Mars - Thermodynamic stabilities of primary minerals /and their alteration products/ from mafic igneous rocks

    Science.gov (United States)

    Gooding, J. L.

    1978-01-01

    Chemical weathering on Mars is examined theoretically from the standpoint of thermodynamic equilibrium between primary rock-forming minerals and the atmospheric gases O2, H2O, and CO2. The primary minerals considered are those common to mafic igneous rocks and include olivine, pyroxene, plagioclase, magnetite, troilite, pyrrhotite, and apatite. The importance of kinetics and reaction mechanisms in controlling possible weathering processes on Mars is discussed within the limits of currently available data, and the possible influence of liquid water on Martian weathering processes is evaluated where appropriate. For gas-solid weathering of mafic igneous rocks at the Martian surface, it is concluded that upon attainment of thermodynamic equilibrium: (1) oxides and carbonates should dominate the mineral assemblage of weathering products; (2) hematite rather than goethite should be the stable mineral form of Fe (III); (3) FeSO4 or FeSO4.H2O could be the stable weathering product of iron sulfides in the absence of liquid water; and (4) kaolinite is apparently the only clay mineral that should be thermodynamically stable over all ranges of temperature and water-vapor abundance at the Martian surface.

  19. Effect of soil-rock system on speleothems weathering in Bailong Cave, Yunnan Province, China

    Institute of Scientific and Technical Information of China (English)

    WANG Jing; SONG Lin-hua

    2005-01-01

    Bailong Cave with its well-developed Middle Triassic calcareous dolomite's system was opened as a show cave for visitors in 1988. The speleothem scenery has been strongly weathered as white powder on the outer layers. Study of the cave winds, permeability of soil-rock system and the chemical compositions of the dripping water indicated: (1) The cave dimension structure distinctively affects the cave winds, which were stronger at narrow places. (2) Based on the different soil grain size distribution, clay was the highest in composition in the soil. The response sense of dripping water to the rainwater percolation was slow. The density of joints and other openings in dolomite make the dolomite as mesh seepage body forming piles of thin and high columns and stalactites. (3) Study of 9 dripping water samples by HYDROWIN computer program showed that the major mineral in the water was dolomite.

  20. Controls on Weathering of Pyrrhotite in a Low-Sulfide, Granitic Mine-Waste Rock in the Canadian Arctic

    Science.gov (United States)

    Langman, J. B.; Holland, S.; Sinclair, S.; Blowes, D.

    2013-12-01

    Increased environmental risk is incurred with expansion of mineral extraction in the Arctic. A greater understanding of geochemical processes associated with hard-rock mining in this cold climate is needed to evaluate and mitigate these risks. A laboratory and in-situ experiment was conducted to examine mineral weathering and the generation of acid rock drainage in a low-sulfide, run-of-mine waste rock in an Arctic climate. Rock with different concentrations of sulfides (primarily pyrrhotite [Fe7S8] containing small amounts of Co and Ni) and carbonates were weathered in the laboratory and in-situ, large-scale test piles to examine leachate composition and mineral weathering. The relatively larger sulfide-containing rock produced sufficient acid to overcome carbonate buffering and produced a declining pH environment with concomitant release of SO4, Fe, Co, and Ni. Following carbonate consumption, aluminosilicate buffering stabilized the pH above 4 until a reduction in acid generation. Results from the laboratory experiment assisted in determining that after consumption of 1.6 percent of the total sulfide, the larger sulfide-concentration test pile likely is at an internal steady-state or maximal weathering rate after seven years of precipitation input and weathering that is controlled by an annual freeze-thaw cycle. Further weathering of the test pile should be driven by external factors of temperature and precipitation in this Arctic, semi-arid region instead of internal factors of wetting and non-equilibrium buffering. It is predicted that maximal weathering will continue until at least 20 percent of the total sulfide is consumed. Using the identified evolution of sulfide consumption in this Arctic climate, a variable rate factor can now be assessed for the possible early evolution and maximal weathering of larger scale waste-rock piles and seasonal differences because of changes in the volume of a waste-rock pile undergoing active weathering due to the freeze

  1. Bacterially induced weathering of ultramafic rock and its implications for phytoextraction.

    Science.gov (United States)

    Becerra-Castro, Cristina; Kidd, Petra; Kuffner, Melanie; Prieto-Fernández, Ángeles; Hann, Stephan; Monterroso, Carmela; Sessitsch, Angela; Wenzel, Walter; Puschenreiter, Markus

    2013-09-01

    The bioavailability of metals in soil is often cited as a limiting factor of phytoextraction (or phytomining). Bacterial metabolites, such as organic acids, siderophores, or biosurfactants, have been shown to mobilize metals, and their use to improve metal extraction has been proposed. In this study, the weathering capacities of, and Ni mobilization by, bacterial strains were evaluated. Minimal medium containing ground ultramafic rock was inoculated with either of two Arthrobacter strains: LA44 (indole acetic acid [IAA] producer) or SBA82 (siderophore producer, PO4 solubilizer, and IAA producer). Trace elements and organic compounds were determined in aliquots taken at different time intervals after inoculation. Trace metal fractionation was carried out on the remaining rock at the end of the experiment. The results suggest that the strains act upon different mineral phases. LA44 is a more efficient Ni mobilizer, apparently solubilizing Ni associated with Mn oxides, and this appeared to be related to oxalate production. SBA82 also leads to release of Ni and Mn, albeit to a much lower extent. In this case, the concurrent mobilization of Fe and Si indicates preferential weathering of Fe oxides and serpentine minerals, possibly related to the siderophore production capacity of the strain. The same bacterial strains were tested in a soil-plant system: the Ni hyperaccumulator Alyssum serpyllifolium subsp. malacitanum was grown in ultramafic soil in a rhizobox system and inoculated with each bacterial strain. At harvest, biomass production and shoot Ni concentrations were higher in plants from inoculated pots than from noninoculated pots. Ni yield was significantly enhanced in plants inoculated with LA44. These results suggest that Ni-mobilizing inoculants could be useful for improving Ni uptake by hyperaccumulator plants.

  2. Climate change mitigation: potential benefits and pitfalls of enhanced rock weathering in tropical agriculture.

    Science.gov (United States)

    Edwards, David P; Lim, Felix; James, Rachael H; Pearce, Christopher R; Scholes, Julie; Freckleton, Robert P; Beerling, David J

    2017-04-01

    Restricting future global temperature increase to 2°C or less requires the adoption of negative emissions technologies for carbon capture and storage. We review the potential for deployment of enhanced weathering (EW), via the application of crushed reactive silicate rocks (such as basalt), on over 680 million hectares of tropical agricultural and tree plantations to offset fossil fuel CO2 emissions. Warm tropical climates and productive crops will substantially enhance weathering rates, with potential co-benefits including decreased soil acidification and increased phosphorus supply promoting higher crop yields sparing forest for conservation, and reduced cultural eutrophication. Potential pitfalls include the impacts of mining operations on deforestation, producing the energy to crush and transport silicates and the erosion of silicates into rivers and coral reefs that increases inorganic turbidity, sedimentation and pH, with unknown impacts for biodiversity. We identify nine priority research areas for untapping the potential of EW in the tropics, including effectiveness of tropical agriculture at EW for major crops in relation to particle sizes and soil types, impacts on human health, and effects on farmland, adjacent forest and stream-water biodiversity. © 2017 The Author(s).

  3. Subduction of Serpentinized and Weathered Ultramafic Rocks in the Puerto Rico Trench: Preliminary Results

    Science.gov (United States)

    Horning, G.; Klein, F.

    2012-12-01

    Exposure of mantle peridotite and its interactions with seawater to form serpentinite are integral parts of seafloor spreading, and play a key role in affecting the rheology, chemistry, and microbial habitability of the oceanic lithosphere at slow- and ultra-slow spreading ridges. Away from the spreading centers, within subduction zones, the formation and dehydration of serpentinized peridotite impacts seismicity, element cycling, and melt generation. Here we present preliminary results of a petrographic and spectroscopic study of altered rocks recovered from the from the north wall of the trench Puerto Rico Trench (PRT). In fact, the PRT represents one of two subduction zones worldwide where slow spreading oceanic lithosphere is presently subducted, and where serpentinized peridotite has been directly evidenced by seafloor sampling {Bowin, 1966}. Thin section petrography, XRF analysis, scanning electron microscopy, and confocal Raman spectroscopy reveal that the peridotite, which in all likelihood originated at the Mid-Atlantic Ridge during the early Cretaceous, was virtually completely serpentinized under static conditions (as it is evidenced by the preserved mesh texture after olivine and bastite after orthopyroxene), and underwent subsequent seafloor weathering. While it is questionable where exactly serpentinization and subsequent seafloor weathering took place, our preliminary results strongly suggest that the material presently subducted in the PRT is not simply composed of serpentine, magnetite, and brucite; it is rather a complex disequilibrium assemblage of minerals including serpentine, brucite, chlorite, talc, magnetite, hematite, goethite, sulfur-rich sulfides and various clay minerals. Furthermore, our results imply that serpentinite and its weathering products influence the loci of dehydration and mineral replacement reactions, as well as the water input and element recycling in subduction zones.

  4. Estimating the age of rock glaciers from weathering rind thickness in the yari-hotaka mountain range, northern japanese alps

    OpenAIRE

    AOYAMA, Masafumi

    2001-01-01

    Formative periods of rock glaciers distributed in the Yari-Hotaka Mountain Range, northern Japanese Alps, were estimated from weathering rind thickness. The results suggest that the age of rock glaciers in the Minamisawa-Kita cirque and the most headward of the Tenguppara cirque is between the age of Early Yarisawa Stage II moraines and the Late Yarisawa Stage II moraines, and the age of rock glaciers in the northern part of the Tenguppara cirque and Ohkiretto cirque is same or younger than t...

  5. Updating of the hierarchical rock mass rating (HRMR) system and a new subsystem developed for weathered granite formations

    Institute of Scientific and Technical Information of China (English)

    Miranda Tiago; e Sousa L. Ribeiro; Tinoco Joaquim

    2014-01-01

    The RMR system is still very much applied in rock mechanics engineering context. It is based on the eval-uation of six weights to obtain a final rating. To obtain the final rating a considerable amount of informa-tion is needed concerning the rock mass which can be difficult to obtain in some projects or project stages at least with accuracy. In 2007 an alternative classification scheme based on the RMR, the Hierarchical Rock Mass Rating (HRMR) was presented. The main feature of this system was the adaptation to the level of knowledge existent about the rock mass to obtain the classification of the rock mass since it followed a decision tree approach. However, the HRMR was only valid for hard rock granites with low fracturing degrees. In this work, the database was enlarged with approximately 40%more cases considering other types of granite rock masses including weathered granites and based on this increased database the sys-tem was updated. Granite formations existent in the north of Portugal including Porto city are predom-inantly granites. Some years ago a light rail infrastructure was built in the city of Porto and surrounding municipalities which involved considerable challenges due to the high heterogeneity levels of the granite formations and the difficulties involved in their geomechanical characterization. In this work it is intended to provide also a contribution to improve the characterization of these formations with special emphasis to the weathered horizons. A specific subsystem applicable to the weathered formations was developed. The results of the validation of these systems are presented and show acceptable perfor-mances in identifying the correct class using less information than with the RMR system.

  6. Fluoride in weathered rock aquifers of southern India: Managed Aquifer Recharge for mitigation.

    Science.gov (United States)

    Brindha, K; Jagadeshan, G; Kalpana, L; Elango, L

    2016-05-01

    Climatic condition, geology, and geochemical processes in an area play a major role on groundwater quality. Impact of these on the fluoride content of groundwater was studied in three regions-part of Nalgonda district in Telangana, Pambar River basin, and Vaniyar River basin in Tamil Nadu, southern India, which experience semi-arid climate and are predominantly made of Precambrian rocks. High concentration of fluoride in groundwater above 4 mg/l was recorded. Human exposure dose for fluoride through groundwater was higher in Nalgonda than the other areas. With evaporation and rainfall being one of the major contributors for high fluoride apart from the weathering of fluoride rich minerals from rocks, the effect of increase in groundwater level on fluoride concentration was studied. This study reveals that groundwater in shallow environment of all three regions shows dilution effect due to rainfall recharge. Suitable managed aquifer recharge (MAR) methods can be adopted to dilute the fluoride rich groundwater in such regions which is explained with two case studies. However, in deep groundwater, increase in fluoride concentration with increase in groundwater level due to leaching of fluoride rich salts from the unsaturated zone was observed. Occurrence of fluoride above 1.5 mg/l was more in areas with deeper groundwater environment. Hence, practicing MAR in these regions will increase the fluoride content in groundwater and so physical or chemical treatment has to be adopted. This study brought out the fact that MAR cannot be practiced in all regions for dilution of ions in groundwater and that it is essential to analyze the fluctuation in groundwater level and the fluoride content before suggesting it as a suitable solution. Also, this study emphasizes that long-term monitoring of these factors is an important criterion for choosing the recharge areas.

  7. Novel Microbial Assemblages Dominate Weathered Sulfide-Bearing Rock from Copper-Nickel Deposits in the Duluth Complex, Minnesota, USA.

    Science.gov (United States)

    Jones, Daniel S; Lapakko, Kim A; Wenz, Zachary J; Olson, Michael C; Roepke, Elizabeth W; Sadowsky, Michael J; Novak, Paige J; Bailey, Jake V

    2017-08-15

    The Duluth Complex in northeastern Minnesota hosts economically significant deposits of copper, nickel, and platinum group elements (PGEs). The primary sulfide mineralogy of these deposits includes the minerals pyrrhotite, chalcopyrite, pentlandite, and cubanite, and weathering experiments show that most sulfide-bearing rock from the Duluth Complex generates moderately acidic leachate (pH 4 to 6). Microorganisms are important catalysts for metal sulfide oxidation and could influence the quality of water from mines in the Duluth Complex. Nevertheless, compared with that of extremely acidic environments, much less is known about the microbial ecology of moderately acidic sulfide-bearing mine waste, and so existing information may have little relevance to those microorganisms catalyzing oxidation reactions in the Duluth Complex. Here, we characterized the microbial communities in decade-long weathering experiments (kinetic tests) conducted on crushed rock and tailings from the Duluth Complex. Analyses of 16S rRNA genes and transcripts showed that differences among microbial communities correspond to pH, rock type, and experimental treatment. Moreover, microbial communities from the weathered Duluth Complex rock were dominated by taxa that are not typically associated with acidic mine waste. The most abundant operational taxonomic units (OTUs) were from the genera Meiothermus and Sulfuriferula, as well as from diverse clades of uncultivated Chloroflexi, Acidobacteria, and Betaproteobacteria Specific taxa, including putative sulfur-oxidizing Sulfuriferula spp., appeared to be primarily associated with Duluth Complex rock, but not pyrite-bearing rocks subjected to the same experimental treatment. We discuss the implications of these results for the microbial ecology of moderately acidic mine waste with low sulfide content, as well as for kinetic testing of mine waste.IMPORTANCE Economic sulfide mineral deposits in the Duluth Complex may represent the largest undeveloped

  8. Water-rock interaction on the development of granite gneissic weathered profiles in Garhwal Lesser Himalaya, India

    Science.gov (United States)

    Vyshnavi, S.; Islam, R.

    2015-07-01

    The development and sustainability of weathered profiles are very difficult in the Himalaya due to its complex lithology, tectonic history and fast erosion. Despite this, two weathered profiles namely WPa (weathered profile a) and WPb (weathered profile b) which have sustained erosion are developed on porphyry granite gneiss and granite gneissic lithology in Alaknanda valley of the Garhwal Lesser Himalaya. Systematic sampling of these two weathered profiles was done from bottom to top and they were chemically analysed to understand the elemental mobility in each profile. Major, trace and rare earth element studies show dissimilar behaviour with the advancement of weathering. In WPa profile, the CIA value of LAR (LAR) is 50 which reveals that the rock has not suffered any alteration but in WPb profile, the CIA value of LAR is 64 which indicates significant amount of chemical alteration. A-CN-K projection also exhibits similar behaviour. Further, the relative mobility of all the major and trace elements show variable elemental distribution in both the profiles. Enrichment of Mg, Fe, Ti, Al, Co, Ni, Zr, LREE and depletion of Na, K, P, Ca, Si, LILE and HFSE are observed in WPa profile; while the depletion of Na, K, Ca, P, Si, HREE and enhancement of Fe, Mn, Ti, Sc, Co, Zr, LREE are noticed in WPb profile. The rare earth elements also show a dissimilar mobilization pattern in both the profiles due to their strong dependency on lithology, and corresponding climate and tectonic interaction. Contrasting elemental mobility in both the profiles depict the major role in disparity of lithological characters and subsequent development of fractures produced by the major thrust system (Ramgarh thrust) which made an easy passage for rain water, thus causing the development of a chemically altered profile in the Lesser Himalayan region. Further, the present study infers the climate and tectonic milieu which is responsible for the development of such weathered profiles in Himalayan

  9. Water–rock interaction on the development of granite gneissic weathered profiles in Garhwal Lesser Himalaya, India

    Indian Academy of Sciences (India)

    S Vyshnavi; R Islam

    2015-07-01

    The development and sustainability of weathered profiles are very difficult in the Himalaya due to its complex lithology, tectonic history and fast erosion. Despite this, two weathered profiles namely WPa (weathered profile a) and WPb (weathered profile b) which have sustained erosion are developed on porphyry granite gneiss and granite gneissic lithology in Alaknanda valley of the Garhwal Lesser Himalaya. Systematic sampling of these two weathered profiles was done from bottom to top and they were chemically analysed to understand the elemental mobility in each profile. Major, trace and rare earth element studies show dissimilar behaviour with the advancement of weathering. In WPa profile, the CIA value of LAR (LAR) is 50 which reveals that the rock has not suffered any alteration but in WPb profile, the CIA value of LAR is 64 which indicates significant amount of chemical alteration. A–CN–K projection also exhibits similar behaviour. Further, the relative mobility of all the major and trace elements show variable elemental distribution in both the profiles. Enrichment of Mg, Fe, Ti, Al, Co, Ni, Zr, LREE and depletion of Na, K, P, Ca, Si, LILE and HFSE are observed in WPa profile; while the depletion of Na, K, Ca, P, Si, HREE and enhancement of Fe, Mn, Ti, Sc, Co, Zr, LREE are noticed in WPb profile. The rare earth elements also show a dissimilar mobilization pattern in both the profiles due to their strong dependency on lithology, and corresponding climate and tectonic interaction. Contrasting elemental mobility in both the profiles depict the major role in disparity of lithological characters and subsequent development of fractures produced by the major thrust system (Ramgarh thrust) which made an easy passage for rain water, thus causing the development of a chemically altered profile in the Lesser Himalayan region. Further, the present study infers the climate and tectonic milieu which is responsible for the development of such weathered profiles in

  10. Anomalous Features on Anomalous Rocks — Deciphering the Physical Weathering History of Iron Meteorites found on Mars using Terrestrial Analogues

    Science.gov (United States)

    Ashley, J.

    2015-12-01

    Non-indigenous rocks (meteorites) found on Mars by rover science teams offer insights into probable recent (mid- to late-Amazonian) weathering processes within 15° of the martian equator. While source materials are often in question for indigenous martian alteration scenarios, the starting materials for most meteorites are known as unweathered, curated falls in Earth-based collections. Both chemical and mechanical weathering processes have modified at least 21 confirmed and candidate exogenic rocks found at three rover landing sites. Such processes have been shown to include acidic corrosion, oxide production, and aeolian scouring. The unknown martian surface exposure duration of the meteorites makes separating physical from chemical weathering effects challenging: Saltating sand grains may accomplish alone what oxidation and rust removal by aeolian scouring may accomplish in a shorter time interval, for example. However, aeolian abrasion appears to dominate for at least some of the surface features in martian irons. Iron meteorites are resistant to wind-blown sand relative to silicate rocks, but are malleable and able to preserve aeolian abrasion effects. These include 1) regmaglypts enlarged into hollows with overhanging cornices; 2) surfaces scalloped or deeply fluted by straight-line groves, and/or 3) deep 'boreholes' present across many surfaces. The flutings, boreholes, and scallops have oriented symmetry and are therefore potentially useful as paleo-wind direction indicators. Boreholes tend to be clean-edged, elliptical to round, of varying diameter, and often occur independently of local topography. Ventifacted igneous rocks found at Garnet Hill, San Gorgonio Pass, California, present features that resemble many aspects of those found in the metal masses on Mars. Though of different petrologies and mineralogies, both rock types are massive, homogeneous and unfractured, which may conceivably account for some apparent similarities in mechanical weathering

  11. Proposal of a New Parameter for the Weathering Characterization of Carbonate Flysch-Like Rock Masses: The Potential Degradation Index (PDI)

    Science.gov (United States)

    Cano, M.; Tomás, R.

    2016-07-01

    The susceptibility of clay bearing rocks to weathering (erosion and/or differential degradation) is known to influence the stability of heterogeneous slopes. However, not all of these rocks show the same behaviour, as there are considerable differences in the speed and type of weathering observed. As such, it is very important to establish relationships between behaviour quantified in a laboratory environment with that observed in the field. The slake durability test is the laboratory test most commonly used to evaluate the relationship between slaking behaviour and rock durability. However, it has a number of disadvantages; it does not account for changes in shape and size in fragments retained in the 2 mm sieve, nor does its most commonly used index (Id2) accurately reflect weathering behaviour observed in the field. The main aim of this paper is to propose a simple methodology for characterizing the weathering behaviour of carbonate lithologies that outcrop in heterogeneous rock masses (such as Flysch slopes), for use by practitioners. To this end, the Potential Degradation Index (PDI) is proposed. This is calculated using the fragment size distribution curves taken from material retained in the drum after each cycle of the slake durability test. The number of slaking cycles has also been increased to five. Through laboratory testing of 117 samples of carbonate rocks, extracted from strata in selected slopes, 6 different rock types were established based on their slaking behaviour, and corresponding to the different weathering behaviours observed in the field.

  12. The Behaviour of Chromium Isotopes during the Oxidative Weathering of Ultramafic Rocks

    DEFF Research Database (Denmark)

    Paulukat, Cora Stefanie; Døssing, Lasse Nørbye; Mondal, Sisir K.

    The chromium isotope system has been proven to be a redox-sensitve proxy in ancient and modern environmental studies (e.g. [1], [2]). In this study we investigated Cr isotope fractionation during soil formation from Archean (3.1-3.3 Ga) ultramafic rocks, intruded into metamorphic rocks of the Iro...

  13. Effects of Weathering at Waste Rock Dump on Water Quality Inside the Mine Wastes; A Case Study in Korea

    Science.gov (United States)

    Yim, G.; Cheong, Y.; Park, H.; Ji, S.; Lee, H.

    2008-05-01

    This study was carried out to investigate the route of acid rock drainage production and some of the important factors at the abandoned Geo-pung copper mine in Okcheon, Korea. In this research area, planting and remediation have been carried out to prevent environmental pollution, but these effects turned out to be a failure and that acid rock drainage is observed around waste rock dump and planted vegetation is dying. Currently, the slope of mine waste rock dump in the study site is about 40°. It is composed of particles with a variety of shapes, with the surface exposure to atmosphere being transformed to oxide minerals due to weathering. Since groundwater level underneath the mine wastes is directly related to rainfall, a comparative evaluation of weather records and groundwater level data obtained using on-site measuring device (CTD diver) would allow estimation of locational media-specific pattern of rainfall effect in term of infiltration flux and time of threshold impact on groundwater. Sampling and analysis of there borehole water were conducted in July and September, 2007. It was found that all of the borehole water had highly variable levels of Fe (0.4-588 mg/l), Al (8.2-41.9 mg/l), Cu (6.0-32.2 mg/l), Zn (22.2-226.7 mg/l) and other elements. Also, in general, pH of the borehole waters decreased while electric conducivity measured. Such a high variance in the water quality among different borehole water suggests that geochemical environment inside the mine wastes is largely dependent on the local variation in rainfall infiltration of waste rock dump and underneath groundwater level. Vadose zone which has vertical variation of 2-4 m is directly impacted by amount of rainfall and maintains oxidizing condition due to diffusion of oxygen carred by rainfall. Therefore, sulfide minerals within in the zone continued to be oxidized, producing acid rock drainage. To prevent production of acid rock drainage of mine waste, it is necessary to control infiltration of

  14. Integrating topography, hydrology and rock structure in weathering rate models of spring watersheds

    NARCIS (Netherlands)

    Pacheco, F.A.L.; Weijden, C.H. van der

    2012-01-01

    Weathering rate models designed for watersheds combine chemical data of discharging waters with morphologic and hydrologic parameters of the catchments. At the spring watershed scale, evaluation of morphologic parameters is subjective due to difficulties in conceiving the catchment geometry. Besides

  15. Rock and stone weathering at Citadel fortifications, Gozo (Malta): benefits from terrestrial laser scanning combined with conventional investigations

    Science.gov (United States)

    Tapete, D.; Gigli, G.; Mugnai, F.; Vannocci, P.; Pecchioni, E.; Morelli, S.; Fanti, R.; Casagli, N.

    2012-04-01

    Military architecture heritage is frequently built on rock masses affected by slope instability and weathering processes, which progressively undermine the foundations and cause collapses and toppling of the masonries. The latter can be also weakened by alteration of the stone surfaces, as a consequence of the interactions with the local environmental conditions. These conservation issues are emphasized for those sites, whose susceptibility to structural damages is also due to the similarity between the lithotypes constituting the geologic substratum and the construction materials. Effective solutions for the protection from such a type of phenomena can be achieved if the whole "rock mass - built heritage system" is analyzed. In this perspective, we propose a new approach for the study of the weathering processes affecting historic hilltop sites, taking benefits from the combination of terrestrial laser scanning (TLS) and conventional investigations, the latter including geotechnical and minero-petrographic analyses. In particular, the results here presented were obtained from specific tests on the fortifications of Citadel, Gozo (Malta), performed in co-operation with the Restoration Unit, Works Division, Maltese Ministry for Resources and Rural Affairs and the private company Politecnica Ingegneria e Architettura. The Citadel fortifications are built at the top of a relatively stiff and brittle limestone plate, formed by Upper Coralline Limestone (UCL) and overlying a thick Blue Clay (BC) layer. Differential weathering creates extensively fractured ledges on the cap and erosion niches in the strata beneath, thereby favouring block detachment, even rockfall events, such as the last one occurred in 2001. The locally quarried Globigerina Limestone (GL), historically employed in restoration masonries, is also exposed to alveolization and powdering, and several collapses damaged the underwalling interventions. Since the erosion pattern distribution suggested a

  16. Weathering profiles in granitoid rocks of the Sila Massif uplands, Calabria, southern Italy: New insights into their formation processes and rates

    Science.gov (United States)

    Scarciglia, Fabio; Critelli, Salvatore; Borrelli, Luigi; Coniglio, Sabrina; Muto, Francesco; Perri, Francesco

    2016-05-01

    In this paper we characterized several weathering profiles developed on granitoid rocks in the Sila Massif upland (Calabria, southern Italy), integrating detailed macro- and micromorphological observations with physico-mechanical field tests and petrographic, mineralogical and geochemical analyses. We focused our attention on the main weathering and pedogenetic processes, trying to understand apparent discrepancies between weathering grade classes based on field description and geomechanical properties, and two common weathering indices, such as the micropetrographic index (Ip) and the chemical index of alteration (CIA). Our results showed that sericite on plagioclase and biotite chloritization, that represent inherited features formed during late-stage hydrothermal alteration of granitoid rocks, may cause an overestimation of the real degree of weathering of primary mineral grains under meteoric conditions, especially in lower weathering grade classes. Moreover, the frequent identification of Fe-Mn oxides and clay coatings of illuvial origin (rather than or in addition to those formed in situ), both at the macro- and microscale, may also explain an overestimation of the weathering degree with respect to field-based classifications. Finally, some apparent inconsistencies between field geomechanical responses and chemical weathering were interpreted as related to physical weathering processes (cryoclastism and thermoclastism), that lead to rock breakdown even when chemical weathering is not well developed. Hence, our study showed that particular caution is needed for evaluating weathering grades, because traditional field and geochemical-petrographic tools may be biased by inherited hydrothermal alteration, physical weathering and illuvial processes. On the basis of chronological constraints to soil formation obtained from a 42 ka-old volcanic input (mixed to granite parent materials) detected in the soil cover of the Sila Massif upland, a first attempt to estimate

  17. Cr-isotope fractionation during oxidative weathering of ultramafic rocks and its impact on river waters

    DEFF Research Database (Denmark)

    Paulukat, Cora Stefanie; Døssing, Lasse Nørbye; Mondal, Sisir K.

    We investigated Cr isotope fractionation during soil formation from Precambrian ultramafic rocks. A soil profile was logged in an active open-cast chromite mine (Sukinda Valley, India). In addition, mine and river waters, as well as seawater were collected to trace the Cr-isotope signal into the ...

  18. Upscaling Fracture Network Models to Continua: An Example Using Weathered Granitic Rock

    Science.gov (United States)

    Clark, A.; Doe, T.; Jones, J. W.

    2006-12-01

    In the early 1990's, a proposed landfill site on the Campo Indian Reservation in San Diego County, California, was the object of a characterization program involving over ninety exploration and monitoring wells, geophysical investigations, flow meter logging, tracer testing, and fracture characterization. This intensively studied site rests on deeply weathered tonalite. The weathered zone extends several tens to about 100 feet below the surface; however, the deeply weathered material follows hydraulically active fractures to even greater depths. The flow meter logging was especially valuable both for locating conductive fractures but also, in un- pumped mode, for defining regions of upward and downward vertical flow. The deep weathering on the conductive fractures gives each pathway a large effective porosity that translates to lower flow velocities compared with unweathered fractures with similar transmissivities. The simulation of the groundwater flow at this site used a local-scale fracture network model which was upscaled to a continuum code at regional scales. At the largest scale we generated a small number of major fractures to match the topographic lineaments. At an intermediate scale we had geophysical lineaments that were deterministic under the site footprint, and stochastic elsewhere using generation parameters based on the lengths, orientations and intensities of the deterministic features. The fractures of the most detailed scale were background fractures that were stochastically generated from borehole data. The site-scale fracture network model was incorporated into a regional-scale MODFLOW model, by overlaying the MODFLOW grid on the fracture network model and calculating equivalent porous medium properties for each MODFLOW grid cell using the Oda tensor method. This fast algorithm calculates a permeability tensor for each MODFLOW grid cell by summing the oriented area-weighted permeabilities of each fracture. The resulting MODFLOW model was then

  19. Effect of geological structures, rock weathering, and clay mineralogy in the formation of various landslides along Mugling-Narayanghat road section, Central Nepal Himalaya

    OpenAIRE

    Regmi, Amar Deep; YOSHIDA, Kohki

    2013-01-01

    The present study was conducted on the landslide prone area around Mugling-Narayanghat road section that consists of Lesser Himalayan and Siwaliks rocks. From more than 250 mapped landslides, ten were selected for detailed study that are supposed to the representative of the whole area. Detailed study showed that large and complex landslides are related to deep rock weathering followed by the intervention of geological structures as faults, joints, and fractures. Large landslides formed by gr...

  20. In search for coastal amplification of rock weathering in polar climates - pilot Schmidt hammer rock tests surveys from sheltered fjords of Svalbard and tsunami-affected coasts of Western Greenland.

    Science.gov (United States)

    Strzelecki, Matt

    2014-05-01

    Recent decade has seen the major advance in Arctic coastal geomorphology due to research progress along ice-rich permafrost coastlines of Siberia, Alaska and NW Canada. On the contrary little attention was paid to Arctic rocky coastlines and their response to the reduction of sea ice cover and increased number of storms reaching Arctic region. In this paper I present results from a pilot survey of rock resistance using Schmidt Hammer Rock Tests across rocky cliffs and shore platforms developed in: - sheltered bays of Billefjorden, Svalbard characterised by prolonged sea-ice conditions and very limited operation of wave and tidal action - Vaigat Strait and Isfjorden in W Greenland influenced by landslide-triggered tsunamis and waves induced by ice-berg roll events. The aim of a pilot study was to test the hypothesized coastal impact on the rate of rock weathering in polar climates. To do so I characterise the changes in the rock resistance on the following coastal landforms: - modern and uplifted wave-washed abrasion platforms- focusing on a relation between the degree of rock surface weathering and the distance from the shoreline as well as thickness of sediment cover on shore platform surface - modern and uplifted rocky cliffs - focusing on a relation between the degree of rock surface weathering and the distance from the shoreline as well as difference in height above the sea level and relation to rock lithology. The results present another line of argument supporting intensification of rock weathering processes in the Arctic coastal zone. This work is a contribution to the National Science Centre in Poland research project no. 2011/01/B/ST10/01553.

  1. Water-rock interaction during mineral carbonation and volcanic ash weathering

    OpenAIRE

    Helgi Arnar Alfreðsson 1984

    2015-01-01

    The reduction of atmospheric carbon dioxide (CO2) is considered one of the greatest challenges of this century. Carbon capture and storage (CCS) is one of the means proposed to lower the atmospheric CO2 content. The aim of the CarbFix project in Iceland was to design and test a CO2 re-injection system, in which CO2 from the Hellisheidi geothermal power plant was injected, fully dissolved in water, into basaltic rocks. In this way the carbon is mineralized upon basalt dissolution by the precip...

  2. 40Ar/39Ar dating of exceptional concentration of metals by weathering of Precambrian rocks at the Precambrian–Cambrian boundary

    DEFF Research Database (Denmark)

    Parnell, John; Mark, Darren F.; Frei, Robert

    2014-01-01

    The sub-Cambrian surface, including diverse metalliferous deposits, shows evidence of intense weathering of Precambrian rocks to form supergene-enriched ores and metalliferous placers, followed by widespread peneplanation. Much of the metal would have been flushed to the Cambrian ocean during pen...

  3. Spatial and temporal variation of uranium in a shallow weathered rock aquifer in southern India

    Indian Academy of Sciences (India)

    K Brindha; L Elango; R N Nair

    2011-10-01

    Uranium occurs naturally in groundwater and surface water. The objective of this study is to understand the causes for the occurrence of uranium and its spatio-temporal variation in groundwater in a part of Nalgonda district, Andhra Pradesh, south India. Uranium deposits occur in the southeastern part of this area. Groundwater samples were collected from 44 wells every two months from March 2008 to January 2009. The samples were analyzed for pH, ORP and uranium concentration. The uranium concentration in groundwater varies from 0.2 ppb to a maximum of 68 ppb with a mean of 18.5 ppb. About 21.6% of the samples were above the drinking water limit of 30 ppb set by USEPA. The uranium concentration varied with fluctuation in groundwater level, pH and ORP. Uranium concentration in groundwater changes depending on lithology, degree of weathering and rainfall recharge.

  4. Efficacy of nanolime in restoration procedures of salt weathered limestone rock

    Science.gov (United States)

    Ruffolo, Silvestro A.; La Russa, Mauro F.; Aloise, Piergiorgio; Belfiore, Cristina M.; Macchia, Andrea; Pezzino, Antonino; Crisci, Gino M.

    2014-03-01

    Salt crystallisation process is one of the most powerful weathering agents in stone materials, especially in the coastal areas, where sea-spray transports large amount of salts on the stone surface. The consolidation of such degraded stone material represents a critical issue in the field of restoration of cultural heritage. In this paper, the nanolime consolidation behaviour in limestone degraded by salt crystallization has been assessed. For this purpose, a stone material taken from a Sicilian historical quarry and widely used in the eastern Sicilian Baroque architecture has been artificially degraded by the salt crystallization test. Then degraded samples have been treated with NanoRestore®, a suspension of nanolime in isopropyl alcohol. To evaluate the consolidating effectiveness, the peeling test and point load test were performed. Moreover, mercury intrusion porosimetry has been executed to evaluate the variations induced by treatment, while colorimetric measurements have been aimed to assess aesthetical issues.

  5. Behavior of major and trace elements upon weathering of peridotites in New Caledonia : A possible site on ultramafic rocks for the Critical Zone Exploration Network (CZEN) ?

    Science.gov (United States)

    Juillot, Farid; Fandeur, D.; Fritsch, E.; Morin, G.; Ambrosi, J. P.; Olivi, L.; Cognigni, A.; Hazemann, J. L.; Proux, O.; Webb, S.; Brown, G. E., Jr.

    2010-05-01

    Ultramafic rocks cover about 1% of the continental surfaces and are related to ophiolitic bodies formed near convergent plate boundaries (Coleman, 1977). The most typical ultramafic rocks are dunite and harzburgite, which are composed of easily weatherable ferromagnesian mineral species (olivines and pyroxenes), but also of more resistant spinels (chromite and magnetite). Oceanic serpentinization of these ultramafic rocks usually lead to partial transformation of these initial mineral assemblages by forming hydrous layer silicates such as serpentine (lizardite, chrysotile and antigorite) talc, chlorite and actinolite (Malpas, 1992). It also lead to the formation of highly sheared textures, which favor meteoric weathering through preferential water flows. Compared to their crystalline rock counterpart that covers most of the continental surfaces, these ultramafic rocks mainly differ by their lower SiO2, Al2O3 and K2O contents (less than 50%, 10% and 1%, respectively) and, on the opposite, much higher MgO content (more than 18%). Moreover, they commonly have higher concentrations in FeO and other trace elements, such as Ni, Cr, Mn and Co. Weathering of these rocks is then at the origin of major geochemical anomalies on continental surfaces, especially when they occur in tropical and subtropical regions. Such conditions are encountered in New Caledonia where one third of the surface is covered with peridotites (mainly harzburgite with small amounts of dunite) obducted about 35 millions years ago during large tectonic events in the Southwest Pacific at the Late Eocene (Cluzel et al., 2001). Tropical weathering of these ultramafic rocks lead to the development of thick lateritic regoliths where almost all Mg and Si have been leached out and Fe, Mn, Ni, Cr and Co have been relatively concentrated. In these oxisols, Ni, Cr and Co can exhibit concentration up to several wt%, which make them good candidates for ore mining (New Caledonia is the third Ni producer in the world

  6. Experimental Acid Weathering of Fe-Bearing Mars Analog Minerals and Rocks: Implications for Aqueous Origin of Hematite-Bearing Sediments in Meridiani Planum, Mars

    Science.gov (United States)

    Golden, D. C.; Koster, A. M.; Ming, D. W.; Morris, R. V.; Mertzman, S. A.

    2011-01-01

    A working hypothesis for Meridiani evaporite formation involves the evaporation of fluids derived from acid weathering of Martian basalts and subsequent diagenesis [1, 2]. However, there are no reported experimental studies for the formation of jarosite and gray hematite (spherules), which are characteristic of Meridiani rocks from Mars analog precursor minerals. A terrestrial analog for hematite spherule formation from basaltic rocks under acidic hydrothermal conditions has been reported [3], and we have previously shown that the hematite spherules and jarosite can be synthetically produced in the laboratory using Fe3+ -bearing sulfate brines under hydrothermal conditions [4]. Here we expand and extend these studies by reacting Mars analog minerals with sulfuric acid to form Meridiani-like rock-mineral compositions. The objective of this study is to provide environmental constraints on past aqueous weathering of basaltic materials on Mars.

  7. Diavik Waste Rock Project: Evolution of Mineral Weathering, Element Release, and Acid Generation and Neutralization during a Five-Year Humidity Cell Experiment

    Directory of Open Access Journals (Sweden)

    Jeff B. Langman

    2014-04-01

    Full Text Available A five-year, humidity-cell experiment was used to study the weathering evolution of a low-sulfide, granitic waste rock at 5 and 22 °C. Only the rock with the highest sulfide content (0.16 wt % released sufficient acid to overcome a limited carbonate acid-neutralization capacity and produce a substantial decline in pH. Leached SO4 and Ca quickly increased then decreased during the first two years of weathering. Sulfide oxidation continued to release acid and SO4 after carbonate depletion, resulting in an increase in acid-soluble elements, including Cu and Zn. With the dissolution of Al-bearing minerals, the pH stabilized above 4, and sulfide oxidation continued to decline until the end of the experiment. The variation in activation energy of sulfide oxidation correlates with changes in sulfide availability, where the lowest activation energies occurred during the largest releases of SO4. A decrease in sulfide availability was attributed to consumption of sulfide and weathered rims on sulfide grains that reduced the oxidation rate. Varying element release rates due to changing carbonate and sulfide availability provide identifiable geochemical conditions that can be viewed as neutralization sequences and may be extrapolated to the field site for examining the evolution of mineral weathering of the waste rock.

  8. Determination of Granite Rock Massif Weathering and Cracking of Surface Layers in the Oldest Parts of Medieval Mine Depending on Used Mining Method

    Science.gov (United States)

    Lednická, Markéta; Kaláb, Zdeněk

    2016-06-01

    The paper presents the use of selected non-destructive testing methods for the purpose of specifying information on weathering and cracking of surface layers of granite rock massif in the medieval Jeroným Mine (the Czech Republic). This mine has been declared the National Heritage Site of the Czech Republic and its opening as a mining museum to the public is gradually prepared. Geological and geomechanical evaluation documents the possibility to find all kinds of weathering grades of rock massif in this mine. Two non-destructive methods have been tested, namely the measurement of ultrasonic pulse velocity and the measurement of Schmidt hammer rebound value. Field measurements were performed in two selected galleries to verify the application of such methods in specific conditions of underground spaces. Used mining method is one of the parameters later influencing cracking of rock massif. In selected galleries, two different mining methods were used which means that a part of a gallery profile was mined out by hand tools in the Middle Ages and another part of the profile was later mined out by blasting. Measurements in these galleries have enabled to analyse the influence of used mining methods on cracking of rock massif in the impaired zone, and, consequently, on ongoing weathering processes in those zones.

  9. Observation and research of weathered rock subgrade settlement%风化岩路基填料沉降观测试验研究

    Institute of Scientific and Technical Information of China (English)

    韩伟

    2011-01-01

    为了揭示风化岩填料路基的工程性质,结合室内击实实验与施工段现场沉降观测实验,深入分析了风化岩路基沉降随时间的变化规律,同时,对风化岩填料路基的边坡防护进行了概述.该研究成果可用于指导、评价山区高速公路风化岩路基填筑,这不仅是对保护环境、实施可持续发展战略的双重要求,而且具有较高的经济和社会效益.%In order to reveal the weathered rock subgrade engineering properties of packing, combining with the compaction test and construction of indoor experiment site settlement observation period, in-depth analysis of the rock embankment settlement may chang with time and the weathered rock fill embankment slope protection is also taken into consideration.Therefore this research results can be used to guide mountainous highway roadbed compactness of a weathered rock,which not only benefits environmental protection and sustainable development strategy, but also meats the dual requirement with high economic and social benefits.

  10. The effects of weathering on the strength and chemistry of Columbia River Basalts and their implications for Mars Exploration Rover Rock Abrasion Tool (RAT) results

    Science.gov (United States)

    Thomson, B. J.; Hurowitz, J. A.; Baker, L. L.; Bridges, N. T.; Lennon, A. M.; Paulsen, G.; Zacny, K.

    2014-08-01

    Basalt physical properties such as compressive strength and density are directly linked to their chemistry and constitution; as weathering progresses, basalts gradually become weaker and transition from intact rock to saprolite and ultimately, to soil. Here we quantify the degree of weathering experienced by the Adirondack-class basalts at the Mars Exploration Rover Spirit site by performing comparative analyses on the strength and chemistry of a series of progressively weathered Columbia River Basalt (CRB) from western Idaho and eastern Washington. CRB samples were subjected to compressive strength tests, Rock Abrasion Tool grinds, neutron activation analysis, and inductively coupled plasma optical emission spectroscopy. Analyses of terrestrial basalts indicate linked strength-chemical changes, as expected. Weathering sufficient to induce the loss of more than 50% of some cations (including >50% of MgO and MnO as well as ∼38% of Fe2O3 and 34% of CaO) was observed to weaken these samples by as much as 50% of their original strength. In comparison with the terrestrial samples, Adirondack-class basalts are most similar to the weakest basalt samples measured in terms of compressive strength, yet they do not exhibit a commensurate amount of chemical alteration. Since fluvial and lacustrine activity in Gusev crater appears to have been limited after the emplacement of flood basalt lavas, the observed weakness is likely attributable to thin-film weathering on exposed, displaced rocks in the Gusev plains (in addition to some likely shock effects). The results indicate that Adirondack-class basalts may possess a several mm-thick weak outer rind encasing an interior that is more pristine than otherwise indicated, and also suggest that long rock residence times may be the norm.

  11. Schmidt Hammer studies in the maritime Antarctic: Application to dating Holocene deglaciation and estimating the effects of macrolichens on rock weathering

    Science.gov (United States)

    Guglielmin, M.; Worland, M. R.; Convey, P.; Cannone, N.

    2012-06-01

    In order to contribute to the reconstruction of the deglaciation history of the Marguerite Bay area (~ 68°S, Maritime Antarctic) and to estimate the rock weathering rate in this Antarctic sector, 28 sites (7 on Rothera Point and 21 on Anchorage Island) were characterised using Schmidt Hammer values. The weathering effect of two of the most widespread species of macrolichens in this area (Usnea sphacelata and Umbilicaria decussata) was tested at 5 different sites on Rothera Point. Schmidt Hammer data, in conjunction with recent 14C age, suggest a deglaciation age for the Marguerite Bay area of around 12 ka, and an average uplift rate of 5.4 mm year- 1 on Anchorage Island for the period between 3.3 and 5.2 ka. The weathering rates are extremely slow (e.g. three times slower than reported in Norway). Our data confirm that lichens exert a strong impact on weathering, decreasing the Schmidt Hammer R-values on lichenised surfaces by a factor of 3-4 compared to bare rock surfaces. The effect of lichens on weathering is mainly due to edaphic conditions and the type of the lichen involved rather the period of exposure.

  12. Characterization and petrophysical properties of hydrothemally altered lacustrine volcanistic rock in Geyser Valley (Kamchatka) and its transformation by weathering

    Science.gov (United States)

    Gvozdeva, Irina; Zerkal, Oleg; Samarin, Evgeny

    2013-04-01

    Work is devoted to the study of volcano sedimentary hydrothermally altered rocks in Geyser Valley (Kamchatka peninsula, Russia). The Geyser Valley is one of the most unique nature objects in Russia. There are quite large geyser fields. The valley of the river is part of the Uson-Geysernaya depression, where hydrothermal activity is very high. Besides geysers here are hot springs, mud pots and fumarols. In the late Pleistocene (about 45-35 thousand years ago) the lake was located in the site of the modern valley of the Geysernaya river, where sediments accumulated intensively. Sedimentary material came from several sources in the form of pyroclastic flows, ash falls, was supplied by permanent and temporary water streams. The total deposit thickness reached several hundred meters. In the late Pleistocene there was breakthrough of reservoir and further conditions for the lacustrine deposits formation did not arose. Later the rocks were intensively processed by thermal water. In 2007 large landslide was formed in lower part of the Geysernaya River on their left slope. Deposits of Geysernaya (Q34grn) series and Pemsovaya (Q34pmz) series were involved in landslide displacement. The headscarp was formed up to 100 m and a length of 800 m, exposing the volcano-sedimentary section of hydrothermally altered rocks - a unique opportunity for sampling and subsequent laboratory study. Thickness of lake sediments is interbedding of coarse-grain, medium-grain, fine-grain tuffites predominantly acidic composition. The study of thin sections revealed that all samples are lithoclastic and vitroclastic hydrothermally altered tuffits. Currently, the primary minerals and volcanic glass is largely replaced by clay minerals of the smectite group. Pores and cracks are made zeolites (heulandite and clinoptilolite). All this points to the low-temperature (weathered to clayey state tuffites inherit structural and textural features of the primary species. The composition also varies: increased

  13. Laboratory investigation on streaming potential for sandy soil and weathered rock; Shitsunai jikken ni yoru sashitsu jiban oyobi fuka ganban no ryudo den`i no kento

    Energy Technology Data Exchange (ETDEWEB)

    Sato, H.; Shima, H. [OYO Corp., Tokyo (Japan)

    1996-10-01

    Laboratory experiment on sandy soil and weathered rock was conducted to clarify the generation mechanism of streaming potential due to underground fluid. Streaming potential is caused by underground fluid flow, namely by fluid flow in porous substances as electrokinetic phenomenon. In experiment, Inagi sand, Toyoura sand and strongly decomposed weathered granite were used. In Inagi and Toyoura sands, positive streaming potential was observed downstream in fluid flow. Streaming potential could be nearly determined as primary function of fluid velocity, and generated streaming potential increased with fluid resistivity. Streaming potential was higher in Inagi sand than Toyoura sand, probably depending on hydraulic radius, size of bleeding channel, and conductivity of sand surface. In weathered granite, negative streaming potential was measured. In the case of positive {zeta} potential, negative streaming potential is theoretically generated downstream in fluid flow. This experiment suggested possible generation of negative streaming potential in some kinds of ground. 2 refs., 6 figs., 1 tab.

  14. Permafrost and snow monitoring at Rothera Point (Adelaide Island, Maritime Antarctica): Implications for rock weathering in cryotic conditions

    Science.gov (United States)

    Guglielmin, Mauro; Worland, M. Roger; Baio, Fabio; Convey, Peter

    2014-11-01

    In February 2009 a new permafrost borehole was installed close to the British Antarctic Survey Station at Rothera Point, Adelaide Island (67.57195°S 68.12068°W). The borehole is situated at 31 m asl on a granodiorite knob with scattered lichen cover. The spatial variability of snow cover and of ground surface temperature (GST) is characterised through the monitoring of snow depth on 5 stakes positioned around the borehole and with thermistors placed at three different rock surfaces (A, B and C). The borehole temperature is measured by 18 thermistors placed at different depths between 0.3 and 30 m. Snow persistence is very variable both spatially and temporally with snow free days per year ranging from 13 and more than 300, and maximum snow depths varying between 0.03 and 1.42 m. This variability is the main cause of high variability in GST, that ranged between - 3.7 and - 1.5 °C. The net effect of the snow cover is a cooling of the surface. Mean annual GST, mean summer GST, and the degree days of thawing and the n-factor of thawing were always much lower at sensor A where snow persistence and depth were greater than in the other sensor locations. At sensor A the potential freeze-thaw events were negligible (0-3) and the thermal stress was at least 40% less than in the other sensor locations. The zero curtain effect at the rock surface occurred only at surface A, favouring chemical weathering over mechanical action. The active layer thickness (ALT) ranged between 0.76 and 1.40 m. ALT was directly proportional to the mean air temperature in summer, and inversely proportional to the maximum snow depth in autumn. ALT temporal variability was greater than reported at other sites at similar latitude in the Northern Hemisphere, or with the similar mean annual air temperature in Maritime Antarctica, because vegetation and a soil organic horizon are absent at the study site. Zero annual amplitude in temperature was observed at about 16 m depth, where the mean annual

  15. Temperature profiles from MBT casts from the CASTLE ROCK from Ocean Weather Station C (OWS-C) in the North Atlantic Ocean 01 July 1964 to 06 August 1964 (NODC Accession 6400054)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathythermograph data were collected from the CASTLE ROCK within a 1-mile radius of Ocean Weather Station C (5245N 0350W) and in transit. Data were collected by the...

  16. Oceanographic station data from bottle casts from the CASTLE ROCK from Ocean Weather Station C (OWS-C) in the North Atlantic Ocean 04 May 1970 to 11 May 1970 (NODC Accession 7000819)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Oceanographic station data were collected from the CASTLE ROCK within a 1-mile radius of Ocean Weather Station C (5245N 03530W) and in transit. Data were collected...

  17. Oceanographic station data from bottle casts from the CASTLE ROCK from Ocean Weather Station D (OWS-D) in the North Atlantic Ocean 04 March 1970 to 24 March 1970 (NODC Accession 7000759)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Oceanographic station data were collected from the CASTLE ROCK within a 1-mile radius of Ocean Weather Station D (4400N 04100W) and in transit. Data were collected...

  18. Oceanographic station data from bottle casts from the CASTLE ROCK from Ocean Weather Station E (OWS-E) in the North Atlantic Ocean 14 July 1968 to 08 August 1968 (NODC Accession 6800276)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Oceanographic station data were collected from the CASTLE ROCK within a 1-mile radius of Ocean Weather Station E (3500N 04800W) and in transit. Data were collected...

  19. Long-term, High Resolution Records of Rock Cracking, Weather and Climate from Mid-Latitude, Desert and Humid-Temperate Sites

    Science.gov (United States)

    Eppes, M. C.; Magi, B. I.

