an evolutionary model based on geomorphologic and tectonic characteristics of the maharashtra coast india abstract the maharashtra coast is part of the central west coast of the tectonically passive and divergent western continental margin of india major tectonic elements that characterize the region are the west coast fault and the panvel flexure these features have played a major role in the development of coastal geomorphic features which have been further modified by marine and fluvial processes neotectonism is expressed in associated raised marine terraces the coastal tract of maharashtra has been divided in three geomorphic blocks on the basis of the role of tectonic elements and spatial distribution of various geomorphic features

prospect of hydrocarbon associated with fossil rift structures of the southern indus basin pakistan the southern indus basin 550 x 250 km is characterized by tectonic upwarping on the western margin of the indo pakistan subcontinent several hypotheses have so far been proposed to explain the origin of these crustal features but these basement upwarps remain puzzling aeromagnetic data have been analyzed and interpreted supplemented with seismicity and geological information from the integrated study we inferred basement configuration and developed models for tectonic evolution of these exotic crustal features and their impact on hydrocarbon potential associated with the southern indus basin the southern indus basin is identified as an extension basin resulting from an inferred fossil rift crustal feature overlain by a thick sedimentary sequence extension was a consequence of temporal divergence of the indo pakistan subcontinent from gondwanaland during the early paleozoic based on magnetic anomaly trends the indus basin fossil rift feature is characterized by horst and graben structures together with a system of transcurrent faults the association of seismicity events and basement crustal features suggests that tertiary reactivation of individual segments of the inferred rift structure has deformed overlying sequences of the indus basin and also the surrounding areas particularly the fold and thrust belt of pakistan on the western side of the basin the proposed geological models also illustrate the potential for appropriate environments for development of hydrocarbon source rocks sufficient heat for thermal maturity and structures for reservoirs and seals suggesting more bright prospects in the southern indus basin

trace element chemistry of atmospheric deposition along the wasatch front utah usa reflects regional playa dust and local urban aerosols abstract atmospheric deposition to urban areas and mountain snowpack often contains a mixture of playa dust and anthropogenic aerosols yet the relative contribution of trace elements from each source is not well understood to evaluate dust contributions from regional playas to an urban area we sampled playa dust sources urban dust deposition and snow dust deposition across the wasatch front in northern utah usa dust samples were analyzed for trace and major element chemistry grain size distribution and mineralogy playa urban and snow dust samples contained similar mineralogy dominated by silicate carbonate and evaporite minerals grain size distribution between playa urban and snow dust samples was also similar suggesting that playas are a primary dust source for the region principal component analysis and enrichment diagrams revealed similar chemistry of playa urban and snow dust with some exceptions compared with playa dust urban and snow dust had lower concentrations of li na sr u mg and ca and higher concentrations of fe al be sb se mo cr la and cu the first set of elements are found in evaporite and carbonate minerals while the second set of elements are sourced from anthropogenic activities mass balance calculations suggest that 90 of the dust mass deposited to the wasatch front is from playas with small additions from local sources that alter the dust chemistry sequential leaching of dust samples showed that some elements were readily leached with weak acids including b k na sr ca u mo cd and se suggesting that they are environmentally available and may serve as important macronutrients or contaminants to ecosystems this is the first study to directly compare the geochemistry of playa dust sources with dust deposition to urban areas and mountain snowpack in the western us with implications for understanding how water diversions land use changes and population growth may affect the regional dust cycle in the future