    2014-12-01

    The mechanical breakdown of rock by physical weathering represents a significant rate limiting step for erosion, sediment supply, chemical weathering, and atmospheric- and landscape- evolution across the globe. Yet, the primary drivers of physical weathering are poorly quantified. Recent work highlights the importance of solar-induced thermal stress as a key driver in physical weathering, particularly in mid-latitudes, but to date the role of climate in thermal stress cracking has not been extensively explored. Here we examine two long-term acoustic emission (AE) records of rock cracking in both a humid-temperate (North Carolina - 1 year of data ) and a semi-arid (New Mexico - 3 years of data) location. We use AE energy as a proxy for rock cracking. We compare on-site average ambient daily temperature for days in which cracking occurs to the average temperatures for those dates derived from climate records from the nearest weather stations. The range of temperatures for days on which cracking occurs is similar for both stations (-10 C to +30 C). The majority of cracking in both locations occurs on warm days (> 15 C). In the semi-arid climate, 73% of cracking occurs on hot days (> 20 C) while only 0.1% occurs on very cold days (-8 C to -3 C). In the humid-temperate climate, 21% of cracking occurs on hot days, while 17% occurs on cold days. When days during which cracking occurs are compared to climate averages, 81% (NC) and 51% (NM) of all cracking occurs on days with absolute temperature anomalies >1, regardless of the temperature. The proportion of cracking that occurs on anomalously hot or cold days rises to 92% and 77% when the data is normalized to account for uneven sampling of the days with extreme temperatures. We examine these results in the context of prior analyses of this dataset which indicates that the majority of cracking, even that occurring in freezing temperatures, is caused by thermal-stress processes. Here we attribute a majority of observed

  20. Stages of weathering mantle formation from carbonate rocks in the light of rare earth elements (REE) and Sr-Nd-Pb isotopes

    Science.gov (United States)

    Hissler, Christophe; Stille, Peter

    2015-04-01

    Weathering mantles are widespread and include lateritic, sandy and kaolinite-rich saprolites and residuals of partially dissolved rocks. These old regolith systems have a complex history of formation and may present a polycyclic evolution due to successive geological and pedogenetic processes that affected the profile. Until now, only few studies highlighted the unusual high content of associated trace elements in weathering mantles originating from carbonate rocks, which have been poorly studied, compared to those developing on magmatic bedrocks. For instance, these enrichments can be up to five times the content of the underlying carbonate rocks. However, these studies also showed that the carbonate bedrock content only partially explains the soil enrichment for all the considered major and trace elements. Up to now, neither soil, nor saprolite formation has to our knowledge been geochemically elucidated. Therefore, the aim of this study was to examine more closely the soil forming dynamics and the relationship of the chemical soil composition to potential sources. REE distribution patterns and Sr-Nd-Pb isotope ratios have been used because they are particularly well suited to identify trace element migration, to recognize origin and mixing processes and, in addition, to decipher possible anthropogenic and/or "natural" atmosphere-derived contributions to the soil. Moreover, leaching experiments have been applied to identify mobile phases in the soil system and to yield information on the stability of trace elements and especially on their behaviour in these Fe-enriched carbonate systems. All these geochemical informations indicate that the cambisol developing on such a typical weathering mantle ("terra fusca") has been formed through weathering of a condensed Bajocian limestone-marl facies. This facies shows compared to average world carbonates important trace element enrichments. Their trace element distribution patterns are similar to those of the soil

  1. Silica- and sulfate-bearing rock coatings in smelter areas: Products of chemical weathering and atmospheric pollution I. Formation and mineralogical composition

    Science.gov (United States)

    Mantha, Nathalie M.; Schindler, Michael; Murayama, Mitsuhiro; Hochella, Michael F.

    2012-05-01

    Black rock-coatings occur in proximity to smelters and roast yards of the Greater Sudbury area, Ontario, Canada and contain information about the past interactions between surface minerals, and gaseous and particulate atmospheric components, many of which were pollutants. Rock-coatings were collected from various locations within the Sudbury area and are characterized with scanning electron microscopy, transmission electron microscopy, X-ray diffraction, electron microprobe analysis, infrared spectroscopy and X-ray photoelectron spectroscopy. Acidic fumigations and rain, the result of vast quantities of SO2 released from smelting, increased the chemical weathering rate of exposed rocks in the Sudbury area. Non-stoichiometric dissolution of the silicate minerals under acidic conditions resulted in the accumulation of silicic acid and the subsequent formation of a silica-gel type coating. The silica gel transformed overtime into amorphous silica, opal (opal C and opal-CT) and cristobalite. Dissolution of the underlying rock and also of metal-bearing particles by sulfuric acid resulted in the in situ formation of metal-sulfate-rich layers on the interfaces between the atmosphere and the silica-rich coating (atmosphere-coating interface, ACI) and between the silica-rich coating and the underlying rock (rock-coating interface, RCI). These metal-sulfate-rich layers contain nanometer aggregates of Fe-Cu-sulfate-hydroxide, goldichite, mereiterite, guildite, butlerite and antlerite. The silica-rich matrix also contains a mix of detrital grains from adjacent rocks and soils (feldspar, quartz, hematite, chlorite, montmorillonite) and non-dissolved smelter-derived nano- to micro-size particulates (metal-silicates, metal-oxides, C-spheres). The apparent disequilibrium between the embedded particles and the Fe-Cu-sulfates suggests that trapped nanoparticles were encapsulated into pores which prevented their equilibration with acidic metal-sulfate-bearing fluids. An XPS depth

  2. Geochemistry of Late Triassic pelitic rocks in the NE part of Songpan-Ganzi Basin, western China: Implications for source weathering, provenance and tectonic setting

    Directory of Open Access Journals (Sweden)

    Yan Tang

    2012-09-01

    Full Text Available Major, trace and rare earth element (REE concentrations of Late Triassic sediments (fine-grained sandstones and mudstones from Hongcan Well 1 in the NE part of the Songpan-Ganzi Basin, western China, are used to reveal weathering, provenance and tectonic setting of inferred source areas. The Chemical Index of Alteration (CIA reflects a low to moderate degree of chemical weathering in a cool and somewhat dry climate, and an A-CN-K plot suggests an older upper continental crust provenance dominated by felsic to intermediate igneous rocks of average tonalite composition. Based on the various geochemical tectonic setting discrimination diagrams, the Late Triassic sediments are inferred to have been deposited in a back-arc basin situated between an active continental margin (the Kunlun-Qinling Fold Belt and a continental island arc (the Yidun Island Arc. The Triassic sediments in the study area underwent a rapid erosion and burial in a proximal slope-basin environment by the petrographic data, while the published flow directions of Triassic turbidites in the Aba-Zoige region was not supported Yidun volcanic arc source. Therefore, we suggest that the Kunlun-Qinling terrane is most likely to have supplied source materials to the northeast part of the Songpan-Ganzi Basin during the Late Triassic.

  3. Geotechnical Descriptions of Rock and Rock Masses.

    Science.gov (United States)

    1985-04-01

    weathering is presented by Dornbusch (1982). 39. Mechanical, or physical, weathering of rock occurs primarily by (a) freeze expansion (or frost wedging...34Engineering Classifica- tion of In-Situ Rock," Technical Report No. AFWL-TR-67-144, Air Force Weapons Laboratory, Kirtland Air Force Base, N. Mex. Dornbusch , W

  4. PETROCHEMISTRY AND MINERALOGY EVIDENCES FOR THE WEATHERING PROCESS OF THE WEATHERING PITS ON ROCK SURFACES OF MOUNTAIN LAOSHAN,CHINA%崂山山顶风化坑化学风化过程的岩石化学与矿物学证据

    Institute of Scientific and Technical Information of China (English)

    王为; 周尚哲; 李炳元; 林志海; 刘志鹏; 黄日辉; 赖宜讯; 陈科景

    2012-01-01

    After the first field trip in July of 2010,the authors made a second field trip in May of 2011 to investigate the weathering pits on the top of Mountain Laoshan, which is composed of Mesozoic granite with its highest peak 1132. 7meters above sea level and located on the shore of the Yellow Sea, China. The conclusion of the first investigation is that the so-called glacial potholes in Mountain Laoshan are nothing but weathering pits as are generally found in the other granite areas around the world and then the pits on the rock surface of Mountain Laoshan are not originated from glaciers. In this paper, the evidence collected in this field investigation for the weathering origin of the pits is discussed.The detritus in the weathering pits and the surface rock outside the pits were taken from 7 weathering pits ,4 of which at Laoding,the top of the mountain about l000m's high, and 3 in Hualou area, northwest of Laoding with elevations of 280 ~340m. X-Ray fluorescence(XRF) and X-ray diffraction ( XRD ) methods are used to measure the type and the amount of minerals and chemical elements of the rock samples. Based on the result of XDF and XDR, the samples' chemical index CIA, weathering ratios and element transformation ratio were calculated. The weathering process of the pits was analyzed and discussed in the following aspects: 1) The relation of the chemical weathering to the mineral weathering of the pit detritus; 2)Chemical element transferring between the pit detritus and the surface rock; 3)The different weathering intensity of the pits and the surface rock of Mountain Laoshan and its cause. The result of the study shows that: l)The ratio between quartz and feldspar of the detritus is higher than those of the surface rock, indicating the feldspar being degenerated by weathering while the quartz remaining the same in the pits; 2)The weathered feldspars in the pit are mainly perthite and potassium feldspars owing to a lack of plagioclase in their original rocks; 3

  5. Testing the limits of micro-scale analyses of Si stable isotopes by femtosecond laser ablation multicollector inductively coupled plasma mass spectrometry with application to rock weathering

    Energy Technology Data Exchange (ETDEWEB)

    Schuessler, Jan A., E-mail: jan.schuessler@gfz-potsdam.de; Blanckenburg, Friedhelm von

    2014-08-01

    signature of rock weathering at the micro-scale in a corestone sampled from a highly weathered roadcut profile in the tropical Highlands of Sri Lanka. The results show that secondary weathering products accumulated in cracks and grain boundaries are isotopically lighter than their unweathered plagioclase host, consistent with isotopically heavy dissolved Si found in rivers. - Highlights: • A second-generation custom-built UV-femtosecond laser ablation system is presented. • UV-fsLA-MC-ICP-MS for micrometer-scale stable isotope analyses of metals/metalloids. • Analytical conditions for precise Si stable isotope measurements were optimised. • Non-matrix-matched calibration was validated for analysis of geological materials. • Highly variable Si isotope ratios were found on the micro-scale in weathered rock.

  6. Linking Weathering, Rock Moisture Dynamics, Geochemistry, Runoff, Vegetation and Atmospheric Processes through the Critical Zone: Graduate Student led Research at the Eel River Critical Zone Observatory

    Science.gov (United States)

    Dietrich, W. E.

    2014-12-01

    In the Eel River Critical Zone Observatory lies Rivendell, a heavily-instrumented steep forested hillslope underlain by nearly vertically dipping argillite interbedded with sandstone. Under this convex hillslope lies "Zb", the transition to fresh bedrock, which varies from less than 6 m below the surface near the channel to 20 m at the divide. Rempe and Dietrich (2014, PNAS) show that the Zb profile can be predicted from the assumption that weathering occurs when drainage is induced in the uplifting fresh bedrock under hillslopes by lateral head gradients driven by channel incision at the hillslope boundary. Infiltrating winter precipitation is impeded at the lower conductivity boundary at Zb, generating perched groundwater that dynamically pulses water laterally to the channel, controlling stream runoff. Below the soil and above the water table lies an unsaturated zone through which all recharge to the perched groundwater (and thus all runoff to channels) occurs. It is this zone and the waters in them that profoundly affect critical zone processes. In our seasonally dry environment, the first rains penetrate past the soil and moisten the underlying weathered bedrock (Salve et al., 2012, WRR). It takes about 200 to 400 mm of cumulative rain, however, before the underlying groundwater rises significantly. Oshun et al (in review) show that by this cumulative rainfall the average of the wide-ranging isotopic signature of rain reaches a nearly constant average annual value. Consequently, the recharging perched groundwater shows only minor temporal isotopic variation. Kim et al, (2014, GCA) find that the winter high-flow groundwater chemistry is controlled by relatively fast-reacting cation exchange processes, likely occurring in transit in the unsaturated zone. Oshun also demonstrates that the Douglas fir rely on this rock moisture as a water source, while the broadleaf trees (oaks and madrone) use mostly soil moisture. Link et al (2014 WRR) show that Doug fir declines

  7. Impact of weathering on the geomechanical properties of rocks along thermal metamorphic contact belts and morpho-evolutionary processes: The deep-seated gravitational slope deformations of Mt. Granieri Salincriti (Calabria Italy)

    Science.gov (United States)

    Pellegrino, A.; Prestininzi, A.

    2007-06-01

    Numerous Deep-Seated Gravitational Slope Deformations (DSGSDs) occur throughout Italy, that originate from particular tectono-stratigraphic settings, relief, seismicity, deglaciation, as well as from intense and deep processes of chemico-physical weathering of crystalline-metamorphic rocks. These DSGSDs are particularly widespread in the Calabrian mountains. This study is focused on the Mt. Granieri-Salincriti slope, on the Ionian side of the Serre Massif, where granites and granodiorites (Stilo Unit, Palaeozoic) are in contact with metamorphites through a thermal-metamorphic aureole. This setting generates deep geochemical processes, inducing intense chemical weathering. These processes are mainly due to the interaction between groundwater and the sulphides that are contained in the local pegmatitic-hydrothermal intrusions, especially along the thermal-metamorphic contact belt. The Mt. Granieri-Salincriti slope has an important DSGSD, which is associated with many active and/or quiescent landslides. Among these landslides, the Salincriti rock avalanche-debris flow (about 2 M m 3) represents the paroxysmal and terminal stage of the deep creep deformations of Mt. Granieri, typifying a geological setting that is common in the Calabrian Arc. This multi-disciplinary study assessed the weathering susceptibility of the local crystalline-metamorphic rocks, especially those lying along thermal-metamorphic contact belts, by characterising the weathering horizons and the spatial distribution of weathering in the rock mass. The study was also aimed at identifying the relations between weathering, above all deep geochemical processes, effects on rocks and slope morphodynamics. The methodology was based on detailed geological data, geological-engineering surveys, geomorphology and surface hydrogeology analyses, as well as physico-mechanical laboratory tests. These investigations, supported by a monitoring program, led to the development of an engineering-geological model of the

  8. Detrital mode and whole-rock geochemistry of the fluvial succession, Pishin Belt, Pakistan: Implications on provenance and source area weathering in periferal foreland basins

    DEFF Research Database (Denmark)

    Kasi, Aimal Khan; Kassi, Akhtar Muhammad; Friis, Henrik;

    2016-01-01

    derived from Muslim Bagh-Zhob Ophiolite. Malthanai Formation has higher CIA and CIW values (68.96 and 77.53) than Dasht Murgha Group (63.87 & 70.93); however, they both indicate low to moderate weathering intensities. Dasht Murgha group and Malthanai Formation have higher weathering of the source area...

  9. Experimental Study on Dynamic Elasticity Modulus and Damping Ratio of Highly Weathered Rock which Covered by Loess%黄土层下覆强风化岩动弹性模量和阻尼比试验研究

    Institute of Scientific and Technical Information of China (English)

    王平; 王杰民; 刘红玫; 王谦

    2011-01-01

    A series of studies on dynamic elasticity modulus and damping ratio of highly weathered rock which covered by loess are conducted with small strain ed, using triaxial shear equipment and their dynamics properties are analyzed. The results show that the dynamic stress and strain relation of highly weathered rock is nonlinear elastic relations, and fit the model of hyperbolic type with small strain ed. Within the same strain range, the mudstone's damping ratio is greater than the red sandstone's. In the same consolidation condition, the initial elastic modulus of red sandstone is greater than the one of mudstone. The research provides experimental technology and dynamic property parameters to dynamic response analysis and seismic deformation mechanism study for highly weathered rock which covered by thick layer of loess.%运用扭剪仪对小应变εd时黄土层下覆强风化岩的动模量和阻尼比进行了系列研究,分析了其动力学特性.结果表明,在小应变情况下风化岩体的动应力与动应变关系为非线性弹性关系,基本符合双曲线型模型;在相同应变范围内,泥岩阻尼比大于红砂岩的阻尼比;在相同固结条件下,红砂岩的初始动弹模大于泥岩初始动弹模.研究为厚覆盖层黄土场地及其下覆强风化岩层、隧道、高边坡动力反应分析和地震后土体变形机理研究提供了必要试验技术和参数.

  10. Petrography and whole-rock geochemistry of Oligocene-Miocene Khojak Formation Khojak-Pishin Belt, Pakistan: Implications on provenance and source-area weathering

    DEFF Research Database (Denmark)

    Kakar, Din Muhammad; Kasi, Aimal K.; Kassi, Aktar Muhammad

    2016-01-01

    . The higher SiO2/Al2O3 ratios (4.0) show moderately mature nature of the sandstone. The weathering indices such as Chemical Index of Alteration (CIA; 76.69), Chemical Index of Weathering (CIW; 86.79), Chemical Proxy of Alteration (CPA; 92.33) and Index of Chemical Variability (ICV; 16.83) suggest moderate...... to intense weathering of the source terrain. The high Th/U values (5.25) as compared to Upper Continental Crust (UCC; 3.82) also support the enhanced weathering of the source area. Trace elements such as Zr, Nb, Y, Th and U are slightly enriched compared to UCC suggest the dominantly felsic sources...... by distant Kohistan Island Arc and en-route Waziristan, Zhob and Muslim Bagh Ophiolite and associated Mélages. The sediment dispersal towards south-southwest was controlled by Chaman-Nushki transform fault system....

  11. Feições intempéricas em rochas alcalinas félsicas de Nova Iguaçu, RJ Weathering fabrics in felsic alkaline rocks of Nova Iguaçu, State of Rio de Janeiro, Brazil

    Directory of Open Access Journals (Sweden)

    Akihisa Motoki

    2007-09-01

    Full Text Available Esse artigo apresenta descrições de campo e considerações genéticas de feições intempéricas observadas em rochas alcalinas félsicas de Nova Iguaçu, RJ, com atenção especial aos clastos traquíticos de brecha vulcânica. Observam-se dois tipos de feições notáveis: "case hardening", o endurecimento da superfície da rocha por cimentação dos minerais intempéricos com o auxílio de hidróxidos dissolvidos na água superficial percolante; "dissociação mineral", o intemperismo seletivo de minerais e a conseqüente formação de cavidades na superfície da rocha. Nos afloramentos intemperizados das brechas, o case hardening forma saliência centimétrica dos clastos traquíticos sobre a superfície da matriz. Os clastos maiores do que 30 cm mostram a feição de saliência e reentrância na borda, que é originada do contraste entre a superfície endurecida e a subsuperfície não endurecida. Esses clastos têm suave saliência central cuja subsuperfície é composta do núcleo sem alteração. A lixiviação dos fenocristais de feldspato alcalino forma numerosas cavidades na superfície intemperizada de clastos de traquito porfirítico, gerando uma estrutura pseudovesicular, porém, na subsuperfície, a rocha menos alterada com textura maciça está presente. Esse fato demonstra que essas não são bombas, spatter ou escória. Essas observações são desfavoráveis à hipótese do Vulcão de Nova Iguaçu, que adota uma origem extrusiva dos clastos como um argumento fundamental.This paper presents the field description and genetic consideration of weathering fabrics observed in the Nova Iguaçu felsic alkaline rocks, State of Rio de Janeiro, Brazil, with special attention to trachytic clasts of volcanic breccia. Two types of notable fabrics are observed: "case hardening", the rock surface induration by cementation of weathered minerals with the help of the hydroxides dissolved in the surface water; and "mineral dissociation", the

  12. 岩石冻融风化作用积累泥石流物源试验研究%The Study on Debris Flows Material Source Accumulation by Rock Freezing and Thawing Weathering Test

    Institute of Scientific and Technical Information of China (English)

    成玉祥; 段玉贵; 李格烨; 张骏; 王霞

    2015-01-01

    Weathering leads to broken of surface rocks, and is one of the main sources of the solid material of debris flow.The research on rocks weathering has important theoretical significance to the study on the solid materi-al cumulative effects and the formation mechanism of debris flow.In cold areas, rocks weather mainly in physical style because of the changes in temperature and moisture.Argillaceous sandstone in Yushu in Qinghai Province is selected and divided into of six different water contents for freeze-thaw test.The freeze-thaw cycle time is designed to be 10 times, 20 times, 40 times, 60 times and 80 times.Longitudinal wave velocity measurement, CT scans and tensile strength measurements are then done on all freezing and thawing rock samples to compare the degree of weathering of rocks in different test condition.It is found that rock samples longitudinal wave velocity, CT number and tensile strength are decreasing with the increasing of freeze-thaw cycle times.Comprehensive analysis results show that the temperature difference and ice split effect are the main geological actions in the alpine region.Under dry conditions, temperature effects become more pronounced.Under aqueous conditions, temperature difference and ice split weathering effects exist and mutually reinforcing.%风化作用导致地表岩石的破碎,是泥石流固体物质的主要来源之一。研究岩石风化作用对于研究高原泥石流物源的积累效应和泥石流的形成机理具有重要意义。在高寒地区,地表岩石以物理风化为主。温度和水分的变化是物理风化作用的主要原因。该文选择青海省玉树州泥质砂岩,分6级不同含水率,分别开展了循环10次、20次、40次、60次、80次冻融试验,并对冻融岩样进行纵波波速测量、 CT扫描和抗拉强度测量,横向比较岩石的风化程度。通过试验得出不同含水率条件下,随着冻融循环次数的增加,岩样的纵波波速、 CT数

  13. Groundwater flow dynamics of weathered hard-rock aquifers under climate-change conditions: an illustrative example of numerical modeling through the equivalent porous media approach in the north-western Pyrenees (France)

    Science.gov (United States)

    Jaunat, J.; Dupuy, A.; Huneau, F.; Celle-Jeanton, H.; Le Coustumer, P.

    2016-09-01

    A numerical groundwater model of the weathered crystalline aquifer of Ursuya (a major water source for the north-western Pyrenees region, south-western France) has been computed based on monitoring of hydrological, hydrodynamic and meteorological parameters over 3 years. The equivalent porous media model was used to simulate groundwater flow in the different layers of the weathered profile: from surface to depth, the weathered layer (5 · 10-8 ≤ K ≤ 5 · 10-7 m s-1), the transition layer (7 · 10-8 ≤ K ≤ 1 · 10-5 m s-1, the highest values being along major discontinuities), two fissured layers (3.5 · 10-8 ≤ K ≤ 5 · 10-4 m s-1, depending on weathering profile conditions and on the existence of active fractures), and the hard-rock basement simulated with a negligible hydraulic conductivity ( K = 1 10 -9 ). Hydrodynamic properties of these five calculation layers demonstrate both the impact of the weathering degree and of the discontinuities on the groundwater flow. The great agreement between simulated and observed hydraulic conditions allowed for validation of the methodology and its proposed use for application on analogous aquifers. With the aim of long-term management of this strategic aquifer, the model was then used to evaluate the impact of climate change on the groundwater resource. The simulations performed according to the most pessimistic climatic scenario until 2050 show a low sensitivity of the aquifer. The decreasing trend of the natural discharge is estimated at about -360 m3 y-1 for recharge decreasing at about -5.6 mm y-1 (0.8 % of annual recharge).

  14. 岩石风化碳汇研究的最新进展和展望%New progress and prospects in the study of rock-weathering-related carbon sinks

    Institute of Scientific and Technical Information of China (English)

    刘再华

    2012-01-01

    , the contribution of silicate weathering to the atmospheric CO2 sink may be only 6%, while the other 94% is accounted for by carbonate weathering. On the other hand, owing to the aquatic photosynthetic uptake of the weathering-related DIC and burial of some of the resulting (autochthonous) organic C, the atmospheric CO2 sink relating tocarbonate weathering might be important in controlling both short-term and long-term climate change. Another new finding is that rock-weathering-related carbon sinks have increased with global warming and land-use change, acting as a negative mechanism for global warming. Future investigation should focus on the in-depth study of rock weathering processes and mechanisms in carbon capture and storage, so as to reveal the regulating potential of the carbon sink according to the climate and land use, which will serve countries in their decision making with respect to climate change. Important study topics include (1) rock weathering processes and controlling mechanisms of climate and land use in carbon sinks, (2) the importance of small amounts of carbonate minerals in controlling the DIC and carbon sink of silicate watersheds, (3) the ratio of autochthonous carbon in total organic carbon, and (4) the regulating potential of rock-weathering-related carbon sinks according to climate and land use.

  15. Oceanographic station data from bottle casts from the CASTLE ROCK and MELLON from Ocean Weather Station D (OWS-D) and V (OWS-V) in the North Atlantic Ocean and North Pacific Ocean 04 May 1969 to 27 May 1969 (NODC Accession 6900726)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Oceanographic station data were collected from the CASTLE ROCK and MELLON within a 1-mile radius of Ocean Weather Station D (4400N 04100W), V (3400N 16400E), and in...

  16. 龙门石窟碳酸盐岩体文物风化作用模拟试验研究%Simulation experiment for weathering of culture relic on carbonate rock palisades in Longmen grottoes

    Institute of Scientific and Technical Information of China (English)

    张傲; 方云; 徐敏; 陈建平; 范子龙

    2012-01-01

    为了研究凝结水对龙门石窟碳酸盐岩表面的风化作用机理,在现场进行凝结水观测、CO2浓度监测的基础上,利用自行研制、能模拟现场温湿度环境、能提供CO2外部来源,并能对反应过程进行监控的室内模拟试验装置系统对石窟碳酸盐岩风化作用进行模拟实验.实验结果表明,凝结水会造成碳酸盐岩表面的溶解,在CO2加入的条件下风化效果加剧,岩石的质量损失和孔隙率同时增大.经过78次的模拟试验后,灰岩岩样质量损失率为0.077%~0.088%,孔隙率由实验前的0.39 %~0.40%增长到0.71%~0.74%;白云岩岩样的质量损失率为0.032%~0.038%,孔隙率由实验前的0.61%~0.68%增长为0.77%~0.85 %;灰岩和白云岩的平均溶蚀深度分别为89.475 μm和36.865 μm,溶蚀速度分别为0.0956 μm/h和0.0575μm/h,风化溶蚀作用对龙门石窟文物的影响破坏较大.%In order to research the weathering mechanism on the surface of carbonate rock by condensation water in Longmen grottoes, in light of monitoring for condensation water and CO2 concentration on the spot, the weathering process is stimulated with a self-made indoor experimental tester that enabling stimulating temperature and humidity conditions, providing external source of CO2, and monitoring the reaction process. It shows that condensation water can dissolve the surface of carbonate rock, and that the mass loss and porosity of the rocks will increase when CO2 is added. Based on 78 tests, it proves that the mass loss of limestone sample is 0. 077 %~0. 088 % and the porosity increased from 0. 39 %~0. 40 % to 0. 71 %~0. 74 %; mass loss of dolomite sample is 0. 032 %~0. 038 % and the porosity increased from 0. 61 %~0. 68 % to 0. 77 %~0. 85 %; the average corrosion depth and velocity of limestone is 89. 475 μm and 0. 0956 μm/h, those of dolomite is 36. 865 μm and 0. 0575 μm/h. It is concluded that the corrosive weathering is of great

  17. Relationship Between Minerals and Mineral Nutrients of Soil Weathering from Different Rocks in Guizhou Province%贵州不同岩石背景土壤矿物与矿质养分的关系

    Institute of Scientific and Technical Information of China (English)

    任明强; 于晓红

    2012-01-01

    The mineral nutrients of two different soils developed from different soil parent materials were determined to scientifically guide crop cultivation in different soils in Guizhou. The results showed that the soil developed from clastic rocks with higher feldspar and mica content in soil powder minerals and high chlorite content and lower kaolmite content in soil clay mineral, a lower weathering degree and relative abundant soil nutrients had strong sustained release capacity of mineral nutrient. However, the soil developed from carbonatite rocks with lower feldspar and mica content in soil powder minerals and lower chlorite content and higher kaolinite content in soil clay mineral, a higher weathering degree and relative poor nutrients had poor sustained release capacity of mineral nutrient.%为了更好地了解优质农作物生长与不同岩石背景土壤养分的关系,科学指导农业种植,叶两种不同岩石背景土壤中矿物与土壤主要矿质养分的关系进行研究.结果表明:碎屑岩背景区土壤粉粒矿物中长石、云母含量较碳酸盐岩背景区土壤中的高,土壤粘粒矿物中绿泥石含量较碳酸盐岩背景区土壤中的高,高岭石含量较低,土壤风化程度较低,持续释放矿质养分的能力较强,土壤养分相对充裕;而碳酸盐岩背景区土壤粉粒矿物中长石、云母含量较碎屑岩背景区土壤中的低.土壤粘粒矿物中绿泥石含量较碎屑岩背景区土壤中的低,高岭石含量较高,土壤风化程度较高.持续释放矿质养分的能力弱,土壤养分相对缺乏.

  18. Wacky Weather

    Science.gov (United States)

    Sabarre, Amy; Gulino, Jacqueline

    2013-01-01

    What do a leaf blower, water hose, fan, and ice cubes have in common? Ask the students who participated in an integrative science, technology, engineering, and mathematics (I-STEM) education unit, "Wacky Weather," and they will tell say "fun and severe weather"--words one might not have expected! The purpose of the unit…

  19. Wacky Weather

    Science.gov (United States)

    Sabarre, Amy; Gulino, Jacqueline

    2013-01-01

    What do a leaf blower, water hose, fan, and ice cubes have in common? Ask the students who participated in an integrative science, technology, engineering, and mathematics (I-STEM) education unit, "Wacky Weather," and they will tell say "fun and severe weather"--words one might not have expected! The purpose of the unit…

  20. Rock-degrading endophytic bacteria in cacti

    Science.gov (United States)

    M. Esther Puente; Ching Y. Li; Yoav Bashan

    2009-01-01

    A plant-bacterium association of the cardon cactus (Pachycereus pringlei) and endophytic bacteria promotes establishment of seedlings and growth on igneous rocks without soil. These bacteria weather several rock types and minerals, unbind significant amounts of useful minerals for plants from the rocks, fix in vitro N2. produce...

  1. Mirador - Weather

    Data.gov (United States)

    National Aeronautics and Space Administration — Earth Science data access made simple. Our weather system includes the dynamics of the atmosphere and its interaction with the oceans and land. The improvement of...

  2. Soft rocks in Argentina

    Institute of Scientific and Technical Information of China (English)

    Giambastiani; Mauricio

    2014-01-01

    Soft rocks are a still fairly unexplored chapter in rock mechanics. Within this category are the clastic sedimentary rocks and pyroclastic volcanic rocks, of low to moderate lithification (consolidation, cemen-tation, new formed minerals), chemical sedimentary rocks and metamorphic rocks formed by minerals with Mohs hardness less than 3.5, such as limestone, gypsum, halite, sylvite, between the first and phyllites, graphitic schist, chloritic shale, talc, etc., among the latter. They also include any type of rock that suffered alteration processes (hydrothermal or weathering). In Argentina the study of low-strength rocks has not received much attention despite having extensive outcrops in the Andes and great impact in the design criteria. Correlation between geomechanical properties (UCS, deformability) to physical index (porosity, density, etc.) has shown promising results to be better studied. There are many studies and engineering projects in Argentina in soft rock geological environments, some cited in the text (Chihuído dam, N. Kirchner dam, J. Cepernic Dam, etc.) and others such as International Tunnel in the Province of Mendoza (Corredor Bioceánico), which will require the valuable contribution from rock mechanics. The lack of consistency between some of the physical and mechanical parameters explored from studies in the country may be due to an insufficient amount of information and/or non-standardization of criteria for testing materials. It is understood that more and better academic and professional efforts in improv-ing techniques will result in benefits to the better understanding of the geomechanics of weak rocks.

  3. Collecting Rocks

    Institute of Scientific and Technical Information of China (English)

    孙铮

    2007-01-01

    My hobby is collecting rocks.It is very special,isn’t it?I began to collect rocks about four years ago.I usually go hiking in the mountains,or near the river to look for rocks.When I find a rock,I pick it up and clean it with the brush and water.Then I put it into my bag.Most of the rocks I have collected are quartzite~*.They are really

  4. The chemical, mechanical, and hydrological evolution of weathering granitoid

    Science.gov (United States)

    Goodfellow, Bradley W.; Hilley, George E.; Webb, Samuel M.; Sklar, Leonard S.; Moon, Seulgi; Olson, Christopher A.

    2016-08-01

    Surprisingly few studies connect the chemical, mechanical, and hydrological evolution of rock as it weathers to saprolite and soil. We assess this coevolution in granodiorite from Monterey Peninsula, California, by measuring changes in bulk chemistry, mineralogy, volumetric strain, the oxidation state of Fe in biotite crystals, tensile strength, abrasion rate, connected porosity, and hydraulic conductivity in samples covering a range of weathering grades. We identify the oxidative dissolution of biotite as the key chemical reaction because of the volumetric expansion that accompanies formation of altered biotite and precipitation of ferrihydrite. We show how the associated accumulation of elastic strain produces an energy density that is sufficient to support rock fracturing over length scales equivalent to constituent crystals. The resulting intragranular and intergranular cracking profoundly reduces tensile strength and increases the abrasion rate, connected porosity, and hydraulic conductivity of the rock matrix. These changes increase the rate of plagioclase weathering, and ultimately the rock disintegrates into grus and clay. Major changes in rock properties can occur with only minor element leaching, and the threshold behavior of weathering that arises from the coevolution of chemical, hydrological, and mechanical properties may be difficult to capture using simplified weathering models that fail to incorporate these properties. Our results, which combine the mechanical and hydrological evolution of weathering rock with more common measurements of chemical changes, should help to more accurately model the effects of, and mechanical and hydrological feedbacks upon, chemical weathering of rock.

  5. Stormy Weather

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Inspired by the deep abyss of the unknown; a constant source for investigation and discovery, heating and destruction, all simultaneously. Beneath the deep darkness, millions of species vibrantly thrive in another universe wholly untouched by human hands, though affected by their choices. The weathered pieces and people associated with seaside villages, the deep wrinkles that tell a story of one's life and experiences like

  6. 煤系古风化岩相似材料配比研究%LABORATORY STUDY ON PROPORTION OF SIMILAR MATERIAL FOR SIMULATING ANCIENT WEATHERED ROCK IN COAL STRATA

    Institute of Scientific and Technical Information of China (English)

    丁卿峰; 岳艳艳; 李文平; 白汉营

    2015-01-01

    the critical content of cement and aggregate.The variable ranges of compressive strength and elastic modulus are 0 ~17.5MPa and 0.3 ~2.02GPa,respectively.The weathered rock can be simulated well using similar material in this range.

  7. Rock Stars

    Institute of Scientific and Technical Information of China (English)

    张国平

    2000-01-01

    Around the world young people are spending unbelievable sums of money to listen to rock music. Forbes Magazine reports that at least fifty rock stars have incomes between two million and six million dollars per year.

  8. KREEP Rocks

    Institute of Scientific and Technical Information of China (English)

    邹永廖; 徐琳; 欧阳自远

    2004-01-01

    KREEP rocks with high contents of K, REE and P were first recognized in Apollo-12 samples, and it was confirmed later that there were KREEP rock fragments in all of the Apollo samples, particularly in Apollo-12 and-14 samples. The KREEP rocks distributed on the lunar surface are the very important objects of study on the evolution of the moon, as well as to evaluate the utilization prospect of REE in KREEP rocks. Based on previous studies and lunar exploration data, the authors analyzed the chemical and mineral characteristics of KREEP rocks, the abundance of Th on the lunar surface materials, the correlation between Th and REE of KREEP rocks in abundance, studied the distribution regions of KREEP rocks on the lunar surface, and further evaluated the utilization prospect of REE in KREEP rocks.

  9. Rock Art

    Science.gov (United States)

    Henn, Cynthia A.

    2004-01-01

    There are many interpretations for the symbols that are seen in rock art, but no decoding key has ever been discovered. This article describes one classroom's experiences with a lesson on rock art--making their rock art and developing their own personal symbols. This lesson allowed for creativity, while giving an opportunity for integration…

  10. Rock Art

    Science.gov (United States)

    Henn, Cynthia A.

    2004-01-01

    There are many interpretations for the symbols that are seen in rock art, but no decoding key has ever been discovered. This article describes one classroom's experiences with a lesson on rock art--making their rock art and developing their own personal symbols. This lesson allowed for creativity, while giving an opportunity for integration…

  11. Rock Finding

    Science.gov (United States)

    Rommel-Esham, Katie; Constable, Susan D.

    2006-01-01

    In this article, the authors discuss a literature-based activity that helps students discover the importance of making detailed observations. In an inspiring children's classic book, "Everybody Needs a Rock" by Byrd Baylor (1974), the author invites readers to go "rock finding," laying out 10 rules for finding a "perfect" rock. In this way, the…

  12. Resources of Kaolinite Rocks in China Coal Measures

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The proved reserve of kaolinite rocks in China coal measures is about 1. 673 billion tons. The types of kaolinite rocks contain tonstein, flintclay and soft kaolin. Their origin modes include alteration of volcanic ash, terrigenous clay deposit and weathering of coal and adjacent rocks. The organic matter and organic acid play an important role in the formation of kaolinite rocks of coal measures. The difference in properties between kaolinite rock and traditional kaolin requires different processing technologies.

  13. 'Escher' Rock

    Science.gov (United States)

    2004-01-01

    [figure removed for brevity, see original site] Chemical Changes in 'Endurance' Rocks [figure removed for brevity, see original site] Figure 1 This false-color image taken by NASA's Mars Exploration Rover Opportunity shows a rock dubbed 'Escher' on the southwestern slopes of 'Endurance Crater.' Scientists believe the rock's fractures, which divide the surface into polygons, may have been formed by one of several processes. They may have been caused by the impact that created Endurance Crater, or they might have arisen when water leftover from the rock's formation dried up. A third possibility is that much later, after the rock was formed, and after the crater was created, the rock became wet once again, then dried up and developed cracks. Opportunity has spent the last 14 sols investigating Escher, specifically the target dubbed 'Kirchner,' and other similar rocks with its scientific instruments. This image was taken on sol 208 (Aug. 24, 2004) by the rover's panoramic camera, using the 750-, 530- and 430-nanometer filters. The graph above shows that rocks located deeper into 'Endurance Crater' are chemically altered to a greater degree than rocks located higher up. This chemical alteration is believed to result from exposure to water. Specifically, the graph compares ratios of chemicals between the deep rock dubbed 'Escher,' and the more shallow rock called 'Virginia,' before (red and blue lines) and after (green line) the Mars Exploration Rover Opportunity drilled into the rocks. As the red and blue lines indicate, Escher's levels of chlorine relative to Virginia's went up, and sulfur down, before the rover dug a hole into the rocks. This implies that the surface of Escher has been chemically altered to a greater extent than the surface of Virginia. Scientists are still investigating the role water played in influencing this trend. These data were taken by the rover's alpha particle X-ray spectrometer.

  14. 'Escher' Rock

    Science.gov (United States)

    2004-01-01

    [figure removed for brevity, see original site] Chemical Changes in 'Endurance' Rocks [figure removed for brevity, see original site] Figure 1 This false-color image taken by NASA's Mars Exploration Rover Opportunity shows a rock dubbed 'Escher' on the southwestern slopes of 'Endurance Crater.' Scientists believe the rock's fractures, which divide the surface into polygons, may have been formed by one of several processes. They may have been caused by the impact that created Endurance Crater, or they might have arisen when water leftover from the rock's formation dried up. A third possibility is that much later, after the rock was formed, and after the crater was created, the rock became wet once again, then dried up and developed cracks. Opportunity has spent the last 14 sols investigating Escher, specifically the target dubbed 'Kirchner,' and other similar rocks with its scientific instruments. This image was taken on sol 208 (Aug. 24, 2004) by the rover's panoramic camera, using the 750-, 530- and 430-nanometer filters. The graph above shows that rocks located deeper into 'Endurance Crater' are chemically altered to a greater degree than rocks located higher up. This chemical alteration is believed to result from exposure to water. Specifically, the graph compares ratios of chemicals between the deep rock dubbed 'Escher,' and the more shallow rock called 'Virginia,' before (red and blue lines) and after (green line) the Mars Exploration Rover Opportunity drilled into the rocks. As the red and blue lines indicate, Escher's levels of chlorine relative to Virginia's went up, and sulfur down, before the rover dug a hole into the rocks. This implies that the surface of Escher has been chemically altered to a greater extent than the surface of Virginia. Scientists are still investigating the role water played in influencing this trend. These data were taken by the rover's alpha particle X-ray spectrometer.

  15. Enhanced weathering strategies for stabilizing climate and averting ocean acidification

    OpenAIRE

    Taylor, Lyla L.; Quirk, Joe; Thorley, Rachel M S; Kharecha, Pushker A.; Hansen, James; Ridgwell, Andy; Lomas, Mark R.; Banwart, Steve A.; Beerling, David J.

    2016-01-01

    Chemical breakdown of rocks, weathering, is an important but very slow part of the carbon cycle that ultimately leads to CO2 being locked up in carbonates on the ocean floor. Artificial acceleration of this carbon sink via distribution of pulverized silicate rocks across terrestrial landscapes may help offset anthropogenic CO2 emissions. We show that idealized enhanced weathering scenarios over less than a third of tropical land could cause significant drawdown of atmospheric CO2 and ameliora...

  16. 'Earhart' Rock

    Science.gov (United States)

    2004-01-01

    This false-color image taken by NASA's Mars Exploration Rover Opportunity shows a rock informally named 'Earhart' on the lower slopes of 'Endurance Crater.' The rock was named after the pilot Amelia Earhart. Like 'Escher' and other rocks dotting the bottom of Endurance, scientists believe fractures in Earhart could have been formed by one of several processes. They may have been caused by the impact that created Endurance Crater, or they might have arisen when water leftover from the rock's formation dried up. A third possibility is that much later, after the rock was formed, and after the crater was created, the rock became wet once again, then dried up and developed cracks. Rover team members do not have plans to investigate Earhart in detail because it is located across potentially hazardous sandy terrain. This image was taken on sol 219 (Sept. 4) by the rover's panoramic camera, using its 750-, 530- and 430-nanometer filters.

  17. Rock Art

    OpenAIRE

    Huyge, Dirk

    2009-01-01

    Rock art, basically being non-utilitarian, non-textual anthropic markings on natural rock surfaces, was an extremely widespread graphical practice in ancient Egypt. While the apogee of the tradition was definitely the Predynastic Period (mainly fourth millennium BCE), examples date from the late Palaeolithic (c. 15,000 BCE) until the Islamic era. Geographically speaking, “Egyptian” rock art is known from many hundreds of sites along the margins of the Upper Egyptian and Nubian Nile Valley and...

  18. Rock blocks

    OpenAIRE

    Turner, W.

    2007-01-01

    Consider representation theory associated to symmetric groups, or to Hecke algebras in type A, or to q-Schur algebras, or to finite general linear groups in non-describing characteristic. Rock blocks are certain combinatorially defined blocks appearing in such a representation theory, first observed by R. Rouquier. Rock blocks are much more symmetric than general blocks, and every block is derived equivalent to a Rock block. Motivated by a theorem of J. Chuang and R. Kessar in the case of sym...

  19. Monthly Weather Review

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Supplements to the Monthly Weather Review publication. The Weather Bureau published the Monthly weather review Supplement irregularly from 1914 to 1949. The...

  20. Weather Prediction Models

    Science.gov (United States)

    Bacmeister, Julio T.

    Awareness of weather and concern about weather in the proximate future certainly must have accompanied the emergence of human self-consciousness. Although weather is a basic idea in human existence, it is difficult to define precisely.

  1. Weathering and vegetation effects in early stages of soil formation

    Science.gov (United States)

    Jonathan D. Phillips; Alice V. Turkington; Daniel A. Marion

    2008-01-01

    Bedrock surfaces in the Ouachita Mountains, Arkansas, exposed by spillway construction and which had not previously been subjected to surface weathering environments, developed 15?20 cm thick soil covers in less than three decades. All open bedrock joints showed evidence of weathering and biological activity. Rock surfaces and fragments also showed evidence of...

  2. Evolution of Oxidative Continental Weathering

    Science.gov (United States)

    Konhauser, Kurt; Lalonde, Stefan

    2014-05-01

    The Great Oxidation Event (GOE) is currently viewed as a protracted process during which atmospheric oxygen levels increased above 10-5 times the present atmospheric level. This value is based on the loss of sulphur isotope mass independent fractionation (S-MIF) from the rock record, beginning at 2.45 Ga and disappearing by 2.32 Ga. However, a number of recent papers have pushed back the timing for oxidative continental weathering, and by extension, the onset of atmospheric oxygenation several hundreds of million years earlier despite the presence of S-MIF (e.g., Crowe et al., 2013). This apparent discrepancy can, in part, be resolved by the suggestion that recycling of older sedimentary sulphur bearing S-MIF might have led to this signal's persistence in the rock record for some time after atmospheric oxygenation (Reinhard et al., 2013). Here we suggest another possibility, that the earliest oxidative weathering reactions occurred in environments at profound redox disequilibrium with the atmosphere, such as biological soil crusts, riverbed and estuarine sediments, and lacustrine microbial mats. We calculate that the rate of O2 production via oxygenic photosynthesis in these terrestrial microbial ecosystems provides largely sufficient oxidizing potential to mobilise sulphate and a number of redox-sensitive trace metals from land to the oceans while the atmosphere itself remained anoxic with its attendant S-MIF signature. These findings reconcile geochemical signatures in the rock record for the earliest oxidative continental weathering with the history of atmospheric sulphur chemistry, and demonstrate the plausible antiquity of a terrestrial biosphere populated by cyanobacteria. Crowe, S.A., Dossing, L.N., Beukes, N.J., Bau, M., Kruger, S.J., Frei, R. & Canfield, D.E. Atmospheric oxygenation three billion years ago. Nature 501, 535-539 (2013). Reinhard, C.T., Planavsky, N.J. & Lyons, T.W. Long-term sedimentary recycling of rare sulphur isotope anomalies. Nature 497

  3. Art Rocks with Rock Art!

    Science.gov (United States)

    Bickett, Marianne

    2011-01-01

    This article discusses rock art which was the very first "art." Rock art, such as the images created on the stone surfaces of the caves of Lascaux and Altimira, is the true origin of the canvas, paintbrush, and painting media. For there, within caverns deep in the earth, the first artists mixed animal fat, urine, and saliva with powdered minerals…

  4. Art Rocks with Rock Art!

    Science.gov (United States)

    Bickett, Marianne

    2011-01-01

    This article discusses rock art which was the very first "art." Rock art, such as the images created on the stone surfaces of the caves of Lascaux and Altimira, is the true origin of the canvas, paintbrush, and painting media. For there, within caverns deep in the earth, the first artists mixed animal fat, urine, and saliva with powdered minerals…

  5. Weather in Your Life.

    Science.gov (United States)

    Kannegieter, Sandy; Wirkler, Linda

    Facts and activities related to weather and meteorology are presented in this unit. Separate sections cover the following topics: (1) the water cycle; (2) clouds; (3) the Beaufort Scale for rating the speed and force of wind; (4) the barometer; (5) weather prediction; (6) fall weather in Iowa (sleet, frost, and fog); (7) winter weather in Iowa…

  6. ROCK ON

    National Research Council Canada - National Science Library

    Thomas Grose

    2014-01-01

    ..., however, was music - especially the high-pitched sounds of pop and rock, which boosted energy output by up to 40 percent. By contrast, classical music's lower pitches barely raised effectiveness. O...

  7. Subarctic physicochemical weathering of serpentinized peridotite

    Science.gov (United States)

    Ulven, O. I.; Beinlich, A.; Hövelmann, J.; Austrheim, H.; Jamtveit, B.

    2017-06-01

    Frost weathering is effective in arctic and subarctic climate zones where chemical reactions are limited by the reduced availability of liquid water and the prevailing low temperature. However, small scale mineral dissolution reactions are nevertheless important for the generation of porosity by allowing infiltration of surface water with subsequent fracturing due to growth of ice and carbonate minerals. Here we combine textural and mineralogical observations in natural samples of partly serpentinized ultramafic rocks with a discrete element model describing the fracture mechanics of a solid when subject to pressure from the growth of ice and carbonate minerals in surface-near fractures. The mechanical model is coupled with a reaction-diffusion model that describes an initial stage of brucite dissolution as observed during weathering of serpentinized harzburgites and dunites from the Feragen Ultramafic Body (FUB), SE-Norway. Olivine and serpentine are effectively inert at relevant conditions and time scales, whereas brucite dissolution produces well-defined cm to dm thick weathering rinds with elevated porosity that allows influx of water. Brucite dissolution also increases the water saturation state with respect to hydrous Mg carbonate minerals, which are commonly found as infill in fractures in the fresh rock. This suggests that fracture propagation is at least partly driven by carbonate precipitation. Dissolution of secondary carbonate minerals during favorable climatic conditions provides open space available for ice crystallization that drives fracturing during winter. Our model reproduces the observed cm-scale meandering fractures that propagate into the fresh part of the rock, as well as dm-scale fractures that initiate the breakup of larger domains. Rock disintegration increases the reactive surface area and hence the rate of chemical weathering, enhances transport of dissolved and particulate matter in the weathering fluid, and facilitates CO2 uptake by

  8. Topographic imprint on chemical weathering in deeply weathered soil-mantled landscapes (southern Brazil)

    Science.gov (United States)

    Vanacker, Veerle; Schoonejans, Jerome; Ameijeiras-Marino, Yolanda; Opfergelt, Sophie; Minella, Jean

    2017-04-01

    The regolith mantle is defined as the thin layer of unconsolidated material overlaying bedrock that contributes to shape the Earth's surface. The development of the regolith mantle in a landscape is the result of in-situ weathering, atmospheric input and downhill transport of weathering products. Bedrock weathering - the physical and chemical transformations of rock to soil - contributes to the vertical development of the regolith layer through downward propagation of the weathering front. Lateral transport of soil particles, aggregates and solutes by diffusive and concentrated particle and solute fluxes result in lateral redistribution of weathering products over the hillslope. In this study, we aim to expand the empirical basis on long-term soil evolution at the landscape scale through a detailed study of soil weathering in subtropical soils. Spatial variability in chemical mass fluxes and weathering intensity were studied along two toposequences with similar climate, lithology and vegetation but different slope morphology. This allowed us to isolate the topographic imprint on chemical weathering and soil development. The toposequences have convexo-concave slope morphology, and eight regolith profiles were analysed involving the flat upslope, steep midslope and flat toeslope part. Our data show a clear topographic imprint on soil development. Along hillslope, the chemical weathering intensity of the regolith profiles increases with distance from the crest. In contrast to the upslope positions, the soils in the basal concavities develop on in-situ and transported regolith. While the chemical weathering extent on the slope convexities (the upslope profiles) is similar for the steep and gentle toposequence, there is a clear difference in the rate of increase of the chemical weathering extent with distance from the crest. The increase of chemical weathering extent along hillslope is highest for the steep toposequence, suggesting that topography enhances soil particle

  9. Narrative report: Target Rock National Wildlife Refuge: January - December, 1970

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Target Rock NWR outlines Refuge accomplishments during the 1970 calendar year. The report begins by summarizing the weather...

  10. On nutrients and trace metals: Effects from Enhanced Weathering

    Science.gov (United States)

    Amann, T.; Hartmann, J.

    2015-12-01

    The application of rock flour on suitable land ("Enhanced Weathering") is one proposed strategy to reduce the increase of atmospheric CO2 concentrations. At the same time it is an old and established method to add fertiliser and influence soil properties. Investigations of this method focused on the impact on the carbonate system, as well as on engineering aspects of a large-scale application, but potential side effects were never discussed quantitatively. We analysed about 120,000 geochemically characterised volcanic rock samples from the literature. Applying basic statistics, theoretical release rates of nutrients and potential contaminants by Enhanced Weathering were evaluated for typical rock types. Applied rock material can contain significant amounts of essential or beneficial nutrients (potassium, phosphorus, micronutrients). Their release can partly cover the demand of major crops like wheat, rice or corn, thereby increasing crop yield on degraded soils. However, the concentrations of considered elements are variable within a specific rock type, depending on the geological setting. High heavy metal concentrations are found in (ultra-) basic rocks, the class with the highest CO2 drawdown potential. More acidic rocks contain less or no critical amounts, but sequester less CO2. Findings show that the rock selection determines the capability to supply significant amounts of nutrients, which could partly substitute industrial mineral fertiliser usage. At the same time, the release of harmful trace element has to be considered. Through careful selection of regionally available rocks, benefits could be maximised and drawbacks reduced. The deployment of Enhanced Weathering to sequester CO2 and to ameliorate soils necessitates an ecosystem management, considering the release and fate of weathered elements in plants, soils and water. Cropland with degraded soils would benefit while having a net negative CO2 effect, while other carbon dioxide removal strategies, like

  11. Migration and enrichment of trace elements of Lower Palaeozoic carbonate rock strata in Beijing

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Analyses of trace elements of the Lower Palaeozoic carbonate rock strata in Beijing show that the contents of As, Hg, F increase from primary carbonate rocks to weathered carbonate rocks and from primary carbonate rocks to the soil coexisting with carbonate rocks, but the distribution regularity of S is not obvious. In the whole weathered stages, the sorption of As is mainly affected by Fe2O3. In soil Fe2O3 is also the main affecting factor of Hg enrichment. The main existing forms of Hg in primary carbonate rocks should simply be physical adsorption, coprecipitation and false isomorphous form between surface of carbonate rock and Hg. In soil the enrichment of F has little relationship with sul-fides and Fe2O3. In primary carbonate rocks, F is mainly absorbed by sulfides and clay minerals, etc. Weathered samples have closer genetic relationships with primary carbonate rocks. This also implies that weathered carbonate rocks have the close existing forms to that of primary carbonate rocks. In primary carbonate rocks FeS2 and FeS are the main forms of S, and sulfides have fixation effect on some heavy metals, whereas in weathered carbonate rocks and soil the fixation effect is weakened.

  12. 'Wopmay' Rock

    Science.gov (United States)

    2004-01-01

    This approximate true-color image taken by NASA's Mars Exploration Rover Opportunity shows an unusual, lumpy rock informally named 'Wopmay' on the lower slopes of 'Endurance Crater.' The rock was named after the Canadian bush pilot Wilfrid Reid 'Wop' May. Like 'Escher' and other rocks dotting the bottom of Endurance, scientists believe the lumps in Wopmay may be related to cracking and alteration processes, possibly caused by exposure to water. The area between intersecting sets of cracks eroded in a way that created the lumpy appearance. Rover team members plan to drive Opportunity over to Wopmay for a closer look in coming sols. This image was taken by the rover's panoramic camera on sol 248 (Oct. 4, 2004), using its 750-, 530- and 480-nanometer filters.

  13. Sr isotope evolution during chemical weathering of granites -- impact of relative weathering rates of minerals

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The Sr isotopic systematics in the weathering profiles of biotite granite and granite porphyry in southern Jiangxi Province were investigated. The results showed that during the chemical weathering of granites, remarked fractionation occurred between Rb and Sr. During the early stages of chemical weathering of granites, the released Sr/Si and Sr/Ca ratios are larger than those of the parent rocks, and the leaching rate of Sr is higher than those of Si, Ca, K, Rb, etc. Dynamic variations in relative weathering rates of the main Sr-contributing minerals led to fluctuation with time in 87Sr/86Sr ratios of inherent and released Sr in the weathering crust of granite. Successive weathering of biotite, plagioclase and K-feldspar made 87Sr/86Sr ratios in the weathering residues show such a fluctuation trend as to decrease first, increase, and then decrease again till they maintain stable. This work further indicates that when Sr isotopes are used to trace biogeochemical processes on both the catchment and global scales, one must seriously take account of the prefer-ential release of Sr from dissolving solid phase and the fluctuation of 87Sr/86Sr ratios caused by the variations of relative weathering rates of Sr-contributing minerals.

  14. Source rock

    OpenAIRE

    Abubakr F. Makky; Mohamed I. El Sayed; Ahmed S. Abu El-Ata; Ibrahim M. Abd El-Gaied; Mohamed I. Abdel-Fattah; Zakaria M. Abd-Allah

    2014-01-01

    West Beni Suef Concession is located at the western part of Beni Suef Basin which is a relatively under-explored basin and lies about 150 km south of Cairo. The major goal of this study is to evaluate the source rock by using different techniques as Rock-Eval pyrolysis, Vitrinite reflectance (%Ro), and well log data of some Cretaceous sequences including Abu Roash (E, F and G members), Kharita and Betty formations. The BasinMod 1D program is used in this study to construct the burial history ...

  15. Land Surface Weather Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — METAR is the international standard code format for hourly surface weather observations. The acronym roughly translates from French as Aviation Routine Weather...

  16. Project Weather and Water.

    Science.gov (United States)

    Hansen, Pal J. Kirkeby

    2000-01-01

    Introduces Project Weather and Water with the goal of developing and testing ideas of how to implement weather topics and water physics in an integrated way. Discusses teacher preparation, implementation, and evaluation of this project. (ASK)

  17. Pilot Weather Reports

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Aviation weather reports relayed from pilots to FAA air traffic controllers or National Weather Service personnel. Elements include sky cover, turbulence, wind...

  18. Natural Weathering Exposure Station

    Data.gov (United States)

    Federal Laboratory Consortium — The Corps of Engineers' Treat Island Natural Weathering Exposure Station is a long-term natural weathering facility used to study concrete durability. Located on the...

  19. Surface Weather Observations Hourly

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard hourly observations taken at Weather Bureau/National Weather Service offices and airports throughout the United States. Hourly observations began during the...

  20. Surface Weather Observing Manuals

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Manuals and instructions for taking weather observations. Includes the annual Weather Bureau 'Instructions for Preparing Meteorological Forms...' and early airways...

  1. Daily Weather Records

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These daily weather records were compiled from a subset of stations in the Global Historical Climatological Network (GHCN)-Daily dataset. A weather record is...

  2. Winter Weather Emergencies

    Science.gov (United States)

    Severe winter weather can lead to health and safety challenges. You may have to cope with Cold related health problems, including ... there are no guarantees of safety during winter weather emergencies, you can take actions to protect yourself. ...

  3. National Convective Weather Diagnostic

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current convective hazards identified by the National Convective Weather Detection algorithm. The National Convective Weather Diagnostic (NCWD) is an automatically...

  4. Internet Weather Source

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Weather Service (NWS) National Telecommunications Gateway provides weather, hydrologic, and climate forecasts and warnings for the United States, its...

  5. Weather Radar Stations

    Data.gov (United States)

    Department of Homeland Security — These data represent Next-Generation Radar (NEXRAD) and Terminal Doppler Weather Radar (TDWR) weather radar stations within the US. The NEXRAD radar stations are...

  6. The power of weather

    OpenAIRE

    Christian Huurman; Francesco Ravazzolo; Chen Zhou

    2010-01-01

    This paper examines the predictive power of weather for electricity prices in day ahead markets in real time. We find that next-day weather forecasts improve the forecast accuracy of Scandinavian day-ahead electricity prices substantially in terms of point forecasts, suggesting that weather forecasts can price the weather premium. This improvement strengthens the confidence in the forecasting model, which results in high center-mass predictive densities. In density forecast, such a predictive...

  7. Questa Baseline and Pre-mining Ground-Water Quality Investigation, 7. A Pictorial Record of Chemical Weathering, Erosional Processes, and Potential Debris-flow Hazards in Scar Areas Developed on Hydrothermally Altered Rocks

    Science.gov (United States)

    Plumlee, Geoffrey S.; Ludington, Steve; Vincent, Kirk R.; Verplanck, Philip L.; Caine, Jonathan S.; Livo, K. Eric

    2009-01-01

    Erosional scar areas developed along the lower Red River basin, New Mexico, reveal a complex natural history of mineralizing processes, rapid chemical weathering, and intense physical erosion during periodic outbursts of destructive, storm-induced runoff events. The scar areas are prominent erosional features with craggy headwalls and steep, denuded slopes. The largest scar areas, including, from east to west, Hottentot Creek, Straight Creek, Hansen Creek, Lower Hansen Creek, Sulfur Gulch, and Goat Hill Gulch, head along high east-west trending ridges that form the northern and southern boundaries of the lower Red River basin. Smaller, topographically lower scar areas are developed on ridge noses in the inner Red River valley. Several of the natural scar areas have been modified substantially as a result of large-scale open-pit and underground mining at the Questa Mine; for example, much of the Sulfur Gulch scar was removed by open pit mining, and several scars are now partially or completely covered by mine waste dumps.

  8. Weather Fundamentals: Meteorology. [Videotape].

    Science.gov (United States)

    1998

    The videos in this educational series, for grades 4-7, help students understand the science behind weather phenomena through dramatic live-action footage, vivid animated graphics, detailed weather maps, and hands-on experiments. This episode (23 minutes) looks at how meteorologists gather and interpret current weather data collected from sources…

  9. Cold-Weather Sports

    Science.gov (United States)

    ... Surgery? A Week of Healthy Breakfasts Shyness Cold-Weather Sports KidsHealth > For Teens > Cold-Weather Sports A A A What's in this article? ... Equipment Ahh, winter! Shorter days. Frigid temperatures. Foul weather. What better time to be outdoors? Winter sports ...

  10. Convective Weather Avoidance with Uncertain Weather Forecasts

    Science.gov (United States)

    Karahan, Sinan; Windhorst, Robert D.

    2009-01-01

    Convective weather events have a disruptive impact on air traffic both in terminal area and in en-route airspaces. In order to make sure that the national air transportation system is safe and efficient, it is essential to respond to convective weather events effectively. Traffic flow control initiatives in response to convective weather include ground delay, airborne delay, miles-in-trail restrictions as well as tactical and strategic rerouting. The rerouting initiatives can potentially increase traffic density and complexity in regions neighboring the convective weather activity. There is a need to perform rerouting in an intelligent and efficient way such that the disruptive effects of rerouting are minimized. An important area of research is to study the interaction of in-flight rerouting with traffic congestion or complexity and developing methods that quantitatively measure this interaction. Furthermore, it is necessary to find rerouting solutions that account for uncertainties in weather forecasts. These are important steps toward managing complexity during rerouting operations, and the paper is motivated by these research questions. An automated system is developed for rerouting air traffic in order to avoid convective weather regions during the 20- minute - 2-hour time horizon. Such a system is envisioned to work in concert with separation assurance (0 - 20-minute time horizon), and longer term air traffic management (2-hours and beyond) to provide a more comprehensive solution to complexity and safety management. In this study, weather is dynamic and uncertain; it is represented as regions of airspace that pilots are likely to avoid. Algorithms are implemented in an air traffic simulation environment to support the research study. The algorithms used are deterministic but periodically revise reroutes to account for weather forecast updates. In contrast to previous studies, in this study convective weather is represented as regions of airspace that pilots

  11. Weather Conditions, Weather Information and Car Crashes

    Directory of Open Access Journals (Sweden)

    Adriaan Perrels

    2015-11-01

    Full Text Available Road traffic safety is the result of a complex interaction of factors, and causes behind road vehicle crashes require different measures to reduce their impacts. This study assesses how strongly the variation in daily winter crash rates associates with weather conditions in Finland. This is done by illustrating trends and spatiotemporal variation in the crash rates, by showing how a GIS application can evidence the association between temporary rises in regional crash rates and the occurrence of bad weather, and with a regression model on crash rate sensitivity to adverse weather conditions. The analysis indicates that a base rate of crashes depending on non-weather factors exists, and some combinations of extreme weather conditions are able to substantially push up crash rates on days with bad weather. Some spatial causation factors, such as variation of geophysical characteristics causing systematic differences in the distributions of weather variables, exist. Yet, even in winter, non-spatial factors are normally more significant. GIS data can support optimal deployment of rescue services and enhance in-depth quantitative analysis by helping to identify the most appropriate spatial and temporal resolutions. However, the supportive role of GIS should not be inferred as existence of highly significant spatial causation.

  12. Rock Paintings.

    Science.gov (United States)

    Jones, Julienne Edwards

    1998-01-01

    Discusses the integration of art and academics in a fifth-grade instructional unit on Native American culture. Describes how students studied Native American pictographs, designed their own pictographs, made their own tools, and created rock paintings of their pictographs using these tools. Provides a list of references on Native American…

  13. Ayers Rock

    Institute of Scientific and Technical Information of China (English)

    王慧茹

    2002-01-01

    Ayers Rock is right in the centre of Australia.It's nearly two thousand kilometres______Sydney.So we flew most of the way.h was rather cloudy______But after we left the mountains behind us, there was hardly a cloud in thesky.

  14. Intellektuaalne rock

    Index Scriptorium Estoniae

    2007-01-01

    Briti laulja-helilooja ja näitleja Toyah Willcox ning Bill Rieflin ansamblist R.E.M. ja Pat Mastelotto King Krimsonist esinevad koos ansamblitega The Humans ja Tuner 25. okt. Tallinnas Rock Cafés ja 27. okt Tartu Jaani kirikus

  15. Intellektuaalne rock

    Index Scriptorium Estoniae

    2007-01-01

    Briti laulja-helilooja ja näitleja Toyah Willcox ning Bill Rieflin ansamblist R.E.M. ja Pat Mastelotto King Krimsonist esinevad koos ansamblitega The Humans ja Tuner 25. okt. Tallinnas Rock Cafés ja 27. okt Tartu Jaani kirikus

  16. Comparative study of static and dynamic parameters of rock for the Xishan Rock Cliff Statue

    Institute of Scientific and Technical Information of China (English)

    Jin JIANG; Jin-zhong SUN

    2011-01-01

    Ultrasonic wave testing was applied to investigate the quality and weathering status of rock specimens obtained in two borings situated in the Xishan Buddha rock slope in Taiyuan,China.This paper pays special attention to the distribution of bulk density,dynamic parameters and static parameters of rock specimens as well as the relationship between static and dynamic parameters.The results illustrate that the distribution of both parameters is identical along the depth of two drilled holes in the rock slope.When the hole depth increases,the density of rock mass,saturated compression strength and static elastic modulus,dynamic elastic modulus and wave velocity also show increase tendency.The weathering degree in the rock mass ranging from the surface of cliffto the depth of 2.5 m is the highest while the rock mass is unsalted and more rigid when the depth is larger than 3.0 m.The relationship between dynamic elastic modulus,sonic wave velocity and horizontal depth indicates that dynamic elastic modulus is more sensitive than sonic wave velocity.Conversely,by comparing quantity relationship between static elastic modulus and sonic wave velocity,it is found that the composition of rock has a great influence on the relationship between static and dynamic parameters,that is,inequality of rock composition will lead to dispersion and abnormality of the distribution of static and dynamic parameters.

  17. Mass wasting process at the surface of the Sangun metamorphic rocks in Kaminishigawa area, Asahi-machi, Okayama Prefecture.

    OpenAIRE

    新宮原, 秀和; 平山, 恭之; 津島, 淳; 於保, 幸正

    1999-01-01

    The relation among microstructures, weathering and mass wasting of the Sangun metamorphic rocks in the Kaminishigawa area, Asahi-machi, Okayama Prefecture, was studied. Three stages of penetrative planar structures are recognized; S1 schistosity, S2 crenulation cleavage and S3 crenulation cleavage. The S2 cleavage is the most commonly observed structure. The deree of weathering is divided into two classes on the base of appearance; slightly weathered and highly weathered rock. The three types...

  18. A visual analytical approach to rock art panel condition assessment

    Science.gov (United States)

    Vogt, Brandon J.

    Rock art is a term for pecked, scratched, or painted symbols found on rock surfaces, most typically joint faces called rock art panels. Because rock art exists on rock at the atmosphere interface, it is highly susceptible to the destructive processes of weathering. Thus, rock weathering scientists, including those that study both natural and cultural surfaces, play a key role towards understanding rock art longevity. The mapping of weathering forms on rock art panels serves as a basis from which to assess overall panel instability. This work examines fissures, case hardened surfaces, crumbly disintegration, and lichen. Knowledge of instability, as measured through these and other weathering forms, provides integral information to land managers and archaeological conservators required to prioritize panels for remedial action. The work is divided into five chapters, three of which are going to be submitted as a peer-reviewed journal manuscript. The second chapter, written as a manuscript for International Newsletter on Rock Art, describes a specific set of criteria that lead to the development of a mapping tool for weathering forms, called 'mapping weathering forms in three dimensions' (MapWeF). The third chapter, written as a manuscript for Remote Sensing of Environment, presents the methodology used to develop MapWeF. The chapter incorporates terrestrial laser scanning, a geographic information system (GIS), geovisualization, image analysis, and exploratory spatial data analysis (ESDA) to identify, map, and quantify weathering features known to cause instability on rock art panels. The methodology implemented in the third chapter satisfies the criteria described in Chapter Two. In the fourth chapter, prepared as a manuscript for Geomorphology, MapWeF is applied to a site management case study, focusing on a region---southeastern Colorado---with notoriously weak and endangered sandstone rock art panels. The final conclusions chapter describes contributions of the

  19. Direct quantification of long-term rock nitrogen inputs to temperate forest ecosystems.

    Science.gov (United States)

    Morford, Scott L; Houlton, Benjamin Z; Dahlgren, Randy A

    2016-01-01

    Sedimentary and metasedimentary rocks contain large reservoirs of fixed nitrogen (N), but questions remain over the importance of rock N weathering inputs in terrestrial ecosystems. Here we provide direct evidence for rock N weathering (i.e., loss of N from rock) in three temperate forest sites residing on a N-rich parent material (820-1050 mg N kg(-1); mica schist) in the Klamath Mountains (northern California and southern Oregon), USA. Our method combines a mass balance model of element addition/ depletion with a procedure for quantifying fixed N in rock minerals, enabling quantification of rock N inputs to bioavailable reservoirs in soil and regolith. Across all sites, -37% to 48% of the initial bedrock N content has undergone long-term weathering in the soil. Combined with regional denudation estimates (sum of physical + chemical erosion), these weathering fractions translate to 1.6-10.7 kg x ha(-1) x yr(-1) of rock N input to these forest ecosystems. These N input fluxes are substantial in light of estimates for atmospheric sources in these sites (4.5-7.0 kg x ha(-1) x yr(-1)). In addition, N depletion from rock minerals was greater than sodium, suggesting active biologically mediated weathering of growth-limiting nutrients compared to nonessential elements. These results point to regional tectonics, biologically mediated weathering effects, and rock N chemistry in shaping the magnitude of rock N inputs to the forest ecosystems examined.

  20. Weatherization and Intergovernmental Program - Weatherization Assistance Program

    Energy Technology Data Exchange (ETDEWEB)

    None

    2010-06-01

    The U.S. Department of Energy’s (DOE) Weatherization Assistance Program reduces energy costs for low-income households by increasing the energy efficiency of their homes, while ensuring their health and safety.

  1. Artificial weathering of granite

    Directory of Open Access Journals (Sweden)

    Silva Hermo, B.

    2008-06-01

    Full Text Available This article summarizes a series of artificial weathering tests run on granite designed to: simulate the action of weathering agents on buildings and identify the underlying mechanisms, determine the salt resistance of different types of rock; evaluate consolidation and water-repellent treatment durability; and confirm hypotheses about the origin of salts such as gypsum that are often found in granite buildings. Salt crystallization tests were also conducted, using sodium chloride, sodium sulphate, calcium sulphate and seawater solutions. One of these tests was conducted in a chamber specifically designed to simulate salt spray weathering and another in an SO2 chamber to ascertain whether granite is subject to sulphation. The test results are analyzed and discussed, along with the shortcomings of each type of trial as a method for simulating the decay observed in monuments. The effect of factors such as wet-dry conditions, type of saline solution and the position of the planes of weakness on the type of decay is also addressed.En este trabajo se hace una síntesis de varios ensayos de alteración artificial realizados con rocas graníticas. Estos ensayos tenían distintos objetivos: reproducir las formas de alteración encontradas en los edificios para llegar a conocer los mecanismos que las generan, determinar la resistencia de las diferentes rocas a la acción de las sales, evaluar la durabilidad de tratamientos de consolidación e hidrofugación y constatar hipótesis acerca del origen de algunas sales, como el yeso, que aparecen frecuentemente en edificios graníticos. En los ensayos de cristalización de sales se utilizaron disoluciones de cloruro de sodio, sulfato de sodio, sulfato de calcio y agua de mar. Uno de estos ensayos se llevó a cabo en una cámara especialmente diseñada para reproducir la alteración por aerosol marino y otro se realizó en una cámara de SO2, con el objeto de comprobar si en rocas graníticas se puede producir

  2. Land plants, weathering, and Paleozoic climatic evolution

    Science.gov (United States)

    Goddéris, Yves; Maffre, Pierre; Donnadieu, Yannick; Carretier, Sébastien

    2017-04-01

    At the end of the Paleozoic, the Earth plunged into the longest and most severe glaciation of the Phanerozoic eon (Montanez et al., 2013). The triggers for this event (called the Late Paleozoic Ice Age, LPIA) are still debated. Based on field observations and laboratory experiments showing that CO2 consumption by rock weathering is enhanced by the presence of plants, the onset of the LPIA has been related to the colonization of the continents by vascular plants in the latest Devonian. By releasing organic acids, concentrating respired CO2 in the soil, and by mechanically breaking rocks with their roots, land plants may have increased the weatherability of the continental surfaces. The "greening" of the continents may also have contributed to an enhanced burial of organic carbon in continental sedimentary basins, assuming that lignin decomposers have not yet evolved (Berner, 2004). As a consequence, CO2 went down, setting the conditions for the onset of the LPIA. This scenario is now widely accepted in the scientific community, and reinforces the feeling that biotic evolutionary steps are main drivers of the long-term climatic evolution. Although appealing, this scenario suffers from some weaknesses. The timing of the continent colonization by vascular plants was achieved in the late Devonian, several tens of million years before the onset of the LPIA (Davies and Gibling, 2013). Second, lignin decomposer fungi were present at the beginning of the Carboniferous, 360 million years ago while the LPIA started around 340-330 Ma (Nelsen et al., 2016). Land plants have also decreased the continental albedo, warming the Earth surface and promoting runoff. Weathering was thus facilitated and CO2 went down. Yet, temperature may have stayed constant, the albedo change compensating for the CO2 fall (Le Hir et al., 2010). From a modelling point of view, the effect of land plants on CO2 consumption by rock weathering is accounted for by forcing the weatherability of the

  3. Landslides as weathering reactors; links between physical erosion and weathering in rapidly eroding mountain belts

    Science.gov (United States)

    Emberson, R.; Hovius, N.; Galy, A.

    2014-12-01

    The link between physical erosion and chemical weathering is generally modelled with a surface-blanketing weathering zone, where the supply of fresh minerals is tied to the average rate of denudation. In very fast eroding environments, however, sediment production is dominated by landsliding, which acts in a stochastic fashion across the landscape, contrasting strongly with more uniform denudation models. If physical erosion is a driver of weathering at the highest erosion rates, then an alternative weathering model is required. Here we show that landslides can be effective 'weathering reactors'. Previous work modelling the effect of landslides on chemical weathering (Gabet 2007) considered the fresh bedrock surfaces exposed in landslide scars. However, fracturing during the landslide motion generates fresh surfaces, the total surface area of which exceeds that of the exposed scar by many orders of magnitude. Moreover, landslides introduce concavity into hillslopes, which acts to catch precipitation. This is funnelled into a deposit of highly fragmented rock mass with large reactive surface area and limited hydraulic conductivity (Lo et al. 2007). This allows percolating water reaction time for chemical weathering; any admixture of macerated organic debris could yield organic acid to further accelerate weathering. In the South island of New Zealand, seepage from recent landslide deposits has systematically high solute concentrations, far outstripping concentration in runoff from locations where soils are present. River total dissolved load in the western Southern Alps is highly correlated with the rate of recent (erosion; this contrasts with persistent and ubiquitous weathering associated with soil production. Solute fluxes from fast eroding landscapes therefore likely depend on climatic or tectonic forcing of mass wasting; greater precipitation would drive increased weathering, while earthquakes, in generating landslides (Dadson et al. 2003; Chen & Hawkins 2009

  4. Geochemical investigation of weathering processes in a forested headwater catchment: Mass-balance weathering fluxes

    Science.gov (United States)

    Jones, B.F.; Herman, J.S.

    2008-01-01

    Geochemical research on natural weathering has often been directed towards explanations of the chemical composition of surface water and ground water resulting from subsurface water-rock interactions. These interactions are often defined as the incongruent dissolution of primary silicates, such as feldspar, producing secondary weathering products, such as clay minerals and oxyhydroxides, and solute fluxes (Meunier and Velde, 1979). The chemical composition of the clay-mineral product is often ignored. However, in earlier investigations, the saprolitic weathering profile at the South Fork Brokenback Run (SFBR) watershed, Shenandoah National Park, Virginia, was characterized extensively in terms of its mineralogical and chemical composition (Piccoli, 1987; Pochatila et al., 2006; Jones et al., 2007) and its basic hydrology. O'Brien et al. (1997) attempted to determine the contribution of primary mineral weathering to observed stream chemistry at SFBR. Mass-balance model results, however, could provide only a rough estimate of the weathering reactions because idealized mineral compositions were utilized in the calculations. Making use of detailed information on the mineral occurrence in the regolith, the objective of the present study was to evaluate the effects of compositional variation on mineral-solute mass-balance modelling and to generate plausible quantitative weathering reactions that support both the chemical evolution of the surface water and ground water in the catchment, as well as the mineralogical evolution of the weathering profile. ?? 2008 The Mineralogical Society.

  5. Evaluating the effects of terrestrial ecosystems, climate and carbon dioxide on weathering over geological time: a global-scale process-based approach

    National Research Council Canada - National Science Library

    Lyla L. Taylor; Steve A. Banwart; Paul J. Valdes; Jonathan R. Leake; David J. Beerling

    2012-01-01

    .... Catchment-scale field studies consistently indicate that vegetation increases silicate rock weathering, but incorporating the effects of trees and fungal symbionts into geochemical carbon cycle...

  6. Seafloor Weathering As a Long-Term Climate Regulation Mechanism

    Science.gov (United States)

    Farahat, N. X.; Abbot, D. S.; Archer, D. E.

    2014-12-01

    The global carbon cycle determines the distribution of carbon between the atmosphere, ocean, and solid earth. Carbon from the mantle enters the Earth's surficial environment as CO2 by volcanic outgassing, and carbon is buried in the oceanic crust as carbonate rocks during silicate rock weathering. The subduction of carbonate-rich oceanic plates returns carbon to the mantle, closing the cycle. Subtle adjustments in continental silicate weathering, widely held to consume atmospheric CO2 at a rate controlled by climate, are believed to have maintained habitable conditions throughout Earth's history. This long term climate regulation mechanism is known as a climate-weathering feedback. Seafloor weathering, low-temperature basalt alteration and carbonate precipitation in the permeable upper oceanic crust, has been proposed as a climate-weathering feedback as well, but the link to climate is presently poorly understood. Such a climate regulation mechanism would be particularly important on waterworld planets where continental silicate weathering cannot regulate climate. It has so far not been possible to determine whether changes in seafloor weathering could contribute to climate regulation on Earth or in a waterworld scenario because the necessary modeling framework has not yet been developed. However, advances in porous media flow modeling and reactive transport modeling, as well as the availability of inexpensive computational power, allow the seafloor weathering problem to be looked at in greater detail. We have developed a spatially resolved two-dimmensional (2D) numerical model of seafloor weathering in the permeable upper oceanic crust. This model simulates 2D off-axis hydrothermal flow coupled to geochemical alteration of seafloor basalt by modeling reactive transport of chemical species in seawater-derived hydrothermal fluids. The focus of this research is to use the model to determine the effect of geological and climatic factors on seafloor weathering, which

  7. Benign Weather Modification

    Science.gov (United States)

    2007-11-02

    operational interest in modifying weather to support combat operations increased, ultimately leading to a multi-service effort called PROJECT POPEYE . The goal...This, coupled with the revelations concerning weather modification use in the Vietnam War (PROJECT POPEYE ), was a double blow to weather modification...AWS-TR-74-247, June 1984. Cobb, James T., Jr., et. al. Project Popeye : Final Report. China Lake, CA: Naval Weapons Center, 1967. Langmuir, Irving

  8. Is Weather Chaotic?

    CERN Document Server

    Raidl, A

    1998-01-01

    The correlation dimension and K2-entropy are estimated from meteorological time- series. The results lead us to claim that seasonal variability of weather is under influence of low dimensional dynamics, whereas changes of weather from day to day are governed by high dimensional system(s). Error-doubling time of this system is less than 3 days. We suggest that the outstanding feature of the weather dynamics is deterministic chaos.

  9. Oxidation of sulfides and rapid weathering in recent landslides

    Science.gov (United States)

    Emberson, Robert; Hovius, Niels; Galy, Albert; Marc, Odin

    2016-09-01

    Linking together the processes of rapid physical erosion and the resultant chemical dissolution of rock is a crucial step in building an overall deterministic understanding of weathering in mountain belts. Landslides, which are the most volumetrically important geomorphic process at these high rates of erosion, can generate extremely high rates of very localised weathering. To elucidate how this process works we have taken advantage of uniquely intense landsliding, resulting from Typhoon Morakot, in the T'aimali River and surrounds in southern Taiwan. Combining detailed analysis of landslide seepage chemistry with estimates of catchment-by-catchment landslide volumes, we demonstrate that in this setting the primary role of landslides is to introduce fresh, highly labile mineral phases into the surface weathering environment. There, rapid weathering is driven by the oxidation of pyrite and the resultant sulfuric-acid-driven dissolution of primarily carbonate rock. The total dissolved load correlates well with dissolved sulfate - the chief product of this style of weathering - in both landslides and streams draining the area (R2 = 0.841 and 0.929 respectively; p governed by the same weathering reactions. The predominance of coupled carbonate-sulfuric-acid-driven weathering is the key difference between these sites and previously studied landslides in New Zealand (Emberson et al., 2016), but in both settings increasing volumes of landslides drive greater overall solute concentrations in streams. Bedrock landslides, by excavating deep below saprolite-rock interfaces, create conditions for weathering in which all mineral phases in a lithology are initially unweathered within landslide deposits. As a result, the most labile phases dominate the weathering immediately after mobilisation and during a transient period of depletion. This mode of dissolution can strongly alter the overall output of solutes from catchments and their contribution to global chemical cycles if

  10. Space Weather Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Space Weather Computational Laboratory is a Unix and PC based modeling and simulation facility devoted to research analysis of naturally occurring electrically...

  11. Space Weather Analysis

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Space Weather Analysis archives are model output of ionospheric, thermospheric and magnetospheric particle populations, energies and electrodynamics

  12. From Rocks to Cement. What We Make. Science and Technology Education in Philippine Society.

    Science.gov (United States)

    Philippines Univ., Quezon City. Science Education Center.

    This module deals with the materials used in making concrete hollow blocks. Topics discussed include: (1) igneous, metamorphic, and sedimentary rocks; (2) weathering (the process of breaking down rocks) and its effects on rocks; (3) cement; (4) stages in the manufacturing of Portland cement; and (5) the transformation of cement into concrete…

  13. Iron isotopic fractionation during continental weathering

    Energy Technology Data Exchange (ETDEWEB)

    Fantle, Matthew S.; DePaolo, Donald J.

    2003-10-01

    The biological activity on continents and the oxygen content of the atmosphere determine the chemical pathways through which Fe is processed at the Earth's surface. Experiments have shown that the relevant chemical pathways fractionate Fe isotopes. Measurements of soils, streams, and deep-sea clay indicate that the {sup 56}Fe/{sup 54}Fe ratio ({delta}{sup 56}Fe relative to igneous rocks) varies from +1{per_thousand} for weathering residues like soils and clays, to -3{per_thousand} for dissolved Fe in streams. These measurements confirm that weathering processes produce substantial fractionation of Fe isotopes in the modern oxidizing Earth surface environment. The results imply that biologically-mediated processes, which preferentially mobilize light Fe isotopes, are critical to Fe chemistry in weathering environments, and that the {delta}{sup 56}Fe of marine dissolved Fe should be variable and negative. Diagenetic reduction of Fe in marine sediments may also be a significant component of the global Fe isotope cycle. Iron isotopes provide a tracer for the influence of biological activity and oxygen in weathering processes through Earth history. Iron isotopic fractionation during weathering may have been smaller or absent in an oxygen-poor environment such as that of the early Precambrian Earth.

  14. Weather and emotional state

    Science.gov (United States)

    Spasova, Z.

    2010-09-01

    Introduction Given the proven effects of weather on the human organism, an attempt to examine its effects on a psychic and emotional level has been made. Emotions affect the bio-tonus, working ability and concentration, hence their significance in various domains of economic life, such as health care, education, transportation, tourism, etc. Data and methods The research has been made in Sofia City within a period of 8 months, using 5 psychological methods (Eysenck Personality Questionnaire (EPQ), State-Trait Anxiety Inventory (STAI), Test for Self-assessment of the emotional state (developed by Wessman and Ricks), Test for evaluation of moods and Test "Self-confidence - Activity - Mood" (developed by the specialists from the Military Academy in Saint Petersburg). The Fiodorov-Chubukov's complex-climatic method was used to characterize meteorological conditions because of the purpose to include in the analysis a maximal number of meteorological elements. 16 weather types are defined in dependence of the meteorological elements values according to this method. Abrupt weather changes from one day to another, defined by the same method, were considered as well. Results and discussions The results obtained by t-test show that the different categories of weather lead to changes in the emotional status, which indicates a character either positive or negative for the organism. The abrupt weather changes, according to expectations, have negative effect on human emotions but only when a transition to the cloudy weather or weather type, classified as "unfavourable" has been realized. The relationship between weather and human emotions is rather complicated since it depends on individual characteristics of people. One of these individual psychological characteristics, marked by the dimension "neuroticism", has a strong effect on emotional reactions in different weather conditions. Emotionally stable individuals are more "protected" to the weather influence on their emotions

  15. Sliding rocks on Racetrack Playa, Death Valley National Park: first observation of rocks in motion.

    Science.gov (United States)

    Norris, Richard D; Norris, James M; Lorenz, Ralph D; Ray, Jib; Jackson, Brian

    2014-01-01

    The engraved trails of rocks on the nearly flat, dry mud surface of Racetrack Playa, Death Valley National Park, have excited speculation about the movement mechanism since the 1940s. Rock movement has been variously attributed to high winds, liquid water, ice, or ice flotation, but has not been previously observed in action. We recorded the first direct scientific observation of rock movements using GPS-instrumented rocks and photography, in conjunction with a weather station and time-lapse cameras. The largest observed rock movement involved > 60 rocks on December 20, 2013 and some instrumented rocks moved up to 224 m between December 2013 and January 2014 in multiple move events. In contrast with previous hypotheses of powerful winds or thick ice floating rocks off the playa surface, the process of rock movement that we have observed occurs when the thin, 3 to 6 mm, "windowpane" ice sheet covering the playa pool begins to melt in late morning sun and breaks up under light winds of -4-5 m/s. Floating ice panels 10 s of meters in size push multiple rocks at low speeds of 2-5 m/min. along trajectories determined by the direction and velocity of the wind as well as that of the water flowing under the ice.

  16. Sliding rocks on Racetrack Playa, Death Valley National Park: first observation of rocks in motion.

    Directory of Open Access Journals (Sweden)

    Richard D Norris

    Full Text Available The engraved trails of rocks on the nearly flat, dry mud surface of Racetrack Playa, Death Valley National Park, have excited speculation about the movement mechanism since the 1940s. Rock movement has been variously attributed to high winds, liquid water, ice, or ice flotation, but has not been previously observed in action. We recorded the first direct scientific observation of rock movements using GPS-instrumented rocks and photography, in conjunction with a weather station and time-lapse cameras. The largest observed rock movement involved > 60 rocks on December 20, 2013 and some instrumented rocks moved up to 224 m between December 2013 and January 2014 in multiple move events. In contrast with previous hypotheses of powerful winds or thick ice floating rocks off the playa surface, the process of rock movement that we have observed occurs when the thin, 3 to 6 mm, "windowpane" ice sheet covering the playa pool begins to melt in late morning sun and breaks up under light winds of -4-5 m/s. Floating ice panels 10 s of meters in size push multiple rocks at low speeds of 2-5 m/min. along trajectories determined by the direction and velocity of the wind as well as that of the water flowing under the ice.

  17. Modeling the role of weathering in shore platform development

    Science.gov (United States)

    Trenhaile, Alan S.

    2008-02-01

    A mathematical, wave-erosional model was modified to study the additional effect of weathering by wetting and drying and salt weathering on the development of shore platforms in macro- to mesotidal environments. Model rates of downwearing by these processes, at different tidal elevations, were based on data obtained from a series of laboratory experiments on sandstones from eastern Canada. Backwearing by mechanical wave erosion was calculated using basic wave equations. There were several types of run which were designed to determine the effect of: weathering and the production of fine-grained sediment; the periodic accumulation of debris on weathering in the upper intertidal zone; and weathering in reducing rock resistance and facilitating wave quarrying. The results implied that, compared to mechanical wave erosion, the direct effect of weathering and fine-grained sediment production makes only a small contribution to the long-term development of shore platforms. The relationship between cliff-foot debris occurrence and platform development and morphology was inconsistent because of the negative feedback relationship between erosion rates, surface gradients, and rates of wave attenuation. The model suggested that weathering can play an important, indirect role in assisting wave quarrying of joint blocks and other rock fragments.

  18. Evaporation and weather

    NARCIS (Netherlands)

    Bruin, H.A.R. de; Feddes, R.A.; Holtslag, A.A.M.; Lablans, W.N.; Schuurmans, C.J.E.; Shuttleworth, W.J.

    1987-01-01

    Data on evaporation to be used in agriculture, hydrology, forestry, etc. are usually supplied by meteorologists. Meteorologists themselves also use evaporation data. Air mass properties determining weather are strongly dependent on the input of water vapour from the surface. So for weather

  19. Designing a Weather Station

    Science.gov (United States)

    Roman, Harry T.

    2012-01-01

    The collection and analysis of weather data is crucial to the location of alternate energy systems like solar and wind. This article presents a design challenge that gives students a chance to design a weather station to collect data in advance of a large wind turbine installation. Data analysis is a crucial part of any science or engineering…

  20. Evaporation and weather

    NARCIS (Netherlands)

    Bruin, H.A.R. de; Feddes, R.A.; Holtslag, A.A.M.; Lablans, W.N.; Schuurmans, C.J.E.; Shuttleworth, W.J.

    1987-01-01

    Data on evaporation to be used in agriculture, hydrology, forestry, etc. are usually supplied by meteorologists. Meteorologists themselves also use evaporation data. Air mass properties determining weather are strongly dependent on the input of water vapour from the surface. So for weather predictio

  1. Weather and road capacity

    DEFF Research Database (Denmark)

    Jensen, Thomas Christian

    2014-01-01

    The paper presents estimations of the effect of bad weather on the observed speed on a Danish highway section; Køge Bugt Motorvejen. The paper concludes that weather, primarily precipitation and snow, has a clear negative effect on speed when the road is not in hypercongestion mode. Furthermore......, the capacity of the highway seems to be reduced in bad weather and there are indications that travel time variability is also increased, at least in free-flow conditions. Heavy precipitation reduces speed and capacity by around 5-8%, whereas snow primarily reduces capacity. Other weather variables......-parametrically against traffic density and in step 2 the residuals from step 1 are regressed linearly against the weather variables. The choice of a non-parametric method is made to avoid constricting ties from a parametric specification and because the focus here is not on the relationship between traffic flow...

  2. Weather in Mountainous Terrain (Overcoming Scientific Barriers to Weather Support)

    Science.gov (United States)

    2011-02-15

    Weather in Mountainous Terrain (Overcoming Scientific Barriers to Weather Support) Fiesta Resort & Conference Center Tempe, AZ February 1...Meteorology Overcoming Scientific Barriers to Weather Support Fiesta Resort & Conference Center Tempe, AZ February 1 & 2, 2010 Hosted by University

  3. Fluorine geochemistry in volcanic rock series

    DEFF Research Database (Denmark)

    Stecher, Ole

    1998-01-01

    A new analytical procedure has been established in order to determine low fluorine concentrations (30–100 ppm F) in igneous rocks, and the method has also proven successful for higher concentrations (100–4000 ppm F). Fluorine has been measured in a series of olivine tholeiites from the Reykjanes...... Peninsula, a tholeiite to rhyolitic rock series from Kerlingarfjöll, central Iceland, and an alkaline rock series from Jan Mayen that ranges from ankaramites to trachytes. Fluorine is not appreciably degassed during extrusion and appears to be insensitive to slight weathering. The olivine tholeiites from...... the Reykjanes Peninsula have F contents of 30–300 ppm and exhibit linear increases proportional to the incompatible elements K, P, and Ti. Such incompatible behaviour for F has been confirmed for the less evolved rocks of the other series. The tholeiites from Kerlingarfjöll (100–2000 ppm F) show a linear...

  4. WEATHERING PROCESS IN EOCENE FLYSCH IN REGION OF SPLIT (CROATIA

    Directory of Open Access Journals (Sweden)

    Predrag Miščević

    2001-12-01

    Full Text Available The Eocene flysh in the region of Split (Dalmatia, Croatia is char¬acterized by the presence of layers with different characteristics. It mainly includes thin-layered marls, clayey marls, calcareous marls, clastic lay¬ered limestones, calcarenites and breccias. Those parts that can be de¬scribed as the soft rocks or hard clays by the mechanical means, exposed to weathering reduce the durability within "an engineering time scale". The paper deals with the factors that influence the weathering process. The analyzed weathering is a combination of processes acting simulta¬neously. Most of these processes depend on the change of the water con¬tent, thus the weathering process mainly develops when a material is subjected to the wetting-drying process, On the base of these results form of degradation process is modeled. The weathering process can be main¬ly described as physical weathering combined with chemical weathering on the free surfaces and on the cracks walls. Erosion as a result of weath¬ering, is the dominant geomorphic process on analyzed flysch terrain. According to the analysis, as the most appropriate due to the characteris¬tics the tests are chosen as index properties. Some of these tests are modified in order to adapt them to the determined characteristics of ma¬terials from flysch layers. The correlations between the measured values are used as the basis for the classification proposal of the analyzed mate¬rial, according to its resistance to weathering processes. Roughly, three main groups of samples are recognizable: the first one with carbonate content more then 90% is not weathered at the engineers time scale; the second group with carbonate content from 75% to 90% include samples susceptible to weathering in engineers time scale; the third group with carbonate content less then 75% include samples in which the weather¬ing occurs immediately after the exposition to the weathering factors.

  5. Search for magnetic minerals in Martian rocks: Overview of the Rock Abrasion Tool (RAT) magnet investigation on Spirit and Opportunity

    DEFF Research Database (Denmark)

    Goetz, W.; Leer, K.; Gunnlaugsson, H.P.;

    2008-01-01

    The Rock Abrasion Tool (RAT) on board the Mars Exploration Rovers (MER) is a grinding tool designed to remove dust coatings and/or weathering rinds from rocks and expose fresh rock material. Four magnets of different strengths that are built into the structure of the RAT have been attracting...... substantial amounts of magnetic material during RAT activities from rocks throughout both rover missions. The RAT magnet experiment as performed on Spirit demonstrates the presence of a strongly ferrimagnetic phase in Gusev crater rocks, which based on Mossbauer and visible/near-infrared reflectance spectra...... is interpreted as magnetite. The amount of abraded rock material adhering to the magnets varied strongly during the mission and is correlated in a consistent way to the amount of magnetite inferred from Mossbauer spectra for the corresponding rock. The RAT magnet experiment as performed on Opportunity also...

  6. Quantification of rock fall processes on recently deglaciated rock slopes, Gepatsch glacier, Tyrol (Austria)

    Science.gov (United States)

    Vehling, Lucas; Rohn, Joachim; Moser, Michael

    2014-05-01

    The recently deglaciated area in alpine glacier forefields is characterized by intensified mass movement processes in particular debris flows, shallow landslides and rockfalls. Due to enhanced geomorphic activity, rock slopes adjacent to shrinking glaciers contribute in a substantial way to the sediment budget. In this study, direct measurements of rock fall intensity are conducted by rock fall collector nets and natural sediment traps. The study area is a high mountain (1750-3520m a.s.l) catchment, which is recently about 30% glaciated. The extension of the Gepatsch glacier has been reducing since the little ice age maximum in the mid of the 19th century with an average annual shrinking rate of a few decameters at its tongue. The first results of the direct measurements demonstrate that on the recently deglaciated rock slopes, rock fall intensity is at least one order of magnitude higher (2,38-6,64 g/m2/d - corresponding backweathering rate: 0,3-0,9 mm/a) than on rock slopes which had has ice free since the last Pleistocene deglaciation (0,04-0,38 g/m2/d - backweathering rate: 0,005-0,05 mm/a). The highest rock fall intensity is attributed to the recent deglaciated rock slopes which are located close to larger fault systems (>60 g/m2/d - backweathering rate: >8 mm/a). Rock fall intensity shows also considerable intra-annual variations which are related to cold climate weathering processes and rainstorm activity.

  7. Weathering of Pisha-Sandstones in the Wind-Water Erosion Crisscross Region on the Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Two types of pisha-sandstones of purple sandstones and gray sandstones, widely distributing in the wind-water erosion crisscross region of China, were selected and used in laboratory experiments for a better understanding of the drying-wetting-freezing weathering process resulting from the apportionment of water or salt solution to rock samples. Weathering experiments were carried out under the conditions of environment control (including temperature, moisture and salt solution). All rock samples were frequently subjected to 140 drying-wetting-freezing cycles. The influences of weathering process were evaluated. It was found that the different treatments of moisture and salt solution applications could affect the nature of the weathering products resulting from drying-wetting-freezing. It was also observed that salt solution could effectively alleviate the weathering of pisha-sandstones. Although not all the observations could be explained, it was apparent that simulated environmental factors had both direct and indirect effects on the weathering of rocks.

  8. Acidic weathering of carbonate building stones: experimental assessment

    Directory of Open Access Journals (Sweden)

    Ryszard Kryza

    2009-06-01

    Full Text Available Three types of carbonate rocks, travertine, limestone and marble have been studied to determine their selected technical parameters (water absorption, resistance to salt crystallization damage and reaction to experimentally modelled acid rain weathering imitating the polluted urban atmospheric conditions. The acidic agents present in natural acid rain precipitation, H2SO4, HCl, HNO3, CH3COOH and mixture of all the acids, “Acid mix”, were tested. The initial stages of acid weathering involve, apart from chemical dissolution, particularly intense physical detachment of rock particles (granular disintegration significantly contributing to the total mass loss. Travertine was found to be most prone to salt crystallization damage and to acid weathering, and these features should be taken into account especially in external architectural usage of this stone in cold climate conditions and polluted urban atmosphere.

  9. CERN Rocks

    CERN Document Server

    2004-01-01

    The 15th CERN Hardronic Festival took place on 17 July on the terrace of Rest 3 (Prévessin). Over 1000 people, from CERN and other International Organizations, came to enjoy the warm summer night, and to watch the best of the World's High Energy music. Jazz, rock, pop, country, metal, blues, funk and punk blasted out from 9 bands from the CERN Musiclub and Jazz club, alternating on two stages in a non-stop show.  The night reached its hottest point when The Canettes Blues Band got everybody dancing to sixties R&B tunes (pictured). Meanwhile, the bars and food vans were working at full capacity, under the expert management of the CERN Softball club, who were at the same time running a Softball tournament in the adjacent "Higgs Field". The Hardronic Festival is the main yearly CERN music event, and it is organized with the support of the Staff Association and the CERN Administration.

  10. Oil Rig Weather Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Weather observations taken at offshore platforms along the United States coastlines. The majority are located in oil-rich areas of the Gulf of Mexico, Gulf of...

  11. Uruguay - Surface Weather Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Surface weather observation forms for 26 stations in Uruguay. Period of record 1896-2005, with two to eight observations per day. Files created through a...

  12. Cape Kennedy Weather Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Digitized data taken from original weather observations taken at Cape Kennedy Air Force Station, Florida. Elements recorded are wind speed and direction,...

  13. Monthly Weather Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Surface Weather Observation 1001 Forms is a set of historical manuscript records for the period 1893-1948. The collection includes two very similar form types: Form...

  14. Daily Weather Maps

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Several different government offices have published the Daily weather maps over its history. The publication has also gone by different names over time. The U.S....

  15. Weather Information Processing

    Science.gov (United States)

    1991-01-01

    Science Communications International (SCI), formerly General Science Corporation, has developed several commercial products based upon experience acquired as a NASA Contractor. Among them are METPRO, a meteorological data acquisition and processing system, which has been widely used, RISKPRO, an environmental assessment system, and MAPPRO, a geographic information system. METPRO software is used to collect weather data from satellites, ground-based observation systems and radio weather broadcasts to generate weather maps, enabling potential disaster areas to receive advance warning. GSC's initial work for NASA Goddard Space Flight Center resulted in METPAK, a weather satellite data analysis system. METPAK led to the commercial METPRO system. The company also provides data to other government agencies, U.S. embassies and foreign countries.

  16. Space Weather Products

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of space weather datasets from the National Oceanic and Atmospheric Administration and from the World Data Service for Geophysics,...

  17. Lateral weathering gradients in glaciated catchments

    Science.gov (United States)

    McGuire, K. J.; Bailey, S. W.; Ross, D. S.; Strahm, B. D.; Schreiber, M. E.

    2016-12-01

    Mineral dissolution and the distribution of weathering products are fundamental processes that drive development and habitability of the Earth's critical zone; yet, the spatial configuration of these processes in some systems is not well understood. Feedbacks between hydrologic flows and weathering fluxes are necessary to understanding how the critical zone develops. In upland glaciated catchments of the northeastern USA, primary mineral dissolution and the distribution of weathering products are spatially distinct and predictable over short distances. Hillslopes, where shallow soils force lateral hydrologic fluxes through accumulated organic matter, produce downslope gradients in mineral depletion, weathering product accumulation, soil development, and solute chemistry. We propose that linked gradients in hydrologic flow paths, soil depth, and vegetation lead to predictable differences in the location and extent of mineral dissolution in regolith (soil, subsoil, and rock fragments) and bedrock, and that headwater catchments within the upland glaciated northeast show a common architecture across hillslopes as a result. Examples of these patterns and processes will be illustrated using observations from the Hubbard Brook Experimental Forest in New Hampshire where laterally distinct soils with strong morphological and biogeochemical gradients have been documented. Patterns in mineral depletion and product accumulation are essential in predicting how ecosystems will respond to stresses, disturbance, and management.

  18. Nitrogen fixation in lichens is important for improved rock weathering

    Indian Academy of Sciences (India)

    Gamini Seneviratne; I K Indrasena

    2006-12-01

    It is known that cyanobacteria in cyanolichens fix nitrogen for their nutrition. However, specific uses of the fixed nitrogen have not been examined. The present study shows experimentally that a mutualistic interaction between a heterotrophic N2 fixer and lichen fungi in the presence of a carbon source can contribute to enhanced release of organic acids, leading to improved solubilization of the mineral substrate. Three lichen fungi were isolated from Xanthoparmelia mexicana, a foliose lichen, and they were cultured separately or with a heterotrophic N2 fixer in nutrient broth media in the presence of a mineral substrate. Cells of the N2-fixing bacteria attached to the mycelial mats of all fungi, forming biofilms. All biofilms showed higher solubilizations of the substrate than cultures of their fungi alone. This finding has bearing on the significance of the origin and existence of N2-fixing activity in the evolution of lichen symbiosis. Further, our results may explain why there are N2-fixing photobionts even in the presence of non-fixing photobionts (green algae) in some remarkable lichens such as Placopsis gelida. Our study sheds doubt on the idea that the establishment of terrestrial eukaryotes was possible only through the association between a fungus and a phototroph.

  19. A Bibliography on the Chemical Weathering of Granitic Rocks

    Science.gov (United States)

    1988-09-01

    bank of the Rio Curoca). Garcia de Orta: Serie de Geografia , vol. 1, pp. 1-34. _ 1984. (Concerning the landscapes with "inselbergs" (or island mountains...had Polska Zachodnia. Seria A. Geografia Fizyc:na, vol. 24, pp. 179-185. 13 IL S Kwaad, F. J. D. M. 1970. Experiments on the granular disintegration

  20. Genetically optimizing weather predictions

    Science.gov (United States)

    Potter, S. B.; Staats, Kai; Romero-Colmenero, Encarni

    2016-07-01

    humidity, air pressure, wind speed and wind direction) into a database. Built upon this database, we have developed a remarkably simple approach to derive a functional weather predictor. The aim is provide up to the minute local weather predictions in order to e.g. prepare dome environment conditions ready for night time operations or plan, prioritize and update weather dependent observing queues. In order to predict the weather for the next 24 hours, we take the current live weather readings and search the entire archive for similar conditions. Predictions are made against an averaged, subsequent 24 hours of the closest matches for the current readings. We use an Evolutionary Algorithm to optimize our formula through weighted parameters. The accuracy of the predictor is routinely tested and tuned against the full, updated archive to account for seasonal trends and total, climate shifts. The live (updated every 5 minutes) SALT weather predictor can be viewed here: http://www.saao.ac.za/ sbp/suthweather_predict.html

  1. Cockpit weather information system

    Science.gov (United States)

    Tu, Jeffrey Chen-Yu (Inventor)

    2000-01-01

    Weather information, periodically collected from throughout a global region, is periodically assimilated and compiled at a central source and sent via a high speed data link to a satellite communication service, such as COMSAT. That communication service converts the compiled weather information to GSDB format, and transmits the GSDB encoded information to an orbiting broadcast satellite, INMARSAT, transmitting the information at a data rate of no less than 10.5 kilobits per second. The INMARSAT satellite receives that data over its P-channel and rebroadcasts the GDSB encoded weather information, in the microwave L-band, throughout the global region at a rate of no less than 10.5 KB/S. The transmission is received aboard an aircraft by means of an onboard SATCOM receiver and the output is furnished to a weather information processor. A touch sensitive liquid crystal panel display allows the pilot to select the weather function by touching a predefined icon overlain on the display's surface and in response a color graphic display of the weather is displayed for the pilot.

  2. Rollerjaw Rock Crusher

    Science.gov (United States)

    Peters, Gregory; Brown, Kyle; Fuerstenau, Stephen

    2009-01-01

    The rollerjaw rock crusher melds the concepts of jaw crushing and roll crushing long employed in the mining and rock-crushing industries. Rollerjaw rock crushers have been proposed for inclusion in geological exploration missions on Mars, where they would be used to pulverize rock samples into powders in the tens of micrometer particle size range required for analysis by scientific instruments.

  3. High potential for weathering and climate effects of non-vascular vegetation in the Late Ordovician

    Science.gov (United States)

    Porada, P.; Lenton, T. M.; Pohl, A.; Weber, B.; Mander, L.; Donnadieu, Y.; Beer, C.; Pöschl, U.; Kleidon, A.