properties of modern dust accumulating in the uinta mountains utah usa and implications for the regional dust system of the rocky mountains a growing body of work is illuminating the importance of dust as a component of soil development and biogeochemical cycling in alpine environments of the rocky mountains nonetheless important questions remain about the dust system in this region due to a paucity of focused studies and direct measurements this project involved deployment of modified marble dust traps in the alpine zone of the uinta mountains of utah to trap modern atmospheric dust over a two year period results indicate that dust accumulation rates are similar to values previously reported for the wind river range of wyoming but less than values for south western colorado suggesting a south to north decrease in regional dust flux the overall mean grain size of uinta dust is similar to values reported by prior studies in colorado indicating a general uniformity in grain size distribution uinta dust is dominated by quartz plagioclase k feldspar and illite with trace amounts of kaolinite chlorite and amphibole in contrast only quartz and k feldspar are present in the uinta bedrock confirming an exotic origin for the dust arriving in the alpine zone exotic mineralogies have also been reported in dust from other mountain ranges in the western united states indicating that eolian delivery of allochthonous minerals is a widespread process geochemical analysis reveals that bi na p zn sn cu cd ba ni w sb pb and tl in uinta dust are elevated 10 to 80 times above their abundances in local bedrock these results support reports of anthropogenic elemental enrichment in lake sediments from colorado and utah patterns of elemental loading suggest that certain elements are delivered by winds arriving from different directions raising the possibility that some elements could be associated with unique source areas copyright 2014 john wiley sons ltd

rift basins in western margin of india and their hydrocarbon prospects with special reference to kutch basin the western continental margin of india can be classed as a divergent or passive margin the western continental shelf is an extensive carbonate bank bombay offshore basin passing into clastic sediments on the north and south three craton margin embayed basins kutch cambay and narmada in the northern part of the shelf are filled predominantly with clastic sediments these basins occupy grabens bounded by faults diverging seaward the grabens were formed by three rift systems along major precambrian tectonic trends the rifting developed sequentially from north to south around the saurashtra horst kutch basin was formed in the early jurassic followed by cambay basin in early cretaceous time and the narmada in the late cretaceous it appears that these rifting ev nts occurred at successive stages during the northward migration of the indian plate after its break from gondwanaland in late triassic or early jurassic it is inferred that these rift basins opened up successively as a result of the counterclockwise drift of the indian craton bombay offshore and cambay are two major oil producing basins in the western margin these basins are characterized by high geothermal gradients attributed to the shallowness of the mantle in this region oil has not been found in kutch basin which is mainly an onshore mesozoic basin the basin depocenter shifted offshore at the northwestern part of the continental shelf where the shelf is wide

uncertainty assessment of coal tonnage by spatial modeling of seam distribution and coal quality coal reserve estimation requires comprehensive spatial analysis of geologic and geochemical data for determination of coal reserve uncertainty associated with tonnage and grade quality we present a new approach that stands on spatial modeling of seam distribution and coal quality a multilayer coal deposit in east kalimantan indonesia was selected as a case study site coal quality was evaluated by ash and sodium contents total sulphur and heating value their spatial models were produced by geostatistical methods ordinary kriging and sequential gaussian simulation which were effective to evaluate local or global uncertainty by honoring spatial correlation structures the seam distribution was modeled by a binary transformation of the geologic data and the three dimensional optimization method it is demonstrated that the lower seam sequence has the highest degree of uncertainty because of low average coal accumulation tonnage and the sparseness of sample data points in the north part of the study area this study demonstrates that uncertainty of coal accumulation is related to the seam distribution and that spatial variability patterns of coal qualities are opposing between ash content and total sulphur this difference might have been caused by geological controls

structure and evolution of the western continental margin of india deduced from gravity seismic geomagnetic and geochronological studies abstract available geochronological gravity seismic and geomagnetic data on the western continental margin of india between 8 20 n are presented based on the data three models describing the evolution of the crustal structure are developed model 1 describes the evolution of the crustal structure along 19 n the main basic igneous activity that accompanied the tectonic events since the late cretaceous resulted in the formation of rifts along the coast thus giving rise to the present day structure the acid volcanic event that preceded the above activity at about 93 ma ago is responsible for the observed crustal structure along 13 30 n shown in model 2 this event resulted in the formation of the st mary group of islands along this latitude counterclockwise rotation of the indian plate during the tertiary period caused rifting of the continental blocks giving rise to the laccadive kerala graben bounded by the chagos laccadive ridge on the west and the west coast fault on the east vertical movements of the rifted blocks promoted the deposition of both continental and marine sediments on the coast west of the west coast fault this tectonic event was accompanied by upwarping of the mantle crust thus giving rise to the present day structure shown in model 3