    2016-07-01

    It has been hypothesized that predecessors of today's bryophytes significantly increased global chemical weathering in the Late Ordovician, thus reducing atmospheric CO2 concentration and contributing to climate cooling and an interval of glaciations. Studies that try to quantify the enhancement of weathering by non-vascular vegetation, however, are usually limited to small areas and low numbers of species, which hampers extrapolating to the global scale and to past climatic conditions. Here we present a spatially explicit modelling approach to simulate global weathering by non-vascular vegetation in the Late Ordovician. We estimate a potential global weathering flux of 2.8 (km3 rock) yr-1, defined here as volume of primary minerals affected by chemical transformation. This is around three times larger than today's global chemical weathering flux. Moreover, we find that simulated weathering is highly sensitive to atmospheric CO2 concentration. This implies a strong negative feedback between weathering by non-vascular vegetation and Ordovician climate.

  4. Red Rock Lakes Migratory Waterfowl Refuge: September - December 1962: [Narrative report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Red Rock Lakes NWR outlines Refuge accomplishments from September through December of 1962. The report begins by summarizing the weather...

  5. Red Rock Lakes National Wildlife Refuge: Narrative report: January 1 to December 31, 1965

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Red Rock Lakes NWR outlines Refuge accomplishments during the 1965 calendar year. The report begins by summarizing the weather...

  6. Red Rock Lakes National Wildlife Refuge: Narrative report: January 1 to December 31, 1966

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Red Rock Lakes NWR outlines Refuge accomplishments during the 1966 calendar year. The report begins by summarizing the weather...

  7. Alteration of Lunar Rock Surfaces through Interaction with the Space Environment

    Science.gov (United States)

    Frushour, A. M.; Noble, S. K; Christoffersen, R.; Keller, L P.

    2014-01-01

    Space weathering occurs on all ex-posed surfaces of lunar rocks, as well as on the surfaces of smaller grains in the lunar regolith. Space weather-ing alters these exposed surfaces primarily through the action of solar wind ions and micrometeorite impact processes. On lunar rocks specifically, the alteration products produced by space weathering form surface coatings known as patina. Patinas can have spectral reflectance properties different than the underlying rock. An understanding of patina composition and thickness is therefore important for interpreting re-motely sensed data from airless solar system bodies. The purpose of this study is to try to understand the physical and chemical properties of patina by expanding the number of patinas known and characterized in the lunar rock sample collection.

  8. Effects of weathering of organic matter in the La Luna Formation, Maracaibo Basin, Western Venezuela

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, N.

    1986-01-01

    The effect of weathering of organic matter in the La Luna Formation, the main source rock of Cretaceous oil in Western Venezuela was studied by means of organic petrography. Two outcrop samples from zero to about 10 cm depth were studied microscopically, both in whole rock and kerogen extract mode. This permitted recognizing some characteristics and consequences of weathering, such as: increased porosity of huminite and solid bitumens and the decrease of its reflectance (% anti Ro); disappearance of micrinite, presence of exudation substances and lower fluorescence emission of liptinite under blue light excitation. The mass reduction of the organic matter was determined by the difference of total organic carbon values, and by the weight reduction of the sample before and after extraction, in both weathered and unweathered samples. The loss of organic matter by weathering is considerable, as much as 87% in the first 0.5 cm of the weathering halo are lost.

  9. Space weather & telecommunications

    CERN Document Server

    Goodman, John M

    2006-01-01

    This book is both a survey of practical concepts for forecasting the performance of various telecommunication systems as well as a balanced treatment of space-weather phenomena that give rise to telecommunication impairment episodes. It bridges the gap in the relationship that exists between the following two disciplines: space weather and telecommunication system performance. There are a number of books that address one of the two disciplines in some detail, but only merely mention the other as an afterthought. In this book the author has married the two disciplines so that the readership can

  10. Kinematics analysis of a robotic rock grinder

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    With the aim to discover water, life and resources in other planets, robotic sampling instrument is a crucial part of the space exploration robot. To remove dusty and weathered surfaces and expose the fresh rock underneath the planetary surface, a robotic rock grinder is considered to replace the geologist's rock hammer to carry out the geological investigation. A primary prototype of the robotic rock grinder with three degrees of freedom has been developed in this paper. Planetary transmission system is used in the grinding driving system with two inputs (rotation motor and revolution motor) and two outputs (grinding wheel and cutting brush). The grinding wheel with two teeth has been used to abrade the rock. The cutting brush is used to sweep the debris. The third actuator is to feed the grinding system. Kinematics of the grinding system has been analyzed. To get a continuous and smooth fresh face over the rock, grinding trajectory of the grinding wheel has been discussed and planned. Lastly, abrasion experiments have been made to testify the feasibility and the basic function of this system.

  11. Can Low Water/Rock Hydrothermal Alteration of Impact Materials Explain the Rock Component of the Martian Soil?

    Science.gov (United States)

    Nelson, M. J.; Newsom, H. E.

    2003-01-01

    The martian regolith is a globally homogenized product of chemical and aeolian weathering processes. The soil is thought to consist of a rock component, with lesser amounts of mobile elements (Ca, Na, and K) than a presumed protolith, and a salt or mobile element component enriched in sulfur and chlorine. In this study we consider the contributions of hydrothermal processes to the origin of the rock component of the martian soil.

  12. High potential for weathering and climate effects of non-vascular vegetation in the Late Ordovician

    Science.gov (United States)

    Porada, Philipp; Lenton, Tim; Pohl, Alexandre; Weber, Bettina; Mander, Luke; Donnadieu, Yannick; Beer, Christian; Pöschl, Ulrich; Kleidon, Axel

    2017-04-01

    Early non-vascular vegetation in the Late Ordovician may have strongly increased chemical weathering rates of surface rocks at the global scale. This could have led to a drawdown of atmospheric CO2 and, consequently, a decrease in global temperature and an interval of glaciations. Under current climatic conditions, usually field or laboratory experiments are used to quantify enhancement of chemical weathering rates by non-vascular vegetation. However, these experiments are constrained to a small spatial scale and a limited number of species. This complicates the extrapolation to the global scale, even more so for the geological past, where physiological properties of non-vascular vegetation may have differed from current species. Here we present a spatially explicit modelling approach to simulate large-scale chemical weathering by non-vascular vegetation in the Late Ordovician. For this purpose, we use a process-based model of lichens and bryophytes, since these organisms are probably the closest living analogue to Late Ordovician vegetation. The model explicitly represents multiple physiological strategies, which enables the simulated vegetation to adapt to Ordovician climatic conditions. We estimate productivity of Ordovician vegetation with the model, and relate it to chemical weathering by assuming that the organisms dissolve rocks to extract phosphorus for the production of new biomass. Thereby we account for limits on weathering due to reduced supply of unweathered rock material in shallow regions, as well as decreased transport capacity of runoff for dissolved weathered material in dry areas. We simulate a potential global weathering flux of 2.8 km3 (rock) per year, which we define as volume of primary minerals affected by chemical transformation. Our estimate is around 3 times larger than today's global chemical weathering flux. Furthermore, chemical weathering rates simulated by our model are highly sensitive to atmospheric CO2 concentration, which implies

  13. Provenance control on chemical indices of weathering (Taiwan river sands)

    Science.gov (United States)

    Garzanti, Eduardo; Resentini, Alberto

    2016-05-01

    Geochemical parameters obtained from the analysis of sediments and sedimentary rocks are widely used to infer weathering and paleo-weathering conditions in source areas. Chemical indices of weathering, however, may not reflect weathering only, or even principally. The concentration of chemical elements in terrigenous sediments is constrained by the original mineralogy of source rocks, and is thus provenance-dependent. Moreover, the mineralogy and consequently the geochemistry of sediments may undergo substantial modifications by diverse physical processes during transport and deposition, including recycling and hydraulic sorting by size, density or shape, and/or by chemical dissolution and precipitation during diagenesis. Around the island of Taiwan, temperature and rainfall are consistently high and relatively homogeneous, and no significant correlation is observed between geochemical and climatic parameters. Physical erosion, fostered by landslides induced by frequent earthquakes and typhoons, prevails because of high relief and extreme rates of tectonic uplift. In such a dynamic orogenic setting, all chemical indices of weathering are controlled principally by the geology of source terranes. Sedimentaclastic and metasedimentaclastic sands carried by western Taiwan rivers draining the pro-wedge display the strongest depletion in Na, Ca, Mg and Sr relative to average upper continental crust, and no depletion or even enrichment in K, Rb and Ba. Low WIP indices reflect erosion of phyllosilicate-dominated rocks in the Slate Belt and extensive recycling of clastic rocks exposed in the Western Foothills. Instead, metamorphiclastic sands carried by eastern Taiwan rivers draining the retro-wedge show no depletion or even enrichment in Mg and Ca, and low CIA and PIA, reflecting contributions from the Tailuko Belt and Coastal Range. Volcaniclastic sands have the same CIA values of their andesitic source rocks (47 ± 1 versus 47 ± 7), indicating that weathering is

  14. Dress for the Weather

    Science.gov (United States)

    Glen, Nicole J.; Smetana, Lara K.

    2010-01-01

    "If someone were traveling to our area for the first time during this time of year, what would you tell them to bring to wear? Why?" This question was used to engage students in a guided-inquiry unit about how climate differs from weather. In this lesson, students explored local and national data sets to give "travelers" advice…

  15. Microbial Weathering of Olivine

    Science.gov (United States)

    McKay, D. S.; Longazo, T. G.; Wentworth, S. J.; Southam, G.

    2002-01-01

    Controlled microbial weathering of olivine experiments displays a unique style of nanoetching caused by biofilm attachment to mineral surfaces. We are investigating whether the morphology of biotic nanoetching can be used as a biosignature. Additional information is contained in the original extended abstract.

  16. Winter Weather: Indoor Safety

    Science.gov (United States)

    ... Part 3 of 3) Hot Weather Tips Heat Stress in Older Adults FAQs Extreme Heat PSAs Related Links MMWR Bibliography CDC's Program Floods Flood Readiness Personal Hygiene After a Disaster Cleanup of Flood Water After a Flood Worker Safety Educational Materials Floods ...

  17. Winter Weather: Frostbite

    Science.gov (United States)

    ... Part 3 of 3) Hot Weather Tips Heat Stress in Older Adults FAQs Extreme Heat PSAs Related Links MMWR Bibliography CDC's Program Floods Flood Readiness Personal Hygiene After a Disaster Cleanup of Flood Water After a Flood Worker Safety Educational Materials Floods ...

  18. Winter Weather Checklists

    Science.gov (United States)

    ... Part 3 of 3) Hot Weather Tips Heat Stress in Older Adults FAQs Extreme Heat PSAs Related Links MMWR Bibliography CDC's Program Floods Flood Readiness Personal Hygiene After a Disaster Cleanup of Flood Water After a Flood Worker Safety Educational Materials Floods ...

  19. Weather at LANL

    Energy Technology Data Exchange (ETDEWEB)

    Bruggeman, David Alan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-04-19

    This report gives general information about how to become a meteorologist and what kinds of jobs exist in that field. Then it goes into detail about why weather is monitored at LANL, how it is done, and where the data can be accessed online.

  20. Cold Weather Pet Safety

    Science.gov (United States)

    ... they can be knocked over, potentially starting a fire. Check your furnace before the cold weather sets in to make ... avoided because of the risk of burns or fire. Heated pet mats should also be used ... to burrow, get them back inside quickly because they are showing signs of ...

  1. Dress for the Weather

    Science.gov (United States)

    Glen, Nicole J.; Smetana, Lara K.

    2010-01-01

    "If someone were traveling to our area for the first time during this time of year, what would you tell them to bring to wear? Why?" This question was used to engage students in a guided-inquiry unit about how climate differs from weather. In this lesson, students explored local and national data sets to give "travelers" advice…

  2. 'Is it the weather?'

    NARCIS (Netherlands)

    B. Jacobsen (Ben); W.A. Marquering (Wessel)

    2004-01-01

    textabstractWe show that results in the recent strand of the literature that tries to explain stock returns by weather induced mood shifts of investors might be data-driven inference. More specifically, we consider two recent studies (Kamstra, Kramer and Levi, 2003a and Cao and Wei, 2004) that claim

  3. Weatherization Works: An interim report of the National Weatherization Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Brown, M.A.; Berry, L.G. [Oak Ridge National Lab., TN (United States); Kinney, L.F. [Synertech Systems Corp., Syracuse, NY (United States)

    1993-11-01

    The National Weatherization Evaluation is the first comprehensive evaluation of the Weatherization Assistance Program since 1984. The evaluation was designed to accomplish the following goals: Estimate energy savings and cost effectiveness; Assess nonenergy impacts; Describe the weatherization network; Characterize the eligible population and resources; and Identify factors influencing outcomes and opportunities for the future. As a national program, weatherization incorporates considerable diversity due to regional differences. Therefore, evaluation results are presented both in aggregate and for three climate regions: cold, moderate and hot.

  4. Weatherization Works: An interim report of the National Weatherization Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Brown, M.A.; Berry, L.G. [Oak Ridge National Lab., TN (United States); Kinney, L.F. [Synertech Systems Corp., Syracuse, NY (United States)

    1993-11-01

    The National Weatherization Evaluation is the first comprehensive evaluation of the Weatherization Assistance Program since 1984. The evaluation was designed to accomplish the following goals: Estimate energy savings and cost effectiveness; Assess nonenergy impacts; Describe the weatherization network; Characterize the eligible population and resources; and Identify factors influencing outcomes and opportunities for the future. As a national program, weatherization incorporates considerable diversity due to regional differences. Therefore, evaluation results are presented both in aggregate and for three climate regions: cold, moderate and hot.

  5. Beneath it all: bedrock geology of the Catskill Mountains and implications of its weathering.

    Science.gov (United States)

    Ver Straeten, Charles A

    2013-09-01

    The Devonian-age bedrock of the Catskill Mountains has been the focus of many studies. This paper reviews the character and composition of the rocks of the Catskills, and examines weathering (rock decay) processes and their implications in the Catskills. Rocks of the Catskills and closest foothills consist of siliciclastic rocks (sandstones, mudrocks, conglomerates) with minimal, locally dispersed carbonate rocks. The former are dominated by quartz, metamorphic and sedimentary rock fragments, and clay minerals. Other minor sediment components include cements, authigenic and heavy minerals, and fossil organic matter. Physical, chemical, and biological weathering of the Catskill bedrock since uplift of the Appalachian region, combined with glaciation, have dissected a plateau of nearly horizontally layered rocks into a series of ridges, valleys, and peaks. The varied weathering processes, in conjunction with many factors (natural and anthropogenic), fragment the rocks, forming sediment and releasing various elements and compounds. These may have positive, neutral, or negative implications for the region's soils, waters, ecology, and human usage. A new generation of studies and analyses of the Catskill bedrock is needed to help answer a broad set of questions and problems across various fields of interest.

  6. North America Synoptic Weather Maps

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Series of Synoptic Weather Maps. Maps contains a surface analysis comprised of plotted weather station observations, isobars indicating low and high-pressure...

  7. Severe Weather Data Inventory (SWDI)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Severe Weather Data Inventory (SWDI) is an integrated database of severe weather records for the United States. SWDI enables a user to search through a variety...

  8. The Rock Cycle

    Science.gov (United States)

    Singh, Raman J.; Bushee, Jonathan

    1977-01-01

    Presents a rock cycle diagram suitable for use at the secondary or introductory college levels which separates rocks formed on and below the surface, includes organic materials, and separates products from processes. (SL)

  9. What characterizes planetary space weather?

    OpenAIRE

    2014-01-01

    International audience; Space weather has become a mature discipline for the Earth space environment. With increasing efforts in space exploration, it is becoming more and more necessary to understand the space environments of bodies other than Earth. This is the background for an emerging aspect of the space weather discipline: planetary space weather. In this article, we explore what characterizes planetary space weather, using some examples throughout the solar system. We consider energy s...

  10. Severe Weather Planning for Schools

    Science.gov (United States)

    Watson, Barbara McNaught; Strong, Christopher; Bunting, Bill

    2008-01-01

    Flash floods, severe thunderstorms, and tornadoes occur with rapid onset and often no warning. Decisions must be made quickly and actions taken immediately. This paper provides tips for schools on: (1) Preparing for Severe Weather Emergencies; (2) Activating a Severe Weather Plan; (3) Severe Weather Plan Checklist; and (4) Periodic Drills and…

  11. My Pet Rock

    Science.gov (United States)

    Lark, Adam; Kramp, Robyne; Nurnberger-Haag, Julie

    2008-01-01

    Many teachers and students have experienced the classic pet rock experiment in conjunction with a geology unit. A teacher has students bring in a "pet" rock found outside of school, and the students run geologic tests on the rock. The tests include determining relative hardness using Mohs scale, checking for magnetization, and assessing luster.…

  12. My Pet Rock

    Science.gov (United States)

    Lark, Adam; Kramp, Robyne; Nurnberger-Haag, Julie

    2008-01-01

    Many teachers and students have experienced the classic pet rock experiment in conjunction with a geology unit. A teacher has students bring in a "pet" rock found outside of school, and the students run geologic tests on the rock. The tests include determining relative hardness using Mohs scale, checking for magnetization, and assessing luster.…

  13. Role of Lichens in Weathering and Soil—Forming Processes in Fildes Peninsula,Antarctic

    Institute of Scientific and Technical Information of China (English)

    CHENJIE; GONGZi-TONG

    1995-01-01

    Lichens play an unparalleledly vital role in weathering and soil-forming processes in Antarctic region,In this study some related chemical components and micromorphological analyses have been carried out on the samples of the weathered rocks and the lichens grown on them from Files Peninsula,Antarctic,The results indicatied that the major chemical components in the bioweathering surface layer of the sampled rocks have been obviously altered and the weathering potential in this layer has greatly decreased by and average range around 4.66 percent in 4 samples,In the weathering surface layer ferruginiztion of some minerals in varying degress was seen by means of microscopic examination through the thin section of the weathered rocks,and its products proved to be dominated by hematitie,limonite,goethite and free iron oxides Meanwhile,the study suggested that the dissolution and absorption of lichens by their secretion accelerated the process of calcitization of minerals in the bio-weathering suface layer,Eventually,the results also show that different species of lichens play different roles in weathering and soil-forming proesses.

  14. Weathering, Soil Production, and Erosion Across Climatic and Tectonic Gradients

    Science.gov (United States)

    Norton, K. P.; Larsen, I. J.

    2014-12-01

    Weathering is one of the fundamental processes that sustain life on our planet. Physical weathering breaks down rock for soil production and chemical weathering is thought to operate as the ultimate long-term negative feedback on atmospheric CO2 concentrations. There remains, however, uncertainty as to the relationship between chemical and physical weathering at very fast rates. If chemical weathering becomes kinetically limited at rapid erosion rates, as has been shown in a number of locations around the globe, then the fastest erosion rates will be associated with reduced chemical weathering. This has led to a debate as to whether tectonically active mountain ranges or rolling plains are the main source of CO2 drawdown through silicate weathering. At the heart of this debate is the dearth of chemical weathering data at fast erosion rates. New cosmogenic nuclide-derived denudation rates from the West Coast of the New Zealand Southern Alps are among the fastest in the world and are linearly correlated with chemical weathering rates. The associated soil production rates reach an order of magnitude faster than previous estimates and far exceed the suggested maximum soil production rate. This suggests that very fast weathering and soil production is possible in such active landscapes and extreme climates. We investigate the controls on these rapid rates with a climate-driven soil production model. At the most basic level, soil production requires chemical weathering of primary minerals to secondary minerals. We apply soil production models with both exponential and hump-shaped dependencies on soil thickness. Mean annual temperature and precipitation are incorporated in the form of a modified Arrhenius equation that controls the maximum soil production rate. When applied to the Southern Alps, the model predicts very rapid soil production that matches the magnitude of the cosmogenic nuclide-derived rates. High annual precipitation in the Southern Alps supports rapid

  15. Whether weather affects music

    Science.gov (United States)

    Aplin, Karen L.; Williams, Paul D.

    2012-09-01

    The creative output of composers, writers, and artists is often influenced by their surroundings. To give a literary example, it has been claimed recently that some of the characters in Oliver Twist and A Christmas Carol were based on real-life people who lived near Charles Dickens in London [Richardson, 2012]. Of course, an important part of what we see and hear is not only the people with whom we interact but also our geophysical surroundings. Of all the geophysical phenomena to influence us, the weather is arguably the most significant because we are exposed to it directly and daily. The weather was a great source of inspiration for artists Claude Monet, John Constable, and William Turner, who are known for their scientifically accurate paintings of the skies [e.g., Baker and Thornes, 2006].

  16. Biogenic Cracks in Porous Rock

    Science.gov (United States)

    Hemmerle, A.; Hartung, J.; Hallatschek, O.; Goehring, L.; Herminghaus, S.

    2014-12-01

    Microorganisms growing on and inside porous rock may fracture it by various processes. Some of the mechanisms of biofouling and bioweathering are today identified and partially understood but most emphasis is on chemical weathering, while mechanical contributions have been neglected. However, as demonstrated by the perseverance of a seed germinating and cracking up a concrete block, the turgor pressure of living organisms can be very significant. Here, we present results of a systematic study of the effects of the mechanical forces of growing microbial populations on the weathering of porous media. We designed a model porous medium made of glass beads held together by polydimethylsiloxane (PDMS), a curable polymer. The rheological properties of the porous medium, whose shape and size are tunable, can be controlled by the ratio of crosslinker to base used in the PDMS (see Fig. 1). Glass and PDMS being inert to most chemicals, we are able to focus on the mechanical processes of biodeterioration, excluding any chemical weathering. Inspired by recent measurements of the high pressure (~0.5 Mpa) exerted by a growing population of yeasts trapped in a microfluidic device, we show that yeast cells can be cultured homogeneously within porous medium until saturation of the porous space. We investigate then the effects of such an inner pressure on the mechanical properties of the sample. Using the same model system, we study also the complex interplay between biofilms and porous media. We focus in particular on the effects of pore size on the penetration of the biofilm within the porous sample, and on the resulting deformations of the matrix, opening new perspectives into the understanding of life in complex geometry. Figure 1. Left : cell culture growing in a model porous medium. The white spheres represent the grains, bonds are displayed in grey, and microbes in green. Right: microscopy picture of glass beads linked by PDMS bridges, scale bar: 100 μm.

  17. The Weather Man

    Institute of Scientific and Technical Information of China (English)

    蒋涵毅

    2009-01-01

    Secondly. the weather man一定会告诉我们每天的最高和最低温度(the highest and the lowest temperature)。我们用℃来表示摄氏度,有的地方则用°F,那是华氏温度。°F=9/5×℃+32

  18. Tactical Weather Expert System.

    Science.gov (United States)

    The objective of this project was to assess the feasibility of developing an expert system for tactical weather prediction. Using WILLARD, an expert ...indicate that intelligent interpretations of cloud formations can be made. These inferences can then be automatically passed to the expert system for...processing as another piece of information. It is anticipated that this technology will significantly reduce the dependence of the expert system on a

  19. Space Weather Ballooning

    Science.gov (United States)

    Phillips, Tony; Johnson, Sam; Koske-Phillips, Amelia; White, Michael; Yarborough, Amelia; Lamb, Aaron; Herbst, Anna; Molina, Ferris; Gilpin, Justin; Grah, Olivia; Perez, Ginger; Reid, Carson; Harvey, Joey; Schultz, Jamie

    2016-10-01

    We have developed a "Space Weather Buoy" for measuring upper atmospheric radiation from cosmic rays and solar storms. The Buoy, which is carried to the stratosphere by helium balloons, is relatively inexpensive and uses off-the-shelf technology accessible to small colleges and high schools. Using this device, we have measured two Forbush Decreases and a small surge in atmospheric radiation during the St. Patrick's Day geomagnetic storm of March 2015.

  20. Weathering the financial storm

    DEFF Research Database (Denmark)

    Ólafsson, Tjörvi; Pétursson, Thórarinn G.

    2011-01-01

    to explain a significant share of the cross-country variation in the depth and duration of the crisis and provide quite sharp predictions of the incidence of banking and currency crises. This suggests that country-specific initial conditions played an important role in determining the economic impact...... of the crisis and, in particular, that countries with sound fundamentals and flexible economic frameworks were better able to weather the financial storm....

  1. Areosynchronous weather imager

    Science.gov (United States)

    Puschell, Jeffery J.; Lock, Robert

    2016-09-01

    Mars is characterized by rapidly changing, poorly understood weather that is a concern for future human missions. Future Areosynchronous Mars Orbit (AMO) communication satellites offer possible platforms for Mars weather imagers similar to the geosynchronous Earth orbit (GEO) weather imagers that have been observing Earth since 1966. This paper describes an AReosynchronous Environmental Suite (ARES) that includes two imagers: one with two emissive infrared bands (10.8 μm and 12.0 μm) at 4 km resolution and the other with three VNIR bands (500 nm, 700 nm, 900 nm) at 1 km resolution. ARES stares at Mars and provides full disk coverage as fast as every 40 sec in the VNIR bands and every 2 min in the emissive bands with good sensitivity (SNR 200 in the VNIR for typical radiances and NEDT 0.2K at 180 K scene temperature in the emissive infrared). ARES size, mass, power and data rate characteristics are compatible with expectations for hosted payloads onboard future AMO communication satellites. Nevertheless, more work is needed to optimize ARES for future missions, especially in terms of trades between data rate, full disk coverage rate, sensitivity, number of spectral bands and spatial resolution and in study of approaches for maintaining accurate line of sight knowledge during data collection.

  2. Rock History and Culture

    OpenAIRE

    Gonzalez, Éric

    2013-01-01

    Two ambitious works written by French-speaking scholars tackle rock music as a research object, from different but complementary perspectives. Both are a definite must-read for anyone interested in the contextualisation of rock music in western popular culture. In Une histoire musicale du rock (i.e. A Musical History of Rock), rock music is approached from the point of view of the people – musicians and industry – behind the music. Christophe Pirenne endeavours to examine that field from a m...

  3. Weather Monitoring Station: A Review

    Directory of Open Access Journals (Sweden)

    Mr. Dipak V. Sose

    2016-06-01

    Full Text Available Weather monitoring plays a very important role in human life hence study of weather system is necessary. Currently there are two types of the weather monitoring stations available i.e. wired and wireless. Wireless system has some advantages over the wired one hence popular now a days. The parameters are include in weather monitoring usually temperature, humidity atmospheric pressure, light intensity, rainfall etc. There are many techniques existed using different processor such as PIC, AVR, ARM etc. Analog to digital channel are used to fetch the analog output of the sensors. The wireless techniques used in the weather monitoring having GSM, FM channel, Zigbee, RF etc Protocols

  4. Can the Weather Affect My Child's Asthma?

    Science.gov (United States)

    ... Year-Old Can the Weather Affect My Child's Asthma? KidsHealth > For Parents > Can the Weather Affect My ... empeorar el asma de mi hijo? Weather and Asthma The effect of weather on asthma symptoms isn' ...

  5. Space Weather Services of Korea

    Science.gov (United States)

    Yoon, K.; Hong, S.; Jangsuk, C.; Dong Kyu, K.; Jinyee, C.; Yeongoh, C.

    2016-12-01

    The Korean Space Weather Center (KSWC) of the National Radio Research Agency (RRA) is a government agency which is the official source of space weather information for Korean Government and the primary action agency of emergency measure to severe space weather condition. KSWC's main role is providing alerts, watches, and forecasts in order to minimize the space weather impacts on both of public and commercial sectors of satellites, aviation, communications, navigations, power grids, and etc. KSWC is also in charge of monitoring the space weather condition and conducting research and development for its main role of space weather operation in Korea. In this study, we will present KSWC's recent efforts on development of application-oriented space weather research products and services on user needs, and introduce new international collaborative projects, such as IPS-Driven Enlil model, DREAM model estimating electron in satellite orbit, global network of DSCOVR and STEREO satellites tracking, and ARMAS (Automated Radiation Measurement for Aviation Safety).

  6. Space Weather Services of Korea

    Science.gov (United States)

    Yoon, KiChang; Kim, Jae-Hun; Kim, Young Yun; Kwon, Yongki; Wi, Gwan-sik

    2016-07-01

    The Korean Space Weather Center (KSWC) of the National Radio Research Agency (RRA) is a government agency which is the official source of space weather information for Korean Government and the primary action agency of emergency measure to severe space weather condition. KSWC's main role is providing alerts, watches, and forecasts in order to minimize the space weather impacts on both of public and commercial sectors of satellites, aviation, communications, navigations, power grids, and etc. KSWC is also in charge of monitoring the space weather condition and conducting research and development for its main role of space weather operation in Korea. In this study, we will present KSWC's recent efforts on development of application-oriented space weather research products and services on user needs, and introduce new international collaborative projects, such as IPS-Driven Enlil model, DREAM model estimating electron in satellite orbit, global network of DSCOVR and STEREO satellites tracking, and ARMAS (Automated Radiation Measurement for Aviation Safety).

  7. Enhanced Weathering Strategies for Stabilizing Climate and Averting Ocean Acidification

    Science.gov (United States)

    Taylor, Lyla L.; Quirk, Joe; Thorley, Rachel M. S.; Kharecha, Pushker A.; Hansen, James; Ridgwell, Andy; Lomas, Mark R.; Banwart, Steve A.; Beerling, David J.

    2015-01-01

    Chemical breakdown of rocks, weathering, is an important but very slow part of the carbon cycle that ultimately leads to CO2 being locked up in carbonates on the ocean floor. Artificial acceleration of this carbon sink via distribution of pulverized silicate rocks across terrestrial landscapes may help offset anthropogenic CO2 emissions. We show that idealized enhanced weathering scenarios over less than a third of tropical land could cause significant drawdown of atmospheric CO2 and ameliorate ocean acidification by 2100. Global carbon cycle modelling driven by ensemble Representative Concentration Pathway (RCP) projections of twenty-first-century climate change (RCP8.5, business-as-usual; RCP4.5, medium-level mitigation) indicates that enhanced weathering could lower atmospheric CO2 by 30-300 ppm by 2100, depending mainly on silicate rock application rate (1 kg or 5 kg m(exp -2) yr (exp -1)) and composition. At the higher application rate, end-of-century ocean acidification is reversed under RCP4.5 and reduced by about two-thirds under RCP8.5. Additionally, surface ocean aragonite saturation state, a key control on coral calcification rates, is maintained above 3.5 throughout the low latitudes, thereby helping maintain the viability of tropical coral reef ecosystems. However, we highlight major issues of cost, social acceptability, and potential unanticipated consequences that will limit utilization and emphasize the need for urgent efforts to phase down fossil fuel emissions.

  8. Fossil Microorganisms and Formation of Early Precambrian Weathering Profiles

    Science.gov (United States)

    Rozanov, A. Yu; Astafieva, M. M.; Vrevsky, A. B.; Alfimova, N. A.; Matrenichev, V. A.; Hoover, R. B.

    2009-01-01

    Weathering crusts are the only reliable evidences of the existence of continental conditions. Often they are the only source of information about exogenous processes and subsequently about conditions under which the development of the biosphere occurred. A complex of diverse fossil microorganisms was discovered as a result of Scanning Electron Microscope investigations. The chemical composition of the discovered fossils is identical to that of the host rocks and is represented by Si, Al, Fe, Ca and Mg. Probably, the microorganisms fixed in rocks played the role of catalyst. The decomposition of minerals comprising the rocks and their transformation into clayey (argillaceous) minerals, most likely occurred under the influence of microorganisms. And may be unique weathering crusts of Early Precambrian were formed due to interaction between specific composition of microorganism assemblage and conditions of hypergene transformations. So it is possible to speak about colonization of land by microbes already at that time and about existence of single raw from weathering crusts (Primitive soils) to real soils.

  9. Enhanced weathering strategies for stabilizing climate and averting ocean acidification

    Science.gov (United States)

    Taylor, Lyla L.; Quirk, Joe; Thorley, Rachel M. S.; Kharecha, Pushker A.; Hansen, James; Ridgwell, Andy; Lomas, Mark R.; Banwart, Steve A.; Beerling, David J.

    2016-04-01

    Chemical breakdown of rocks, weathering, is an important but very slow part of the carbon cycle that ultimately leads to CO2 being locked up in carbonates on the ocean floor. Artificial acceleration of this carbon sink via distribution of pulverized silicate rocks across terrestrial landscapes may help offset anthropogenic CO2 emissions. We show that idealized enhanced weathering scenarios over less than a third of tropical land could cause significant drawdown of atmospheric CO2 and ameliorate ocean acidification by 2100. Global carbon cycle modelling driven by ensemble Representative Concentration Pathway (RCP) projections of twenty-first-century climate change (RCP8.5, business-as-usual; RCP4.5, medium-level mitigation) indicates that enhanced weathering could lower atmospheric CO2 by 30-300 ppm by 2100, depending mainly on silicate rock application rate (1 kg or 5 kg m-2 yr-1) and composition. At the higher application rate, end-of-century ocean acidification is reversed under RCP4.5 and reduced by about two-thirds under RCP8.5. Additionally, surface ocean aragonite saturation state, a key control on coral calcification rates, is maintained above 3.5 throughout the low latitudes, thereby helping maintain the viability of tropical coral reef ecosystems. However, we highlight major issues of cost, social acceptability, and potential unanticipated consequences that will limit utilization and emphasize the need for urgent efforts to phase down fossil fuel emissions.

  10. Municipalities' Preparedness for Weather Hazards and Response to Weather Warnings

    Science.gov (United States)

    Mehiriz, Kaddour; Gosselin, Pierre

    2016-01-01

    The study of the management of weather-related disaster risks by municipalities has attracted little attention even though these organizations play a key role in protecting the population from extreme meteorological conditions. This article contributes to filling this gap with new evidence on the level and determinants of Quebec municipalities’ preparedness for weather hazards and response to related weather warnings. Using survey data from municipal emergency management coordinators and secondary data on the financial and demographic characteristics of municipalities, the study shows that most Quebec municipalities are sufficiently prepared for weather hazards and undertake measures to protect the population when informed of imminent extreme weather events. Significant differences between municipalities were noted though. Specifically, the level of preparedness was positively correlated with the municipalities’ capacity and population support for weather-related disaster management policies. In addition, the risk of weather-related disasters increases the preparedness level through its effect on population support. We also found that the response to weather warnings depended on the risk of weather-related disasters, the preparedness level and the quality of weather warnings. These results highlight areas for improvement in the context of increasing frequency and/or severity of such events with current climate change. PMID:27649547

  11. Numerical modelling of the effect of weathering on the progressive failure of underground limestone mines

    CERN Document Server

    Ghabezloo, Siavash

    2008-01-01

    The observations show that the collapse of underground limestone mines results from a progressive failure due to gradual weathering of the rockmass. The following stages can be considered for the limestone weathering and degradation process in underground mines: condensation of the water on the roof of the gallery, infiltration of water in the porous rock, migration of the air CO2 molecules in the rock pore water by convection and molecular diffusion, dissolution of limestone by CO2 rich water and consequently, reduction of the strength properties of rock. Considering this process, a set of equations governing different hydrochemo-mechanical aspects of the weathering phenomenon and progressive failure occurring in these mines is presented. Then the feasibility of numerical modelling of this process is studied and a simple example of application is presented.

  12. Evolution of trees and mycorrhizal fungi intensifies silicate mineral weathering

    Science.gov (United States)

    Quirk, Joe; Beerling, David J.; Banwart, Steve A.; Kakonyi, Gabriella; Romero-Gonzalez, Maria E.; Leake, Jonathan R.

    2012-01-01

    Forested ecosystems diversified more than 350 Ma to become major engines of continental silicate weathering, regulating the Earth's atmospheric carbon dioxide concentration by driving calcium export into ocean carbonates. Our field experiments with mature trees demonstrate intensification of this weathering engine as tree lineages diversified in concert with their symbiotic mycorrhizal fungi. Preferential hyphal colonization of the calcium silicate-bearing rock, basalt, progressively increased with advancement from arbuscular mycorrhizal (AM) to later, independently evolved ectomycorrhizal (EM) fungi, and from gymnosperm to angiosperm hosts with both fungal groups. This led to ‘trenching’ of silicate mineral surfaces by AM and EM fungi, with EM gymnosperms and angiosperms releasing calcium from basalt at twice the rate of AM gymnosperms. Our findings indicate mycorrhiza-driven weathering may have originated hundreds of millions of years earlier than previously recognized and subsequently intensified with the evolution of trees and mycorrhizas to affect the Earth's long-term CO2 and climate history. PMID:22859556

  13. 风化岩地基全螺纹玻璃纤维增强聚合物抗浮锚杆承载特征现场试验%Field test on load-bearing characteristics of full-thread GFRP anti-floating anchor in weathered rock site

    Institute of Scientific and Technical Information of China (English)

    白晓宇; 张明义; 刘鹤; 寇海磊

    2014-01-01

    玻璃纤维增强聚合物(GFRP)抗浮锚杆是一种由树脂和玻璃纤维复合而成的新型材料,与传统的钢筋锚杆相比,它具有比强度高、耐腐蚀性强和抗电磁干扰能力强的优点。基于6根GFRP抗浮锚杆和4根钢筋抗浮锚杆现场足尺拉拔破坏性试验,研究了中风化花岗岩中GFRP抗浮锚杆的承载特征和界面黏结特性。试验结果表明,抗浮锚杆的破坏形式有2种:锚杆和砂浆界面剪切破坏,砂浆和围岩界面剪切破坏。直径为28 mm 的GFRP抗浮锚杆和钢筋抗浮锚杆的极限抗拔承载力均为225 kN,直径为32 mm GFRP抗浮锚杆极限抗拔承载力为250 kN,能够满足工程实际需要;GFRP抗浮锚杆与砂浆(第一界面)的平均黏结强度为1.50~1.54 MPa;GFRP抗浮锚杆砂浆与围岩(第二界面)的平均黏结强度为0.32~0.37 MPa,略低于钢筋抗浮锚杆第二界面的平均黏结强度;直径为32 mm的GFRP抗浮锚杆第二界面平均黏结强度高于直径为28 mm的GFRP抗浮锚杆。在此基础上,进一步分析论证了GFRP抗浮锚杆的破坏机制,为GFRP抗浮锚杆的工程应用提供了理论依据。%The glass fiber reinforced plastics(GFRP) anti-floating anchor is one kind of new materials which bonds by the resin and the glass fiber. Compared with the steel bar anchor rod, it has the high specific strength, nonelectric conductivity, nonmagnetic nature and corrosion resistance. Based on the full-scale drawing destructive field tests of six GFRP anti-floating anchor and four steel bolts, the load-bearing characteristics and interface bond properties of GFRP anti-floating anchor in moderately weathered granite are studied. By the test results, several conclusions are drawn:(1) There are two failure modes of anti-floating anchor as follows:shear failure between the anchorage rod and grout;and shear failure between the grout and surrounding rock mass. (2) Under the condition of M32.5 grout

  14. Investigation of Hydrologic and Geochemical Properties of an Unsaturated Waste Rock Pile at Key Lake, Saskatchewan

    Science.gov (United States)

    Stockwell, J.; Smith, L.; Beckie, R.

    2001-12-01

    Waste rock is any rock that must be removed to gain access to the ore at a mine. Waste rock piles at mine sites often rest above the water table, which exposes the rock to oxygen, and promotes the oxidation of sulfide minerals releasing sulfuric acid, metals and heat. Water flow through unsaturated waste rock and its role in geochemical processes is not well understood. The objective of this work was to identify spatial relationships between hydrologic and geochemical properties of waste rock. A 12-meter high waste rock pile was deconstructed and sampled during the summer of 2000. Approximately 175 samples were collected to assess the physical properties of matric potential, volumetric water content, and grain-size distribution and the geochemical properties of temperature, paste pH, pore-water chemistry, mineralogy, and bulk rock chemistry. In addition, we characterized weathering using selective extractions that target the weathering products that contain sulfur and iron. We discuss the influence of fluid flow paths, gain-size distribution, mineralogy and sample volume on the characterization of waste rock weathering.

  15. Principles of rock mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Turchaninov, I.A.; Iofis, M.A.; Kasparyan, E.V.

    1979-01-01

    This book presents the principles of rock mechanics in a systematic way, reflecting both the historic development and the contemporary status of theoretical and experimental techniques used for the determination of the properties and stress state of rock masses, calculation of elements of systems for exploitation of useful mineral deposits and the design of mine openings. The subject of rock mechanics is discussed and methods and basic approaches are analyzed. The most widely used methods for determining the properties of rock in specimens and in situ are described. Problems of determining the stress strain state of the rock around mine openings by both experimental and analytic methods are discussed. The primary results of the study of the stress state of rock around main, development and production openings are presented. Problems of the movement of rock due to extraction of minerals are analyzed in detail, as are the conditions and causes of the development of rock bursts and sudden release of rock and gas in both surface and underground mines. Procedures for preventing or localizing rock bursts or sudden outbursts are described. (313 refs.)

  16. The Weather in Richmond

    OpenAIRE

    Harless, William Edwin

    2014-01-01

    ABSTRACT: The Weather in Richmond is a short documentary about the Oilers, the football team at Richmond High School in downtown Richmond, California, as they struggle in 2012 with the legacy of winning no games, with the exception of a forfeit, in two years. The video documents the city of Richmond’s poverty and violence, but it also is an account of the city’s cultural diversity, of the city’s industrial history and of the hopes of some of the people who grow up there. The...

  17. Combating bad weather

    CERN Document Server

    Mukhopadhyay, Sudipta

    2015-01-01

    Every year lives and properties are lost in road accidents. About one-fourth of these accidents are due to low vision in foggy weather. At present, there is no algorithm that is specifically designed for the removal of fog from videos. Application of a single-image fog removal algorithm over each video frame is a time-consuming and costly affair. It is demonstrated that with the intelligent use of temporal redundancy, fog removal algorithms designed for a single image can be extended to the real-time video application. Results confirm that the presented framework used for the extension of the

  18. Severe Weather Forecast Decision Aid

    Science.gov (United States)

    Bauman, William H., III; Wheeler, Mark M.; Short, David A.

    2005-01-01

    This report presents a 15-year climatological study of severe weather events and related severe weather atmospheric parameters. Data sources included local forecast rules, archived sounding data, Cloud-to-Ground Lightning Surveillance System (CGLSS) data, surface and upper air maps, and two severe weather event databases covering east-central Florida. The local forecast rules were used to set threat assessment thresholds for stability parameters that were derived from the sounding data. The severe weather events databases were used to identify days with reported severe weather and the CGLSS data was used to differentiate between lightning and non-lightning days. These data sets provided the foundation for analyzing the stability parameters and synoptic patterns that were used to develop an objective tool to aid in forecasting severe weather events. The period of record for the analysis was May - September, 1989 - 2003. The results indicate that there are certain synoptic patterns more prevalent on days with severe weather and some of the stability parameters are better predictors of severe weather days based on locally tuned threat values. The results also revealed the stability parameters that did not display any skill related to severe weather days. An interactive web-based Severe Weather Decision Aid was developed to assist the duty forecaster by providing a level of objective guidance based on the analysis of the stability parameters, CGLSS data, and synoptic-scale dynamics. The tool will be tested and evaluated during the 2005 warm season.

  19. Geochemical and tectonic uplift controls on rock nitrogen inputs across terrestrial ecosystems

    Science.gov (United States)

    Morford, Scott L.; Houlton, Benjamin Z.; Dahlgren, Randy A.

    2016-02-01

    Rock contains > 99% of Earth's reactive nitrogen (N), but questions remain over the direct importance of rock N weathering inputs to terrestrial biogeochemical cycling. Here we investigate the factors that regulate rock N abundance and develop a new model for quantifying rock N mobilization fluxes across desert to temperate rainforest ecosystems in California, USA. We analyzed the N content of 968 rock samples from 531 locations and compiled 178 cosmogenically derived denudation estimates from across the region to identify landscapes and ecosystems where rocks account for a significant fraction of terrestrial N inputs. Strong coherence between rock N content and geophysical factors, such as protolith, (i.e. parent rock), grain size, and thermal history, are observed. A spatial model that combines rock geochemistry with lithology and topography demonstrates that average rock N reservoirs range from 0.18 to 1.2 kg N m-3 (80 to 534 mg N kg-1) across the nine geomorphic provinces of California and estimates a rock N denudation flux of 20-92 Gg yr-1 across the entire study area (natural atmospheric inputs ~ 140 Gg yr-1). The model highlights regional differences in rock N mobilization and points to the Coast Ranges, Transverse Ranges, and the Klamath Mountains as regions where rock N could contribute meaningfully to ecosystem N cycling. Contrasting these data to global compilations suggests that our findings are broadly applicable beyond California and that the N abundance and variability in rock are well constrained across most of the Earth system.

  20. Weathering of the New Albany Shale, Kentucky, USA: I. Weathering zones defined by mineralogy and major-element composition

    Science.gov (United States)

    Tuttle, M.L.W.; Breit, G.N.

    2009-01-01

    Comprehensive understanding of chemical and mineralogical changes induced by weathering is valuable information when considering the supply of nutrients and toxic elements from rocks. Here minerals that release and fix major elements during progressive weathering of a bed of Devonian New Albany Shale in eastern Kentucky are documented. Samples were collected from unweathered core (parent shale) and across an outcrop excavated into a hillside 40 year prior to sampling. Quantitative X-ray diffraction mineralogical data record progressive shale alteration across the outcrop. Mineral compositional changes reflect subtle alteration processes such as incongruent dissolution and cation exchange. Altered primary minerals include K-feldspars, plagioclase, calcite, pyrite, and chlorite. Secondary minerals include jarosite, gypsum, goethite, amorphous Fe(III) oxides and Fe(II)-Al sulfate salt (efflorescence). The mineralogy in weathered shale defines four weathered intervals on the outcrop-Zones A-C and soil. Alteration of the weakly weathered shale (Zone A) is attributed to the 40-a exposure of the shale. In this zone, pyrite oxidization produces acid that dissolves calcite and attacks chlorite, forming gypsum, jarosite, and minor efflorescent salt. The pre-excavation, active weathering front (Zone B) is where complete pyrite oxidation and alteration of feldspar and organic matter result in increased permeability. Acidic weathering solutions seep through the permeable shale and evaporate on the surface forming abundant efflorescent salt, jarosite and minor goethite. Intensely weathered shale (Zone C) is depleted in feldspars, chlorite, gypsum, jarosite and efflorescent salts, but has retained much of its primary quartz, illite and illite-smectite. Goethite and amorphous FE(III) oxides increase due to hydrolysis of jarosite. Enhanced permeability in this zone is due to a 14% loss of the original mass in parent shale. Denudation rates suggest that characteristics of Zone C

  1. NASA Space Weather Center Services: Potential for Space Weather Research

    Science.gov (United States)

    Zheng, Yihua; Kuznetsova, Masha; Pulkkinen, Antti; Taktakishvili, A.; Mays, M. L.; Chulaki, A.; Lee, H.; Hesse, M.

    2012-01-01

    The NASA Space Weather Center's primary objective is to provide the latest space weather information and forecasting for NASA's robotic missions and its partners and to bring space weather knowledge to the public. At the same time, the tools and services it possesses can be invaluable for research purposes. Here we show how our archive and real-time modeling of space weather events can aid research in a variety of ways, with different classification criteria. We will list and discuss major CME events, major geomagnetic storms, and major SEP events that occurred during the years 2010 - 2012. Highlights of major tools/resources will be provided.

  2. Road Weather and Connected Vehicles

    Science.gov (United States)

    Pisano, P.; Boyce, B. C.

    2015-12-01

    On average, there are over 5.8 M vehicle crashes each year of which 23% are weather-related. Weather-related crashes are defined as those crashes that occur in adverse weather or on slick pavement. The vast majority of weather-related crashes happen on wet pavement (74%) and during rainfall (46%). Connected vehicle technologies hold the promise to transform road-weather management by providing improved road weather data in real time with greater temporal and geographic accuracy. This will dramatically expand the amount of data that can be used to assess, forecast, and address the impacts that weather has on roads, vehicles, and travelers. The use of vehicle-based measurements of the road and surrounding atmosphere with other, more traditional weather data sources, and create road and atmospheric hazard products for a variety of users. The broad availability of road weather data from mobile sources will vastly improve the ability to detect and forecast weather and road conditions, and will provide the capability to manage road-weather response on specific roadway links. The RWMP is currently demonstrating how weather, road conditions, and related vehicle data can be used for decision making through an innovative Integrated Mobile Observations project. FHWA is partnering with 3 DOTs (MN, MI, & NV) to pilot these applications. One is a mobile alerts application called the Motorists Advisories and Warnings (MAW) and a maintenance decision support application. These applications blend traditional weather information (e.g., radar, surface stations) with mobile vehicle data (e.g., temperature, brake status, wiper status) to determine current weather conditions. These weather conditions, and other road-travel-relevant information, are provided to users via web and phone applications. The MAW provides nowcasts and short-term forecasts out to 24 hours while the EMDSS application can provide forecasts up to 72 hours in advance. The three DOTs have placed readers and external

  3. Why is there no Universal Law for Rock Wall Retreat?

    Science.gov (United States)

    Krautblatter, Michael; Moore, Jeffrey

    2016-04-01

    Comparing studies of rock slope erosion and soil slope erosion, we find no governing equation similar to the universal soil loss equation for rock slopes. Rock masses in contact with the atmosphere are affected by a suite of physical, chemical and biological processes which degrade intact rock, creating new fractures and extending existing flaws. Complex feedbacks must be explored between changing slope boundary conditions, stress redistribution and fracturing, and weathering by external mechanisms. Rock slope systems are distinguished from soil slope systems by the fundamental nonlinear properties of rock masses. Rock masses represent discontinuous, inhomogeneous, anisotropic, and nonlinearly elastic materials, and contain a record of millions of years of thermal, hydrological, mechanical and chemical (THMC) processes. The origin and evolution of rock mass strength over time can significantly affect bedrock erodibility and engineering performance, the study of which represents a major chance and challenge for the geoscience community. The imprint of THMC processes on rock properties begins with the geological genesis of rocks; however, a significant degree of material behaviour evolves coincidently with the exhumation and evolution of topography. Thus, fracture generation has been investigated as the result of the environmental stress history in geology and geomorphology, partly modulated by incision and topographic stress evolution. Resultant fracture patterns control the degree of discontinuity heterogeneity, anisotropy, and nonlinear mechanical behaviour over millions of years. Here we discuss important novel conceptual approaches to temporally and spatially decipher nonlinear effects on rock slope erosion including incision-related topographic stresses, rock fatigue, paraglacial and paracratering effects etc. and how they could contribute to a more uniform understanding of rockwall retreat.

  4. Rough weather rescue

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    This report, which was commissioned by the Offshore Division of the Health and Safety Executive, reviews the type of equipment and techniques used to rescue people from the water around offshore platforms in rough weather. It also examines the limitations of the equipment in extreme conditions and reports the views of the various industry sectors (as determined by a questionnaire survey). The type of incidents covered by the report include: man overboard; helicopter ditching; and evacuation from totally enclosed motor propelled survival craft (TEMPSC) and life rafts. The report considers: the approach taken by other oil-producing countries; current escape, evacuation and rescue (EER) practices for the UK Continental Shelf (UKCS); environmental limits; methods for rescue and recovery from the water and TEMPSC; launch and recovery systems; fast rescue craft (FSC) and daughter craft; emergency response and rescue vessels; helicopters; casualty personal protection equipment; claimed versus actual equipment performance; training and practice procedures; attitudes to environmental limits; lessons learnt from incidents; mechanical recovery devices; equipment design and use in rough weather; and recommendations for improvements.

  5. Weatherization Apprenticeship Program

    Energy Technology Data Exchange (ETDEWEB)

    Watson, Eric J

    2012-12-18

    Weatherization improvement services will be provided to Native people by Native people. The proposed project will recruit, train and hire two full-time weatherization technicians who will improve the energy efficiency of homes of Alaska Natives/American Indians residing in the Indian areas, within the Cook Inlet Region of Alaska. The Region includes Anchorage as well as 8 small tribal villages: The Native Villages of Eklutna, Knik, Chickaloon, Seldovia, Ninilchik, Kenaitze, Salamatof, and Tyonek. This project will be a partnership between three entities, with Cook Inlet Tribal Council (CITC) as the lead agency: CITCA's Employment and Training Services Department, Cook Inlet Housing Authority and Alaska Works Partnership. Additionally, six of the eight tribal villages within the Cook Inlet Region of Alaska have agreed to work with the project in order to improve the energy efficiency of their tribally owned buildings and homes. The remaining three villages will be invited to participate in the establishment of an intertribal consortium through this project. Tribal homes and buildings within Anchorage fall under Cook Inlet Region, Inc. (CIRI) tribal authority.

  6. Isotopic composition of uranium and thorium in crystalline rocks

    Science.gov (United States)

    Rosholt, John N.

    1983-09-01

    The 238U-234U-230Th-232Th system has been investigated in 84 silicic crystalline rocks obtained from drill cores, surface, and near-surface samples in California, Wyoming, Colorado, and Illinois. Results of these analyses displayed on ternary diagrams with apexes for 238U, 234U, and 230Th indicate five predominant geochemical processes that affected uranium in the rock: (1) bulk uranium leaching where 238U and 234U were removed with little or no fractionation; (2) preferential 234U leaching by alpha recoil displacement (234U recoil loss) with lesser 238U loss; (3) 234U recoil loss with little or no 238U loss; (4) uranium assimilation where both 238U and 234U were added with present-day 234U/238U activity ratios varying from 0.8 to 1.2; and (5) addition of 234U and 230Th by daughter emplacement processes (234U + 230Th recoil gain). Evidence for the existence of 234U and 230Th recoil gain in rocks is the most important finding of this investigation. Radioactive disequilibrium occurs in the majority of rocks analyzed where 234U recoil loss is the predominant process associated with incipient weathering; U assimilation and 234U+230Th recoil gain occur under conditions of substantial water penetration along fractures and into weathered zones in the rocks. Relatively unfractured and petrographically fresh rocks from the UPH-3 drill hole in northern Illinois are closest to being in radioactive equilibrium for any suite of rocks included in this study, and they demonstrate that equilibrium during the last 0.5 m.y. can be maintained over a substantial vertical distance where there has been little or no movement of water in the basement rock. The 238U-234U-230Th system can be a sensitive indicator of geologically recent U mobility and rock/water interaction both in petrographically fresh core samples and in `sealed' fracture zones.

  7. Space Weather- Physics and Effects

    CERN Document Server

    Bothmer, Volker

    2007-01-01

    This book is a state-of-the-art review on the physics of space weather and on space weather impacts on human technology, including manned spaceflight. With contributions from a team of international experts, this comprehensive work covers all aspects of space weather physical processes, and all known aspects of space hazards from humans, both in space and on Earth. Space Weather - Physics and Effects provides the first comprehensive, scientific background of space storms caused by the sun and its impact on geospace focuses on weather issues that have become vital for the development of nationwide technological infrastructures explains magnetic storms on Earth, including the effects of EUV radiation on the atmosphere is an invaluable aid in establishing real-time weather forecasts details the threat that solar effects might have on modern telecommunication systems, including national power grid systems, aircraft and manned spaceflight.

  8. Weather Forecasting Systems and Methods

    Science.gov (United States)

    Mecikalski, John (Inventor); MacKenzie, Wayne M., Jr. (Inventor); Walker, John Robert (Inventor)

    2014-01-01

    A weather forecasting system has weather forecasting logic that receives raw image data from a satellite. The raw image data has values indicative of light and radiance data from the Earth as measured by the satellite, and the weather forecasting logic processes such data to identify cumulus clouds within the satellite images. For each identified cumulus cloud, the weather forecasting logic applies interest field tests to determine a score indicating the likelihood of the cumulus cloud forming precipitation and/or lightning in the future within a certain time period. Based on such scores, the weather forecasting logic predicts in which geographic regions the identified cumulus clouds will produce precipitation and/or lighting within during the time period. Such predictions may then be used to provide a weather map thereby providing users with a graphical illustration of the areas predicted to be affected by precipitation within the time period.

  9. Mars rover rock abrasion tool performance enhanced by ultrasonic technology.

    Science.gov (United States)

    Macartney, A.; Li, X.; Harkness, P.

    2016-12-01

    The Mars exploration Athena science goal is to explore areas where water may have been present on the early surface of Mars, and investigate the palaeo-environmental conditions of these areas in relation to the existence of life. The Rock Abrasion Tool (RAT) designed by Honeybee Robotics has been one of four key Athena science payload instruments mounted on the mechanical arm of the Spirit, Opportunity and Curiosity Mars Exploration Rovers. Exposed rock surfaces weather and chemically alter over time. Although such weathered rock can present geological interest in itself, there is a limit to what can be learned. If the geological history of a landing site is to be constructed, then it is important to analyse the unweathered rock interior as clearly as possible. The rock abrasion tool's role is to substitute for a geologist's hammer, removing the weathered and chemically altered outer surface of rocks in order to view the pristine interior. The RAT uses a diamond resin standard common grinding technique, producing a 5mm depth grind with a relatively high surface roughness, achieved over a number of hours per grind and consumes approximately 11 watts of energy. This study assesses the benefits of using ultrasonic assisted grinding to improve surface smoothness. A prototype Micro-Optic UltraSonic Exfoliator (MOUSE) is tested on a range of rock types and demonstrates a number of advantages over the RAT. In addition to a smoother grind finish, these advantages include a lower rate of tool tip wear when using a tungsten carbide tip as opposed to diamond resin, less moving parts, a grind speed of minutes instead of hours, and a power consumption of only 1-5 Watts.

  10. Lithium isotopes in speleothems: Temperature-controlled variation in silicate weathering during glacial cycles

    Science.gov (United States)

    Pogge von Strandmann, Philip A. E.; Vaks, Anton; Bar-Matthews, Miryam; Ayalon, Avner; Jacob, Ezekiel; Henderson, Gideon M.

    2017-07-01

    Terrestrial chemical weathering of silicate minerals is a fundamental component of the global cycle of carbon and other elements. Past changes in temperature, rainfall, ice cover, sea-level and physical erosion are thought to affect weathering but the relative impact of these controls through time remains poorly constrained. This problem could be addressed if the nature of past weathering could be constrained at individual sites. In this study, we investigate the use of speleothems as local recorders of the silicate weathering proxy, Li isotopes. We analysed δ7 Li and [Li] in speleothems that formed during the past 200 ka in two well-studied Israeli caves (Soreq and Tzavoa), as well as in the overlying soils and rocks. Leaching and mass balance of these soils and rocks show that Li is dominantly sourced from weathering of the overlying aeolian silicate soils. Speleothem δ7 Li values are ubiquitously higher during glacials (∼23‰) than during interglacials (∼10‰), implying more congruent silicate weathering during interglacials (where ;congruent; means a high ratio of primary mineral dissolution to secondary mineral formation). These records provide information on the processes controlling weathering in Israel. Consideration of possible processes causing this change of weathering congruency indicates a primary role for temperature, with higher temperatures causing more congruent weathering (lower δ7Lispeleo). The strong relationship observed between speleothem δ7 Li and climate at these locations suggests that Li isotopes may be a powerful tool with which to understand the local controls on weathering at other sites, and could be used to assess the distribution of weathering changes accompanying climate change, such as that of Pleistocene glacial cycles.

  11. Cenozoic carbon cycle imbalances and a variable weathering feedback

    Science.gov (United States)

    Caves, Jeremy K.; Jost, Adam B.; Lau, Kimberly V.; Maher, Kate

    2016-09-01

    The long-term stability of Earth's climate and the recovery of the ocean-atmosphere system after carbon cycle perturbations are often attributed to a stabilizing negative feedback between silicate weathering and climate. However, evidence for the operation of this feedback over million-year timescales and in response to tectonic and long-term climatic change remains scarce. For example, the past 50 million years of the Cenozoic Era are characterized by long-term cooling and declining atmospheric CO2 (pCO2). During this interval, constant or decreasing carbon fluxes from the solid Earth to the atmosphere suggest that stable or decreasing weathering fluxes are needed to balance the carbon cycle. In contrast, marine isotopic proxies of weathering (i.e., 87Sr/86Sr, δ7 Li , and 187Os/188Os) are interpreted to reflect increasing weathering fluxes. Here, we evaluate the existence of a negative feedback by reconstructing the imbalance in the carbon cycle during the Cenozoic using the surface inventories of carbon and alkalinity. Only a sustained 0.25-0.5% increase in silicate weathering is necessary to explain the long-term decline in pCO2 over the Cenozoic. We propose that the long-term decrease in pCO2 is due to an increase in the strength of the silicate weathering feedback (i.e., the constant of proportionality between the silicate weathering flux and climate), rather than an increase in the weathering flux. This increase in the feedback strength, which mirrors the marine isotope proxies, occurs as transient, 1 million year timescales remains invariant to match the long-term inputs of carbon. Over the Cenozoic, this results in stable long-term weathering fluxes even as pCO2 decreases. We attribute increasing feedback strength to a change in the type and reactivity of rock in the weathering zone, which collectively has increased the reactivity of the surface of the Earth. Increasing feedback strength through the Cenozoic reconciles mass balance in the carbon cycle with

  12. Small Sensors for Space Weather

    Science.gov (United States)

    Nicholas, A. C.

    2015-12-01

    The Naval Research Laboratory is actively pursuing enhancing the nation's space weather sensing capability. One aspect of this plan is the concept of flying Space Weather sensor suites on host spacecraft as secondary payloads. The emergence and advancement of the CubeSat spacecraft architecture has produced a viable platform for scientifically and operationally relevant Space Weather sensing. This talk will provide an overview of NRL's low size weight and power sensor technologies targeting Space Weather measurements. A summary of on-orbit results of past and current missions will be presented, as well as an overview of future flights that are manifested and potential constellation missions.

  13. Bishop Paiute Weatherization Training Program

    Energy Technology Data Exchange (ETDEWEB)

    Carlos Hernandez

    2010-01-28

    The DOE Weatherization Training Grant assisted Native American trainees in developing weatherization competencies, creating employment opportunities for Bishop Paiute tribal members in a growing field. The trainees completed all the necessary training and certification requirements and delivered high-quality weatherization services on the Bishop Paiute Reservation. Six tribal members received all three certifications for weatherization; four of the trainees are currently employed. The public benefit includes (1) development of marketable skills by low-income Native individuals, (2) employment for low-income Native individuals in a growing industry, and (3) economic development opportunities that were previously not available to these individuals or the Tribe.

  14. Study of the engineering geologic feature of weathering zone of bedrock in 810 producing area of Luling Mine

    Institute of Scientific and Technical Information of China (English)

    桂和荣; 孙家斌; 李明好; 李伟; 尹正柱; 陈富勇; 宋晓梅

    2002-01-01

    For a safe extracting of the mine resource of the razor-thin capping rock, a study of waterproof, sand prevention, roof-fall prevention must be made. As a result, its necessary to master the engineering feature of weathering zone of bedrock. According to the lithology appraisal and X diffract analyses, the mineral feature of weathering zone of bedrock in 810 producing area has been studied in this article. By testing the physical mechanics index of weathering zone, we have found out some features of physical mechanic quality. Utilizing the determined result of viscosity index and slaking test, we reach a conclusion of the water stability of weathering zone, that is the weathering zone rock belongs to the type that is easily slaked when encountered water and the water stability is weak.

  15. Characteristics of terrestrial basaltic rock populations: Implications for Mars lander and rover science and safety

    Science.gov (United States)

    Craddock, Robert A.; Golombek, Matthew P.

    2016-08-01

    We analyzed the morphometry of basaltic rock populations that have been emplaced or affected by a variety of geologic processes, including explosive volcanic eruptions (as a proxy for impact cratering), catastrophic flooding, frost shattering, salt weathering, alluvial deposition, and chemical weathering. Morphometric indices for these rock populations were compared to an unmodified population of rocks that had broken off a solidified lava flow to understand how different geologic processes change rock shape. We found that a majority of rocks have an sphericity described as either a disc or sphere in the Zingg classification system and posit that this is a function of cooling fractures in the basalt (Zingg [1935] Schweiz. Miner. Petrogr. Mitt., 15, 39-140). Angularity (roundness) is the most diagnostic morphometric index, but the Corey Shape Factor (CSF), Oblate-Prolate Index (OPI) and deviation from compactness (D) also sometimes distinguished weathering processes. Comparison of our results to prior analyses of rock populations found at the Mars Pathfinder, Spirit, and Curiosity landing sites support previous conclusions. The observation that the size-frequency distribution of terrestrial rock populations follow exponential functions similar to lander and orbital measurements of rocks on Mars, which is expected from fracture and fragmentation theory, indicates that these distributions are being dominantly controlled by the initial fracture and fragmentation of the basalt.

  16. Understanding the signature of rock coatings in laser-induced breakdown spectroscopy data

    Science.gov (United States)

    Lanza, Nina L.; Ollila, Ann M.; Cousin, Agnes; Wiens, Roger C.; Clegg, Samuel M.; Mangold, Nicolas; Bridges, Nathan; Cooper, Daniel; Schmidt, Mariek E.; Berger, Jeffrey; Arvidson, Raymond E.; Melikechi, Noureddine; Newsom, Horton E.; Tokar, Robert; Hardgrove, Craig; Mezzacappa, Alissa; Jackson, Ryan S.; Clark, Benton C.; Forni, Olivier; Maurice, Sylvestre; Nachon, Marion; Anderson, Ryan B.; Blank, Jennifer; Deans, Matthew; Delapp, Dorothea; Léveillé, Richard; McInroy, Rhonda; Martinez, Ronald; Meslin, Pierre-Yves; Pinet, Patrick

    2015-01-01

    Surface compositional features on rocks such as coatings and weathering rinds provide important information about past aqueous environments and water–rock interactions. The search for these features represents an important aspect of the Curiosity rover mission. With its unique ability to do fine-scale chemical depth profiling, the ChemCam laser-induced breakdown spectroscopy instrument (LIBS) onboard Curiosity can be used to both identify and analyze rock surface alteration features. In this study we analyze a terrestrial manganese-rich rock varnish coating on a basalt rock in the laboratory with the ChemCam engineering model to determine the LIBS signature of a natural rock coating. Results show that there is a systematic decrease in peak heights for elements such as Mn that are abundant in the coating but not the rock. There is significant spatial variation in the relative abundance of coating elements detected by LIBS depending on where on the rock surface sampled; this is due to the variability in thickness and spatial discontinuities in the coating. Similar trends have been identified in some martian rock targets in ChemCam data, suggesting that these rocks may have coatings or weathering rinds on their surfaces.

  17. High potential for chemical weathering and climate effects of early lichens and bryophytes in the Late Ordovician

    Science.gov (United States)

    Porada, Philipp; Lenton, Tim; Pohl, Alexandre; Weber, Bettina; Mander, Luke; Donnadieu, Yannick; Beer, Christian; Pöschl, Ulrich; Kleidon, Axel

    2016-04-01

    Non-vascular vegetation in the Late Ordovician may have considerably increased global chemical weathering, thereby reducing atmospheric CO2 concentration and contributing to a decrease in global temperature and the onset of glaciations. Usually, enhancement of weathering by non-vascular vegetation is estimated using field experiments which are limited to small areas and a low number of species. This makes it difficult to extrapolate to the global scale and to climatic conditions of the past, which differ markedly from the recent climate. Here we present a global, spatially explicit modelling approach to estimate chemical weathering by non-vascular vegetation in the Late Ordovician. During this period, vegetation probably consisted of early forms of today's lichens and bryophytes. We simulate these organisms with a process-based model, which takes into account their physiological diversity by representing multiple species. The productivity of lichens and bryophytes is then related to chemical weathering of surface rocks. The rationale is that the organisms dissolve rocks to extract phosphorus for the production of new biomass. To account for the limited supply of unweathered rock material in shallow regions, we cap biotic weathering at the erosion rate. We estimate a potential global weathering flux of 10.2 km3 yr-1 of rock, which is around 12 times larger than today's global chemical weathering. The high weathering potential implies a considerable impact of lichens and bryophytes on atmospheric CO2 concentration in the Ordovician. Moreover, we find that biotic weathering is highly sensitive to atmospheric CO2, which suggests a strong feedback between chemical weathering by lichens and bryophytes and climate.

  18. Using Forecasting to Teach Weather Science

    Science.gov (United States)

    Tsubota, Y.; Takahashi, T.

    2009-09-01

    Weather affects our lives and hence, is a popular topic in daily conversations and in the media. Therefore, it is not only important to teach weather, but is also a good idea to use 'weather' as a topic in science teaching. Science education has two main objectives: to acquire scientific concepts and methods. Weather forecasting is an adequate theme to teach scientific methods because it is dependent on observation. However, it is not easy to forecast weather using only temporal observation. We need to know the tendency of 'weather change' via consecutive and/or continuous weather observation. Students will acquire scientific-observation skills through weather observation. Data-processing skills would be enhanced through a weather-forecasting contest. A contest should be announced within 5 days of school events, such as a school excursion and field day. Students submit their own weather forecast by gathering weather information through the internet, news paper and so on. A weather-forecasting contest compels the student to observe the weather more often. We currently have some different weather forecasts. For example, American weather-related companies such as ACCU weather and Weather Channel provide weather forecast for the many locations all over the world. Comparing these weather forecasting with actual weather, participants such as students could evaluate the differences between forecasted and actual temperatures. Participants will judge the best weather forecast based on the magnitude of the difference. Also, participants evaluate the 'hitting ratio' of each weather forecast. Students can learn elementary statistics by comparing various weather forecasts. We have developed our weather web-site that provides our own weather forecasting and observation. Students acquire science skills using our weather web-site. We will report our lessen plans and explain our weather web-site.

  19. Rock Cycle Roulette.

    Science.gov (United States)

    Schmidt, Stan M.; Palmer, Courtney

    2000-01-01

    Introduces an activity on the rock cycle. Sets 11 stages representing the transitions of an earth material in the rock cycle. Builds six-sided die for each station, and students move to the stations depending on the rolling side of the die. Evaluates students by discussing several questions in the classroom. Provides instructional information for…

  20. Some topics on geochemistry of weathering: a review

    Directory of Open Access Journals (Sweden)

    Milton L.L. Formoso

    2006-12-01

    Full Text Available Weathering is a complex process comprising physical disaggregation, chemical and biological decomposition of rocks and minerals transforming complex structure minerals in simpler ones. Hydrolysis of silicates is perhaps the most important process but associated certainly to biological weathering. It is discussed the role ofwaters: activities/concentrations of chemical species, pH, Eh, importance of complexes. Weathering is not only a destructive process. It can concentrate chemical species and form mineral deposits (kaolin, bauxite, Fe, Mn, P, Nb, Au. Weathering studies are important in pedology, engineering geology, hydrogeology, paleoclimatology and ecology. The use of stonemeal is based upon the study of rock weathering.Intemperismo é um processo complexo compreendendo desagregação física, decomposição química e biológica de rochas e minerais transformando minerais de estrutura complexa em estruturas mais simples. Hidrólise de silicates é talvez o mais importante mas certamente associado ao intemperismo biológico. É discutido o papel da água: atividades/concentrações de espécies químicas, pH, Eh, importância dos complexos. Intemperismo não é somente um processo destrutivo. O intemperismo pode concentrar espécies químicas e formar depósitos minerais (caolim, bauxita, Fe, Mn, P, Nb, Au. Estudos de intemperismo são importantes em pedologia, geologia de engenharia, hidrogeologia, paleoclimatologia e ecologia. O uso de rochagem é baseado em estudo de intemperismo de rocha.

  1. The weathering of micrometeorites from the Transantarctic Mountains

    Science.gov (United States)

    van Ginneken, Matthias; Genge, Matthew J.; Folco, Luigi; Harvey, Ralph P.

    2016-04-01

    Micrometeorites are cosmic dust particles recovered from the Earth's surface that dominate the influx of extraterrestrial material accreting to our planet. This paper provides the first in-depth study of the weathering of micrometeorites within the Antarctic environment that will allow primary and secondary features to be distinguished. It is based on the analysis of 366 particles from Larkman Nunatak and 25 from the Transantarctic Mountain collection. Several important morphological categories of weathering effects were identified: (1) irregular and faceted cavities, (2) surface etch pits, (3) infilled cavities, (4) replaced silicate phases, and (5) hydrated and replaced metal. These features indicate that congruent dissolution of silicate phases, in particular olivine, is important in generating new pore space within particles. Comparison of the preservation of glass and olivine also indicates preferential dissolution of olivine by acidic solutions during low temperature aqueous alteration. Precipitation of new hydrous phases within cavities, in particular ferrihydrite and jarosite, results in pseudomorph textures within heavily altered particles. Glass, in contrast, is altered to palagonite gels and shows a sequential replacement indicative of varying water to rock ratios. Metal is variably replaced by Fe-oxyhydroxides and results in decreases in Ni/Fe ratio. In contrast, sulphides within metal are largely preserved. Magnetite, an essential component of micrometeorites formed during atmospheric entry, is least altered by interaction with the terrestrial environment. The extent of weathering in the studied micrometeorites is sensitive to differences in their primary mineralogy and varies significantly with particle type. Despite these differences, we propose a weathering scale for micrometeorites based on both their degree of terrestrial alteration and the level of encrustation by secondary phases. The compositions and textures of weathering products, however

  2. Weather Fundamentals: Hurricanes & Tornadoes. [Videotape].

    Science.gov (United States)

    1998

    The videos in this educational series, for grades 4-7, help students understand the science behind weather phenomena through dramatic live-action footage, vivid animated graphics, detailed weather maps, and hands-on experiments. This episode (23 minutes) features information on the deadliest and most destructive storms on Earth. Through satellite…

  3. Tibetan History of Weather Monitoring

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    Modem weather monitoring began in Tibet at the end of the 19th century. In 1894, the British set up a weather monitoting station in Chunpei of Yadong,which continued to operate until August 1956. In the 1940s, the Nationalist Govemment's Ministry of Communications set up a rainfall measuring station in Qamdo, Xikang Province.

  4. Weather Modification: Finding Common Ground.

    Science.gov (United States)

    Garstang, Michael; Bruintjes, Roelof; Serafin, Robert; Orville, Harold; Boe, Bruce; Cotton, William; Warburton, Joseph

    2005-05-01

    Research and operational approaches to weather modification expressed in the National Research Council's 2003 report on “Critical Issues in Weather Modification Research” and in the Weather Modification Association's response to that report form the basis for this discussion. There is agreement that advances in the past few decades over a broad front of understanding physical processes and in technology have not been comprehensively applied to weather modification. Such advances need to be capitalized upon in the form of a concerted and sustained national effort to carry out basic and applied research in weather modification. The need for credible scientific evidence and the pressure for action should be resolved. Differences in the perception of current knowledge, the utility of numerical models, and the specific needs of research and operations in weather modification must be addressed. The increasing demand for water and the cost to society inflicted by severe weather require that the intellectual, technical, and administrative resources of the nation be combined to resolve whether and to what degree humans can influence the weather.The National Center for Atmospheric Research is sponsored by the National Science Foundation

  5. Japanese space weather research activities

    Science.gov (United States)

    Ishii, M.

    2017-01-01

    In this paper, we present existing and planned Japanese space weather research activities. The program consists of several core elements, including a space weather prediction system using numerical forecasts, a large-scale ground-based observation network, and the cooperative framework "Project for Solar-Terrestrial Environment Prediction (PSTEP)" based on a Grant-in Aid for Scientific Research on Innovative Areas.

  6. Weather to Make a Decision

    Science.gov (United States)

    Hoyle, Julie E.; Mjelde, James W.; Litzenberg, Kerry K.

    2006-01-01

    DECIDE is a teacher-friendly, integrated approach designed to stimulate learning by allowing students to make decisions about situations they face in their lives while using scientific weather principles. This learning unit integrates weather science, decision theory, mathematics, statistics, geography, and reading in a context of decision…

  7. Enhanced oxidative weathering in glaciated mountain catchments: A stabilising feedback on atmospheric carbon dioxide?

    Science.gov (United States)

    Horan, K.; Hilton, R. G.; Burton, K. W.; Selby, D. S.; Ottley, C. J.

    2015-12-01

    Mountain belts act as sources of carbon dioxide (CO2) to the atmosphere if physical erosion and exhumation expose rock-derived organic carbon ('petrogenic' organic carbon, OCpetro) to chemical weathering. Estimates suggest 15x1021g of carbon is stored in rocks globally as OCpetro, ~25,000 times the amount of carbon in the pre-industrial atmosphere. Alongside volcanic and metamorphic degassing, OCpetro weathering is thought to be the main source of CO2 to the atmosphere over geological timescales. Erosion in mountain river catchments has been shown to enhance oxidative weathering and CO2 release. However, we still lack studies which quantify this process. In addition, it is not clear how glaciation may impact OCpetro oxidation. In analogy with silicate weathering, large amounts of fine sediment in glacial catchments may enhance oxidative weathering. Here we quantify oxidative weathering in nine catchments draining OCpetro bearing rocks in the western Southern Alps, New Zealand. Using rhenium (Re) as a tracer of oxidative weathering, we develop techniques to precisely measure Re concentration at sub-ppt levels in river waters. Using [Re]water/[Re]rock as a weathering tracer, we estimate that the weathering efficiency in glacial catchments is >4 times that of non-glacial catchments. Combining this with the OCpetro content of rocks and dissolved Re flux, we estimate the CO2 release by OCpetro oxidation. The analysis suggests that non-glacial catchments in the western Southern Alps release similar amounts of CO2 as catchments in Taiwan where erosion rates are comparable. In this mountain belt, the CO2 release does not negate CO2 drawdown by silicate weathering and by riverine transfer of organic matter. Based on our results, we propose that mountain glaciation may greatly enhance OCpetro oxidation rates. Depending on the global fluxes involved, this provides a feedback to damp low atmospheric CO2 levels and global cooling. During glacial periods (low CO2, low global

  8. Cool Stars and Space Weather

    CERN Document Server

    Vidotto, A A; Cameron, A C; Morin, J; Villadsen, J; Saar, S; Alvarado, J; Cohen, O; Holzwarth, V; Poppenhaeger, K; Reville, V

    2014-01-01

    Stellar flares, winds and coronal mass ejections form the space weather. They are signatures of the magnetic activity of cool stars and, since activity varies with age, mass and rotation, the space weather that extra-solar planets experience can be very different from the one encountered by the solar system planets. How do stellar activity and magnetism influence the space weather of exoplanets orbiting main-sequence stars? How do the environments surrounding exoplanets differ from those around the planets in our own solar system? How can the detailed knowledge acquired by the solar system community be applied in exoplanetary systems? How does space weather affect habitability? These were questions that were addressed in the splinter session "Cool stars and Space Weather", that took place on 9 Jun 2014, during the Cool Stars 18 meeting. In this paper, we present a summary of the contributions made to this session.

  9. Detection of Weather Radar Clutter

    DEFF Research Database (Denmark)

    Bøvith, Thomas

    2008-01-01

    Weather radars provide valuable information on precipitation in the atmosphere but due to the way radars work, not only precipitation is observed by the weather radar. Weather radar clutter, echoes from non-precipitating targets, occur frequently in the data, resulting in lowered data quality....... Especially in the application of weather radar data in quantitative precipitation estimation and forecasting a high data quality is important. Clutter detection is one of the key components in achieving this goal. This thesis presents three methods for detection of clutter. The methods use supervised...... and precipitating and non-precipitating clouds. Another method uses the difference in the motion field of clutter and precipitation measured between two radar images. Furthermore, the direction of the wind field extracted from a weather model is used. The third method uses information about the refractive index...

  10. Quantifying chemical weathering rates along a precipitation gradient on Basse-Terre Island, French Guadeloupe: New insight from U-series isotopes in weathering rinds

    Science.gov (United States)

    Engel, Jacqueline M.; Ma, Lin; Sak, Peter B.; Gaillardet, Jerome; Ren, Minghua; Engle, Mark A.; Brantley, Susan L.

    2016-12-01

    Inside soil and saprolite, rock fragments can form weathering clasts (alteration rinds surrounding an unweathered core) and these weathering rinds provide an excellent field system for investigating the initiation of weathering and long term weathering rates. Recently, uranium-series (U-series) disequilibria have shown great potential for determining rind formation rates and quantifying factors controlling weathering advance rates in weathering rinds. To further investigate whether the U-series isotope technique can document differences in long term weathering rates as a function of precipitation, we conducted a new weathering rind study on tropical volcanic Basse-Terre Island in the Lesser Antilles Archipelago. In this study, for the first time we characterized weathering reactions and quantified weathering advance rates in multiple weathering rinds across a steep precipitation gradient. Electron microprobe (EMP) point measurements, bulk major element contents, and U-series isotope compositions were determined in two weathering clasts from the Deshaies watershed with mean annual precipitation (MAP) = 1800 mm and temperature (MAT) = 23 °C. On these clasts, five core-rind transects were measured for locations with different curvature (high, medium, and low) of the rind-core boundary. Results reveal that during rind formation the fraction of elemental loss decreases in the order: Ca ≈ Na > K ≈ Mg > Si ≈ Al > Zr ≈ Ti ≈ Fe. Such observations are consistent with the sequence of reactions after the initiation of weathering: specifically, glass matrix and primary minerals (plagioclase, pyroxene) weather to produce Fe oxyhydroxides, gibbsite and minor kaolinite. Uranium shows addition profiles in the rind due to the infiltration of U-containing soil pore water into the rind as dissolved U phases. U is then incorporated into the rind as Fe-Al oxides precipitate. Such processes lead to significant U-series isotope disequilibria in the rinds. This is the first time

  11. Experiments and Spectral Studies of Martian Volcanic Rocks: Implications for the Origin of Pathfinder Rocks and Soils

    Science.gov (United States)

    Rutherford, Malcolm J.; Mustard, Jack; Weitz, Catherine

    2002-01-01

    The composition and spectral properties of the Mars Pathfinder rocks and soils together with the identification of basaltic and andesitic Mars terrains based on Thermal Emission Spectrometer (TES) data raised interesting questions regarding the nature and origin of Mars surface rocks. We have investigated the following questions: (1) are the Pathfinder rocks igneous and is it possible these rocks could have formed by known igneous processes, such as equilibrium or fractional crystallization, operating within SNC magmas known to exist on Mars? If it is possible, what P (depth) and PH2O conditions are required? (2) whether TES-based interpretations of plagioclase-rich basalt and andesitic terrains in the south and north regions of Mars respectively are unique. Are the surface compositions of these regions plagioclase-rich, possibly indicating the presence of old AI-rich crust of Mars, or are the spectra being affected by something like surface weathering processes that might determine the spectral pyroxene to plagioclase ratio?

  12. CRITERIA FOR ROCK ENGINEERING FAILURE

    Institute of Scientific and Technical Information of China (English)

    ZHUDeren; ZHANGYuzhuo

    1995-01-01

    A great number of underground rock projects are maintained in the rock mass which is subject to rock damage and failure development. In many cases, the rock. engineering is still under normal working conditions even though rock is already fails to some extent. This paper introduces two different concepts: rock failure and rock engineering failure. Rock failure is defined as a mechanical state under which an applicable characteristic is changed or lost.However, the rock engineering failure is an engineering state under which an applicable function is changed or lost. The failure of surrounding rocks is the major reason of rock engineering failure. The criterion of rock engineering failure depends on the limit of applicable functions. The rock engineering failure state possesses a corresponding point in rock failure state. In this paper, a description of rock engineering failure criterion is given by simply using a mechanical equation or expression. It is expected that the study of rock engineering failure criterion will be an optimal approach that combines research of rock mechanics with rock engineering problems.

  13. Space weathering of asteroids

    CERN Document Server

    Shestopalov, D I; Cloutis, E A

    2012-01-01

    Analysis of laboratory experiments simulating space weathering optical effects on atmosphereless planetary bodies reveals that the time needed to alter the spectrum of an ordinary chondrite meteorite to resemble the overall spectral shape and slope of an S-type asteroid is about ~ 0.1 Myr. The time required to reduce the visible albedo of samples to ~ 0.05 is ~ 1 Myr. Since both these timescales are much less than the average collisional lifetime of asteroids larger than several kilometers in size, numerous low-albedo asteroids having reddish spectra with subdued absorption bands should be observed instead of an S-type dominated population. It is not the case because asteroid surfaces cannot be considered as undisturbed, unlike laboratory samples. We have estimated the number of collisions occurring in the time of 105 yr between asteroids and projectiles of various sizes and show that impact-activated motions of regolith particles counteract the progress of optical maturation of asteroid surfaces. Continual r...

  14. Cold-Weather Sports and Your Family

    Science.gov (United States)

    ... Feeding Your 1- to 2-Year-Old Cold-Weather Sports and Your Family KidsHealth > For Parents > Cold- ... once the weather turns frosty. Beating the Cold-Weather Blahs Once a chill is in the air, ...

  15. Space weathering on airless bodies

    Science.gov (United States)

    Pieters, Carle M.; Noble, Sarah K.

    2016-10-01

    Space weathering refers to alteration that occurs in the space environment with time. Lunar samples, and to some extent meteorites, have provided a benchmark for understanding the processes and products of space weathering. Lunar soils are derived principally from local materials but have accumulated a range of optically active opaque particles (OAOpq) that include nanophase metallic iron on/in rims formed on individual grains (imparting a red slope to visible and near-infrared reflectance) and larger iron particles (which darken across all wavelengths) such as are often found within the interior of recycled grains. Space weathering of other anhydrous silicate bodies, such as Mercury and some asteroids, produces different forms and relative abundance of OAOpq particles depending on the particular environment. If the development of OAOpq particles is minimized (such as at Vesta), contamination by exogenic material and regolith mixing become the dominant space weathering processes. Volatile-rich bodies and those composed of abundant hydrous minerals (dwarf planet Ceres, many dark asteroids, and outer solar system satellites) are affected by space weathering processes differently than the silicate bodies of the inner solar system. However, the space weathering products of these bodies are currently poorly understood and the physics and chemistry of space weathering processes in different environments are areas of active research.

  16. Rolling stones; fast weathering of olivine in shallow seas for cost-effective CO2 capture and mitigation of global warming and ocean acidification

    NARCIS (Netherlands)

    Schuiling, R.D.; Boer, P.L. de

    2011-01-01

    Human CO2 emissions may drive the Earth into a next greenhouse state. They can be mitigated by accelerating weathering of natural rock under the uptake of CO2. We disprove the paradigm that olivine weathering in nature would be a slow process, and show that it is not needed to mill olivine to very f

  17. Applicability of geomechanical classifications for estimation of strength properties in Brazilian rock masses.

    Science.gov (United States)

    Santos, Tatiana B; Lana, Milene S; Santos, Allan E M; Silveira, Larissa R C

    2017-01-01

    Many authors have been proposed several correlation equations between geomechanical classifications and strength parameters. However, these correlation equations have been based in rock masses with different characteristics when compared to Brazilian rock masses. This paper aims to study the applicability of the geomechanical classifications to obtain strength parameters of three Brazilian rock masses. Four classification systems have been used; the Rock Mass Rating (RMR), the Rock Mass Quality (Q), the Geological Strength Index (GSI) and the Rock Mass Index (RMi). A strong rock mass and two soft rock masses with different degrees of weathering located in the cities of Ouro Preto and Mariana, Brazil; were selected for the study. Correlation equations were used to estimate the strength properties of these rock masses. However, such correlations do not always provide compatible results with the rock mass behavior. For the calibration of the strength values obtained through the use of classification systems, ​​stability analyses of failures in these rock masses have been done. After calibration of these parameters, the applicability of the various correlation equations found in the literature have been discussed. According to the results presented in this paper, some of these equations are not suitable for the studied rock masses.

  18. Geophysics in the Critical Zone: Constraints on Deep Weathering and Water Storage Potential in the Southern Sierra CZO

    Science.gov (United States)

    Holbrook, W.; Riebe, C. S.; Hayes, J. L.; Reeder, K.; Harry, D. L.; Malazian, A. I.; Dosseto, A.; Hartsough, P. C.; Hopmans, J. W.

    2012-12-01

    Quantifying the depth and degree of subsurface weathering in landscapes is crucial for quantitative understanding of the biogeochemistry of weathering, the mechanics of hillslope sediment transport, and biogeochemical cycling of nutrients and carbon over both short and long timescales. Although the degree of weathering can be readily measured from geochemical and physical properties of regolith and rock, many distributed samples are needed to measure it over broad spatial scales. Moreover, quantifying the thickness of subsurface weathering has remained challenging, in part because the interface between altered and unaltered rock is often buried at difficult to access depths. To overcome these challenges, we combined seismic refraction and resistivity surveys to estimate regolith thickness and generate representative hillslope-scale images of subsurface weathering and water storage at the Southern Sierra Critical Zone Observatory (SSCZO). Inferred seismic velocities and electrical resistivities of the subsurface provide evidence for a weathering zone with thickness ranging from 10 to 35 m (average = 23 m) along one intensively studied transect. This weathering zone consists of roughly equal thicknesses of saprolite (P-velocity < 2 km/s) and moderately weathered bedrock (P-velocity < 4 km/s). We use a rock physics model of seismic velocities, based on Hertz-Mindlin contact theory, to estimate lateral and vertical variations in porosity as a metric of water storage potential along the transect. Inferred porosities are as high as 55% near the surface and decrease to zero at the base of weathered rock. Model-predicted porosities are broadly consistent with values measured from physical properties of saprolite, suggesting that our analysis of the geophysical data provides realistic estimates of subsurface water storage potential. A major advantage of our geophysical approach is that it quickly and non-invasively quantifies porosity over broad vertical and lateral scales

  19. Space Weather Forecasting: An Enigma

    Science.gov (United States)

    Sojka, J. J.

    2012-12-01

    The space age began in earnest on October 4, 1957 with the launch of Sputnik 1 and was fuelled for over a decade by very strong national societal concerns. Prior to this single event the adverse effects of space weather had been registered on telegraph lines as well as interference on early WWII radar systems, while for countless eons the beauty of space weather as mid-latitude auroral displays were much appreciated. These prior space weather impacts were in themselves only a low-level science puzzle pursued by a few dedicated researchers. The technology boost and innovation that the post Sputnik era generated has almost single handedly defined our present day societal technology infrastructure. During the decade following Neil's walk on the moon on July 21, 1969 an international thrust to understand the science of space, and its weather, was in progress. However, the search for scientific understand was parsed into independent "stove pipe" categories: The ionosphere-aeronomy, the magnetosphere, the heliosphere-sun. The present day scientific infrastructure of funding agencies, learned societies, and international organizations are still hampered by these 1960's logical divisions which today are outdated in the pursuit of understanding space weather. As this era of intensive and well funded scientific research progressed so did societies innovative uses for space technologies and space "spin-offs". Well over a decade ago leaders in technology, science, and the military realized that there was indeed an adverse side to space weather that with each passing year became more severe. In 1994 several U.S. agencies established the National Space Weather Program (NSWP) to focus scientific attention on the system wide issue of the adverse effects of space weather on society and its technologies. Indeed for the past two decades a significant fraction of the scientific community has actively engaged in understanding space weather and hence crossing the "stove

  20. Extreme Weather and Natural Disasters

    CERN Document Server

    Healey, Justin

    2012-01-01

    Australia is a vast land in which weather varies significantly in different parts of the continent. Recent extreme weather events in Australia, such as the Queensland floods and Victorian bushfires, are brutal reminders of nature's devastating power. Is global warming increasing the rate of natural disasters? What part do La Niña and El Niño play in the extreme weather cycle? Cyclones, floods, severe storms, bushfires, landslides, earthquakes, tsunamis - what are the natural and man-made causes of these phenomena, how predictable are they, and how prepared are we for the impacts of natural dis

  1. Days of Rock

    Institute of Scientific and Technical Information of China (English)

    YUAN

    2004-01-01

    FROM last October 1 st to 3rd, at the foot of Fragrant Hill, a suburban Beijing resort famous for its flaming maple leaves in autumn, more than 20,000 rock fans indulged themselves in music for three days.

  2. Writing Rock Music Reviews.

    Science.gov (United States)

    Brown, Donal

    1980-01-01

    Suggests ways student reviewers of rock music groups can write better reviews. Among the suggestions made are that reviewers occasionally discuss the audience or what makes a particular group unique, support general comment with detail, and avoid ecstatic adjectives. (TJ)

  3. Rock kinoekraanil / Katrin Rajasaare

    Index Scriptorium Estoniae

    Rajasaare, Katrin

    2008-01-01

    7.-11. juulini kinos Sõprus toimuval filminädalal "Rock On Screen" ekraanile jõudvatest rockmuusikuid portreteerivatest filmidest "Lou Reed's Berlin", "The Future Is Unwritten: Joe Strummer", "Control: Joy Division", "Hurriganes", "Shlaager"

  4. Art on Rock

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    With sprawling deserts and serene lakes, the natural wonders of Ningxia Hui Autonomous Region have never failed totake the breath away from visitors. The areahas another major attraction, though: the Helan Mountain rock engravings.

  5. Rock kinoekraanil / Katrin Rajasaare

    Index Scriptorium Estoniae

    Rajasaare, Katrin

    2008-01-01

    7.-11. juulini kinos Sõprus toimuval filminädalal "Rock On Screen" ekraanile jõudvatest rockmuusikuid portreteerivatest filmidest "Lou Reed's Berlin", "The Future Is Unwritten: Joe Strummer", "Control: Joy Division", "Hurriganes", "Shlaager"

  6. Pop & rock / Berk Vaher

    Index Scriptorium Estoniae

    Vaher, Berk, 1975-

    2001-01-01

    Uute heliplaatide Redman "Malpractice", Brian Eno & Peter Schwalm "Popstars", Clawfinger "A Whole Lot of Nothing", Dario G "In Full Color", MLTR e. Michael Learns To Rock "Blue Night" lühitutvustused

  7. Pop & rock / Berk Vaher

    Index Scriptorium Estoniae

    Vaher, Berk, 1975-

    2001-01-01

    Uute heliplaatide Redman "Malpractice", Brian Eno & Peter Schwalm "Popstars", Clawfinger "A Whole Lot of Nothing", Dario G "In Full Color", MLTR e. Michael Learns To Rock "Blue Night" lühitutvustused

  8. Art on Rock

    Institute of Scientific and Technical Information of China (English)

    HU YUE

    2010-01-01

    @@ With sprawling deserts and serene lakes, the natural wonders of Ningxia Hui Autonomous Region have never failed to take the breath away from visitors. The area has another major attraction, though: the Helan Mountain rock engravings.

  9. STEREO Space Weather and the Space Weather Beacon

    Science.gov (United States)

    Biesecker, D. A.; Webb, D F.; SaintCyr, O. C.

    2007-01-01

    The Solar Terrestrial Relations Observatory (STEREO) is first and foremost a solar and interplanetary research mission, with one of the natural applications being in the area of space weather. The obvious potential for space weather applications is so great that NOAA has worked to incorporate the real-time data into their forecast center as much as possible. A subset of the STEREO data will be continuously downlinked in a real-time broadcast mode, called the Space Weather Beacon. Within the research community there has been considerable interest in conducting space weather related research with STEREO. Some of this research is geared towards making an immediate impact while other work is still very much in the research domain. There are many areas where STEREO might contribute and we cannot predict where all the successes will come. Here we discuss how STEREO will contribute to space weather and many of the specific research projects proposed to address STEREO space weather issues. We also discuss some specific uses of the STEREO data in the NOAA Space Environment Center.

  10. Rock avalanches on glaciers

    OpenAIRE

    Shugar, Daniel

    2011-01-01

    This thesis examines relations between rock avalanches and the glaciers on which they are deposited. I have attempted to understand a geophysical phenomenon from two viewpoints: sedimentology and glaciology. The contributions are both methodological, and practical. I have used a GIS to quantify debris sheet geomorphology. A thorough characterization of rock avalanche debris is a necessary step in understanding the flow mechanics of large landslide. I have also developed a technique for solvin...

  11. Evolution of sedimentary rock formation of a rock association level

    Science.gov (United States)

    Kuznetsov, V. G.

    2017-07-01

    The evolution of sedimentary rock formation of a highly organized level (paragenetic rock associations) is more complex than that of a poorly organized level (rocks). Subjacent rock associations are established for the entire geological evolution of the Earth: they varied in time and were obsolescent or, in contrast, nascent and momentary. A certain cyclicity of evolution is identified along with directed changes.

  12. Astrobiological implications of rock varnish in Tibet.

    Science.gov (United States)

    Krinsley, David; Dorn, Ronald I; DiGregorio, Barry

    2009-01-01

    The study of terrestrial geomicrobiology and its relationship to rock weathering processes is an essential tool in developing analogues for similar processes that may have occurred on Mars. Most studies of manganese-enhanced rock varnish have focused on samples taken from warm arid desert regions. Here, we examine samples obtained from eolian-abraded lava flows of the 4700-4800 m high Ashikule Basin in Tibet. Because it receives approximately 300 mm of precipitation annually, this site is nowhere near as dry as Atacama Desert locales. However, the dusty, sulfate-rich, high-altitude and high-UV flux environment of the Tibetan locale offers new insight into rock varnish formation processes in a terrestrial environment that displays some attributes similar to those expected on early Mars. Microprobe measurements reveal that Mn enhancements in varnish are two orders of magnitude above the dust source, but Fe is only enhanced by a factor of three. Manganese-enhancing bacterial forms are not abundant but are still approximately 3 times more common than in Mojave and Sonoran Desert varnishes. In addition to its occurrence in subaerial positions, Tibetan varnish also occurs in micron-scale "pods" enveloped by silica glaze and as remobilized constituents that have migrated into the underlying weathering rind. A lack of surficial Mn-rich varnish, therefore, might not imply the absence of varnish. In contrast to suggestions that silica glaze might be a good source of microbial fossils and a key to varnish formation, we did not observe any clear microfossil forms entombed in silica glaze; further, there is no gradation between varnish and silica glaze but only distinct contacts.

  13. Geomorphology's role in the study of weathering of cultural stone

    Science.gov (United States)

    Pope, Gregory A.; Meierding, Thomas C.; Paradise, Thomas R.

    2002-10-01

    Great monumental places—Petra, Giza, Angkor, Stonehenge, Tikal, Macchu Picchu, Rapa Nui, to name a few—are links to our cultural past. They evoke a sense of wonderment for their aesthetic fascination if not for their seeming permanence over both cultural and physical landscapes. However, as with natural landforms, human constructs are subject to weathering and erosion. Indeed, many of our cultural resources suffer from serious deterioration, some natural, some enhanced by human impact. Groups from the United Nations to local civic and tourism assemblies are deeply interested in maintaining and preserving such cultural resources, from simple rock art to great temples. Geomorphologists trained in interacting systems, process and response to thresholds, rates of change over time, and spatial variation of weathering processes and effects are able to offer insight into how deterioration occurs and what can be done to ameliorate the impact. Review of recent literature and case studies presented here demonstrate methodological and theoretical advances that have resulted from the study of cultural stone weathering. Because the stone was carved at a known date to a "baseline" or zero-datum level, some of the simplest methods (e.g., assessing surface weathering features or measuring surface recession in the field) provide useful data on weathering rates and processes. Such data are difficult or impossible to obtain in "natural" settings. Cultural stone weathering studies demonstrate the importance of biotic and saline weathering agents and the significance of weathering factors such as exposure (microclimate) and human impact. More sophisticated methods confirm these observations, but also reveal discrepancies between field and laboratory studies. This brings up two important caveats for conservators and geomorphologists. For the conservator, are laboratory and natural setting studies really analogous and useful for assessing stone damage? For the geomorphologist, does

  14. Hillslope evolution in landscapes dominated by layered rocks

    Science.gov (United States)

    Glade, R.; Anderson, R. S.

    2016-12-01

    Geologic structure and lithology can exert fundamental control over hillslope evolution. Landforms common across the western US, such as mesas, hogbacks, flatirons, and symmetric ridges bounding dikes, develop in the face of differential weathering of layered rocks in a horizontal, tilted, or vertical structural orientation. These features exhibit a characteristic form distinct from that of homogeneous, soil-mantled hillslopes; linear-to-concave up slopes developed on soft underlying rock typically display a thin, non-uniform layer of mobile regolith and are armored by debris derived from the resistant layers. Feedbacks between weathering and transport of both easily eroded rock and embedded resistant material can explain this general form where debris is dominated by large resistant blocks. In the more general case, however, relationships between the size distribution of the resistant material, relative weathering rates, and boundary condition history are not well-understood. Here we use a 1-D numerical model to explore the evolution of two end-member landforms: a hogback associated with a tilted sandstone bed, and a symmetrical ridge associated with a vertical basalt dike, both bounded by shale bedrock. The first, modeled after the Dakota Hogback near Boulder, Colorado, produces large sandstone blocks that both armor the underlying slope from weathering and stall regolith motion. The vertical dike, modeled after Shiprock, New Mexico, produces both large blocks and small basalt chips that armor the bounding slopes. We show that in both settings, feedbacks between armor and soft rock lead to autogenic processes that modulate base level signals, alter hillslope form, and increase relief over time when compared to a control case with no armor. We explore a variety of boundary conditions in which the presence of these feedbacks leads to a quasi-steady state hillslope form that differs both quantitatively and qualitatively from that expected of a traditional parabolic

  15. KZBW Center Weather Advisory (CWA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The CWA is an aviation weather warning for conditions meeting or approaching national in-flight advisory (AIRMET, SIGMET or SIGMET for convection) criteria. CWAs are...

  16. Fish Springs weather CY 2011

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Weather data for calendar year 2011 at Fish Springs National Wildlife Refuge. Data is provided for each month and includes maximum temperature, minimum temperature,...

  17. Fish Springs weather CY 2010

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Weather data for calendar year 2010 at Fish Springs National Wildlife Refuge. Data is provided for each month and includes maximum temperature, minimum temperature,...

  18. The science of space weather.

    Science.gov (United States)

    Eastwood, Jonathan P

    2008-12-13

    The basic physics underpinning space weather is reviewed, beginning with a brief overview of the main causes of variability in the near-Earth space environment. Although many plasma phenomena contribute to space weather, one of the most important is magnetic reconnection, and recent cutting edge research in this field is reviewed. We then place this research in context by discussing a number of specific types of space weather in more detail. As society inexorably increases its dependence on space, the necessity of predicting and mitigating space weather will become ever more acute. This requires a deep understanding of the complexities inherent in the plasmas that fill space and has prompted the development of a new generation of scientific space missions at the international level.

  19. KZOA Center Weather Advisory (CWA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The CWA is an aviation weather warning for conditions meeting or approaching national in-flight advisory (AIRMET, SIGMET or SIGMET for convection) criteria. CWAs are...

  20. KZSE Center Weather Advisory (CWA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The CWA is an aviation weather warning for conditions meeting or approaching national in-flight advisory (AIRMET, SIGMET or SIGMET for convection) criteria. CWAs are...

  1. KZMA Center Weather Advisory (CWA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The CWA is an aviation weather warning for conditions meeting or approaching national in-flight advisory (AIRMET, SIGMET or SIGMET for convection) criteria. CWAs are...

  2. US Weather Bureau Storm Reports

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Weather Bureau and US Army Corps and other reports of storms from 1886-1955. Hourly precipitation from recording rain gauges captured during heavy rain, snow,...

  3. Surface Weather Observations (Pre-1893)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Monthly weather records from U.S. Army Forts stations (~1820-1871), U.S. Army Signal Service Stations (1871-1892), Smithsonian Institution voluntary observer network...

  4. KZLC Center Weather Advisory (CWA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The CWA is an aviation weather warning for conditions meeting or approaching national in-flight advisory (AIRMET, SIGMET or SIGMET for convection) criteria. CWAs are...

  5. Weather data communication and utilization

    Science.gov (United States)

    Mcfarland, R. H.; Nickum, J. D.; Mccall, D. L.

    1983-01-01

    The communication of weather data to aircraft is discussed. Problems encountered because of the great quantities of data available and the limited capacity to transfer this via radio link to an aircraft are discussed. Display devices are discussed.

  6. Practical Weathering for Geology Students.

    Science.gov (United States)

    Hodder, A. Peter

    1990-01-01

    The design and data management of an activity to study weathering by increasing the rate of mineral dissolution in a microwave oven is described. Data analysis in terms of parabolic and first-order kinetics is discussed. (CW)

  7. WARP Weather Information Network Server

    Data.gov (United States)

    Department of Transportation — WINS is the dissemination module of the WARP system that provides an interface to various NAS Users/systems that require weather data/products/information from WARP...

  8. Northern Hemisphere Synoptic Weather Maps

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Daily Series of Synoptic Weather Maps. Part I consists of plotted and analyzed daily maps of sea-level and 500-mb maps for 0300, 0400, 1200, 1230, 1300, and 1500...

  9. Existing State and Partitioning of Rare Earth on Weathered Ores

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The existing state and partitioning of rare earth (RE) on weathered ores in Longnan County (LN), Xingfeng County(XF) and Ninghua County(NH) were characterized systematically by standard geological analytical methods. It is found that RE in the weathered rare earth ores exist as four phases: (a) water soluble, (b) ion-exchangeable, (c) colloidal sediment (oxides), (d) minerals, in which mainly as ion exchangeable phase, accounting for nearly 80% of total RE,with about 20% in the form of colloid sediment phase and mineral phase, but very little as aqueous soluble phase. These rare earth partitioning were mainly chosen mid-heavy RE elements, occupying above 60%, but not equal in the four phases. The mid-heavy RE elements were primarily enriched in the ion exchangeable phase up to 40%, while the containment of cerium dioxide is below 2%. The cerium deficiency occurs in the ion exchangeable phase in weathered ore. It results from that the Ce3+ is oxidized into Ce4+ and changes into CeO2. For LN ore, the containment of Y is high in weathered ore because Y-minerals are abundant in original rock.

  10. Experimental geobiology links evolutionary intensification of rooting systems and weathering

    Science.gov (United States)

    Quirk, Joe; Beerling, David; Leake, Jonathan

    2016-04-01

    The evolution of mycorrhizal fungi in partnership with early land plants over 440 million years ago led to the greening of the continents by plants of increasing biomass, rooting depth, nutrient demand and capacity to alter soil minerals, culminating in modern forested ecosystems. The later co-evolution of trees and rooting systems with arbuscular mycorrhizal (AM) fungi, together driving the biogeochemical cycling of elements and weathering of minerals in soil to meet subsequent increased phosphorus demands is thought to constitute one the most important biotic feedbacks on the geochemical carbon cycle to emerge during the Phanerozoic, and fundamentally rests on the intensifying effect of trees and their root-associating mycorrhizal fungal partners on mineral weathering. Here I present experimental and field evidence linking these evolutionary events to a mechanistic framework whereby: (1) as plants evolved in stature, biomass, and rooting depth, their mycorrhizal fungal partnerships received increasing amounts of plant photosynthate; (2) this enabled intensification of plant-driven fungal weathering of rocks to release growth-limiting nutrients; (3) in turn, this increased land-to-ocean export of Ca and P and enhanced ocean carbonate precipitation impacting the global carbon cycle and biosphere-geosphere-ocean-atmosphere interactions over the past 410 Ma. Our findings support an over-arching hypothesis that evolution has selected plant and mycorrhizal partnerships that have intensified mineral weathering and altered global biogeochemical cycles.