saltating particles playa crusts and dust aerosols at owens dry lake california as part of the multinational lake owens dust experiment lode we have studied the generation of dust storms on the south sand sheet of owens dry lake california an anthropogenically desiccated playa reported to be the single greatest source of particulate matter in north america during march 1993 we performed an intensive field study including eight significant dust storms building on our prior work 1978 1984 and preliminary studies 1991 1992 we studied sources and magnitude of coarse saltating particles the meteorological conditions that allow them to become mobile across the flat playa of owens dry lake and how the motion of saltating particles across different types of playa surfaces results in the generation of pm10 dusts aerosol particles smaller than 10 m aerodynamic diameter saltating grains of lacustrine sand and broken crust abrade and disaggregate the playa surface into fine aerosols and the resulting pm10 concentrations recorded during major dust storms are among the highest ever recorded in north america on 23 march 1993 we measured a 2 h concentration on the playa of 40 620 g m 3 as far as we can determine the highest ambient pm10 value ever recorded in the u s a abrasion of salt silt clay crusts by saltation is shown to be responsible for all but a small part of one dust storm the quantity sand run saltating particle transport multiplied by wind run is shown to be very closely correlated with dust aerosol concentration finally we have established that on lake bed studies are essential for quantitative prediction of dust events on the owens dry lake bed despite the difficult conditions encountered

coal quality related to microfractures identified by ct image analysis abstract identification of microfractures developed in coal are indispensable to coal quality assessment and helpful to understanding the tectonic history x ray computed tomography ct scanning has promised to be one of the most powerful non destructive testing methods for these factors in this work we aimed to develop methods for identifying microfractures from ct images and to identify the relationship between these properties and coal quality lati coal mine in east kalimantan indonesia was selected as a case study area and fifteen samples were taken from three seams we developed a successful process of setting the samples in water to avoid cupping artifacts in the ct images and applied image processing to characterize fractures in detail ash content increased in proportion to the total length of microfractures correlations of ct values with coal quality such as the ash and caloric content cal g suggest that coal quality is inversely proportional to the ct values positive correlation was found between ash and the total number of microfracture widths which is interpreted to mean that the coal contained mineral impurities a source of ash in proportion to the development of microfractures because local structures control microfracture occurrence and microfracture development controls coal quality by allowing the infilling of mineral impurities local structures influence coal quality

characteristics and origins of coal cleat a review abstract cleats are natural opening mode fractures in coal beds they account for most of the permeability and much of the porosity of coalbed gas reservoirs and can have a significant effect on the success of engineering procedures such as cavity stimulations because permeability and stimulation success are commonly limiting factors in gas well performance knowledge of cleat characteristics and origins is essential for successful exploration and production although the coal cleat literature spans at least 160 years mining issues have been the principal focus and quantitative data are almost exclusively limited to orientation and spacing information few data are available on apertures heights lengths connectivity and the relation of cleat formation to diagenesis characteristics that are critical to permeability moreover recent studies of cleat orientation patterns and fracture style suggest that new investigations of even these well studied parameters can yield insight into coal permeability more effective predictions of cleat patterns will come from advances in understanding cleat origins although cleat formation has been speculatively attributed to diagenetic and or tectonic processes a viable mechanical process for creating cleats has yet to be demonstrated progress in this area may come from recent developments in fracture mechanics and in coal geochemistry

structural imaging of mesozoic sediments of kachchh india and their hydrocarbon prospects travel time modelling of first and second arrivals has been used to produce p wave velocity models of the shallow sub surface structure of kachchh india using new wide angle reflection refraction profiles results obtained from the 2 d tomographic modelling have also been corroborated with magnetotelluric and borehole data within the proximity of these profiles based on multiple geophysical data a composite sub surface model is presented in this article the prominent features of the model include the presence of more than 3 km thick mesozoic sediments residing above the precambrian basement its correlation with available lithological knowledge shows that the mesozoic rocks have been deposited from early triassic to late cretaceous until the eruption of the deccan flood basalts at the cretaceous tertiary boundary the new results suggest that the mesozoic rocks of kachchh can be sub divided in two major parts which correspond to late and early mesozoic deposits respectively the sub surface models successfully demarcate the regional variations in the basaltic layer across the region and show maximum thickness of 1 2 km the modelling results also exhibit that the precambrian basement in this region varies between 4 and 6 km depth the new data provide a much clearer picture than was hitherto available of the entire sedimentary succession in the basins that underlie the kachchh region they show a significant variability in thickness of the various sedimentary layers and in particular illustrate a marked topographic irregularity at the base of the sedimentary succession