  11. Naturally occurring radionuclides and rare earth elements in weathered Japanese soil samples

    Science.gov (United States)

    Sahoo, Sarata; Hosoda, Masahiro; Prasad, Ganesh; Takahashi, Hiroyuki; Sorimachi, Atsuyuki; Ishikawa, Tetsuo; Tokonami, Shinji; Uchida, Shigeo

    2013-08-01

    The activity concentrations of 226Ra and 228Ac in weathered Japanese soils from two selected prefectures have been measured using a γ-ray spectroscopy system with high purity germanium detector. The uranium, thorium, and rare earth elements (REEs) concentrations were determined from the same soil samples using inductively coupled plasma mass spectrometry (ICP-MS). For example, granitic rocks contain higher amounts of U, Th, and light REEs compared to other igneous rocks such as basalt and andesites. Therefore, it is necessary to understand the interaction between REEs and nature of soils since soils are complex heterogeneous mixture of organic and inorganic solids, water, and gases. In this paper, we will discuss about distribution pattern of 238U and 232Th along with REEs in soil samples of weathered acid rock (granite) collected from two prefectures of Japan: Hiroshima and Miyagi.

  12. Acid Sulfate Weathering on Mars: Results from the Mars Exploration Rover Mission

    Science.gov (United States)

    Ming, Douglas W.; Morris, R. V.; Golden, D. C.

    2006-01-01

    Sulfur has played a major role in the formation and alteration of outcrops, rocks, and soils at the Mars Exploration Rover landing sites on Meridiani Planum and in Gusev crater. Jarosite, hematite, and evaporite sulfates (e.g., Mg and Ca sulfates) occur along with siliciclastic sediments in outcrops at Meridiani Planum. The occurrence of jarosite is a strong indicator for an acid sulfate weathering environment at Meridiani Planum. Some outcrops and rocks in the Columbia Hills in Gusev crater appear to be extensively altered as suggested by their relative softness as compared to crater floor basalts, high Fe(3+)/FeT, iron mineralogy dominated by nanophase Fe(3+) oxides, hematite and/or goethite, corundum-normative mineralogies, and the presence of Mg- and Casulfates. One scenario for aqueous alteration of these rocks and outcrops is that vapors and/or fluids rich in SO2 (volcanic source) and water interacted with rocks that were basaltic in bulk composition. Ferric-, Mg-, and Ca-sulfates, phosphates, and amorphous Si occur in several high albedo soils disturbed by the rover's wheels in the Columbia Hills. The mineralogy of these materials suggests the movement of liquid water within the host material and the subsequent evaporation of solutions rich in Fe, Mg, Ca, S, P, and Si. The presence of ferric sulfates suggests that these phases precipitated from highly oxidized, low-pH solutions. Several hypotheses that invoke acid sulfate weathering environments have been suggested for the aqueous formation of sulfate-bearing phases on the surface of Mars including (1) the oxidative weathering of ultramafic igneous rocks containing sulfides; (2) sulfuric acid weathering of basaltic materials by solutions enriched by volcanic gases (e.g., SO2); and (3) acid fog (i.e., vapors rich in H2SO4) weathering of basaltic or basaltic-derived materials.

  13. Geophysical and Chemical Weathering Signatures Across the Deep Weathered-Unweathered Granite Boundary of the Calhoun Critical Zone Observatory

    Science.gov (United States)

    Richter, D., Jr.; Bacon, A. R.; Brantley, S. L.; Holbrook, W. S.

    2015-12-01

    To understand the relationship between geophysical measurements and chemical weathering at Earth's surface, we combine comprehensive chemical and physical analyses of a 70-m granite weathering profile in the Southern Piedmont in the southeastern United States. The research site is in the uplands of the Calhoun Critical Zone Observatory and is similar to many geomorphically stable, ancient, and highly-weathered Ultisol soils of the region. Surface and downhole geophysical analyses suggest significant physical changes to depths of about 40 m, where geophysical properties are consistent with competent and unweathered granite. At this depth, surface refraction velocities increase to >4.5 km/s; variations in downhole sonic velocities decrease by more than two-fold; and deviations in the downhole caliper log sharply decrease as well. Forty meters depth is also the depth of initiation of plagioclase feldspar weathering, as inferred from bulk geochemical measurement of the full 70-m deep core. Specifically, element-depth profiles, cast as mass transfer coefficient profiles using Ti and Zr as immobile elements, document inferred loss of plagioclase in the depth interval between 15 and 40-m depth. Plagioclase feldspar is the most abundant of the highly reactive minerals in the granite. Such a wide reaction front is characteristic of weathering granites. Some loss of K is observed at these depths but most K loss, as well as Mg loss, occurs at shallower depths. Nearby geophysical profiles and 3D stress models have been interpreted as showing that seismic velocities decrease at 40 m depth due to opening of fractures as rock is exhumed toward the surface. Given our interpretations of both the geochemical and geophysical data, we infer that the onset of chemical weathering of feldspar coincides with the opening of these fractures. The data highlight the ability of geochemistry and geophysics to complement each other and enrich our understanding of Earth's Critical Zone.

  14. Geomorphic controls on mineral weathering, elemental transport, and production of mineral surface area in a schist bedrock weathering profile, Piedmont Pennsylvania

    Science.gov (United States)

    Wenell, B.; Yoo, K.; Aufdenkampe, A. K.; Mahoney, J. B.; Lepak, L.

    2013-12-01

    We assess a deep chemical weathering profile in the context of geomorphic evolution in the Laurels Schist, a late proterozoic greenschist formation in the Christina River Basin Critical Zone Observatory located in the Piedmont region in southeastern Pennsylvania. Two 21-meter deep rotosonic drill cores were sampled at the ridge top and footslope positions in a first-order, forested watershed. The top meter was sampled at high-resolution in a soil pit adjacent to each drill core and along a hillslope transect to assess geomorphic controls on the weathering profile. Weathering processes in soil and saprolite were examined by observing changes in mineralogy, including the emergence of secondary phyllosilicate and oxide minerals; measuring specific surface area of bulk soil and saprolite; and by quantifying elemental mass changes of major and minor rock-forming elements. Mineral profiles were assessed using clay and bulk XRD, and reveal that kaolinite, a common secondary phyllosilicate, is present above 1.5 meters in the weathering profile. Specific surface area (SSA) values decrease with increasing depth to a critical depth around 2 meters, where the values of untreated (carbon-loaded) and muffled (carbon removed by heating) mineral grains converge to baseline SSA values below 10 m2g-1, indicating that carbon is sorbed with mineral surface area in the upper 2 meters. Immobile element concentrations decrease with increasing depth up to 3 meters, indicating that the preferential removal of mobile elements extends beyond the depth of C-mineral adsorption. Variability of immobile elements in the deep weathering profile reveal variations that could be the result of weathering in fractures but are more likely inherited by the rock composition and particle size of pre-metamorphosed parent rock.

  15. Salt-Induced Physical Weathering of Stone

    Science.gov (United States)

    Schiro, M.; Ruiz-Agudo, E.; Rodriguez-Navarro, C.

    2010-12-01

    Salt weathering is recognized as an important mechanism that contributes to the modeling and shaping of the earth’s surface, in a range of environments spanning from the Sahara desert to Antarctica. It also contributes to the degradation and loss of cultural heritage, particularly carved stone and historic buildings. Soluble salts have recently been suggested to contribute to the shaping of rock outcrops on Mars and are being identified in other planetary bodies such as the moons of Jupiter (Europa and IO)1. Soluble salts such as sulfates, nitrates, chlorides and carbonates of alkali and alkali earth metals can crystallize within the porous system of rocks and building stones, exerting sufficient pressure against the pore walls to fracture the substrate. This physical damage results in increased porosity, thus providing a higher surface area for salt-enhanced chemical weathering. To better understand how salt-induced physical weathering occurs, we have studied the crystallization of the particularly damaging salt, sodium sulfate2, in a model system (a sintered porous glass of controlled porosity and pore size). For this elusive task of studying sub-surface crystallization in pores, we combined a variety of instruments to identify which phases crystallized during evaporation and calculated the supersaturation and associated crystallization pressure that caused damage. The heat of crystallization was measured using differential scanning calorimetry (DSC), providing the timing of crystallization events and phase transitions3, while the evaporation rate was recorded using thermal gravimetry (TG). These methods enabled calculation of the sodium sulfate concentration in solution at every point during evaporation. Two-dimensional X-ray diffraction (2D-XRD) performs synchrotron-like experiments in a normal lab by using a Molybdenum X-ray source (more than 5 times more penetrative than conventional Copper source). Using this method, we determined that the first phase to

  16. Suitability of static tests for acid rock drainage assessment of mine waste rock

    Directory of Open Access Journals (Sweden)

    Päivi M. Kauppila

    2010-12-01

    Full Text Available In the present study, eight rock samples were analysed with a modified acid-base accounting (ABA test and the corresponding net acid generation (NAG test. In addition, the main and trace elements solubilised during the tests were determined with ICPOES/MS. Both the modified ABA and NAG tests classified the rock samples with a lowsulphide-S content (0.1–0.4 % and low carbonate mineral content (≤0.2 % into the category of ‘potentially acid generating’. The low neutralization potentials of these rocks were partly due to additional acid produced in silicate weathering, upon the hydrolyzation of Fe and Al during the tests. In contrast to the modified ABA, the contribution of slowly reactive carbonate minerals to the neutralisation potential was seen in the NAG test and in the carbonate NP calculation, as they classified the rock samples containing these minerals into the category of ‘non-acid generating’. This supports the use of the carbonate neutralizing potential (NP and/or the NAG test in mine waste screening. In the NAG test, acid generation and neutralization reactions either raising or decreasing the pH significantly influenced the solubility of trace metals and Al. This suggests that the extract contents could be useful in assessing contaminant mobility during long-term acid generating reactions.

  17. Titan: Callisto With Weather?

    Science.gov (United States)

    Moore, J. M.; Pappalardo, R. T.

    2008-12-01

    , Titan might have accreted relatively cold. Without being in a forced resonance, Titan's interior may have never undergone significant tidal heating. Analogous to Callisto's tenuous CO2 atmosphere, believed to be generated by sublimation of interior ices, interior clathrated methane within Titan may slowly diffuse outward from the cold interior, rather than the atmosphere being replenished by cryovolcanism. The hypothesis that Titan is "Callisto with weather" -- with geological processes that are principally exogenic -- can be tested through geophysical and thermal modeling, and by modeling the evolution of landscapes that are shaped by exogenic processes alone.

  18. Identifying the changes of geo-engineering properties of dunites due to weathering utilizing electrical resistivity tomography (ERT)

    Science.gov (United States)

    Ündül, Ömer; Tuğrul, Atiye; Özyalın, Şenol; Halil Zarif, İ.

    2015-04-01

    Weathering phenomena have an important role in many construction facilities with varying depths and grades. Due to the anisotropic and heterogeneous nature of weathering profiles of some rocks, uncertainities exist in determining the geo-engineering properties. Geo-electrical studies have been utilized to overcome such uncertainities for various subsurface conditions including the determination of boundaries between weathered and unweathered parts of different rock types. In this study, the electrical resistivity tomography (ERT) results were correlated with conventional methods in determining the effects of weathering on the geo-engineering properties of dunites. During the research, weathering grades were determined by field studies including discontinuity spacings, aperture and properties of fill materials. The detailed petrographical studies, determination of petrophysical properties (e.g. water absorption and effective porosity) and mechanical properties (e.g. unconfined compressive strength (UCS)) constitute the laboratory studies. ERT studies were carried out in a row of sixty electrodes with electrode spacings of 0.5 m utilizing a Wenner-Schlumberger configuration. According to the comparison of the inversion model sections with the weathering profiles obtained by field and laboratory studies it is concluded that the use of ERT with a Wenner-Schlumberger configuration supplies comparable data for wider subsurface areas from the view of weathering and its effect on geo-engineering properties of dunites. In addition, ERT techniques are very useful where conventional techniques are inadequate in determining the full weathering profile.

  19. Evolution of porosity and diffusivity associated with chemical weathering of a basalt clast

    Energy Technology Data Exchange (ETDEWEB)

    Navarre-Sitchler, A.; Steefel, C.I.; Yang, L.; Tomutsa, L.; Brantley, S.L.

    2009-02-15

    Weathering of rocks as a result of exposure to water and the atmosphere can cause significant changes in their chemistry and porosity. In low-porosity rocks, such as basalts, changes in porosity, resulting from chemical weathering, are likely to modify the rock's effective diffusivity and permeability, affecting the rate of solute transport and thus potentially the rate of overall weathering to the extent that transport is the rate limiting step. Changes in total porosity as a result of mineral dissolution and precipitation have typically been used to calculate effective diffusion coefficients through Archie's law for reactive transport simulations of chemical weathering, but this approach fails to account for unconnected porosity that does not contribute to transport. In this study, we combine synchrotron X-ray microcomputed tomography ({mu}CT) and laboratory and numerical diffusion experiments to examine changes in both total and effective porosity and effective diffusion coefficients across a weathering interface in a weathered basalt clast from Costa Rica. The {mu}CT data indicate that below a critical value of {approx}9%, the porosity is largely unconnected in the basalt clast. The {mu}CT data were further used to construct a numerical pore network model to determine upscaled, effective diffusivities as a function of total porosity (ranging from 3 to 30%) for comparison with diffusivities determined in laboratory tracer experiments. By using effective porosity as the scaling parameter and accounting for critical porosity, a model is developed that accurately predicts continuum-scale effective diffusivities across the weathering interface of the basalt clast.

  20. Geochemical characteristics of Early Cretaceous source rocks in Boli Basin

    Institute of Scientific and Technical Information of China (English)

    Hongmei Gao; Fuhong Gao; Fu Fan; Yueqiao Zhang

    2006-01-01

    The Early Cretaceous deposits are composed of important source rocks in Boli Basin. The types of the source rocks include black mudstones and coal (with carbonaceous mudstone). By the organic geochemical analysis methods, the authors discussed the organic petrological characters, abundance of organic matter, degree of maturity and the type of source rocks. The main micro-component of black mudstone is exinite or vitrinite, and the content of vitrinite is high in coal. The weathering of the outcrop is very serious. The abundance of organic matter in source rock reaches the poor to better rank. The major kerogens in mudstone are type-Ⅲ, type-Ⅱ2 and some type-Ⅱ1; the organic type of coal is type-Ⅲ. The thermal evolution of the source rocks in every structural unit is very different, from low-maturity to over-maturity. The depositional environment is reductive, which is good for the preservation of organic matter. The organic matter in source rocks is mainly from aquatic organisms and terrigenous input.

  1. Digital carbonate rock physics

    Science.gov (United States)

    Saenger, Erik H.; Vialle, Stephanie; Lebedev, Maxim; Uribe, David; Osorno, Maria; Duda, Mandy; Steeb, Holger

    2016-08-01

    Modern estimation of rock properties combines imaging with advanced numerical simulations, an approach known as digital rock physics (DRP). In this paper we suggest a specific segmentation procedure of X-ray micro-computed tomography data with two different resolutions in the µm range for two sets of carbonate rock samples. These carbonates were already characterized in detail in a previous laboratory study which we complement with nanoindentation experiments (for local elastic properties). In a first step a non-local mean filter is applied to the raw image data. We then apply different thresholds to identify pores and solid phases. Because of a non-neglectable amount of unresolved microporosity (micritic phase) we also define intermediate threshold values for distinct phases. Based on this segmentation we determine porosity-dependent values for effective P- and S-wave velocities as well as for the intrinsic permeability. For effective velocities we confirm an observed two-phase trend reported in another study using a different carbonate data set. As an upscaling approach we use this two-phase trend as an effective medium approach to estimate the porosity-dependent elastic properties of the micritic phase for the low-resolution images. The porosity measured in the laboratory is then used to predict the effective rock properties from the observed trends for a comparison with experimental data. The two-phase trend can be regarded as an upper bound for elastic properties; the use of the two-phase trend for low-resolution images led to a good estimate for a lower bound of effective elastic properties. Anisotropy is observed for some of the considered subvolumes, but seems to be insignificant for the analysed rocks at the DRP scale. Because of the complexity of carbonates we suggest using DRP as a complementary tool for rock characterization in addition to classical experimental methods.

  2. Space Weather - the Economic Case

    Science.gov (United States)

    Bisi, M. M.; Gibbs, M.

    2015-12-01

    Following on from the UK Government's placement of space weather on it's National Risk Register, in 2011, and the Royal Academy of Engineering's study into the impacts of a severe space weather event, the next piece of key evidence, to underpin future investment decisions, is understanding the socio-economic impact of space weather This poster outlines a study, funded by the UK Space Agency, which will assess the socio-economic cost of space weather, both severe events, such as 1989 & a modern day repeat of the Carrington storm and also the cost of day-to-day impacts. The study will go on to estimate the cost benefit of forecasting and also investigate options for an operational L5 spacecraft mission and knowledge exchange activities with the South African Space Agency. The findings from the initial space weather socio-economic literature review will be presented along with other findings to date and sets out the tasks for the remainder of this programme of work.

  3. Space Weather Research: Indian perspective

    Science.gov (United States)

    Bhardwaj, Anil; Pant, Tarun Kumar; Choudhary, R. K.; Nandy, Dibyendu; Manoharan, P. K.

    2016-12-01

    Space weather, just like its meteorological counterpart, is of extreme importance when it comes to its impact on terrestrial near- and far-space environments. In recent years, space weather research has acquired an important place as a thrust area of research having implications both in space science and technology. The presence of satellites and other technological systems from different nations in near-Earth space necessitates that one must have a comprehensive understanding not only of the origin and evolution of space weather processes but also of their impact on technology and terrestrial upper atmosphere. To address this aspect, nations across the globe including India have been investing in research concerning Sun, solar processes and their evolution from solar interior into the interplanetary space, and their impact on Earth's magnetosphere-ionosphere-thermosphere system. In India, over the years, a substantial amount of work has been done in each of these areas by various agencies/institutions. In fact, India has been, and continues to be, at the forefront of space research and has ambitious future programs concerning these areas encompassing space weather. This review aims at providing a glimpse of this Indian perspective on space weather research to the reader and presenting an up-to-date status of the same.

  4. Session: Hard Rock Penetration

    Energy Technology Data Exchange (ETDEWEB)

    Tennyson, George P. Jr.; Dunn, James C.; Drumheller, Douglas S.; Glowka, David A.; Lysne, Peter

    1992-01-01

    This session at the Geothermal Energy Program Review X: Geothermal Energy and the Utility Market consisted of five presentations: ''Hard Rock Penetration - Summary'' by George P. Tennyson, Jr.; ''Overview - Hard Rock Penetration'' by James C. Dunn; ''An Overview of Acoustic Telemetry'' by Douglas S. Drumheller; ''Lost Circulation Technology Development Status'' by David A. Glowka; ''Downhole Memory-Logging Tools'' by Peter Lysne.

  5. Long-term stability of global erosion rates and weathering during late-Cenozoic cooling.

    Science.gov (United States)

    Willenbring, Jane K; von Blanckenburg, Friedhelm

    2010-05-13

    Over geologic timescales, CO(2) is emitted from the Earth's interior and is removed from the atmosphere by silicate rock weathering and organic carbon burial. This balance is thought to have stabilized greenhouse conditions within a range that ensured habitable conditions. Changes in this balance have been attributed to changes in topographic relief, where varying rates of continental rock weathering and erosion are superimposed on fluctuations in organic carbon burial. Geological strata provide an indirect yet imperfectly preserved record of this change through changing rates of sedimentation. Widespread observations of a recent (0-5-Myr) fourfold increase in global sedimentation rates require a global mechanism to explain them. Accelerated uplift and global cooling have been given as possible causes, but because of the links between rates of erosion and the correlated rate of weathering, an increase in the drawdown of CO(2) that is predicted to follow may be the cause of global climate change instead. However, globally, rates of uplift cannot increase everywhere in the way that apparent sedimentation rates do. Moreover, proxy records of past atmospheric CO(2) provide no evidence for this large reduction in recent CO(2) concentrations. Here we question whether this increase in global weathering and erosion actually occurred and whether the apparent increase in the sedimentation rate is due to observational biases in the sedimentary record. As evidence, we recast the ocean dissolved (10)Be/(9)Be isotope system as a weathering proxy spanning the past approximately 12 Myr (ref. 14). This proxy indicates stable weathering fluxes during the late-Cenozoic era. The sum of these observations shows neither clear evidence for increased erosion nor clear evidence for a pulse in weathered material to the ocean. We conclude that processes different from an increase in denudation caused Cenozoic global cooling, and that global cooling had no profound effect on spatially and

  6. Structural Characteristics and Mechanical Properties of Rock Mass in the Field of Tianwan Nuclear Power Plant, China

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The structural characteristics and mechanical properties of the rock mass are important parts of the feasibility study on the nuclear power engineering field. In this study, by means of in situ investigation and statistics,the structural plane and joint fissure features of the rock mass were analyzed and discussed at different plots and different depth scopes in the Tianwan Nuclear Power engineering field, the rock mass integrality and its weathered degree were evaluated respectively, and especially, the unfavorable geological phenomena of strongly-weathered cystid existing in the field were studied. According to the results of indoor rock mechanical tests, in combination with drilling, the shallow seismic prospecting, sonic logging and point load tests, the statistical results of physical and mechanical indices of rocks at key plots of the field were analyzed, and the design parameters of the field were calculated. It provided scientific basis for the foundation design of the nuclear power plant.

  7. Space Weather, Environment and Societies

    CERN Document Server

    Lilensten, Jean

    2006-01-01

    Our planet exists within a space environment affected by constantly changing solar atmosphere producing cosmic particles and electromagnetic waves. This "space weather" profoundly influences the performance of our technology because we primarily use two means for transmitting information and energy; namely, electromagnetic waves and electricity. On an everyday basis, we have developed methods to cope with the normal conditions. However, the sun remains a fiery star whose 'angry' outbursts can potentially destroy spacecrafts, kill astronauts, melt electricity transformers, stop trains, and generally wreak havoc with human activities. Space Weather is the developing field within astronomy that aims at predicting the sun’s violent activity and minimizing the impacts on our daily lives. Space Weather, Environment, and Societies explains why our technological societies are so dependent on solar activity and how the Sun disturbs the transmission of information and energy. Footnotes expand specific points and the ...

  8. REE Comparison Between Muncung Granite Samples and their Weathering Products, Lingga Regency, Riau Islands

    Directory of Open Access Journals (Sweden)

    Ronaldo Irzon

    2016-12-01

    Full Text Available The increasing demand for Rare Earth Elements (REE is related to the continous development of technology, and these elements are used in modern equipments. REE can occur in igneous and sedimentary rocks in significant amounts as primary deposits, whereas the secondary REE deposit can be produced by intensive lateritic weathering of bedrocks under the tropical or subtropical climate. Lateritic process can increase REE concentration from sub-economic levels in host rocks to be more valuable. Muncung Granite is located in a tropical area of Lingga Regency, Riau Islands Province. REE occurs in the Muncung Granite and in weathered layers (saprolite, laterite, and soil. ICP-MS was applied to measure the REE content in all samples of this study. The average REE content of the Muncung Granite is 265 ppm with Eu anomaly in REE’s spider diagrams. Lateritization process has increased REE content by more than four times compared to that in the Muncung Granite. Ce and Eu anomalies in weathered layers can be associated with weathering process and initial REE contents in the host rock. Ce anomaly in a laterite layer is found to have a negative correlation to REE total enrichment. The REE level in the Muncung Granite is higher than the content in the soil and saprolite layers, but lower than that in the laterite.

  9. Chemical Weathering in the San Gabriel Mountains of California: The influence of erosion rates, soil depth, and transport processes on soil chemical losses (Invited)

    Science.gov (United States)

    Dixon, J. L.; Hartshorn, A. S.; Heimsath, A. M.; Dibiase, R. A.; Whipple, K. X.

    2010-12-01

    What controls the chemical weathering of soils in actively eroding landscapes? In this study, we explore the tectonic signature on soil weathering in the San Gabriel Mountains (SGM) of California, where propagating waves of incision triggered by increasing rock uplift have resulted in distinctly different hillslope morphologies and erosion rates across the range. We quantify downslope patterns of soil weathering across this landscape using sites that bracket low-gradient hillslopes of the stable upland plateau and hillslopes near the margins of the incising landscape. We use elemental mass balances in rock and soil to index the weathered extent of soils, and couple these extents with previously measured 10Be-derived soil production rates to calculate rates of soil weathering and erosion. Across all sites, Tau-Si—the fractional loss or gain of Si from parent material—averages -0.32±0.04, and the weathered extent of soils generally increases with increasing distance from the hillcrest. However, weathering intensities decrease as hillslope gradients steepen beyond 30°. Chemical weathering extents on slopes controlling mineral supply and residence time. These patterns are consistent with previously published predictive models for denudation-weathering relationships based on mineral weathering kinetics. Variable weathering extents in soils indicate that soil weathering in the SGM is largely kinetically limited. This work provides a field-based quantification of the complex relationship between soil erosion and chemical weathering, and together our data suggest that tectonic forcing strongly influences soil weathering rates and extents through its control on erosion rates, transport processes and soil thickness.

  10. Teaching the Rock Cycle with Ease.

    Science.gov (United States)

    Bereki, Debra

    2000-01-01

    Describes a hands-on lesson for teaching high school students the concept of the rock cycle using sedimentary, metamorphic, and igneous rocks. Students use a rock cycle diagram to identify pairs of rocks. From the rock cycle, students explain on paper how their first rock became the second rock and vice versa. (PVD)

  11. Microcraters on lunar rocks.

    Science.gov (United States)

    Morrison, D. A.; Mckay, D. S.; Heiken, G. H.; Moore, H. J.

    1972-01-01

    Microcrater frequency distributions have been obtained for nine Apollo rocks and an exterior chip of an Apollo 12 rock. The frequency distributions indicate that five of the Apollo 14 rocks were tumbled more than once exposing different rock faces whereas four were not tumbled and represent a single exposure interval. The cumulative frequency of craters per square centimeter was extended below optical resolution limits using a SEM scan of an exterior chip of breccia 12073. No craters with central pit diameters less than 15 microns were seen in a total area of 0.44 sq cm. A detailed SEM scan of crystal faces and glassy crater liners revealed no microcraters equal to or larger than the resolution limit of 5 microns. An upper limit of 170 craters per sq cm with central pit diameters larger than 5 microns was set. The slope of the cumulative frequency curve for craters with central pit diameters less than about 75 microns is less than that obtained by other workers.

  12. Umhlanga Rocks coastal defense

    NARCIS (Netherlands)

    De Jong, L.; De Jong, B.; Ivanova, M.; Gerritse, A.; Rietberg, D.; Dorrepaal, S.

    2014-01-01

    The eThekwini coastline is a vulnerable coastline subject to chronic erosion and damage due to sea level rise. In 2007 a severe storm caused major physical and economic damage along the coastline, proving the need for action. Umhlanga Rocks is a densely populated premium holiday destination on the

  13. Rock-hard coatings

    NARCIS (Netherlands)

    Muller, M.

    2007-01-01

    Aircraft jet engines have to be able to withstand infernal conditions. Extreme heat and bitter cold tax coatings to the limit. Materials expert Dr Ir. Wim Sloof fits atoms together to develop rock-hard coatings. The latest invention in this field is known as ceramic matrix composites. Sloof has sign

  14. Slippery Rock University

    Science.gov (United States)

    Arnhold, Robert W.

    2008-01-01

    Slippery Rock University (SRU), located in western Pennsylvania, is one of 14 state-owned institutions of higher education in Pennsylvania. The university has a rich tradition of providing professional preparation programs in special education, therapeutic recreation, physical education, and physical therapy for individuals with disabilities.…

  15. Umhlanga Rocks coastal defense

    NARCIS (Netherlands)

    De Jong, L.; De Jong, B.; Ivanova, M.; Gerritse, A.; Rietberg, D.; Dorrepaal, S.

    2014-01-01

    The eThekwini coastline is a vulnerable coastline subject to chronic erosion and damage due to sea level rise. In 2007 a severe storm caused major physical and economic damage along the coastline, proving the need for action. Umhlanga Rocks is a densely populated premium holiday destination on the e

  16. Abrupt response of chemical weathering to Late Quaternary hydroclimate changes in northeast Africa

    Science.gov (United States)

    Bastian, Luc; Revel, Marie; Bayon, Germain; Dufour, Aurélie; Vigier, Nathalie

    2017-01-01

    Chemical weathering of silicate rocks on continents acts as a major sink for atmospheric carbon dioxide and has played an important role in the evolution of the Earth’s climate. However, the magnitude and the nature of the links between weathering and climate are still under debate. In particular, the timescale over which chemical weathering may respond to climate change is yet to be constrained at the continental scale. Here we reconstruct the relationships between rainfall and chemical weathering in northeast Africa for the last 32,000 years. Using lithium isotopes and other geochemical proxies in the clay-size fraction of a marine sediment core from the Eastern Mediterranean Sea, we show that chemical weathering in the Nile Basin fluctuated in parallel with the monsoon-related climatic evolution of northeast Africa. We also evidence strongly reduced mineral alteration during centennial-scale regional drought episodes. Our findings indicate that silicate weathering may respond as quickly as physical erosion to abrupt hydroclimate reorganization on continents. Consequently, we anticipate that the forthcoming hydrological disturbances predicted for northeast Africa may have a major impact on chemical weathering patterns and soil resources in this region. PMID:28290474

  17. Abrupt response of chemical weathering to Late Quaternary hydroclimate changes in northeast Africa

    Science.gov (United States)

    Bastian, Luc; Revel, Marie; Bayon, Germain; Dufour, Aurélie; Vigier, Nathalie

    2017-03-01

    Chemical weathering of silicate rocks on continents acts as a major sink for atmospheric carbon dioxide and has played an important role in the evolution of the Earth’s climate. However, the magnitude and the nature of the links between weathering and climate are still under debate. In particular, the timescale over which chemical weathering may respond to climate change is yet to be constrained at the continental scale. Here we reconstruct the relationships between rainfall and chemical weathering in northeast Africa for the last 32,000 years. Using lithium isotopes and other geochemical proxies in the clay-size fraction of a marine sediment core from the Eastern Mediterranean Sea, we show that chemical weathering in the Nile Basin fluctuated in parallel with the monsoon-related climatic evolution of northeast Africa. We also evidence strongly reduced mineral alteration during centennial-scale regional drought episodes. Our findings indicate that silicate weathering may respond as quickly as physical erosion to abrupt hydroclimate reorganization on continents. Consequently, we anticipate that the forthcoming hydrological disturbances predicted for northeast Africa may have a major impact on chemical weathering patterns and soil resources in this region.

  18. Constraining the role of early land plants in Palaeozoic weathering and global cooling.

    Science.gov (United States)

    Quirk, Joe; Leake, Jonathan R; Johnson, David A; Taylor, Lyla L; Saccone, Loredana; Beerling, David J

    2015-08-22

    How the colonization of terrestrial environments by early land plants over 400 Ma influenced rock weathering, the biogeochemical cycling of carbon and phosphorus, and climate in the Palaeozoic is uncertain. Here we show experimentally that mineral weathering by liverworts—an extant lineage of early land plants—partnering arbuscular mycorrhizal (AM) fungi, like those in 410 Ma-old early land plant fossils, amplified calcium weathering from basalt grains threefold to sevenfold, relative to plant-free controls. Phosphate weathering by mycorrhizal liverworts was amplified 9-13-fold over plant-free controls, compared with fivefold to sevenfold amplification by liverworts lacking fungal symbionts. Etching and trenching of phyllosilicate minerals increased with AM fungal network size and atmospheric CO2 concentration. Integration of grain-scale weathering rates over the depths of liverwort rhizoids and mycelia (0.1 m), or tree roots and mycelia (0.75 m), indicate early land plants with shallow anchorage systems were probably at least 10-fold less effective at enhancing the total weathering flux than later-evolving trees. This work challenges the suggestion that early land plants significantly enhanced total weathering and land-to-ocean fluxes of calcium and phosphorus, which have been proposed as a trigger for transient dramatic atmospheric CO2 sequestration and glaciations in the Ordovician. © 2015 The Authors.

  19. Verification of Space Weather Forecasts using Terrestrial Weather Approaches

    Science.gov (United States)

    Henley, E.; Murray, S.; Pope, E.; Stephenson, D.; Sharpe, M.; Bingham, S.; Jackson, D.

    2015-12-01

    The Met Office Space Weather Operations Centre (MOSWOC) provides a range of 24/7 operational space weather forecasts, alerts, and warnings, which provide valuable information on space weather that can degrade electricity grids, radio communications, and satellite electronics. Forecasts issued include arrival times of coronal mass ejections (CMEs), and probabilistic forecasts for flares, geomagnetic storm indices, and energetic particle fluxes and fluences. These forecasts are produced twice daily using a combination of output from models such as Enlil, near-real-time observations, and forecaster experience. Verification of forecasts is crucial for users, researchers, and forecasters to understand the strengths and limitations of forecasters, and to assess forecaster added value. To this end, the Met Office (in collaboration with Exeter University) has been adapting verification techniques from terrestrial weather, and has been working closely with the International Space Environment Service (ISES) to standardise verification procedures. We will present the results of part of this work, analysing forecast and observed CME arrival times, assessing skill using 2x2 contingency tables. These MOSWOC forecasts can be objectively compared to those produced by the NASA Community Coordinated Modelling Center - a useful benchmark. This approach cannot be taken for the other forecasts, as they are probabilistic and categorical (e.g., geomagnetic storm forecasts give probabilities of exceeding levels from minor to extreme). We will present appropriate verification techniques being developed to address these forecasts, such as rank probability skill score, and comparing forecasts against climatology and persistence benchmarks. As part of this, we will outline the use of discrete time Markov chains to assess and improve the performance of our geomagnetic storm forecasts. We will also discuss work to adapt a terrestrial verification visualisation system to space weather, to help

  20. Range sections as rock models for intensity rock scene segmentation

    CSIR Research Space (South Africa)

    Mkwelo, S

    2007-11-01

    Full Text Available This paper presents another approach to segmenting a scene of rocks on a conveyor belt for the purposes of measuring rock size. Rock size estimation instruments are used to monitor, optimize and control milling and crushing in the mining industry...

  1. CHEMICAL WEATHERING PROCESSES AND ATMOSPHERIC CO2 CONSUMPTION OF HUANGHE RIVER AND CHANGJIANG RIVER BASINS

    Institute of Scientific and Technical Information of China (English)

    LI Jing-ying; ZHANG Jing

    2005-01-01

    Rock weathering plays an important role in studying the long-term carbon cycles and global climaticchange. According to the statistics analysis, the Huanghe (Yellow) River water chemistry was mainly controlled byevaporite and carbonate weathering, which were responsible for over 90% of total dissolved ions. As compared withthe Huanghe River basin, dissolved load of the Changjiang (Yangtze) River was mainly originated from the carbonate dissolution.The chemical weathering rates were estimated to be 39.29t/(km2·a)and 61.58t/(km2·a)by deduting the HCO3- derived from atmosphere in the Huanghe River and Changjiang River watersheds, respectively. The CO2 con-sumption rates by rock weathering were calculated to be 120.84 × 103mol/km2 and 452.46 × 103mol/km2 annually in thetwo basins, respectively. The total CO2 consumption of the two basins amounted to 918.51 × 109mol/a, accounting for3.83% of the world gross. In contrast to other world watersheds, the stronger evaporite reaction and infirm silicateweathering can explain such feature that CO2 consumption rates were lower than a global average, suggesting that thesequential weathering may be go on in the two Chinese drainage basins.

  2. Working Process Development For Weathering Degree Mapping Of Stone Monument Using Reflectance Spectroscopy

    Science.gov (United States)

    Hyun, C.; Park, H.

    2008-12-01

    Most stone monuments have been weathered on the field with exposure of rain and wind during hundreds or thousands years. Reflectance spectroscopy can be applied to assess weathering degree of those stone monuments composed of granite which is the most general material of stone monument in Korea. Weathering degree was analyzed by using reflected and transmitted electromagnetic energy based on the theory of reflectance spectroscopy on the surface of rock to identify rock forming minerals using their diagnostic spectral absorption features. This method could be used as an improved nondestructive assessment method compared with conventional subjective and qualitative assessment methods. We tested feasibility of this technique for actual granite stone monuments. Granite is generally composed of quartz, feldspars and micas. Feldspars are changed to clay minerals such as kaolinite and illite after weathering process. Biotite of mica produce iron oxides which induce color changes on surface of rocks. The experiments were conducted using field spectrometer FieldSpec®3 of ASD Inc. and the range of measurement was form 350µm to 2500µm wavelength. Spectral reflectance of weathering products at each measuring point was processed by removing delineated convex hull from raw reflectance curves to exclude background effects and to extract quantitative absorption depths which indicate relative distribution degree of weathering products. We produced deterioration map on the surface of the monument by interpolating absorption depth values of each point with consideration of spatial distribution of measurements. For facilitation of practical uses a chain of working process of this method was designed using whole experimental processes.

  3. A Photographic Atlas of Rock Breakdown Features in Geomorphic Environments

    Science.gov (United States)

    Bourke, Mary C. (Editor); Brearley, J. Alexander; Haas, Randall; Viles, Heather A.

    2007-01-01

    A primary goal of geomorphological enquiry is to make genetic associations between process and form. In rock breakdown studies, the links between process, inheritance and lithology are not well constrained. In particular, there is a need to establish an understanding of feature persistence. That is, to determine the extent to which in situ rock breakdown (e.g., aeolian abrasion or salt weathering) masks signatures of earlier geomorphic transport processes (e.g., fluvial transport or crater ejecta). Equally important is the extent to which breakdown during geomorphic transport masks the imprint of past weathering. The use of rock features in this way raises the important question: Can features on the surface of a rock reliably indicate its geomorphic history? This has not been determined for rock surfaces on Earth or other planets. A first step towards constraining the links between process, inheritance, and morphology is to identify pristine features produced by different process regimes. The purpose of this atlas is to provide a comprehensive image collection of breakdown features commonly observed on boulders in different geomorphic environments. The atlas is intended as a tool for planetary geoscientists and their students to assist in identifying features found on rocks on planetary surfaces. In compiling this atlas, we have attempted to include features that have formed 'recently' and where the potential for modification by another geomorphic process is low. However, we acknowledge that this is, in fact, difficult to achieve when selecting rocks in their natural environment. We group breakdown features according to their formative environment and process. In selecting images for inclusion in the atlas we were mindful to cover a wide range of climatic zones. For example, in the weathering chapter, clast features are shown from locations such as the hyper-arid polar desert of Antarctica and the semi-arid canyons of central Australia. This is important as some

  4. Tomorrow's Forecast: Oceans and Weather.

    Science.gov (United States)

    Smigielski, Alan

    1995-01-01

    This issue of "Art to Zoo" focuses on weather and climate and is tied to the traveling exhibition Ocean Planet from the Smithsonian's National Museum of Natural History. The lessons encourage students to think about the profound influence the oceans have on planetary climate and life on earth. Sections of the lesson plan include: (1) "Ocean…

  5. Winter Weather Frequently Asked Questions

    Science.gov (United States)

    ... Part 3 of 3) Hot Weather Tips Heat Stress in Older Adults FAQs Extreme Heat PSAs Related Links MMWR Bibliography CDC's Program Floods Flood Readiness Personal Hygiene After a Disaster Cleanup of Flood Water After a Flood Worker Safety Educational Materials Floods ...

  6. Dynamic Weather Routes Architecture Overview

    Science.gov (United States)

    Eslami, Hassan; Eshow, Michelle

    2014-01-01

    Dynamic Weather Routes Architecture Overview, presents the high level software architecture of DWR, based on the CTAS software framework and the Direct-To automation tool. The document also covers external and internal data flows, required dataset, changes to the Direct-To software for DWR, collection of software statistics, and the code structure.

  7. Mexican Space Weather Service (SCIESMEX)

    Science.gov (United States)

    Gonzalez-Esparza, A.; De la Luz, V.; Mejia-Ambriz, J. C.; Aguilar-Rodriguez, E.; Corona-Romero, P.; Gonzalez, L. X.

    2015-12-01

    Recent modifications of the Civil Protection Law in Mexico include now specific mentions to space hazards and space weather phenomena. During the last few years, the UN has promoted international cooperation on Space Weather awareness, studies and monitoring. Internal and external conditions motivated the creation of a Space Weather Service in Mexico (SCIESMEX). The SCIESMEX (www.sciesmex.unam.mx) is operated by the Geophysics Institute at the National Autonomous University of Mexico (UNAM). The UNAM has the experience of operating several critical national services, including the National Seismological Service (SSN); besides that has a well established scientific group with expertise in space physics and solar- terrestrial phenomena. The SCIESMEX is also related with the recent creation of the Mexican Space Agency (AEM). The project combines a network of different ground instruments covering solar, interplanetary, geomagnetic, and ionospheric observations. The SCIESMEX has already in operation computing infrastructure running the web application, a virtual observatory and a high performance computing server to run numerical models. SCIESMEX participates in the International Space Environment Services (ISES) and in the Inter-progamme Coordination Team on Space Weather (ICTSW) of the Word Meteorological Organization (WMO).

  8. Laboratory tools to quantify biogenic dissolution of rocks and minerals: a model rock biofilm growing in percolation columns

    Directory of Open Access Journals (Sweden)

    Franz eSeiffert

    2016-04-01

    Full Text Available Sub-aerial biofilms (SAB are ubiquitous, self-sufficient microbial ecosystems found on mineral surfaces at all altitudes and latitudes. SABs, which are the principal causes of weathering on exposed terrestrial surfaces, are characterised by patchy growth dominated by associations of algae, cyanobacteria, fungi and heterotrophic bacteria. A recently developed in vitro system to study colonisation of rocks exposed to air included two key SAB participants - the rock-inhabiting ascomycete Knufia petricola (CBS 123872 and the phototrophic cyanobacterium Nostoc punctiforme ATCC29133. Both partners are genetically tractable and we used them here to study weathering of granite, K-feldspar and plagioclase. Small fragments of the various rocks or minerals (1 to 6 mm were packed into flow-through columns and incubated with 0.1% glucose and 10 µM thiamine-hydrochloride (90 µL.min-1 to compare weathering with and without biofilms. Dissolution of the minerals was followed by: analysing (i the degradation products in the effluent from the columns via Inductively Coupled Plasma Spectroscopy and (ii by studying polished sections of the incubated mineral fragment/grains using scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray analyses. K. petricola/N. punctiforme stimulated release of Ca, Na, Mg and Mn. Analyses of the polished sections confirmed depletion of Ca, Na and K near the surface of the fragments. The abrupt decrease in Ca concentration observed in peripheral areas of plagioclase fragments favoured a dissolution-reprecipitation mechanism. Percolation columns in combination with a model biofilm can thus be used to study weathering in closed systems. Columns can easily be filled with different minerals and biofilms, the effluent as well as grains can be collected after long-term exposure under axenic conditions and easily analysed.

  9. Laboratory tools to quantify biogenic dissolution of rocks and minerals: a model rock biofilm growing in percolation columns

    Science.gov (United States)

    Seiffert, Franz; Bandow, Nicole; Kalbe, Ute; Milke, Ralf; Gorbushina, Anna

    2016-04-01

    Sub-aerial biofilms (SAB) are ubiquitous, self-sufficient microbial ecosystems found on mineral surfaces at all altitudes and latitudes. SABs, which are the principal causes of weathering on exposed terrestrial surfaces, are characterised by patchy growth dominated by associations of algae, cyanobacteria, fungi and heterotrophic bacteria. A recently developed in vitro system to study colonisation of rocks exposed to air included two key SAB participants - the rock-inhabiting ascomycete Knufia petricola (CBS 123872) and the phototrophic cyanobacterium Nostoc punctiforme ATCC29133. Both partners are genetically tractable and we used them here to study weathering of granite, K-feldspar and plagioclase. Small fragments of the various rocks or minerals (1 to 6 mm) were packed into flow-through columns and incubated with 0.1% glucose and 10 µM thiamine-hydrochloride (90 µL.min-1) to compare weathering with and without biofilms. Dissolution of the minerals was followed by: analysing (i) the degradation products in the effluent from the columns via Inductively Coupled Plasma Spectroscopy and (ii) by studying polished sections of the incubated mineral fragment/grains using scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray analyses. K. petricola/N. punctiforme stimulated release of Ca, Na, Mg and Mn. Analyses of the polished sections confirmed depletion of Ca, Na and K near the surface of the fragments. The abrupt decrease in Ca concentration observed in peripheral areas of plagioclase fragments favoured a dissolution-reprecipitation mechanism. Percolation columns in combination with a model biofilm can thus be used to study weathering in closed systems. Columns can easily be filled with different minerals and biofilms, the effluent as well as grains can be collected after long-term exposure under axenic conditions and easily analysed.

  10. Mineralogical Control on Microbial Diversity in a Weathered Granite?

    Science.gov (United States)

    Gleeson, D.; Clipson, N.; McDermott, F.

    2003-12-01

    Mineral transformation reactions and the behaviour of metals in rock and soils are affected not only by physicochemical parameters but also by biological factors, particularly by microbial activity. Microbes inhabit a wide range of niches in surface and subsurface environments, with mineral-microbe interactions being generally poorly understood. The focus of this study is to elucidate the role of microbial activity in the weathering of common silicate minerals in granitic rocks. A site in the Wicklow Mountains (Ireland) has been identified that consists of an outcrop surface of Caledonian (ca. 400 million years old) pegmatitic granite from which large intact crystals of variably weathered muscovite, plagioclase, K-feldspar and quartz were sampled, together with whole-rock granite. Culture-based microbial approaches have been widely used to profile microbial communities, particularly from copiotrophic environments, but it is now well established that for oligotrophic environments such as those that would be expected on weathering faces, perhaps less than 1% of microbial diversity can be profiled by cultural means. A number of culture-independent molecular based approaches have been developed to profile microbial diversity and community structure. These rely on successfully isolating environmental DNA from a given environment, followed by the use of the polymerase chain reaction (PCR) to amplify the typically small quantities of extracted DNA. Amplified DNA can then be analysed using cloning based approaches as well as community fingerprinting systems such as denaturing gradient gel electrophoresis (DGGE), terminal restriction fragment length polymorphism (TRFLP) and ribosomal intergenic spacer analysis (RISA). Community DNA was extracted and the intergenic spacer region (ITS) between small (16S) and large (23S) bacterial subunit rRNA genes was amplified. RISA fragments were then electrophoresed on a non-denaturing polyacrylamide gel. Banding patterns suggest that

  11. Elemental geochemistry of sedimentary rocks at Yellowknife Bay, Gale crater, Mars

    NARCIS (Netherlands)

    McLennan, S.M.; Anderson, R.B.; Bell III, J.F.; Bridges, J.C.; Calef III, F.; Campbell, J.L.; Clark, B.C.; Clegg, S.; Conrad, P.; Cousin, A.; Des Marais, D.J.; Dromart, G.; Dyar, M.D.; Edgar, L.A.; Ehlmann, B.L.; Fabre, C.; Forni, O.; Gasnault, O.; Gellert, R.; Gordon, S.; Grant, J.A.; Grotzinger, J.P.; Gupta, S.; Herkenhoff, K.E.; Hurowitz, J.A.; King, P.L.; Mouélic, S.L.; Leshin, L.A.; Léveillé, R.; Lewis, K.W.; Mangold, N.; Maurice, S.; Ming, D.W.; Morris, R.V.; Nachon, M.; Newsom, H.E.; Ollila, A.M.; Perrett, G.M.; Rice, M.S.; Schmidt, M.E.; Schwenzer, S.P.; Stack, K.; Stolper, E.M.; Sumner, D.Y.; Treiman, A.H.; VanBommel, S.; Vaniman, D.T.; Vasavada, A.; Wiens, R.C.; Yingst, R.A.; ten Kate, Inge Loes

    2014-01-01

    Sedimentary rocks examined by the Curiosity rover at Yellowknife Bay, Mars, were derived from sources that evolved from an approximately average martian crustal composition to one influenced by alkaline basalts. No evidence of chemical weathering is preserved, indicating arid, possibly cold, paleocl

  12. Weather-Corrected Performance Ratio

    Energy Technology Data Exchange (ETDEWEB)

    Dierauf, T.; Growitz, A.; Kurtz, S.; Cruz, J. L. B.; Riley, E.; Hansen, C.

    2013-04-01

    Photovoltaic (PV) system performance depends on both the quality of the system and the weather. One simple way to communicate the system performance is to use the performance ratio (PR): the ratio of the electricity generated to the electricity that would have been generated if the plant consistently converted sunlight to electricity at the level expected from the DC nameplate rating. The annual system yield for flat-plate PV systems is estimated by the product of the annual insolation in the plane of the array, the nameplate rating of the system, and the PR, which provides an attractive way to estimate expected annual system yield. Unfortunately, the PR is, again, a function of both the PV system efficiency and the weather. If the PR is measured during the winter or during the summer, substantially different values may be obtained, making this metric insufficient to use as the basis for a performance guarantee when precise confidence intervals are required. This technical report defines a way to modify the PR calculation to neutralize biases that may be introduced by variations in the weather, while still reporting a PR that reflects the annual PR at that site given the project design and the project weather file. This resulting weather-corrected PR gives more consistent results throughout the year, enabling its use as a metric for performance guarantees while still retaining the familiarity this metric brings to the industry and the value of its use in predicting actual annual system yield. A testing protocol is also presented to illustrate the use of this new metric with the intent of providing a reference starting point for contractual content.

  13. Heritage stones and their deterioration in rock-cut monuments in India

    Science.gov (United States)

    Sharma, Vinod K.

    2017-04-01

    India is dotted with thousands of rock- cut monuments of considerable antiquity having artwork of global importance. It is evident from the location of many of these monuments that knowledge of viable selection of site, geotechnical considerations and amenability to sculptures' chisel was vital for construction of rock-cut monuments and sculptures. These rock-cut structures also represent significant achievements of geotechnical and structural engineering and craftsmanship of contemporary period. The paper deals with some of the sites where natural rock-mass exposures were used to hew the monuments and highlight the deterioration owing to geological and climatic conditions. The Kailash temple in Ellora and Ajanta rock-cut caves are among the greatest architectural feats which owe their grandeur to amenability and consistency of basalt of Deccan Volcanic Province from which it is hewn. The Kailash Temple was created through a single, huge top-down excavation 100 feet deep down into the volcanic basaltic cliff rock. These ancient rock cut structures are amazing achievements of structural engineering and craftsmanship. The lava flows are nearly horizontal, competent rock medium facilitated the chiseling for the sculptures. The deterioration of these basalts are seen where the amygdule, vesicles and opening in rock discontinuity had the medium of construction or excavation. The monolithic rock- cut monuments of Mahabalipuram temples are constructed in the form of rathas or chriot and adjoining caves by excavating solid charnockite/granites. The large rock exposures are excavated and cut to perfection with wall decorations and sculptured art. The charnockites are the strongest and the most durable rock, yet quite amenable to fine dressing. These monolithic monuments in charnockite and are cut out of the hillock. The 7th Century monuments now exhibit somewhat rough surface probably due to weathering effect of salt laden winds from the sea side and alteration of feldspars

  14. Reconnaissance of Field Sites for the Study of Chemical Weathering on the Guayana Shield, South America

    Energy Technology Data Exchange (ETDEWEB)

    Steefell, C I

    2003-02-01

    Despite the fact that chemical weathering of silicate rocks plays an important role in the draw-down of CO{sub 2} over geologic time scales (Berner and Berner, 1996), the overall controls on the rate of chemical weathering are still not completely understood. Lacking a mechanistic understanding of these controls, it remains difficult to evaluate a hypothesis such as that presented by Raymo and Ruddiman (1992), who suggested that enhanced weathering and CO{sub 2} draw-down resulting from the uplift of the Himalayas contributed to global cooling during the Cenozoic. At an even more fundamental level, the three to four order of magnitude discrepancy between laboratory and field weathering rates is still unresolved (White et al., 1996). There is as yet no comprehensive, mechanistic model for silicate chemical weathering that considers the coupled effects of precipitation, vadose zone flow, and chemical reactions. The absence of robust process models for silicate weathering and the failure to resolve some of these important questions may in fact be related-the controls on the overall rates of weathering cannot be understood without considering the weathering environment as one in which multiple, time-dependent chemical and physical processes are coupled (Malmstrom, 2000). Once chemical weathering is understood at a mechanistic process level, the important controls on chemical weathering (physical erosion, temperature, precipitation) can be folded into larger scale models tracking the global carbon cycle. Our goal in this study was to carry out the preliminary work needed to establish a field research site for chemical weathering om the Cuayana Shield in South America. The Guayana Shield is a Precambrian province greater than 1.5 billion years old covering portions of Venezuela, Guyana (the country), Surinam, French Guiana, and Brazil (Figure 1). More important than the age of the rocks themselves, however, is the age of the erosion surface developed on the Shield, with

  15. Rock and mineral magnetism

    CERN Document Server

    O’Reilly, W

    1984-01-01

    The past two decades have witnessed a revolution in the earth sciences. The quantitative, instrument-based measurements and physical models of. geophysics, together with advances in technology, have radically transformed the way in which the Earth, and especially its crust, is described. The study of the magnetism of the rocks of the Earth's crust has played a major part in this transformation. Rocks, or more specifically their constituent magnetic minerals, can be regarded as a measuring instrument provided by nature, which can be employed in the service of the earth sciences. Thus magnetic minerals are a recording magnetometer; a goniometer or protractor, recording the directions of flows, fields and forces; a clock; a recording thermometer; a position recorder; astrain gauge; an instrument for geo­ logical surveying; a tracer in climatology and hydrology; a tool in petrology. No instrument is linear, or free from noise and systematic errors, and the performance of nature's instrument must be assessed and ...

  16. Pitted Rock Named Ender

    Science.gov (United States)

    1997-01-01

    This image was taken by the Sojourner rover's right front camera on Sol 33. The rock in the foreground, nicknamed 'Ender', is pitted and marked by a subtle horizontal texture. The bright material on the top of the rock is probably wind-deposited dust. The Pathfinder Lander is seen in the distance at right. The lander camera is the cylindrical object on top of the deployed mast.Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and managed the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

  17. Uranium in alkaline rocks

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, M.; Wollenberg, H.; Strisower, B.; Bowman, H.; Flexser, S.; Carmichael, I.

    1978-04-01

    Geologic and geochemical criteria were developed for the occurrence of economic uranium deposits in alkaline igneous rocks. A literature search, a limited chemical analytical program, and visits to three prominent alkaline-rock localities (Ilimaussaq, Greenland; Pocos de Caldas, Brazil; and Powderhorn, Colorado) were made to establish criteria to determine if a site had some uranium resource potential. From the literature, four alkaline-intrusive occurrences of differing character were identified as type-localities for uranium mineralization, and the important aspects of these localities were described. These characteristics were used to categorize and evaluate U.S. occurrences. The literature search disclosed 69 U.S. sites, encompassing nepheline syenite, alkaline granite, and carbonatite. It was possible to compare two-thirds of these sites to the type localities. A ranking system identified ten of the sites as most likely to have uranium resource potential.

  18. OpenWeather: a peer-to-peer weather data transmission protocol

    CERN Document Server

    Yanes, Adrian

    2011-01-01

    The study of the weather is performed using instruments termed weather stations. These weather stations are distributed around the world, collecting the data from the different phenomena. Several weather organizations have been deploying thousands of these instruments, creating big networks to collect weather data. These instruments are collecting the weather data and delivering it for later processing in the collections points. Nevertheless, all the methodologies used to transmit the weather data are based in protocols non adapted for this purpose. Thus, the weather stations are limited by the data formats and protocols used in them, not taking advantage of the real-time data available on them. We research the weather instruments, their technology and their network capabilities, in order to provide a solution for the mentioned problem. OpenWeather is the protocol proposed to provide a more optimum and reliable way to transmit the weather data. We evaluate the environmental factors, such as location or bandwi...

  19. Alkaline Rocks and Geodynamics

    OpenAIRE

    BONIN, Bernard

    1998-01-01

    Origin of A-type alkali feldspar granites is currently the subject of a world-wide debate. Contrasting hypotheses have been proposed, which range from an entirely crustal origin to an almost complete mantle derivation. A-type alkali feldspar granites belong to either unimodal granite (rhyolite)-dominated association, or bimodal gabbro (basalt)-granite (rhyolite) suite. It is argued that (i) the ultimate mantle origin of basic to intermediate rocks is beyond doubt, (ii) highly evolved felsi...

  20. Using Modeling Clay to Model the Rock Cycle

    Science.gov (United States)

    Cook, H. M.

    2016-12-01

    During this interactive exploration, students will be guided through the rock cycle using modeling clay as a medium. Each student will be given a ball of red clay and a ball of yellow clay. The instructor will introduce students to igneous rocks as they use their red clay to create a volcano. Students will then learn about weathering and erosion as they break their yellow ball of clay into smaller and smaller pieces that they will round into spheres. The "sand" created from the yellow clay gets accumulated and lithified (via gentle compression by the students) to form a sandstone. This sandstone then becomes covered by a lava flow, created by smashing the red clay volcanoes. The process of metamorphism is introduced as students gently cover their sandstone using the lava flow. This also serves a segue for a discussion about the various types of metamorphism beginning with contact metamorphism. Metamorphic grade is discussed as increased pressure further alters the sedimentary rock and lava flow. Ultimately a migmatite is formed by mixing the red and yellow clay together. Finally, they clays become so intermingled that a new larger orange ball is created, beginning the rock cycle anew with an igneous melt. This activity is engaging and effective with students of all ages. Intended as a fun, light-hearted approach to introducing rocks in an undergraduate earth science class, this can be effectively customized for use in an elementary, middle, or high school classroom.

  1. Rock size-frequency distributions analysis at lunar landing sites based on remote sensing and in-situ imagery

    Science.gov (United States)

    Li, Bo; Ling, Zongcheng; Zhang, Jiang; Chen, Jian

    2017-10-01

    Rock populations can supply fundamental geological information about origin and evolution of a planet. In this paper, we used Lunar Reconnaissance Orbiter (LRO) narrow-angle camera (NAC) images to identify rocks at the lunar landing sites (including Chang'e 3 (CE-3), Apollo and Surveyor series). The diameter and area of each identified rock were measured to generate distributions of rock cumulative fractional area and size-frequency on a log-log plot. The two distributions both represented the same shallow slopes at smaller diameters followed by steeper slopes at larger diameters. A reasonable explanation for the lower slopes may be the resolution and space weathering effects. By excluding the smaller diameters, rock populations derived from NAC images showed approximately linear relationships and could be fitted well by power laws. In the last, the entire rock populations derived from both NAC and in-situ imagery could be described by one power function at the lunar landing sites except the CE-3 and Apollo 11 landing sites. This may be because that the process of a large rock breaking down to small rocks even fine particles can be modeled by fractal theories. Thus, rock populations on lunar surfaces can be extrapolated along the curves of rock populations derived from NAC images to smaller diameters. In the future, we can apply rock populations from remote sensing images to estimate the number of rocks with smaller diameters to select the appropriate landing sites for the CE-4 and CE-5 missions.

  2. Fire Danger and Fire Weather Records

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Weather Service (formerly Weather Bureau) and Forest Service developed a program to track meteorological conditions conducive to forest fires, resulting...

  3. SIGWX Charts - High Level Significant Weather

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — High level significant weather (SIGWX) forecasts are provided for the en-route portion of international flights. NOAA's National Weather Service Aviation Center...

  4. Integrating Sphere-based Weathering Device

    Data.gov (United States)

    Federal Laboratory Consortium — Description:In the artificial ultraviolet (UV) weathering of materials, a need exists for weathering devices that can uniformly illuminate test specimens with a high...

  5. NOAA Weather and Climate Toolkit (WCT)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Weather and Climate Toolkit is an application that provides simple visualization and data export of weather and climatological data archived at NCDC. The...

  6. Newspaper Clippings and Articles (Weather-related)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Weather-related newspaper articles and photos, almost exclusively from Baltimore, MD and nearby areas. Includes storm damage, rainfall reports, and weather's affect...

  7. Rainmakers: why bad weather means good productivity.

    Science.gov (United States)

    Lee, Jooa Julia; Gino, Francesca; Staats, Bradley R

    2014-05-01

    People believe that weather conditions influence their everyday work life, but to date, little is known about how weather affects individual productivity. Contrary to conventional wisdom, we predict and find that bad weather increases individual productivity and that it does so by eliminating potential cognitive distractions resulting from good weather. When the weather is bad, individuals appear to focus more on their work than on alternate outdoor activities. We investigate the proposed relationship between worse weather and higher productivity through 4 studies: (a) field data on employees' productivity from a bank in Japan, (b) 2 studies from an online labor market in the United States, and (c) a laboratory experiment. Our findings suggest that worker productivity is higher on bad-, rather than good-, weather days and that cognitive distractions associated with good weather may explain the relationship. We discuss the theoretical and practical implications of our research.

  8. National Weather Service County Warning Area Boundaries

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains polygons corresponding to the County Warning Areas (CWAs) of each Weather Forecast Office (WFO) in the National Weather Service (NWS).

  9. National Weather Service: Watch, Warning, Advisory Display

    Science.gov (United States)

    weather.gov Site Map News Organization Search for: SPC NCEP All NOAA Search by city or zip ... Fire Wx Outlooks RSS Feeds E-Mail Alerts Weather Information Storm Reports Storm Reports Dev. NWS Hazards ...

  10. Adaptive Weather Forecasting using Local Meteorological Information

    NARCIS (Netherlands)

    Doeswijk, T.G.; Keesman, K.J.

    2005-01-01

    In general, meteorological parameters such as temperature, rain and global radiation are important for agricultural systems. Anticipating on future conditions is most often needed in these systems. Weather forecasts then become of substantial importance. As weather forecasts are subject to

  11. Weather Derivatives – Origin, Types and Application

    Directory of Open Access Journals (Sweden)

    Piotr Binkowski

    2008-03-01

    Full Text Available The number of companies that are exposed to the revenues loss risk caused by weather variability is still increasing. The businesses that are mostly exposed to weather risk are following: energy, agriculture, constructions and transport. That situation has initiated dynamic growth of weather derivatives markets as well as the awareness of the weather risk among the market participants. Presently, the weather derivatives markets evaluate rapidly in all the mature economies: USA, Asia and Europe. Constructing weather derivatives relies on qu- antifying climate factors in the form of indexes, what is quite simple task, more difficultly can be gathering precise historical data of required climate factors. Taking into consideration so far development of derivatives ñ especially the financial derivatives based on different types of indexes ñ financial market has at disposal wide range of different types of proved derivatives (futures, forward, options, swaps, which can be successfully utilised on the weather-driven markets both for hedging weather risk and speculating.

  12. World War II Weather Record Transmittances

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — World War II Weather Record Transmittances are a record of the weather and meteorological data observed during World War II and transferred to the archive. It...

  13. Rock blasting and explosives engineering

    Energy Technology Data Exchange (ETDEWEB)

    Persson, P.-A.; Holmberg, R.; Lee, J. (New Mexico Institute of Mining and Technology, Socorro, NM (United States). Research Center for Energetic Materials)

    1994-01-01

    The book covers the practical engineering aspects of different kinds of rock blasting. It includes a thorough analysis of the cost of the entire process of tunneling by drilling and blasting compared with full-face boring. It covers the economics of the entire rock blasting operation and its dependence on the size of excavation. The book highlights the fundamentals of rock mechanics, shock waves and detonation, initiation and mechanics of rock motion. It describes the engineering design principles and computational techniques for many separate mining methods and rock blasting operations. 274 refs.

  14. Rock in Rio: forever young

    Directory of Open Access Journals (Sweden)

    Ricardo Ferreira Freitas

    2014-12-01

    Full Text Available The purpose of this article is to discuss the role of Rock in Rio: The Musical, as herald of megafestival Rock in Rio. Driven by the success that musicals have reached in Brazil, we believe that the design of this spectacle of music, dance and staging renews the brand of the rock festival, once it adds the force of young and healthy bodies to its concept. Moreover, the musical provides Rock in Rio with some distance from the controversal trilogy of sex, drugs and rock and roll, a strong mark of past festivals around the world. Thus, the musical expands the possibilities of growth for the brand.

  15. Rock in Rio: eternamente jovem

    OpenAIRE

    Ricardo Ferreira Freitas; Flávio Lins Rodrigues

    2014-01-01

    The purpose of this article is to discuss the role of Rock in Rio: The Musical, as herald of megafestival Rock in Rio. Driven by the success that musicals have reached in Brazil, we believe that the design of this spectacle of music, dance and staging renews the brand of the rock festival, once it adds the force of young and healthy bodies to its concept. Moreover, the musical provides Rock in Rio with some distance from the controversal trilogy of sex, drugs and rock and roll, a strong mark ...

  16. Towards a geomechanics classification of folded layered rock masses

    Science.gov (United States)

    Agliardi, Federico; Zanchi, Andrea; Bianchi, Federico; Crosta, Giovanni B.

    2016-04-01

    .g. flexural slips, faults, shear fractures and extension veins) and related kinematic indicators. Field data were complemented with the analysis of the RGB-rendered point cloud to characterize local fold geometry (wavelength, interlimb angle), fracture spacing and trace length. At each survey location, an independent estimation of the GSI has been carried out in the field and correlated to the different measured structural and rock mass descriptors. These parameters add better constrains to the relative effects of rock type (intact rock strength and bedding thickness), fold geometry and associated structures on rock mass geometry and weathering, providing inputs to a modified GSI scheme for folded rocks.

  17. Climate-driven thresholds for chemical weathering in postglacial soils of New Zealand

    Science.gov (United States)

    Dixon, Jean L.; Chadwick, Oliver A.; Vitousek, Peter M.

    2016-09-01

    Chemical weathering in soils dissolves and alters minerals, mobilizes metals, liberates nutrients to terrestrial and aquatic ecosystems, and may modulate Earth's climate over geologic time scales. Climate-weathering relationships are often considered fundamental controls on the evolution of Earth's surface and biogeochemical cycles. However, surprisingly little consensus has emerged on if and how climate controls chemical weathering, and models and data from published literature often give contrasting correlations and predictions for how weathering rates and climate variables such as temperature or moisture are related. Here we combine insights gained from the different approaches, methods, and theory of the soil science, biogeochemistry, and geomorphology communities to tackle the fundamental question of how rainfall influences soil chemical properties. We explore climate-driven variations in weathering and soil development in young, postglacial soils of New Zealand, measuring soil elemental geochemistry along a large precipitation gradient (400-4700 mm/yr) across the Waitaki basin on Te Waipounamu, the South Island. Our data show a strong climate imprint on chemical weathering in these young soils. This climate control is evidenced by rapid nonlinear changes along the gradient in total and exchangeable cations in soils and in the increased movement and redistribution of metals with rainfall. The nonlinear behavior provides insight into why climate-weathering relationships may be elusive in some landscapes. These weathering thresholds also have significant implications for how climate may influence landscape evolution and the release of rock-derived nutrients to ecosystems, as landscapes that transition to wetter climates across this threshold may weather and deplete rapidly.

  18. Microclimatic, chemical, and mineralogical evidence for tafoni weathering processes on the Miaowan Island, South China

    Science.gov (United States)

    Huang, Rihui; Wang, Wei

    2017-02-01

    Tafoni were widely distributed around the world; however, their processes of development remain unclear. In this study, the roles of microclimatic, geochemical and mineralogical processes on tafoni development along the subtropical coastline of the Miaowan Island, south China, are investigated. Field observations were carried out during three visits to the island over a four-year period (2011-2015). The orientation of 184 tafoni openings were measured, and micrometeorological changes of three tafoni on opposite sides of the island were monitored by pocket weather trackers (Kestrel 4500) in two periods. Samples of residual debris inside three tafoni hosted in a large boulder, the parent rock of the tafoni, and from the weathering profile of a nearby bedrock outcrop were collected for X-ray fluorescence (XRF) and X-ray diffraction (XRD) analyses. The field observations showed that tafoni were of different sizes and constantly produced flakes and debris inside the tafoni caves, indicating their on-going active development. An increase in Na in residual debris in tafoni caves on the Miaowan Island is the most obvious evidence of salt weathering. Salt weathering inside tafoni caves is not intense and does not match the salt-rich environment outside the caves, indicating that the influence of salt is not strong. The loss of K, Ca, and Mg in the residue samples, and the appearance of the clay mineral montmorillonite are caused by chemical weathering. Most of the tafoni openings face mountains, demonstrating the effect of humidity in tafoni weathering. Tafoni cave shapes are related to the distribution of humid water vapour, which tends to collect at the top of the cave, and leads to more intensive development here than in other parts. Drastic daily changes in relative humidity inside tafoni caves accelerate mechanical weathering owing to swelling and shrinking of salt and clay minerals. The Miaowan Island tafoni are formed by weathering, but they cannot be simply

  19. Decision Making Models Using Weather Forecast Information

    OpenAIRE

    Hiramatsu, Akio; Huynh, Van-Nam; Nakamori, Yoshiteru

    2007-01-01

    The quality of weather forecast has gradually improved, but weather information such as precipitation forecast is still uncertainty. Meteorologists have studied the use and economic value of weather information, and users have to translate weather information into their most desirable action. To maximize the economic value of users, the decision maker should select the optimum course of action for his company or project, based on an appropriate decision strategy under uncertain situations. In...

  20. Distribution of Quercus agrifolia mycorrhizae deep within weathered bedrock: a potential mechanism for transport of stored water

    Science.gov (United States)

    M. Bornyasz; R. Graham; M. Allen

    2002-01-01

    In southwestern California, Quercus agrifolia distribution closely matches regions of granitic regolith. High annual evapotranspiration demand and inherent shallow soil conditions lead to a dependence on a deep rooting system and an ability to access water from deep within the regolith. Most of the plant available water in weathered granitic rock is...

  1. Mineralogy and Sr–Nd isotopes of SPM and sediment from the Mandovi and Zuari estuaries: Influence of weathering and anthropogenic contribution

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, V.P.; Shynu, R.; Singh, S.K.; Naqvi, S.W.A.; Kessarkar, P.M.

    and topography of the drainage basin of the river (Grim, 1968). The parent rocks in the humid, tropical and sub-tropical regions have extensively been lateritized and undergo very large geochemical fractionation during lateritization. Moreover, the clay...Sr ratios are expected from the weathering products of older rocks. Parent rocks (Pre- Cambrian gneisses and schists) in the study area are lateritized (Fig. 1B). High 87Sr/86Sr ratios (M7: 0.7470; Z7: 0.7686; Table 2) than those of parent rocks (0...

  2. Space Weather Receives First "Impact Rating"

    Science.gov (United States)

    Lanzerotti, Louis J.

    2007-08-01

    Journal Citation Reports, published by Thomson Scientific (http://scientific.thomson.com/isi/), has issued its first impact factor for Space Weather. It is 1.610. I consider this number to be very good, strongly validating the impact that Space Weather has already made in its short life within the community of space weather professionals.

  3. Space Weather Effects on Range Operations

    Science.gov (United States)

    2013-02-01

    www.windows2universe.org/space_weather/space_weather.html What are scientists talking about when they say “space weather”? How is it like weather on...particle events observed by ground level, high latitude neutron monitors and the Concorde observations are summarised in Table 1 (Refs. 12 & 13), which

  4. Reducing prediction uncertainty of weather controlled systems

    NARCIS (Netherlands)

    Doeswijk, T.G.

    2007-01-01

    In closed agricultural systems the weather acts both as a disturbance and as a resource. By using weather forecasts in control strategies the effects of disturbances can be minimized whereas the resources can be utilized. In this situation weather forecast uncertainty and model based control are cou

  5. 49 CFR 195.224 - Welding: Weather.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Welding: Weather. 195.224 Section 195.224 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... PIPELINE Construction § 195.224 Welding: Weather. Welding must be protected from weather conditions...

  6. Efficient Ways to Learn Weather Radar Polarimetry

    Science.gov (United States)

    Cao, Qing; Yeary, M. B.; Zhang, Guifu

    2012-01-01

    The U.S. weather radar network is currently being upgraded with dual-polarization capability. Weather radar polarimetry is an interdisciplinary area of engineering and meteorology. This paper presents efficient ways to learn weather radar polarimetry through several basic and practical topics. These topics include: 1) hydrometeor scattering model…

  7. The Early Years: The Wonders of Weather

    Science.gov (United States)

    Ashbrook, Peggy

    2013-01-01

    This article reports on the wonders of winter weather, as it often inspires teachers' and students' interest in collecting weather data, especially if snow falls. Beginning weather data collection in preschool will introduce children to the concepts of making regular observations of natural phenomena, recording the observations (data),…

  8. Reducing prediction uncertainty of weather controlled systems

    NARCIS (Netherlands)

    Doeswijk, T.G.

    2007-01-01

    In closed agricultural systems the weather acts both as a disturbance and as a resource. By using weather forecasts in control strategies the effects of disturbances can be minimized whereas the resources can be utilized. In this situation weather forecast uncertainty and model based control are cou

  9. Efficient Ways to Learn Weather Radar Polarimetry

    Science.gov (United States)

    Cao, Qing; Yeary, M. B.; Zhang, Guifu

    2012-01-01

    The U.S. weather radar network is currently being upgraded with dual-polarization capability. Weather radar polarimetry is an interdisciplinary area of engineering and meteorology. This paper presents efficient ways to learn weather radar polarimetry through several basic and practical topics. These topics include: 1) hydrometeor scattering model…

  10. Matrix diffusion in crystalline rocks: coupling of anion exclusion, surface diffusion and surface complexation

    Energy Technology Data Exchange (ETDEWEB)

    Olin, M.; Valkiainen, M.; Aalto, H. [VTT Chemical Technology, Espoo (Finland)

    1997-12-01

    This report includes both experimental and modelling parts. Also, a novel approach to the diffusion experiments is introduced, where ions of the same electric charge diffuse in opposite directions through the same rock sample. Six rock-types from Olkiluoto radioactive waste disposal investigation site were used in the experiments: granite, weathered granite, mica gneiss, weathered mica gneiss, tonalite and altered mica gneiss/migmatite. The experiments consisted of the determination of the effective diffusion coefficient and the rock capacity factor for tritium, chloride (Cl-36) and sodium (Na-22). The modelling consisted of a chemical model for small pores (< 100 nm), a model for counter ion diffusion and models for the laboratory experiments. 21 refs.

  11. Chemical weathering and runoff chemistry in a steep headwater catchment

    Science.gov (United States)

    Anderson, Suzanne Prestrud; Dietrich, William E.

    2001-07-01

    We present here deductions about the location, rate, and mechanisms of chemical weathering in a small catchment based on a catchment-scale sprinkling experiment. In this experiment demineralized water was applied at an approximately steady rate in the CB1 catchment in the Oregon Coast Range to reach and maintain a quasi-steady discharge for a period of 4 days. Because of nearly steady flow conditions within the catchment, the contribution to solute fluxes from soil and bedrock could be partitioned. One half of the solute flux from the catchment derived from colluvial soil, and one half from weathering in bedrock. This implies more intense weathering in the thin colluvium mantling the catchment than in the thick underlying weathered bedrock. The annual solute flux from the catchment, scaled to the annual runoff from the catchment, is 32 +/- 10 t km-2 year-1, equivalent to published chemical denudation rates for nearby rivers with drainage areas 106 times greater than the experiment site. Soil waters sampled during the sprinkling experiment had steady compositions following a period of transient water flow conditions, implying steady-state chemical evolution in the soil. The waters leached organic anions from shallow depths in the soil, which solubilized aluminium and iron, indicating that podzolization is occurring in these soils. Carbonate dissolution appears to be an important source of solutes from the bedrock, despite being present as only a minor phase in the rock. Water balance suggests that the residence time of water in the catchment is about 2 months, and that typical 24 h storms displace only a fraction of the stored water. A consequence is that runoff chemistry is dominated by old water, which imposes strong limits on the variability of runoff composition.

  12. Simulator Of A "Weather" Cloud

    OpenAIRE

    Khramenkova, Ksenia; Hermant, Olivier; Pawlak, Renaud

    2012-01-01

    International audience; In this article a cloud simulator for the "weather" cloud is considered. The purpose of such a simulator is evaluating different cloud architectures and algorithms before implementation. The main idea is to analyze the performance beforehand, in order to avoid unsuitable algorithms being implemented in a real cloud. Two methods of request allocation policies to the nodes are considered. Their behavior in terms of interaction with nodes' cachememory is compared. Finally...

  13. Weather, Climate and Food Security

    Science.gov (United States)

    Beer, T.

    2016-12-01

    To climatologists food security is dominated by the impacts of weather and climate on food systems. But the link between the atmosphere and food security is more complex. Extreme weather events such as tropical cyclones impact directly on agriculture, but they also impact on the logistical distribution of food and can thus disrupt the food supply chain, especially in urban areas. Drought affects human life and health as well as impacting dramatically on the sustainable development of society. It represents a pending danger for vulnerable agricultural systems that depend on the rainfall, water supply and reservoirs. Developed countries are affected, but the impact is disproportionate within the developing world. Drought, especially when it results in famine, can change the life and economic development of developing nations and stifle their development for decades. A holistic approach is required to understand the phenomena, to forecast catastrophic events such as drought and famine and to predict their societal consequences. In the Food Security recommendations of the Rio+20 Forum on Science, Technology and Innovation for Sustainable Development it states that it is important "To understand fully how to measure, assess and reduce the impacts of production on the natural environment including climate change, recognizing that different measures of impact (e.g. water, land, biodiversity, carbon and other greenhouse gases, etc) may trade-off against each other..." This talk will review the historical link between weather, climate, drought and food supplies; examine the international situation; and summarise the response of the scientific community

  14. The Weather and Climate Toolkit

    Science.gov (United States)

    Ansari, S.; Del Greco, S.; Hankins, B.

    2010-12-01

    The Weather and Climate Toolkit (WCT) is free, platform independent software distributed from NOAA’s National Climatic Data Center (NCDC). The WCT allows the visualization and data export of weather and climate data, including Radar, Satellite and Model data. By leveraging the NetCDF for Java library and Common Data Model, the WCT is extremely scalable and capable of supporting many new datasets in the future. Gridded NetCDF files (regular and irregularly spaced, using Climate-Forecast (CF) conventions) are supported, along with many other formats including GRIB. The WCT provides tools for custom data overlays, Web Map Service (WMS) background maps, animations and basic filtering. The export of images and movies is provided in multiple formats. The WCT Data Export Wizard allows for data export in both vector polygon/point (Shapefile, Well-Known Text) and raster (GeoTIFF, ESRI Grid, VTK, Gridded NetCDF) formats. These data export features promote the interoperability of weather and climate information with various scientific communities and common software packages such as ArcGIS, Google Earth, MatLAB, GrADS and R. The WCT also supports an embedded, integrated Google Earth instance. The Google Earth Browser Plugin allows seamless visualization of data on a native 3-D Google Earth instance linked to the standard 2-D map. Level-II NEXRAD data for Hurricane Katrina GPCP (Global Precipitation Product), visualized in 2-D and internal Google Earth view.

  15. Positive lightning and severe weather

    Science.gov (United States)

    Price, C.; Murphy, B.

    2003-04-01

    In recent years researchers have noticed that severe weather (tornados, hail and damaging winds) are closely related to the amount of positive lightning occurring in thunderstorms. On 4 July 1999, a severe derecho (wind storm) caused extensive damage to forested regions along the United States/Canada border, west of Lake Superior. There were 665,000 acres of forest destroyed in the Boundary Waters Canoe Area Wilderness (BWCAW) in Minnesota and Quetico Provincial Park in Canada, with approximately 12.5 million trees blown down. This storm resulted in additional severe weather before and after the occurrence of the derecho, with continuous cloud-to-ground (CG) lightning occurring for more than 34 hours during its path across North America. At the time of the derecho the percentage of positive cloud-to-ground (+CG) lightning measured by the Canadian Lightning Detection Network (CLDN) was greater than 70% for more than three hours, with peak values reaching 97% positive CG lightning. Such high ratios of +CG are rare, and may be useful indicators for short-term forecasts of severe weather.

  16. Uranium isotope composition of a laterite profile during extreme weathering of basalt in Guangdong, South China

    Science.gov (United States)

    Huang, J.; Zhou, Z.; Gong, Y.; Lundstrom, C.; Huang, F.

    2015-12-01

    Rock weathering and soil formation in the critical zone are important for material cycle from the solid Earth to superficial system. Laterite is a major type of soil in South China forming at hot-humid climate, which has strong effect on the global uranium cycle. Uranium is closely related to the environmental redox condition because U is stable at U(Ⅳ) in anoxic condition and U(Ⅵ) as soluble uranyl ion (UO22+) under oxic circumstance. In order to understand the behavior of U isotopes during crust weathering, here we report uranium isotopic compositions of soil and base rock samples from a laterite profile originated from extreme weathering of basalt in Guangdong, South China. The uranium isotopic data were measured on a Nu Plasma MC-ICP-MS at the University of Illinois at Urbana-Champaign using the double spike method. The δ238U of BCR-1 is -0.29±0.03‰ (relative to the international standard CRM-112A), corresponding to a 238U/235U ratio of 137.911±0.004. Our result of BCR-1 agrees with previous analyses (e.g., -0.28‰ in Weyer et al. 2008) [1]. U contents of the laterite profile decrease from 1.9 ppm to 0.9 ppm with depth, and peak at 160 - 170 cm (2.3 ppm), much higher than the U content of base rocks (~0.5 ppm). In contrary, U/Th of laterites is lower than that of base rock (0.27) except the peak at the depth of 160-170 cm (0.38), indicating significant U loss during weathering. Notably, U isotope compositions of soils show a small variation from -0.38 to -0.28‰, consistent with the base rock within analytical error (0.05‰ to 0.08‰, 2sd). Such small variation can be explained by a "rind effect" (Wang et al., 2015) [2], by which U(Ⅳ) can be completely oxidized to U(VI) layer by layer during basalt weathering by dissolved oxygen. Therefore, our study indicates that U loss during basalt weathering at the hot-humid climate does not change U isotope composition of superficial water system. [1] Weyer S. et al. (2008) Natural fractionation of 238U/235

  17. Differentiating Hydrothermal, Pedogenic, and Glacial Weathering in a Cold Volcanic Mars-Analog Environment

    Science.gov (United States)

    Scudder, N. A.; Horgan, B.; Havig, J.; Rutledge, A.; Rampe, E. B.; Hamilton, T.

    2016-01-01

    Although the current cold, dry environment of Mars extends back through much of its history, its earliest periods experienced significant water- related surface activity. Both geomorphic features (e.g., paleolakes, deltas, and river valleys) and hydrous mineral detections (e.g., clays and salts) have historically been interpreted to imply a "warm and wet" early Mars climate. More recently, atmospheric modeling studies have struggled to produce early climate conditions with temperatures above 0degC, leading some studies to propose a "cold and icy" early Mars dominated by widespread glaciation with transient melting. However, the alteration mineralogy produced in subglacial environments is not well understood, so the extent to which cold climate glacial weathering can produce the diverse alteration mineralogy observed on Mars is unknown. This summer, we will be conducting a field campaign in a glacial weathering environment in the Cascade Range, OR in order to determine the types of minerals that these environments produce. However, we must first disentangle the effects of glacial weathering from other significant alteration processes. Here we attempt a first understanding of glacial weathering by differentiating rocks and sediments weathered by hydrothermal, pedogenic, and glacial weathering processes in the Cascades volcanic range.

  18. Mineral deposit formation in Phanerozoic sedimentary basins of north-east Africa: the contribution of weathering

    Science.gov (United States)

    Germann, Klaus; Schwarz, Torsten; Wipki, Mario

    1994-12-01

    The intra- and epicontinental basins in north-east Africa (Egypt, Sudan) bear ample evidence of weathering processes repeatedly having contributed to the formation of mineral deposits throughout the Phanerozoic. The relict primary weathering mantle of Pan-African basement rocks consists of kaolinitic saprolite, laterite (in places bauxitic) and iron oxide crust. On the continent, the reaccumulation of eroded weathering-derived clay minerals (mainly kaolinite) occurred predominantly in fluvio-lacustrine environments, and floodplain and coastal plain deposits. Iron oxides, delivered from ferricretes, accumulated as oolitic ironstones in continental and marine sediments. Elements leached from weathering profiles accumulated in continental basins forming silcrete and alunite or in the marine environment contributing to the formation of attapulgite/saprolite and phosphorites. The Early Paleozoic Tawiga bauxitic laterite of northern Sudan gives a unique testimony of high latitude lateritic weathering under global greenhouse conditions. It formed in close spatial and temporal vicinity to the Late Ordovician glaciation in north Africa. The record of weathering products is essentially complete for the Late Cretaceous/Early Tertiary. From the continental sources in the south to the marine sinks in the north, an almost complete line of lateritic and laterite-derived deposits of bauxitic kaolin, kaolin, iron oxides and phosphates is well documented.

  19. Investigation and hazard assessment of the 2003 and 2007 Staircase Falls rock falls, Yosemite National Park, California, USA

    Science.gov (United States)

    Wieczorek, G.F.; Stock, Gregory M.; Reichenbach, P.; Snyder, J.B.; Borchers, J.W.; Godt, J.W.

    2008-01-01

    Since 1857 more than 600 rock falls, rock slides, debris slides, and debris flows have been documented in Yosemite National Park, with rock falls in Yosemite Valley representing the majority of the events. On 26 December 2003, a rock fall originating from west of Glacier Point sent approximately 200 m 3 of rock debris down a series of joint-controlled ledges to the floor of Yosemite Valley. The debris impacted talus near the base of Staircase Falls, producing fragments of flying rock that struck occupied cabins in Curry Village. Several years later on 9 June 2007, and again on 26 July 2007, smaller rock falls originated from the same source area. The 26 December 2003 event coincided with a severe winter storm and was likely triggered by precipitation and/or frost wedging, but the 9 June and 26 July 2007 events lack recognizable triggering mechanisms. We investigated the geologic and hydrologic factors contributing to the Staircase Falls rock falls, including bedrock lithology, weathering, joint spacing and orientations, and hydrologic processes affecting slope stability. We improved upon previous geomorphic assessment of rock-fall hazards, based on a shadow angle approach, by using STONE, a three-dimensional rock-fall simulation computer program. STONE produced simulated rock-fall runout patterns similar to the mapped extent of the 2003 and 2007 events, allowing us to simulate potential future rock falls from the Staircase Falls detachment area. Observations of recent rock falls, mapping of rock debris, and simulations of rock fall runouts beneath the Staircase Falls detachment area suggest that rock-fall hazard zones extend farther downslope than the extent previously defined by mapped surface talus deposits.

  20. Investigation and hazard assessment of the 2003 and 2007 Staircase Falls rock falls, Yosemite National Park, California, USA

    Directory of Open Access Journals (Sweden)

    G. F. Wieczorek

    2008-05-01

    Full Text Available Since 1857 more than 600 rock falls, rock slides, debris slides, and debris flows have been documented in Yosemite National Park, with rock falls in Yosemite Valley representing the majority of the events. On 26 December 2003, a rock fall originating from west of Glacier Point sent approximately 200 m3 of rock debris down a series of joint-controlled ledges to the floor of Yosemite Valley. The debris impacted talus near the base of Staircase Falls, producing fragments of flying rock that struck occupied cabins in Curry Village. Several years later on 9 June 2007, and again on 26 July 2007, smaller rock falls originated from the same source area. The 26 December 2003 event coincided with a severe winter storm and was likely triggered by precipitation and/or frost wedging, but the 9 June and 26 July 2007 events lack recognizable triggering mechanisms. We investigated the geologic and hydrologic factors contributing to the Staircase Falls rock falls, including bedrock lithology, weathering, joint spacing and orientations, and hydrologic processes affecting slope stability. We improved upon previous geomorphic assessment of rock-fall hazards, based on a shadow angle approach, by using STONE, a three-dimensional rock-fall simulation computer program. STONE produced simulated rock-fall runout patterns similar to the mapped extent of the 2003 and 2007 events, allowing us to simulate potential future rock falls from the Staircase Falls detachment area. Observations of recent rock falls, mapping of rock debris, and simulations of rock fall runouts beneath the Staircase Falls detachment area suggest that rock-fall hazard zones extend farther downslope than the extent previously defined by mapped surface talus deposits.

  1. Evolution of Sedimentary Rocks

    Science.gov (United States)

    Veizer, J.; MacKenzie, F. T.

    2003-12-01

    For almost a century, it has been recognized that the present-day thickness and areal extent of Phanerozoic sedimentary strata increase progressively with decreasing geologic age. This pattern has been interpreted either as reflecting an increase in the rate of sedimentation toward the present (Barrell, 1917; Schuchert, 1931; Ronov, 1976) or as resulting from better preservation of the younger part of the geologic record ( Gilluly, 1949; Gregor, 1968; Garrels and Mackenzie, 1971a; Veizer and Jansen, 1979, 1985).Study of the rocks themselves led to similarly opposing conclusions. The observed secular (=age) variations in relative proportions of lithological types and in chemistry of sedimentary rocks (Daly, 1909; Vinogradov et al., 1952; Nanz, 1953; Engel, 1963; Strakhov, 1964, 1969; Ronov, 1964, 1982) were mostly given an evolutionary interpretation. An opposing, uniformitarian, approach was proposed by Garrels and Mackenzie (1971a). For most isotopes, the consensus favors deviations from the present-day steady state as the likely cause of secular trends.This chapter attempts to show that recycling and evolution are not opposing, but complementary, concepts. It will concentrate on the lithological and chemical attributes of sediments, but not deal with the evolution of sedimentary mineral deposits (Veizer et al., 1989) and of life ( Sepkoski, 1989), both well amenable to the outlined conceptual treatment. The chapter relies heavily on Veizer (1988a) for the sections dealing with general recycling concepts, on Veizer (2003) for the discussion of isotopic evolution of seawater, and on Morse and Mackenzie (1990) and Mackenzie and Morse (1992) for discussion of carbonate rock recycling and environmental attributes.

  2. Michael Learns to Rock

    Institute of Scientific and Technical Information of China (English)

    汪海涛

    2004-01-01

    夜幕降临.空气中传来北欧的声音,来自丹麦的四人流行乐队Michael Learns to Rock(迈克学摇滚)正把探情款款的歌声带到上海的咖啡厅和酒吧。北欧一直活跃着一批世界顶级的乐队.从丹麦的A-Ha到Aqua,从瑞典的ABBA到Roxette和Ace of Base,从挪威的Se

  3. From stones to rocks

    Science.gov (United States)

    Mortier, Marie-Astrid; Jean-Leroux, Kathleen; Cirio, Raymond

    2013-04-01

    With the Aquila earthquake in 2009, earthquake prediction is more and more necessary nowadays, and people are waiting for even more accurate data. Earthquake accuracy has increased in recent times mainly thanks to the understanding of how oceanic expansion works and significant development of numerical seismic prediction models. Despite the improvements, the location and the magnitude can't be as accurate as citizen and authorities would like. The basis of anticipating earthquakes requires the understanding of: - The composition of the earth, - The structure of the earth, - The relations and movements between the different parts of the surface of the earth. In order to answer these questions, the Alps are an interesting field for students. This study combines natural curiosity about understanding the predictable part of natural hazard in geology and scientific skills on site: observing and drawing landscape, choosing and reading a representative core drilling, replacing the facts chronologically and considering the age, the length of time and the strength needed. This experience requires students to have an approach of time and space radically different than the one they can consider in a classroom. It also limits their imagination, in a positive way, because they realize that prediction is based on real data and some of former theories have become present paradigms thanks to geologists. On each location the analyzed data include landscape, core drilling and the relation established between them by students. The data is used by the students to understand the meaning, so that the history of the formation of the rocks tells by the rocks can be explained. Until this year, the CBGA's perspective regarding the study of the Alps ground allowed students to build the story of the creation and disappearance of the ocean, which was a concept required by French educational authorities. But not long ago, the authorities changed their scientific expectations. To meet the

  4. Operational Space Weather Activities in the US

    Science.gov (United States)

    Berger, Thomas; Singer, Howard; Onsager, Terrance; Viereck, Rodney; Murtagh, William; Rutledge, Robert

    2016-07-01

    We review the current activities in the civil operational space weather forecasting enterprise of the United States. The NOAA/Space Weather Prediction Center is the nation's official source of space weather watches, warnings, and alerts, working with partners in the Air Force as well as international operational forecast services to provide predictions, data, and products on a large variety of space weather phenomena and impacts. In October 2015, the White House Office of Science and Technology Policy released the National Space Weather Strategy (NSWS) and associated Space Weather Action Plan (SWAP) that define how the nation will better forecast, mitigate, and respond to an extreme space weather event. The SWAP defines actions involving multiple federal agencies and mandates coordination and collaboration with academia, the private sector, and international bodies to, among other things, develop and sustain an operational space weather observing system; develop and deploy new models of space weather impacts to critical infrastructure systems; define new mechanisms for the transition of research models to operations and to ensure that the research community is supported for, and has access to, operational model upgrade paths; and to enhance fundamental understanding of space weather through support of research models and observations. The SWAP will guide significant aspects of space weather operational and research activities for the next decade, with opportunities to revisit the strategy in the coming years through the auspices of the National Science and Technology Council.

  5. Enhanced Weathering Strategies for Stabilizing Climate and Averting Ocean Acidification - Supplementary Information

    Science.gov (United States)

    Taylor, Lyla L.; Quirk, Joe; Thorley, Rachel M. S.; Kharecha, Pushker A.; Hansen, James; Ridgwell, Andy; Lomas, Mark R.; Banwart, Steve A.; Beerling, David J.

    2015-01-01

    Chemical breakdown of rocks, weathering, is an important but very slow part of the carbon cycle that ultimately leads to CO2 being locked up in carbonates on the ocean floor. Artificial acceleration of this carbon sink via distribution of pulverized silicate rocks across terrestrial landscapes may help offset anthropogenic CO2 emissions. We show that idealized enhanced weathering scenarios over less than a third of tropical land could cause significant drawdown of atmospheric CO2 and ameliorate ocean acidification by 2100. Global carbon cycle modelling driven by ensemble Representative Concentration Pathway (RCP) projections of twenty-first-century climate change (RCP8.5, business-as-usual; RCP4.5, medium-level mitigation) indicates that enhanced weathering could lower atmospheric CO2 by 30-300 ppm by 2100, depending mainly on silicate rock application rate (1 kg or 5 kg m(exp. -2) yr (exp -1)) and composition. At the higher application rate, end-of-century ocean acidification is reversed under RCP4.5 and reduced by about two-thirds under RCP8.5. Additionally, surface ocean aragonite saturation state, a key control on coral calcification rates, is maintained above 3.5 throughout the low latitudes, thereby helping maintain the viability of tropical coral reef ecosystems. However, we highlight major issues of cost, social acceptability, and potential unanticipated consequences that will limit utilization and emphasize the need for urgent efforts to phase down fossil fuel emissions.

  6. Enhanced Weathering Strategies for Stabilizing Climate and Averting Ocean Acidification - Supplementary Information

    Science.gov (United States)

    Taylor, Lyla L.; Quirk, Joe; Thorley, Rachel M. S.; Kharecha, Pushker A.; Hansen, James; Ridgwell, Andy; Lomas, Mark R.; Banwart, Steve A.; Beerling, David J.

    2015-01-01

    Chemical breakdown of rocks, weathering, is an important but very slow part of the carbon cycle that ultimately leads to CO2 being locked up in carbonates on the ocean floor. Artificial acceleration of this carbon sink via distribution of pulverized silicate rocks across terrestrial landscapes may help offset anthropogenic CO2 emissions. We show that idealized enhanced weathering scenarios over less than a third of tropical land could cause significant drawdown of atmospheric CO2 and ameliorate ocean acidification by 2100. Global carbon cycle modelling driven by ensemble Representative Concentration Pathway (RCP) projections of twenty-first-century climate change (RCP8.5, business-as-usual; RCP4.5, medium-level mitigation) indicates that enhanced weathering could lower atmospheric CO2 by 30-300 ppm by 2100, depending mainly on silicate rock application rate (1 kg or 5 kg m(exp. -2) yr (exp -1)) and composition. At the higher application rate, end-of-century ocean acidification is reversed under RCP4.5 and reduced by about two-thirds under RCP8.5. Additionally, surface ocean aragonite saturation state, a key control on coral calcification rates, is maintained above 3.5 throughout the low latitudes, thereby helping maintain the viability of tropical coral reef ecosystems. However, we highlight major issues of cost, social acceptability, and potential unanticipated consequences that will limit utilization and emphasize the need for urgent efforts to phase down fossil fuel emissions.

  7. Characterization of the Weatherization Assistance Program network. Weatherization Assistance Program

    Energy Technology Data Exchange (ETDEWEB)

    Mihlmester, P.E.; Koehler, W.C. Jr.; Beyer, M.A. [Aspen Systems Corp., Oak Ridge, TN (United States). Applied Management Sciences Div.; Brown, M.A. [Oak Ridge National Lab., TN (United States); Beschen, D.A. Jr. [Department of Energy, Washington, DC (United States). Office of Weatherization Assistance Programs

    1992-02-01

    The Characterization of the Weatherization Assistance Program (WAP) Network was designed to describe the national network of State and local agencies that provide WAP services to qualifying low-income households. The objective of this study was to profile the current WAP network. To achieve the objective, two national surveys were conducted: one survey collected data from 49 State WAP agencies (including the coterminous 48 States and the District of Columbia), and the second survey collected data from 920 (or 81 percent) of the local WAP agencies.

  8. Porosity evolution of artificially weathered sandstones: how reliable are porosimetric measurements for durability prediction?

    Science.gov (United States)

    Prikryl, Richard; Weishauptová, Zuzana

    2017-04-01

    Several types of sandstones were subjected to artificial weathering (cycles of freezing/thawing, salt crystallization). After termination of certain number of cycles (the highest one was 144 cycles), part of specimens were removed and tested for various physical properties. In the recent study, we have focused on the analysis of pore space textural characteristics by means of mercury porosimetry. From the raw data, several durability indices previously proposed in literature were computed. Despite macroscopically visible damage produced by artificial weathering, most of the examined materials were classified as resistant against respective weathering processes by those indices. Additional observation of rock microfabric conducted by SEM-EDS revealed features which must be taken into account during evaluation of durability of porous materials. Therefore, porosimetric data alone cannot be used as a single durability estimate.

  9. Rock critics as 'Mouldy Modernists'

    Directory of Open Access Journals (Sweden)

    Becky Shepherd

    2011-09-01

    Full Text Available Contemporary rock criticism appears to be firmly tied to the past. The specialist music press valorise rock music of the 1960s and 1970s, and new emerging artists are championed for their ‘retro’ sounding music by journalists who compare the sound of these new artists with those included in the established ‘canon’ of rock music. This article examines the narrative tropes of authenticity and nostalgia that frame the retrospective focus of this contemporary rock writing, and most significantly, the maintenance of the rock canon within contemporary popular culture. The article concludes by suggesting that while contemporary rock criticism is predominately characterised by nostalgia, this nostalgia is not simply a passive romanticism of the past. Rather, this nostalgia fuels a process of active recontextualisation within contemporary popular culture.

  10. Fossils, rocks, and time

    Science.gov (United States)

    Edwards, Lucy E.; Pojeta, John

    1999-01-01

    We study our Earth for many reasons: to find water to drink or oil to run our cars or coal to heat our homes, to know where to expect earthquakes or landslides or floods, and to try to understand our natural surroundings. Earth is constantly changing--nothing on its surface is truly permanent. Rocks that are now on top of a mountain may once have been at the bottom of the sea. Thus, to understand the world we live on, we must add the dimension of time. We must study Earth's history. When we talk about recorded history, time is measured in years, centuries, and tens of centuries. When we talk about Earth history, time is measured in millions and billions of years. Time is an everyday part of our lives. We keep track of time with a marvelous invention, the calendar, which is based on the movements of Earth in space. One spin of Earth on its axis is a day, and one trip around the Sun is a year. The modern calendar is a great achievement, developed over many thousands of years as theory and technology improved. People who study Earth's history also use a type of calendar, called the geologic time scale. It looks very different from the familiar calendar. In some ways, it is more like a book, and the rocks are its pages. Some of the pages are torn or missing, and the pages are not numbered, but geology gives us the tools to help us read this book.

  11. Rock Properties Model

    Energy Technology Data Exchange (ETDEWEB)

    C. Lum

    2004-09-16

    The purpose of this model report is to document the Rock Properties Model version 3.1 with regard to input data, model methods, assumptions, uncertainties and limitations of model results, and qualification status of the model. The report also documents the differences between the current and previous versions and validation of the model. The rock properties model provides mean matrix and lithophysae porosity, and the cross-correlated mean bulk density as direct input to the ''Saturated Zone Flow and Transport Model Abstraction'', MDL-NBS-HS-000021, REV 02 (BSC 2004 [DIRS 170042]). The constraints, caveats, and limitations associated with this model are discussed in Section 6.6 and 8.2. Model validation accomplished by corroboration with data not cited as direct input is discussed in Section 7. The revision of this model report was performed as part of activities being conducted under the ''Technical Work Plan for: The Integrated Site Model, Revision 05'' (BSC 2004 [DIRS 169635]). The purpose of this revision is to bring the report up to current procedural requirements and address the Regulatory Integration Team evaluation comments. The work plan describes the scope, objectives, tasks, methodology, and procedures for this process.

  12. A smart rock

    Science.gov (United States)

    Pressel, Phil

    2014-12-01

    This project was to design and build a protective weapon for a group of associations that believed in aliens and UFO's. They collected enough contributions from societies and individuals to be able to sponsor and totally fund the design, fabrication and testing of this equipment. The location of this facility is classified. It also eventually was redesigned by the Quartus Engineering Company for use at a major amusement park as a "shoot at targets facility." The challenge of this project was to design a "smart rock," namely an infrared bullet (the size of a gallon can of paint) that could be shot from the ground to intercept a UFO or any incoming suspicious item heading towards the earth. Some of the challenges to design this weapon were to feed cryogenic helium at 5 degrees Kelvin from an inair environment through a unique rotary coupling and air-vacuum seal while spinning the bullet at 1500 rpm and maintain its dynamic stability (wobble) about its spin axis to less than 10 micro-radians (2 arc seconds) while it operated in a vacuum. Precision optics monitored the dynamic motion of the "smart rock."

  13. Quantitative Relationships Linking Rock Strength to Channel Morphology: A Case Study in Central Arizona

    Science.gov (United States)

    Larimer, J. E.; Yanites, B.

    2016-12-01

    River morphology is a consequence of the erosive forces acting on the channel boundary and the resisting forces that limit erosion. For bedrock rivers, the erosive forces are generated by the stresses exerted by impacting sediment and flowing water, while the resisting forces are controlled by the internal strength regime of the local rock. We investigate the susceptibility of different rock types to different erosional processes (i.e. abrasion and plucking) and how changes in channel morphology reflect rock strength properties across lithologic boundaries. The bedrock rivers in the Prescott National Forest, AZ flow over a number of rock types with variable strength including sedimentary, igneous, and metamorphic lithologies providing a natural experiment to quantify the influence of rock strength on channel morphology. We collected bedrock samples and channel surveys from 12 different rock types. Rock-strength and rock-mass properties include compressive strength, tensile strength, fatigue strength, decimeter scale P-wave velocity (varies by 8-fold), Schmidt rebound value, fracture spacing, fracture aperture, and slake durability (as a proxy for weathering susceptibility. Morphological measurements include channel width, channel steepness (varies by 10-fold), and grain size distribution. To distinguish between the major mechanisms of erosion we measure bedrock surface roughness factor at the centimeter scale. Preliminary results show that channel steepness (ksn) increases with P-wave velocity while normalized channel width (kwn) decreases with P-wave velocity. We use these data to quantify scaling relationships of channel geometry with rock strength properties. We consider the results in the context of the driving mechanistic process to develop new quantitative understandings of how rock strength properties influence the efficiency of erosion processes and how rock strength is reflected in river morphology. By comparing the results among different rock types in a

  14. CO2 driven weathering vs plume driven weathering as inferred from the groundwater of a persistently degassing basaltic volcano: Mt. Etna

    Science.gov (United States)

    Liotta, Marcello; D'Alessandro, Walter

    2016-04-01

    At Mt. Etna the presence of a persistent volcanic plume provides large amounts of volcanogenic elements to the bulk deposition along its flanks. The volcanic plume consists of solid particles, acidic droplets and gaseous species. After H2O and CO2, S, Cl and F represent the most abundant volatile elements emitted as gaseous species from the craters. During rain events acidic gases interact rapidly with droplets lowering the pH of rain. This process favors the dissolution and dissociation of the most acidic gases. Under these conditions, the chemical weathering of volcanic rocks and ashes is promoted by the acid rain during its infiltration. Subsequently during groundwater circulation, chemical weathering of volcanic rocks is also driven by the huge amount of deep magmatic carbon dioxide (CO2) coming up through the volcanic edifice and dissolving in the water. These two different weathering steps occur under very different conditions. The former occurs in a highly acidic environment (pH carbonic acid (H2CO3) after the hydration of CO2. The relative contributions of plume-derived elements/weathering and CO2-driven weathering has been computed for each element. In addition, the comparison between the chemical compositions of the bulk deposition and of groundwater provides a new understanding about the mobility of volatile elements. Other processes such as ion exchange, iddingsite formation, and carbonate precipitation can also play roles, but only to minor extents. The proposed approach has revealed that the persistent plume strongly affects the chemical composition of groundwater at Mt. Etna and probably also at other volcanoes characterized by huge open-conduit degassing activity.

  15. Managing Rock Squirrels in Utah

    OpenAIRE

    Frey, Nicki

    2015-01-01

    Although they do not exist in large colonies like other ground squirrels, rock squirrels can still sometimes generate conflicts with homeowners and farmers alike. Most damage occurs when a few rock squirrels take residence in a homeowner’s back yard, and begin to forage on garden vegetables and fruit trees. There are several direct and indirect ways that private landowners can manage and reduce rock squirrels on their property. This fact sheet give management tips.