beam hardening artifact reduction in microfocus computed tomography for improved quantitative coal characterization microfocus computed tomography ct is a non destructive technique allowing visualization of the internal microstructure of objects this technique can be used to quantify the maceral content and to define the cleat system within coal samples however a number of artifacts intrinsic to the technique hamper the optimal quantitative use of ct one of the most important artifacts is beam hardening which generates streaks on the images near dense inclusions such as ankerite or pyrite and makes the border of the sample appear denser than in reality these artifacts can be minimized by using a dual energy method in which two sets of scans taken at a different energy level are combined in this study existing dual energy methods are combined into a new technique and adapted to be more ideally suitable for coal samples the method is calibrated with an artificial sample made of a plexiglas cylinder in which two aluminum rods are built in plexiglas and aluminum were selected since their x ray attenuation properties are similar to those of vitrinite and dense phases such as ankerite respectively the method is tested on a coal sample bearing relatively high percentages of iron minerals the corrected and uncorrected images from one representative slice through the sample are compared with reflected light microscopy images from the corresponding polished surface the results show that the applied approach creates images in which the border does not appear denser than in reality and in which the artificial streaks near dense inclusions are removed in addition size measurements of the ankerite veins and grains in the sample are much more accurate based on the corrected images it is therefore assumed that the proposed dual energy algorithm minimizes the beam hardening artifact however the corrected images have a lower signal to noise ratio than the uncorrected images consequently this approach magnifies to some extent other artifacts noise scatter and partial volume effect which are also present in the uncorrected images some solutions to correct for these artifacts and to improve the developed dual energy method are proposed

eolian sediments generated by anthropogenic disturbance of playas human impacts on the geomorphic system and geomorphic impacts on the human system abstract in many of the earth s arid and semiarid lands saline lakes playas and similar landforms are disturbed as a result of human activity diversion and or consumptive use of surface or groundwaters has created the effect of a climate change in numerous drainage basins resulting in the desiccation of lakes and reactivation of eolian processes at many locations playas are natural sites for extensive eolian activity because of the deposition of clastic and chemical sediments in basins by surface water via fluvial transport and groundwater via efflorescence wind erosion and deposition of playa sediments has had a major role in the development of landforms and sedimentary units in the present lunette fields worldwide simpson desert australia and geological past from the triassic mercia mudstone england to the quaternary lahontan basin and cima volcanic field usa anthropogenic disturbance or desiccation of playa systems has resulted in the eolian transport of sand e g lop nor china konya basin turkey rajasthan india kappakoola australia several sites in west africa and or dust e g aral sea kazakhstan uzbekistan old wives lake canada kara bogaz gol ex ussr lake texcoco mexico owens dry lake mono lake and other playas usa typically this is accomplished by abstraction of water and or removal of vegetation from terminal lake basins an extensive review of the literature documents many examples and or potential examples of such phenomena in numerous nations the reactivation of eolian processes from closed basins produces air pollution in the form of fugitive dust naturally occurring compounds released into the atmosphere by human actions and has significant environmental and economic impacts on human activities in the surrounding areas restoration or mitigation of degraded land on or surrounding playas has been accomplished at lake texcoco kara bogaz gol and the konya basin and is being actively implemented at mono lake owens dry lake and the aral sea