  16. [Hearing disorders and rock music].

    Science.gov (United States)

    Lindhardt, Bjarne Orskov

    2008-12-15

    Only few studies have investigated the frequency of hearing disorders in rock musicians. Performing rock music is apparently associated with a hearing loss in a fraction of musicians. Tinnitus and hyperacusis are more common among rock musicians than among the background population. It seems as if some sort of resistance against further hearing loss is developed over time. The use of ear protection devices have not been studied systematically but appears to be associated with diminished hearing loss.

  17. Weathering of sulfidic shale and copper mine waste: Secondary minerals and metal cycling in Great Smoky Mountains National Park, Tennessee, and North Carolina, USA

    Science.gov (United States)

    Hammarstrom, J.M.; Seal, R.R.; Meier, A.L.; Jackson, J.C.

    2003-01-01

    Metal cycling via physical and chemical weathering of discrete sources (copper mines) and regional (non-point) sources (sulfide-rich shale) is evaluated by examining the mineralogy and chemistry of weathering products in Great Smoky Mountains National Park, Tennessee, and North Carolina, USA. The elements in copper mine waste, secondary minerals, stream sediments, and waters that are most likely to have negative impacts on aquatic ecosystems are aluminum, copper, zinc, and arsenic because these elements locally exceed toxicity guidelines for surface waters or for stream sediments. Acid-mine drainage has not developed in streams draining inactive copper mines. Acid-rock drainage and chemical weathering processes that accompany debris flows or human disturbances of sulfidic rocks are comparable to processes that develop acid-mine drainage elsewhere. Despite the high rainfall in the mountain range, sheltered areas and intermittent dry spells provide local venues for development of secondary weathering products that can impact aquatic ecosystems.

  18. Potential anthropogenic mobilisation of mercury and arsenic from soils on mineralised rocks, Northland, New Zealand.

    Science.gov (United States)

    Craw, D

    2005-02-01

    Eroded roots of hot spring systems in Northland, New Zealand consist of mineralised rocks containing sulfide minerals. Marcasite and cinnabar are the dominant sulfides with subordinate pyrite. Deep weathering and leached soil formation has occurred in a warm temperate to subtropical climate with up to 3 m/year rainfall. Decomposition of the iron sulfides in natural and anthropogenic rock exposures yields acid rock drainage with pH typically between 2 and 4, and locally down to pH 1. Soils and weathered rocks developed on basement greywacke have negligible acid neutralisation capacity. Natural rainforest soils have pH between 4 and 5 on unmineralised greywacke, and pH is as low as 3.5 in soils on mineralised rocks. Roads with aggregate made from mineralised rocks have pH near 3, and quarries from which the rock was extracted can have pH down to 1. Mineralised rocks are enriched in arsenic and mercury, both of which are environmentally available as solid solution impurities in iron sulfides and phosphate minerals. Base metals (Cu, Pb, Zn) are present at low levels in soils, at or below typical basement rock background. Decomposition of the iron sulfides releases the solid solution arsenic and mercury into the acid rock drainage solutions. Phosphate minerals release their impurities only under strongly acid conditions (pHacid rock drainage areas have arsenic and mercury below drinking water limits. Leaching experiments and theoretical predictions indicate that both arsenic and mercury are least mobile in acid soils, at pH of c. 3-4. This optimum pH range for fixation of arsenic and mercury on iron oxyhydroxides in soils is similar to natural pH at the field site of this study. However, neutralisation of acid soils developed on mineralised rocks is likely to decrease adsorption and enhance mobility of arsenic and mercury. Hence, development of farmland by clearing forest and adding agricultural lime may mobilise arsenic and mercury from underlying soils on mineralised

  19. Tensile Strength of Geological Discontinuities Including Incipient Bedding, Rock Joints and Mineral Veins

    Science.gov (United States)

    Shang, J.; Hencher, S. R.; West, L. J.

    2016-11-01

    Geological discontinuities have a controlling influence for many rock-engineering projects in terms of strength, deformability and permeability, but their characterisation is often very difficult. Whilst discontinuities are often modelled as lacking any strength, in many rock masses visible rock discontinuities are only incipient and have tensile strength that may approach and can even exceed that of the parent rock. This fact is of high importance for realistic rock mass characterisation but is generally ignored. It is argued that current ISRM and other standards for rock mass characterisation, as well as rock mass classification schemes such as RMR and Q, do not allow adequately for the incipient nature of many rock fractures or their geological variability and need to be revised, at least conceptually. This paper addresses the issue of the tensile strength of incipient discontinuities in rock and presents results from a laboratory test programme to quantify this parameter. Rock samples containing visible, natural incipient discontinuities including joints, bedding, and mineral veins have been tested in direct tension. It has been confirmed that such discontinuities can have high tensile strength, approaching that of the parent rock. Others are, of course, far weaker. The tested geological discontinuities all exhibited brittle failure at axial strain less than 0.5 % under direct tension conditions. Three factors contributing to the tensile strength of incipient rock discontinuities have been investigated and characterised. A distinction is made between sections of discontinuity that are only partially developed, sections of discontinuity that have been locally weathered leaving localised residual rock bridges and sections that have been `healed' through secondary cementation. Tests on bedding surfaces within sandstone showed that tensile strength of adjacent incipient bedding can vary considerably. In this particular series of tests, values of tensile strength

  20. Critical issues in soft rocks

    Institute of Scientific and Technical Information of China (English)

    Milton Assis Kanji

    2014-01-01

    This paper discusses several efforts made to study and investigate soft rocks, as well as their physico-mechanical characteristics recognized up to now, the problems in their sampling and testing, and the possibility of its reproduction through artificially made soft rocks. The problems in utilizing current and widespread classification systems to some types of weak rocks are also discussed, as well as other problems related to them. Some examples of engineering works in soft rock or in soft ground are added, with emphasis on their types of problems and solutions.

  1. Cataclastic rheology of carbonate rocks

    Institute of Scientific and Technical Information of China (English)

    LU Xiancai; SUN Yan; SHU Liangshu; GU Lianxing; GUO Jichun; ZHU Wenbin

    2005-01-01

    Based on the knowledge of the shallow-level mylonitization of detrital rocks and intrusive rocks, the poorly-known cataclastic rheology of carbonate rocks is discussed comprehensively in this paper. The cases taken from eastern China are analyzed in various aspects including ductile-brittle fault zone, rock texture and structure, clastomylonite layer, leucocratic stress minerals, and frictional dynamometamorphism. It is proposed that the cataclastic flow structure represented by clastomylonite texture is a cooling pattern of flow assemblage characterized by cooling metamorphism, cooling mylonite and cooling stress minerals. Such a pattern is formed generally in mildly reducing physicochemical environments, and is commonly related to regional tectonism and mesothermal and epithermal mineralization.

  2. Probability for Weather and Climate

    Science.gov (United States)

    Smith, L. A.

    2013-12-01

    Over the last 60 years, the availability of large-scale electronic computers has stimulated rapid and significant advances both in meteorology and in our understanding of the Earth System as a whole. The speed of these advances was due, in large part, to the sudden ability to explore nonlinear systems of equations. The computer allows the meteorologist to carry a physical argument to its conclusion; the time scales of weather phenomena then allow the refinement of physical theory, numerical approximation or both in light of new observations. Prior to this extension, as Charney noted, the practicing meteorologist could ignore the results of theory with good conscience. Today, neither the practicing meteorologist nor the practicing climatologist can do so, but to what extent, and in what contexts, should they place the insights of theory above quantitative simulation? And in what circumstances can one confidently estimate the probability of events in the world from model-based simulations? Despite solid advances of theory and insight made possible by the computer, the fidelity of our models of climate differs in kind from the fidelity of models of weather. While all prediction is extrapolation in time, weather resembles interpolation in state space, while climate change is fundamentally an extrapolation. The trichotomy of simulation, observation and theory which has proven essential in meteorology will remain incomplete in climate science. Operationally, the roles of probability, indeed the kinds of probability one has access too, are different in operational weather forecasting and climate services. Significant barriers to forming probability forecasts (which can be used rationally as probabilities) are identified. Monte Carlo ensembles can explore sensitivity, diversity, and (sometimes) the likely impact of measurement uncertainty and structural model error. The aims of different ensemble strategies, and fundamental differences in ensemble design to support of

  3. Insurance adaptation to extreme weather

    Energy Technology Data Exchange (ETDEWEB)

    Wakeford, C. [Institute for Catastrophic Loss Reduction, Toronto, ON (Canada)

    2005-07-01

    This paper examined the role of climate change as a catalyst for specific changes in insurance practices. The presentation addressed how insurance companies are adapting behaviours in response to increasing climate variability and growth in severe weather damage. It discussed ancient examples of insurance as well as more modern insurance practices. Statistics on the number of disasters, global natural disaster economic and insured losses and infrastructure spending are presented. Internal adaptation such as prospective underwriting and incentives and external adaptation such as working with governments and organizations and individuals were also discussed. It was concluded that directions for the future include continued research, heightened awareness and more resilient communities. 3 tabs.

  4. Rock.XML - Towards a library of rock physics models

    Science.gov (United States)

    Jensen, Erling Hugo; Hauge, Ragnar; Ulvmoen, Marit; Johansen, Tor Arne; Drottning, Åsmund

    2016-08-01

    Rock physics modelling provides tools for correlating physical properties of rocks and their constituents to the geophysical observations we measure on a larger scale. Many different theoretical and empirical models exist, to cover the range of different types of rocks. However, upon reviewing these, we see that they are all built around a few main concepts. Based on this observation, we propose a format for digitally storing the specifications for rock physics models which we have named Rock.XML. It does not only contain data about the various constituents, but also the theories and how they are used to combine these building blocks to make a representative model for a particular rock. The format is based on the Extensible Markup Language XML, making it flexible enough to handle complex models as well as scalable towards extending it with new theories and models. This technology has great advantages as far as documenting and exchanging models in an unambiguous way between people and between software. Rock.XML can become a platform for creating a library of rock physics models; making them more accessible to everyone.

  5. The importance of terrestrial weathering for climate system modelling on extended timescales: a study with the UVic ESCM

    Science.gov (United States)

    Brault, Marc-Olivier; Matthews, Damon; Mysak, Lawrence

    2016-04-01

    The chemical erosion of carbonate and silicate rocks is a key process in the global carbon cycle and, through its coupling with calcium carbonate deposition in the ocean, is the primary sink of carbon on geologic timescales. The dynamic interdependence of terrestrial weathering rates with atmospheric temperature and carbon dioxide concentrations is crucial to the regulation of Earth's climate over multi-millennial timescales. However any attempts to develop a modeling context for terrestrial weathering as part of a dynamic climate system are limited, mostly because of the difficulty in adapting the multi-millennial timescales of the implied negative feedback mechanism with those of the atmosphere and ocean. Much of the earlier work on this topic is therefore based on box-model approaches, abandoning spatial variability for the sake of computational efficiency and the possibility to investigate the impact of weathering on climate change over time frames much longer than those allowed by traditional climate system models. As a result we still have but a rudimentary understanding of the chemical weathering feedback mechanism and its effects on ocean biogeochemistry and atmospheric CO2. Here, we introduce a spatially-explicit, rock weathering model into the University of Victoria Earth System Climate Model (UVic ESCM). We use a land map which takes into account a number of different rock lithologies, changes in sea level, as well as an empirical model of the temperature and NPP dependency of weathering rates for the different rock types. We apply this new model to the last deglacial period (c. 21000BP to 13000BP) as well as a future climate change scenario (c. 1800AD to 6000AD+), comparing the results of our 2-D version of the weathering feedback mechanism to simulations using only the box-model parameterizations of Meissner et al. [2012]. These simulations reveal the importance of two-dimensional factors (i.e., changes in sea level and rock type distribution) in the

  6. Rock the Globe

    CERN Multimedia

    Laëtitia Pedroso

    2010-01-01

    Created in 2005, the Swiss rock band "Wind of Change" is now candidate for the Eurovision Song Contest 2011 with a new song " Night & Light " with the music video filmed at CERN.   With over 20 gigs under their belt and two albums already released, the five members of the band (Alex Büchi, vocals; Arthur Spierer, drums; David Gantner, bass; Romain Mage and Yannick Gaudy, guitar) continue to excite audiences. For their latest composition "Night & Light", the group filmed their music video in the Globe of Science and Innovation. Winning the Eurovision contest would be a springboard in their artistic career for these young musicians. The selection results will be available December 11, 2010.      

  7. Electrochemistry of lunar rocks

    Science.gov (United States)

    Lindstrom, D. J.; Haskin, L. A.

    1979-01-01

    Electrolysis of silicate melts has been shown to be an effective means of producing metals from common silicate materials. No fluxing agents need be added to the melts. From solution in melts of diopside (CaMgSi2O6) composition, the elements Si, Ti, Ni, and Fe have been reduced to their metallic states. Platinum is a satisfactory anode material, but other cathode materials are needed. Electrolysis of compositional analogs of lunar rocks initially produces iron metal at the cathode and oxygen gas at the anode. Utilizing mainly heat and electricity which are readily available from sunlight, direct electrolysis is capable of producing useful metals from common feedstocks without the need for expendable chemicals. This simple process and the products obtained from it deserve further study for use in materials processing in space.

  8. Weathering of ordinary chondrites from Oman: Correlation of weathering parameters with 14C terrestrial ages and a refined weathering scale

    Science.gov (United States)

    Zurfluh, Florian J.; Hofmann, Beda A.; Gnos, Edwin; Eggenberger, Urs; Jull, A. J. Timothy

    2016-09-01

    We have investigated 128 14C-dated ordinary chondrites from Oman for macroscopically visible weathering parameters, for thin section-based weathering degrees, and for chemical weathering parameters as analyzed with handheld X-ray fluorescence. These 128 14C-dated meteorites show an abundance maximum of terrestrial age at 19.9 ka, with a mean of 21.0 ka and a pronounced lack of samples between 0 and 10 ka. The weathering degree is evaluated in thin section using a refined weathering scale based on the current W0 to W6 classification of Wlotzka (1993), with five newly included intermediate steps resulting in a total of nine (formerly six) steps. We find significant correlations between terrestrial ages and several macroscopic weathering parameters. The correlation of various chemical parameters including Sr and Ba with terrestrial age is not very pronounced. The microscopic weathering degree of metal and sulfides with newly added intermediate steps shows the best correlation with 14C terrestrial ages, demonstrating the significance of the newly defined weathering steps. We demonstrate that the observed 14C terrestrial age distribution can be modeled from the abundance of meteorites with different weathering degrees, allowing the evaluation of an age-frequency distribution for the whole meteorite population.

  9. Role of Carbonic Anhydrase as an Activator in Carbonate Rock Dissolution and Its Implication for Atmospheric CO2 Sink

    Institute of Scientific and Technical Information of China (English)

    刘再华

    2001-01-01

    The conversion of CO2 into H+ and is a relatively slow reaction. Hence, its kinetics may be rate determining in carbonate rock dissolution. Carbonic anhydrase (CA), which is widespread in nature, was used to catalyze the CO2 conversion process in dissolution experiments of limestone and dolomite. It was found that the rate of dissolution increases by a factor of about 10 after the addition of CA at a high CO2 partial pressure (Pco2) for limestone and about 3 at low Pco2 for dolomite. This shows that reappraisal is necessary for the importance of chemical weathering (including carbonate rock dissolution and silicate weathering) in the atmospheric CO2 sink and the mysterious missing sink in carbon cycling. It is doubtless that previous studies of weathering underestimated weathering rates due to the ignorance of CA as an activator in weathering, thus the contribution of weathering to the atmospheric CO2 sink is also underestimated. This finding also shows the need to examine the situ distribution and activity of CA in different waters and to investigate the role of CA in weathering.``

  10. Automatic Weather Station (AWS) Lidar

    Science.gov (United States)

    Rall, Jonathan A.R.; Abshire, James B.; Spinhirne, James D.; Smith, David E. (Technical Monitor)

    2000-01-01

    An autonomous, low-power atmospheric lidar instrument is being developed at NASA Goddard Space Flight Center. This compact, portable lidar will operate continuously in a temperature controlled enclosure, charge its own batteries through a combination of a small rugged wind generator and solar panels, and transmit its data from remote locations to ground stations via satellite. A network of these instruments will be established by co-locating them at remote Automatic Weather Station (AWS) sites in Antarctica under the auspices of the National Science Foundation (NSF). The NSF Office of Polar Programs provides support to place the weather stations in remote areas of Antarctica in support of meteorological research and operations. The AWS meteorological data will directly benefit the analysis of the lidar data while a network of ground based atmospheric lidar will provide knowledge regarding the temporal evolution and spatial extent of Type la polar stratospheric clouds (PSC). These clouds play a crucial role in the annual austral springtime destruction of stratospheric ozone over Antarctica, i.e. the ozone hole. In addition, the lidar will monitor and record the general atmospheric conditions (transmission and backscatter) of the overlying atmosphere which will benefit the Geoscience Laser Altimeter System (GLAS). Prototype lidar instruments have been deployed to the Amundsen-Scott South Pole Station (1995-96, 2000) and to an Automated Geophysical Observatory site (AGO 1) in January 1999. We report on data acquired with these instruments, instrument performance, and anticipated performance of the AWS Lidar.

  11. Space weather and space anomalies

    Directory of Open Access Journals (Sweden)

    L. I. Dorman

    2005-11-01

    Full Text Available A large database of anomalies, registered by 220 satellites in different orbits over the period 1971-1994 has been compiled. For the first time, data from 49 Russian Kosmos satellites have been included in a statistical analysis. The database also contains a large set of daily and hourly space weather parameters. A series of statistical analyses made it possible to quantify, for different satellite orbits, space weather conditions on the days characterized by anomaly occurrences. In particular, very intense fluxes (>1000 pfu at energy >10 MeV of solar protons are linked to anomalies registered by satellites in high-altitude (>15000 km, near-polar (inclination >55° orbits typical for navigation satellites, such as those used in the GPS network, NAVSTAR, etc. (the rate of anomalies increases by a factor ~20, and to a much smaller extent to anomalies in geostationary orbits, (they increase by a factor ~4. Direct and indirect connections between anomaly occurrence and geomagnetic perturbations are also discussed.

  12. Microstructural Studies of Space Weathering Effects in Lunar Materials

    Science.gov (United States)

    Keller, L. P.

    2002-01-01

    Space weathering is a term used to include all of the processes which act on material exposed at the surface of a planetary or small body. In the case of the moon, it includes a variety of processes which have formed the lunar regolith, caused the maturation of lunar soils, and formed patina on rock surfaces. The processes include micrometeorite impact and reworking, implantation of solar wind and flare particles, radiation damage and chemical effects from solar particles and cosmic rays, interactions with the lunar atmosphere, and sputtering erosion and deposition. Space weathering effects collectively result in a reddened continuum slope, lowered albedo, and attenuated absorption features in reflectance spectra of lunar soils as compared to finely comminuted rocks from the same Apollo sites. However, the regolith processes that cause these effects are not well known, nor is the petrographic setting of the products of these processes fully understood. An interesting confluence of events occurred in the early 1990s. First, came the discovery of vapor deposited coatings on lunar regolith grains by Keller and McKay, who showed that amorphous coatings from 50-100 nm thick containing fine-grained Fe metal (1-10 nm in diameter) were common in the fine size fraction of several mature lunar soils. The other discovery was the recognition that the optical properties of lunar soils were dominated by fine grain sized material (less than 45 micrometer fraction) by Pieters and coworkers. These discoveries led to coordinated studies that looked at the mineralogy, chemistry, and optical properties of lunar soils as function of composition, maturity, and grain size fraction. One of the major revelations from these studies was the recognition that much of the nanophase Fe metal is surface-correlated especially in the finest size fractions, and that it was this nanophase Fe that dominated the optical properties of the soil.

  13. Subglacial (bio)geochemical weathering and the unexplored Antarctic system

    Science.gov (United States)

    Mitchell, A. C.; Christner, B. C.; Mikucki, J.; Priscu, J. C.

    2009-12-01

    Water exported from Alpine and polar glaciers is often concentrated in a range of major ions, and minor and trace elements, derived from the dissolution of subglacial rocks and minerals. The export of these species from subglacial environments to the oceans via subglacial hydrological systems appears to constitute an important global flux of biochemically essential species, such as Fe, potentially impacting upon plankton activity in the oceans and the associated consumption of CO2 on glacial-interglacial timescales. Recent studies have demonstrated the presence and activity of microorganisms in a range of subglacial environments, from Alpine glaciers, Arctic glaciers, and most recently in sub-Antarctic systems. Equally, isotopic studies at Alpine and Arctic glaciers provide evidence that microbe-mineral associations occur in subglacial environments, and account for the release and transformation of dissolved nutrients. However, the link between microbiological presence & activity, mineral weathering, ionic species transformations, and the configuration of the subglacial hydrological system, remains poorly understood. We will report on Whillans Ice Stream Subglacial Access Research Drilling (WISSARD), an NSF funded integrative study of ice sheet stability and life habitats in sub Antarctic aquatic environments. Direct sterile sampling from a subglacial Antarctic lake and grounding zone, will allow us for the first time to address these gaps in our knowledge, to determine the role of microbes on the weathering of rocks and the release and transport of nutrients in and from the unexplored sub-Antarctic environment. These data will yield seminal information on these systems and test the overarching hypothesis that active hydrological systems connect various subglacial environments and exert major control on geochemistry, metabolic and phylogenetic diversity, and biogeochemical transformations, as well as ice sheet dynamics. This will provide a basis for understanding

  14. Prediction Techniques in Operational Space Weather Forecasting

    Science.gov (United States)

    Zhukov, Andrei

    2016-07-01

    The importance of forecasting space weather conditions is steadily increasing as our society is becoming more and more dependent on advanced technologies that may be affected by disturbed space weather. Operational space weather forecasting is still a difficult task that requires the real-time availability of input data and specific prediction techniques that are reviewed in this presentation, with an emphasis on solar and interplanetary weather. Key observations that are essential for operational space weather forecasting are listed. Predictions made on the base of empirical and statistical methods, as well as physical models, are described. Their validation, accuracy, and limitations are discussed in the context of operational forecasting. Several important problems in the scientific basis of predicting space weather are described, and possible ways to overcome them are discussed, including novel space-borne observations that could be available in future.

  15. Five case studies of multifamily weatherization programs

    Energy Technology Data Exchange (ETDEWEB)

    Kinney, L; Wilson, T.; Lewis, G. [Synertech Systems Corp. (United States); MacDonald, M. [Oak Ridge National Lab., TN (United States)

    1997-12-31

    The multifamily case studies that are the subject of this report were conducted to provide a better understanding of the approach taken by program operators in weatherizing large buildings. Because of significant variations in building construction and energy systems across the country, five states were selected based on their high level of multifamily weatherization. This report summarizes findings from case studies conducted by multifamily weatherization operations in five cities. The case studies were conducted between January and November 1994. Each of the case studies involved extensive interviews with the staff of weatherization subgrantees conducting multifamily weatherization, the inspection of 4 to 12 buildings weatherized between 1991 and 1993, and the analysis of savings and costs. The case studies focused on innovative techniques which appear to work well.

  16. Workshop on hydrology of crystalline basement rocks

    Energy Technology Data Exchange (ETDEWEB)

    Davis, S.N. (comp.)

    1981-08-01

    This workshop covered the following subjects: measurements in relatively shallow boreholes; measurement and interpretation of data from deep boreholes; hydrologic properties of crystalline rocks as interpreted by geophysics and field geology; rock mechanics related to hydrology of crystalline rocks; the possible contributions of modeling to the understanding of the hydrology of crystalline rocks; and geochemical interpretations of the hydrology of crystalline rocks. (MHR)

  17. Rock Art in Kurdistan Iran

    Directory of Open Access Journals (Sweden)

    Jamal Lahafian

    2013-12-01

    Full Text Available Kurdistan, with great potential and prehistoric resources, has numerous petroglyphs in different areas of the province. During the last 14 years of extensive field study, more than 30 sites of rock art have been identified and introduced by the author. In this article, we summarize these rock art areas in Iranian Kurdistan.

  18. Rock Art in Kurdistan Iran

    OpenAIRE

    Jamal Lahafian

    2013-01-01

    Kurdistan, with great potential and prehistoric resources, has numerous petroglyphs in different areas of the province. During the last 14 years of extensive field study, more than 30 sites of rock art have been identified and introduced by the author. In this article, we summarize these rock art areas in Iranian Kurdistan.

  19. Rockin' around the Rock Cycle

    Science.gov (United States)

    Frack, Susan; Blanchard, Scott Alan

    2005-01-01

    In this activity students will simulate how sedimentary rocks can be changed into metamorphic rocks by intense pressure. The materials needed are two small pieces of white bread, one piece of wheat bread, and one piece of a dark bread (such as pumpernickel or dark rye) per student, two pieces of waxed paper, scissors, a ruler, and heavy books.…

  20. Space Weather and Real-Time Monitoring

    OpenAIRE

    2009-01-01

    Recent advance of information and communications technology enables to collect a large amount of ground-based and space-based observation data in real-time. The real-time data realize nowcast of space weather. This paper reports a history of space weather by the International Space Environment Service (ISES) in association with the International Geophysical Year (IGY) and importance of real-time monitoring in space weather.

  1. Extreme weather events and infectious disease outbreaks

    OpenAIRE

    McMichael, Anthony J.

    2015-01-01

    Human-driven climatic changes will fundamentally influence patterns of human health, including infectious disease clusters and epidemics following extreme weather events. Extreme weather events are projected to increase further with the advance of human-driven climate change. Both recent and historical experiences indicate that infectious disease outbreaks very often follow extreme weather events, as microbes, vectors and reservoir animal hosts exploit the disrupted social and environmental c...

  2. Space Weather and Real-Time Monitoring

    Directory of Open Access Journals (Sweden)

    S Watari

    2009-04-01

    Full Text Available Recent advance of information and communications technology enables to collect a large amount of ground-based and space-based observation data in real-time. The real-time data realize nowcast of space weather. This paper reports a history of space weather by the International Space Environment Service (ISES in association with the International Geophysical Year (IGY and importance of real-time monitoring in space weather.

  3. Evaluation of rock mass classification schemes: a case study from the Bowen Basin, Australia

    Science.gov (United States)

    Brook, Martin; Hebblewhite, Bruce; Mitra, Rudrajit

    2016-04-01

    The development of an accurate engineering geological model and adequate knowledge of spatial variation in rock mass conditions are important prerequisites for slope stability analyses, tunnel design, mine planning and risk management. Rock mass classification schemes such as Rock Mass Rating (RMR), Coal Mine Roof Rating (CMRR), Q-system and Roof Strength Index (RSI) have been used for a range of engineering geological applications, including transport tunnels, "hard rock" mining and underground and open-cut coal mines. Often, rock mass classification schemes have been evaluated on subaerial exposures, where weathering has affected joint characteristics and intact strength. In contrast, the focus of this evaluation of the above classification schemes is an underground coal mine in the Bowen Basin, central Queensland, Australia, 15 km east of the town of Moranbah. Rock mass classification was undertaken at 68 sites across the mine. Both the target coal seam and overlying rock show marked spatial variability in terms of RMR, CMRR and Q, but RSI showed limited sensitivity to changes in rock mass condition. Relationships were developed between different parameters with varying degrees of success. A mine-wide analysis of faulting was undertaken, and compared with in situ stress field and local-scale measurements of joint and cleat. While there are no unequivocal relationships between rock mass classification parameters and faulting, a central graben zone shows heterogeneous rock mass properties. The corollary is that if geological features can be accurately defined by remote sensing technologies, then this can assist in predicting rock mass conditions and risk management ahead of development and construction.

  4. Simulating the Hydrological Response of Rock Glaciers to Climate Change with GEOtop

    Science.gov (United States)

    Apaloo, J.; Brenning, A.; Gruber, S.

    2013-05-01

    Rock glaciers are creeping bodies of ice-rich permafrost typical in cold high-mountain environments. In the arid and semi-arid Andes, and presumably other dry high-mountain areas, rock glaciers are considered more significant than glaciers as a water resource. The active layer of rock glaciers, and other seasonally frozen ground, in more temperate high-mountain climates may also represent an important contribution to summer baseflow in lowland rivers. The multi-decadal evolution of rock glacier permafrost and its relationship to climate is largely unknown and presents a massive challenge to assess in-situ due to limited spatial and temporal observations, the resource-intensity of geophysical observation, and lack of meteorological observation in most rock glaciers areas. As a step in addressing these knowledge gaps, this work simulates a rock glacier based on the Murtel-Corvatsch rock glacier in the Upper Engadin, Switzerland - the most intensively studied rock glacier in the world. Three decades of high-quality hourly climate data are used to generate 50 year time-series of synthetic meteorological observations with the Advanced WEather GENerator (AWE-GEN) under the observed climate and 8 additional climate change scenarios. One-dimensional simulations of rock glaciers are conducted with the combined hydrological and energy balance model GEOtop, which is forced by the synthetic meteorological data. The experimental approach consists of three parts: 1) establishing a realistic rock glacier model under the observed climate, 2) subjecting the rock glacier to meteorological forcing from climate change scenarios, and 3) testing the sensitivity of the model to input parameters. For the mountain cryosphere community and many lowland populations around the world, this work represents an important outcome in developing the understanding and methodologies pertaining to the role of seasonal ice and permafrost in the hydrological cycle of high mountain watersheds.

  5. Rock suitability classification RSC 2012

    Energy Technology Data Exchange (ETDEWEB)

    McEwen, T. (ed.) [McEwen Consulting, Leicester (United Kingdom); Kapyaho, A. [Geological Survey of Finland, Espoo (Finland); Hella, P. [Saanio and Riekkola, Helsinki (Finland); Aro, S.; Kosunen, P.; Mattila, J.; Pere, T.

    2012-12-15

    This report presents Posiva's Rock Suitability Classification (RSC) system, developed for locating suitable rock volumes for repository design and construction. The RSC system comprises both the revised rock suitability criteria and the procedure for the suitability classification during the construction of the repository. The aim of the classification is to avoid such features of the host rock that may be detrimental to the favourable conditions within the repository, either initially or in the long term. This report also discusses the implications of applying the RSC system for the fulfilment of the regulatory requirements concerning the host rock as a natural barrier and the site's overall suitability for hosting a final repository of spent nuclear fuel.

  6. New quantitative, in-situ characterization of weathering in geomaterials.

    Science.gov (United States)

    Scrivano, Simona; Gaggero, Laura; Gisbert Aguilar, Josep; Yus Gonzalez, Adrian

    2016-04-01

    The mineralogical and microtextural analyses of weathered rocks and mortars are the main diagnostic tools to address the materials exposed under different environmental conditions in order to enucleate and mitigate the decay factors. The characterization of weathering intensity is mostly descriptive and non-quantitative (ICOMOS Glossary, 2008); the Fitzner indexes in arenites (Fitzner et al., 2002) and more recently applied to marbles (Scrivano et al., 2013) provide an operator dependent method. The current diagnostic of decay (Drdàcky & Slìzkovà, 2014) based on a scotch tape tearing off the surface was improved by a specifically adapted pocket penetrometer, and a joint gravimetric + minero-chemical analysis under SEM of ablational decay products. The steps are the following: i) Preparation of stubs for SEM with adherent conductive carbon tape (surface area 1.3 cm2) ii) Weighing of stub + tape + its plastic envelope at 0.001 g precision iii) Connecting the stub to a pocket penetrometer iv) Non invasive sampling of the incoherent dust applying a constant pressure of 2 kgf for 1 minute, and then packing away the stub without loosing grains v) Weighing of stub + tape + weathering products + their plastic envelope at 0.001 g precision vi) Recast the weight of removed material vii) Addressing the weathering products to SEM - EDS. Our quantitative peeling test was applied on a 96m long cladded wall in the Staglieno Monumental Cemetery in Genoa. The wall shows weathering gradients due to a neighbouring interred stream and to different insulation. Slabs of ophicalcite marble were tested from three different areas (5 samples were collected to the E, 5 samples at the centre, 5 samples to the W). The results highlighted capillary rise up to 2 meters height and a more weathered central area. On the whole, our protocol allows a delicate, virtually not impacting and reproducible factual sampling. Moreover, if carried out on a statistically significant population, the decay

  7. Seismic properties of polyphase rocks

    Science.gov (United States)

    Wang, Qin

    2005-11-01

    Knowledge about the seismic properties of polyphase rocks is fundamental for interpreting seismic refraction and reflection data and for establishing lithospheric structure and composition models. This study aims to obtain more precise relationships between seismic properties of rocks and controlling factors (e.g., pressure, temperature, mineralogical and chemical compositions, microstructure of rocks), particularly for those rocks imprinted by ultrahigh-pressure (UHP) metamorphism. These relationships will be very helpful to extrapolate calculated and measured seismic properties of rocks to depths of interest and to engender interpretations relevant to petrological composition and tectonic process. An Internet Database of Rock Seismic Properties (DRSP) was set up and a Handbook of Seismic Properties of Minerals, Rocks and Ores was published. They comprise almost all data available in the literature during the past 4 decades and can serve as a convenient, comprehensive and concise information source on physical properties of rocks to the earth sciences and geotechnical communities. Statistical results of the DRSP reveal the dependence of seismic properties on density, porosity, humidity, and mineralogical and chemical compositions. Using 16 different averaging methods, we calculated P-wave velocities of 696 dry samples according to the volume fraction and elastic constants of each constituent mineral. Although only 22 common minerals were taken into account in the computation, the calculated P-wave velocities agree well with laboratory values measured at about 300 MPa, where most microcracks are closed and the mean Vp of a polymineralic rock is exclusively controlled by its modal composition. However, none of these mixture rules can simultaneously fit measured P-wave velocities for all lithologies or at all pressures. Therefore, more prudence is required in selecting an appropriate mixture rule for calculation of seismic velocities of different rock types.

  8. Sulfide mineralization: Its role in chemical weathering of Mars

    Science.gov (United States)

    Burns, Roger G.

    1988-01-01

    Pyrrhotite-pentlandite assemblages in mafic and ultramafic igneous rocks may have contributed significantly to the chemical weathering reactions that produced degradation products in the Martian regolith. By analogy with terrestrial processes, a model is proposed whereby supergene alteration of these primary Fe-Ni sulfides on Mars has generated secondary sulfides (e.g., pyrite) below the water table and produced acidic groundwater containing high concentrations of dissolved Fe, Ni and sulfate ions. The low pH solutions also initiated weathering reactions of igneous feldspars and ferromagnesian silicates to form clay silicate and ferric oxyhydroxide phases. Near-surface oxidation and hydrolysis of ferric sulfato- and hydroxo-complex ions and sols formed gossans above the water table consisting of poorly crystalline hydrated ferric sulfates (e.g., jarosite), oxides (ferrihydrite, goethite) and silica (opal). Underlying groundwater, now permafrost, contains hydroxo sulfato complexes of Fe, Al, Mg, Ni, etc., which may be stabilized in frozen acidic solutions beneath the surface of Mars. Sublimation of permafrost may replenish colloidal ferric oxides, sulfates and phyllosilicates during dust storms on Mars.

  9. Quantifying chemical weathering rates along a precipitation gradient on Basse-Terre Island, French Guadeloupe: new insight from U-series isotopes in weathering rinds

    Science.gov (United States)

    Engel, Jacqueline M.; May, Linda; Sak, Peter B.; Gaillardet, Jerome; Ren, Minghua; Engle, Mark A.; Brantley, Susan L.

    2016-01-01

    Inside soil and saprolite, rock fragments can form weathering clasts (alteration rinds surrounding an unweathered core) and these weathering rinds provide an excellent field system for investigating the initiation of weathering and long term weathering rates. Recently, uranium-series (U-series) disequilibria have shown great potential for determining rind formation rates and quantifying factors controlling weathering advance rates in weathering rinds. To further investigate whether the U-series isotope technique can document differences in long term weathering rates as a function of precipitation, we conducted a new weathering rind study on tropical volcanic Basse-Terre Island in the Lesser Antilles Archipelago. In this study, for the first time we characterized weathering reactions and quantified weathering advance rates in multiple weathering rinds across a steep precipitation gradient. Electron microprobe (EMP) point measurements, bulk major element contents, and U-series isotope compositions were determined in two weathering clasts from the Deshaies watershed with mean annual precipitation (MAP) = 1800 mm and temperature (MAT) = 23 °C. On these clasts, five core-rind transects were measured for locations with different curvature (high, medium, and low) of the rind-core boundary. Results reveal that during rind formation the fraction of elemental loss decreases in the order: Ca ≈ Na > K ≈ Mg > Si ≈ Al > Zr ≈ Ti ≈ Fe. Such observations are consistent with the sequence of reactions after the initiation of weathering: specifically, glass matrix and primary minerals (plagioclase, pyroxene) weather to produce Fe oxyhydroxides, gibbsite and minor kaolinite.Uranium shows addition profiles in the rind due to the infiltration of U-containing soil pore water into the rind as dissolved U phases. U is then incorporated into the rind as Fe-Al oxides precipitate. Such processes lead to significant U-series isotope disequilibria in the rinds

  10. Research on Mechanism of Rock Burst Generation and Development for High Stress Rock Tunnels

    Institute of Scientific and Technical Information of China (English)

    高全臣; 赫建明; 王代华

    2001-01-01

    Through the investigation and analysis of high stress distribution in surrounding rock during the excavation of rock tunnels,the key factors to cause rock burst and the mechanism of rock burst generation and development are researched. The result shows that the scale and range of rock burst are related with elastic deformation energy storied in rock mass and the characteristics of unloading stress waves. The measures of preventing from rock burst for high stress rock tunnels are put forward.

  11. Traffic Control Under Complex Weather Conditions in Suining Airport

    Institute of Scientific and Technical Information of China (English)

    吕维峰

    2014-01-01

    Complex weather conditions is meaning thunderstorm freezing turbulence wind-shear low visibility weather affect the flight safety. When confronted with complex weather conditions,the controllers should know the weather condition and trend weather,and notify the aircraft under your control zone.The controllers provide the required services to the pilots,help the pilots to avoid the complex weather.In this paper, through different complex weathers under different control command,get the different methods of control.

  12. The influence of aspect on the biological weathering of granites: observations from the Kunlun Mountains, China

    Science.gov (United States)

    Hall, Kevin; Arocena, Joselito M.; Boelhouwers, Jan; Liping, Zhu

    2005-04-01

    Bedrock and boulder weathering in the higher elevation, permafrost areas of the Qinghai-Tibetan Plateau have usually been ascribed to frost action. For short periods during two summers, an attempt was made to better elucidate weathering processes in this region. A combination of visual observation coupled with rudimentary data regarding removable weathered material from the four cardinal aspects of granite boulders at elevations of 4600-5000 m in the Kunlun Mountains (Qinghai-Tibetan Plateau) showed that there was a distinct aspect influence (south>west>north>east) on weathering. It was also observed that there were aspect-constrained variations in chasmoendolithic communities and for lichen distribution. To further aid understanding, temperature data for the four aspects were collected for several weeks during the summers of 2 years, with data recording at 1-min intervals using ultraresponsive (0.05 s), high precision (0.1 °C), ultrasmall (0.15 mm diameter) thermocouples; humidity data were also collected at the rock face. Based on these data, an attempt is made to evaluate the nature of granite weathering in this region. To better understand what the impact of the lichens/endolithic communities was and how this varies, use is made of XRD and SEM analyses on samples from each aspect. In addition, iron-rich patinas were found on a number of the boulders, and these too were analyzed in an attempt to see their relationship (if any) to the biological action.

  13. Lithological influences on contemporary and long-term regolith weathering at the Luquillo Critical Zone Observatory

    Science.gov (United States)

    Buss, Heather L.; Lara, Maria Chapela; Moore, Oliver; Kurtz, Andrew C.; Schulz, Marjorie S.; White, Arthur F.

    2017-01-01

    Lithologic differences give rise to the differential weatherability of the Earth’s surface and globally variable silicate weathering fluxes, which provide an important negative feedback on climate over geologic timescales. To isolate the influence of lithology on weathering rates and mechanisms, we compare two nearby catchments in the Luquillo Critical Zone Observatory in Puerto Rico, which have similar climate history, relief and vegetation, but differ in bedrock lithology. Regolith and pore water samples with depth were collected from two ridgetops and at three sites along a slope transect in the volcaniclastic Bisley catchment and compared to existing data from the granitic Río Icacos catchment. The depth variations of solid-state and pore water chemistry and quantitative mineralogy were used to calculate mass transfer (tau) and weathering solute profiles, which in turn were used to determine weathering mechanisms and to estimate weathering rates.Regolith formed on both lithologies is highly leached of most labile elements, although Mg and K are less depleted in the granitic than in the volcaniclastic profiles, reflecting residual biotite in the granitic regolith not present in the volcaniclastics. Profiles of both lithologies that terminate at bedrock corestones are less weathered at depth, near the rock-regolith interfaces. Mg fluxes in the volcaniclastics derive primarily from dissolution of chlorite near the rock-regolith interface and from dissolution of illite and secondary phases in the upper regolith, whereas in the granitic profile, Mg and K fluxes derive from biotite dissolution. Long-term mineral dissolution rates and weathering fluxes were determined by integrating mass losses over the thickness of solid-state weathering fronts, and are therefore averages over the timescale of regolith development. Resulting long-term dissolution rates for minerals in the volcaniclastic regolith include chlorite: 8.9 × 10−14 mol m−2 s−1, illite: 2.1

  14. Lithological influences on contemporary and long-term regolith weathering at the Luquillo Critical Zone Observatory

    Science.gov (United States)

    Buss, Heather L.; Chapela Lara, María; Moore, Oliver W.; Kurtz, Andrew C.; Schulz, Marjorie S.; White, Art F.

    2017-01-01

    Lithologic differences give rise to the differential weatherability of the Earth's surface and globally variable silicate weathering fluxes, which provide an important negative feedback on climate over geologic timescales. To isolate the influence of lithology on weathering rates and mechanisms, we compare two nearby catchments in the Luquillo Critical Zone Observatory in Puerto Rico, which have similar climate history, relief and vegetation, but differ in bedrock lithology. Regolith and pore water samples with depth were collected from two ridgetops and at three sites along a slope transect in the volcaniclastic Bisley catchment and compared to existing data from the granitic Río Icacos catchment. The depth variations of solid-state and pore water chemistry and quantitative mineralogy were used to calculate mass transfer (tau) and weathering solute profiles, which in turn were used to determine weathering mechanisms and to estimate weathering rates. Regolith formed on both lithologies is highly leached of most labile elements, although Mg and K are less depleted in the granitic than in the volcaniclastic profiles, reflecting residual biotite in the granitic regolith not present in the volcaniclastics. Profiles of both lithologies that terminate at bedrock corestones are less weathered at depth, near the rock-regolith interfaces. Mg fluxes in the volcaniclastics derive primarily from dissolution of chlorite near the rock-regolith interface and from dissolution of illite and secondary phases in the upper regolith, whereas in the granitic profile, Mg and K fluxes derive from biotite dissolution. Long-term mineral dissolution rates and weathering fluxes were determined by integrating mass losses over the thickness of solid-state weathering fronts, and are therefore averages over the timescale of regolith development. Resulting long-term dissolution rates for minerals in the volcaniclastic regolith include chlorite: 8.9 × 10-14 mol m-2 s-1, illite: 2.1 × 10-14 mol m

  15. The importance of terrestrial weathering changes in multimillennial recovery of the global carbon cycle: a two-dimensional perspective

    Science.gov (United States)

    Brault, Marc-Olivier; Damon Matthews, H.; Mysak, Lawrence A.

    2017-06-01

    In this paper, we describe the development and application of a new spatially explicit weathering scheme within the University of Victoria Earth System Climate Model (UVic ESCM). We integrated a dataset of modern-day lithology with a number of previously devised parameterizations for weathering dependency on temperature, primary productivity, and runoff. We tested the model with simulations of future carbon cycle perturbations, comparing a number of emission scenarios and model versions with each other and with zero-dimensional equivalents of each experiment. Overall, we found that our two-dimensional weathering model versions were more efficient in restoring the carbon cycle to its pre-industrial state following the pulse emissions than their zero-dimensional counterparts; however, in either case the effect of this weathering negative feedback on the global carbon cycle was small on timescales of less than 1000 years. According to model results, the largest contribution to future changes in weathering rates came from the expansion of tropical and mid-latitude vegetation in grid cells dominated by weathering-vulnerable rock types, whereas changes in temperature and river runoff had a more modest direct effect. Our results also confirmed that silicate weathering is the only mechanism that can lead to a full recovery of the carbon cycle to pre-industrial levels on multimillennial timescales.

  16. Estimation of weathering rates and CO2 drawdown based on solute load: Significance of granulites and gneisses dominated weathering in the Kaveri River basin, Southern India

    Science.gov (United States)

    Pattanaik, J. K.; Balakrishnan, S.; Bhutani, R.; Singh, P.

    2013-11-01

    The solute load of the Kaveri River (South India) and its tributaries draining diverse Precambrian terrains during pre-monsoon and monsoon periods was determined. Using average annual flow, total drainage area and atmospheric input corrected major ion concentrations of these rivers chemical weathering rates, annual fluxes of different ionic species to the ocean and CO2 consumption rates were estimated. Bicarbonate is the most dominant ion (27-79% of anion budget) in all the river samples collected during monsoon period followed by Ca2+, whereas, in case of pre-monsoon water samples Na+ is the most dominant ion (in meq/l). Two approaches were adopted to estimate silicate and carbonate weathering rates in the drainage basin. At Musuri silicate weathering rate (SWR) is 9.44 ± 0.29 tons/km2/a and carbonate weathering rate (CWR) is 1.46 ± 0.16 tons/km2/a. More than 90% of the total ionic budget is derived from weathering of silicates in the Kaveri basin. CO2 consumption rate in the basin for silicate weathering FCO2sil is 3.83 ± 0.12 × 105 mol/km2/a (upper limit), which is comparable with the Himalayan rivers at upper reaches. For carbonate weathering (FCO2carb) CO2 consumption rate is 0.15 ± 0.03 × 105 mol/km2/a in the Kaveri basin. The lower limit of CO2 consumption rate corrected for H2SO4 during silicate and carbonate weathering is FCO2sil is 3.24 × 1005 mol/km2/a and FCO2carb 0.13 × 105 mol/km2/a respectively. CO2 sequestered due to silicate weathering in the Kaveri basin is 25.41 (±0.82) × 109 mol/a which represents 0.21 (±0.01)% of global CO2 drawdown. This may be due to tropical climatic condition, high rainfall during both SW and NE monsoon and predominance of silicate rocks in the Kaveri basin.

  17. Tracer tomography (in) rocks!

    Science.gov (United States)

    Somogyvári, Márk; Jalali, Mohammadreza; Jimenez Parras, Santos; Bayer, Peter

    2016-04-01

    Physical behavior of fractured aquifers is rigorously controlled by the presence of interconnected conductive fractures, as they represent the main pathways for flow and transport. Ideally, they are simulated as a discrete fracture network (DFN) in a model to capture the role of fracture system geometry, i.e. fracture length, height, and width (aperture/transmissivity). Such network may be constrained by prior geological information or direct data resources such as field mapping, borehole logging and geophysics. With the many geometric features, however, calibration of a DFN to measured data is challenging. This is especially the case when spatial properties of a fracture network need to be calibrated to flow and transport data. One way to increase the insight in a fractured rock is by combining the information from multiple field tests. In this study, a tomographic configuration that combines multiple tracer tests is suggested. These tests are conducted from a borehole with different injection levels that act as sources. In a downgradient borehole, the tracer is recorded at different levels or receivers, in order to maximize insight in the spatial heterogeneity of the rock. As tracer here we chose heat, and temperature breakthrough curves are recorded. The recorded tracer data is inverted using a novel stochastic trans-dimensional Markov Chain Monte Carlo procedure. An initial DFN solution is generated and sequentially modified given available geological information, such as expected fracture density, orientation, length distribution, spacing and persistency. During this sequential modification, the DFN evolves in a trans-dimensional inversion space through adding and/or deleting fracture segments. This stochastic inversion algorithm requires a large number of thousands of model runs to converge, and thus using a fast and robust forward model is essential to keep the calculation efficient. To reach this goal, an upwind coupled finite difference method is employed

  18. Isotopic and multi-proxy continental records in the Precambrian rocks, Aldan Shield, Russian Federation

    Science.gov (United States)

    Guliy, Vasyl

    2015-04-01

    Clay minerals and hematite from paleo-weathering profiles, observed on and within Precambrian rocks of the apatite deposits, have been investigated from the view-points of geology, mineralogy, pedology. Weathering phenomena have been recognized in the Fedorovskaya and Gorbyliakhskaya Formations of the Precambrian Aldan Shield. Two complexes that differ in rock composition and structure are involved in the geological sections of the deposits. The lower complex (basement) is a stratum (up to 500m) of interlayered gneisses, schists and apatite-bearing carbonate and calc-silicate rocks. The upper complex (up to 200m) is a blanket-like residual deposit intensely crushed and strongly altered formations of the basement. Clay minerals (hydromica, vermiculite, chlorite, illite, and kaolinite) are predominantly developed in the upper complex of the deposits, whereas in the lower complex they occur dissipated as separate crystals and grains or concentrated in layers and nests mainly in the apatite-carbonate rocks. The carbonate rocks are typically medium-grained, massive, mottled or banded, and red-brown in color. Their oxidized character is expressed by high Fe3+/Fe2+ ratio. The banded structure is due to throughgoing bands a few millimeters to several decimeters in thickness. Some of the mottled rocks contain pocket-like isolation and thin beds rich in clay, hematite (after magnetite), and rounded apatite and seem to be of paleo-carstic origin. The isotopic data for the carbonates from coexisting poor and rich in clay minerals bands are similar to those under- and overlaying massive carbonates. It is consistent with the proposed model of simultaneous chemogenic and detrital deposition and intra-formational erosion during weathering processes.

  19. Weather Satellite Enterprise Information Chain

    Science.gov (United States)

    Jamilkowski, M. L.; Grant, K. D.; Miller, S. W.; Cochran, S.

    2015-12-01

    NOAA & NASA are acquiring the next-generation civilian operational weather satellite: Joint Polar Satellite System (JPSS). Contributing the afternoon orbit & ground system (GS) to replace current NOAA POES Satellites, its sensors will collect meteorological, oceanographic & climatological data. The JPSS Common Ground System (CGS), consisting of C3 and IDP segments, is developed by Raytheon. It now flies the Suomi National Polar-orbiting Partnership (S-NPP) satellite, transferring data between ground facilities, processing them into environmental products for NOAA weather centers, and expanding to support JPSS-1 in 2017. As a multi-mission system, CGS provides combinations of C3, data processing, and product delivery for numerous NASA, NOAA, DoD and international missions.The CGS provides a wide range of support to a number of missions: Command and control and mission management for the S-NPP mission today, expanding this support to the JPSS-1 satellite mission in 2017 Data acquisition for S-NPP, the JAXA's Global Change Observation Mission - Water (GCOM-W1), POES, and the Defense Meteorological Satellite Program (DMSP) and Coriolis/WindSat for the DoD Data routing over a global fiber network for S-NPP, JPSS-1, GCOM-W1, POES, DMSP, Coriolis/WindSat, NASA EOS missions, MetOp for EUMETSAT and the National Science Foundation Environmental data processing and distribution for S-NPP, GCOM-W1 and JPSS-1 The CGS plays a key role in facilitating the movement and value-added enhancement of data all the way from satellite-based sensor data to delivery to the consumers who generate forecasts and produce watches and warnings. This presentation will discuss the information flow from sensors, through data routing and processing, and finally to product delivery. It will highlight how advances in architecture developed through lessons learned from S-NPP and implemented for JPSS-1 will increase data availability and reduce latency for end user applications.

  20. Weather pattern climatology of the United States

    Energy Technology Data Exchange (ETDEWEB)

    Barchet, W.R.; Davis, W.E.

    1984-01-01

    In this study the geographic domain covered the 48 conterminous states of the United States. The daily synoptic weather pattern was classified into nine types for the 10-year period January 1, 1969 to December 31, 1978. Weather pattern types were defined relative to the classical polar front model of a mid-latitude cyclonic storm system and its associated air masses. Guidelines for classifying weather patterns on an operational basis were developed. These were applied to 3652 daily surface weather maps to produce a time series of weather pattern type at 120 grid points of a 160 point, 3/sup 0/ latitude by 4/sup 0/ longitude array over the United States. Statistics on the frequency of occurrence, persistence and alternation of weather patterns were calculated for each grid point. Summary statistics for the entire grid and for six regions were also presented. Frequency of occurrence and persistence were found to depend on the size and speed of movement of the weather pattern. Large, slow moving air masses had higher frequency of occurrence and longer persistence than small (fronts) or rapidly moving (or changing) features (fronts, storm centers). Some types showed distinct regional preferences. The subtropical maritime high occurred mainly in the south central and southeast. An indeterminate weather pattern type accounted for those weather patterns that did not fit the polar front model or were too disorganized to be classified. The intermountain thermal low of the desert southwest was one such feature that dominated both frequency of occurrence and persistence in this region. Alternation from one weather pattern to another followed the polar front model of a moving cyclonic storm. The tendency for anticyclonic weather patterns to become disorganized as they weakened was seen in the high percentage of these patterns that changed to an indeterminate pattern as they aged.