compositions of modern dust and surface sediments in the desert southwest united states 1 modern dusts across southwestern united states deserts are compositionally similar to dust rich av soil horizons depths of 0 0 5 cm and 1 4 cm at 35 sites for common crustal elements but distinctly different for some trace elements chemical compositions and magnetic properties of the soil samples are similar among sites relative to dust sources geographic areas and lithologic substrates exceptions are li u and w enriched in owens valley california and mg and sr enriched in soils formed on calcareous fan gravel in southeast nevada the av horizons are dominated by dust and reflect limited mixing with substrate sediments modern dust samples are also similar across the region except that owens valley dusts are higher in mg ba and li and dusts both there and at sites to the north on volcanic substrates are higher in sb and w thus dust and av horizons consist of contributions from many different sources that are well mixed before deposition modern dusts contain significantly greater amounts of as cd cr cu ni pb and sb than do av horizons which record dust additions over hundreds to thousands of years these results suggest that modern dust compositions are influenced by anthropogenic sources and emissions from owens dry lake after its artificial desiccation in 1926 both modern dusts and av horizons are enriched in as ba cu li sb th u and w relative to average crustal composition which we interpret to indicate that the geologic sources of dust in the southwestern united states are geochemically distinctive

petrophysical characterization of tight oil sandstones by microscale x ray computed tomography abstract tight oil sandstones have complex pore structure due to multiple pore types and multiscale pore size ranging from several nanometers to dozens of microns in this study petrophyiscal properties of tight oil sandstones were quantified based on microscale x ray computed tomography xct imaging techniques the pore types in gray scale images were identified porosity pore size distribution psd and pore connectivity were analyzed from segmented image stacks and their permeability was calculated by representative elementary volume rev scale lattice boltzmann method lbm three types of pores including residual interparticle pores grain dissolution pores and micro fractures were identified a multi threshold segmentation algorithm was applied to segment the image stacks into three constituents namely pore matrix and clay the calculated volumetric fraction of the pore constituent from the segmented image stacks was smaller than experimental porosity because a certain amount of porosity was also contributed by clay constituent the psd of the samples was found to be unimodal in the range of 3 69 m with the peak at around 10 15 m the clay constituent led to the increase in the overall connectivity of the images stacks indicating that clays bridged the isolated pores by assigning appropriate porosity and permeability to the clay constituent calculated permeability of the samples using rev scale lbm well matched the experimental data this study provides new insight into characterization of pore structure of tight oil sandstones by xct technique

aeolian controls of soil geochemistry and weathering fluxes in high elevation ecosystems of the rocky mountains colorado abstract when dust inputs are large or have persisted for long periods of time the signature of dust additions are often apparent in soils the of dust will be greatest where the geochemical composition of dust is distinct from local sources of soil parent material in this study the influence of dust accretion on soil geochemistry is quantified for two different soils from the san juan mountains of southwestern colorado usa at both study sites dust is enriched in several trace elements relative to local rock especially cd cu pb and zn mass balance calculations that do not explicitly account for dust inputs indicate the accumulation of some elements in soil beyond what can be explained by weathering of local rock most observed elemental enrichments are explained by accounting for the long term accretion of dust based on modern isotopic and geochemical estimates one notable exception is pb which based on mass balance calculations and isotopic measurements may have an additional source at one of the study sites these results suggest that dust is a major factor influencing the development of soil in these settings and is also an important control of soil weathering fluxes after accounting for dust inputs in mass balance calculations si weathering fluxes from san juan mountain soils are within the range observed for other temperate systems comparing dust inputs with mass balanced based flux estimates suggests dust could account for as much as 50 80 of total long term chemical weathering fluxes these results support the notion that dust inputs may sustain chemical weathering fluxes even in relatively young continental settings given the widespread input of far traveled dust the weathering of dust is likely and important and underappreciated aspect of the global weathering engine

structural interpretation of the eastern sulaiman foldbelt and foredeep pakistan the sulaiman foldbelt is an active tectonic feature on the northwestern margin of the indian plate seismic reflection data have been combined with surface geological mapping and drill hole data to interpret the structural style and tectonic shortening of the eastern sulaiman foldbelt and its adjacent foredeep the data show that the basement is more than 8 km deep near the deformation front and that it deepens towards the west the foredeep adjacent to the eastern sulaiman foldbelt is a broad synclinal structure with a steep western limb the more gentle eastern limb has monoclinal dips from near zero to 2 5 several salt cored anticlines are observed on the eastern part of the monocline but the salt structures are lacking in the western foredeep and in the frontal part of the sulaiman foldbelt the basal decollement under the sulaiman lobe lies either in ductile eocambrian salt or within a deep zone of other material that undergoes ductile behavior near the deformation front ramps from the basal detachment become flats in lower triassic and lower cretaceous shales a steep and highly elevated zone immediately to the west of the frontal folds is interpreted to be underlain by a passive roof duplex the culmination wall of this oblique duplex is separated from the overlying roof sequence by a passive roof thrust in lower cretaceous shales the roof thrust has a backthrust sense of movement relative to the forelandward propagating duplex and may extend obliquely 100 km into the interior of the foldbelt fault propagation and fault bend folds are present in the frontal portion of the eastern sulaiman foldbelt palinspastic restoration of a balanced cross section shows 108 km of shortening in the eastern sulaiman foldbelt east of the kingri strike slip fault the presence of more than 11 km of pre neogene strata on top of basement suggests that the mesozoic rifted margin of the indian subcontinent may lie beneath the sulaiman foldbelt this interpretation is also favored by the presence of ophiolites and flysch deposits overthrusted on late cretaceous shelf strata

temporal profiling of uplift rate along an active fault using river long profile in the kuchchh region western india abstract river long profiles are widely used as tectonic event markers incision uplift rate estimations based on the dating of river terrace or exposed scarp sediment give long term averaged uplift rate values with the limitation of not giving the intermediate phases of highs and lows on the other hand gps based estimates provide only decadal scale uplift rate estimates in our study we adopted the long profile inversion methodology to obtain a temporal profile of uplift rate history over the late pleistocene holocene time period along an active fault the kuchchh mainland fault in kuchchh region western india which has experienced several large magnitude earthquakes in recent past we also used long profiles analysis to quantify the transient response of kuchchh landscape to uplift activity along the kuchchh mainland fault steepness index and chi profiles were estimated to display the spatial variability in landscape disequilibrium integral method based chi profiles were used to obtain the optimum value of basin area exponent of the stream power incision model spim our estimates provide a mean uplift rate value of 1 1 1 4 mm yr along the kuchchh mainland fault during the late pleistocene holocene period which matches with the average uplift rate derived from other independent observations in this region further a chronology of major tectonic phases from the estimated uplift rate time series also corroborates with field based estimates of major incision events in kuchchh region we also tested the robustness and sensitivity of our uplift rate estimates to model parameters such data can be complementary to the existing sparsely both spatially and temporally distributed uplift rate database which is imperative to seismic hazard assessment

the contemporary physical and chemical flux of aeolian dust a synthesis of direct measurements of dust deposition abstract the deposition of aeolian or windblown dust is widely recognized as an important physical and chemical flux to ecosystems dust deposition adds exogenous mineral and organic material to terrestrial surfaces and can be important for the biogeochemical cycling of nutrients there have been many studies that characterize the physical and chemical composition of dust however few studies have synthesized these observations in order to examine patterns geochemical fluxes we have compiled observations of dust deposition rates particle size distributions psd mineralogy and bulk elemental and organic chemistry the rates of dust deposition observed across the globe vary from almost 0 to greater than 450 g m 2 yr 1 sites receiving dust deposition can be partitioned into broad categories based on there distance from dust source regions when compared to global dust models our results suggest some models may underestimate dust deposition rates at the regional and local scales the distance from the source region that dust is deposited also influences the particle size distributions mineralogy and chemical composition of dust however more consistent dust sampling and geochemical analyses are needed to better constrain these spatial patterns on average the concentrations of most major elements si al fe mg ca k in aeolian dust tend to be similar 20 to the composition of the upper continental crust ucc but there is substantial variability from sample to sample in contrast some elements tend to be depleted na or enriched ti in dust likely as a result of soil weathering processes prior to dust emissions trace elements especially heavy metals are consistently enriched in dust relative to the ucc ecologically important nutrients such as n and p are also present in dust deposition the geochemical flux attributable to dust deposition can be substantial in ecosystems located proximal to dust source regions we calculate estimates of elemental flux rates based on the average chemical composition of aeolian dust and varying rates of deposition these estimated flux rates are useful as a rough gauge of the degree to which dust deposition may influence biogeochemical cycling in terrestrial ecosystems and should be utilized to better constrain deposition estimates of global dust models

porosity and permeability characterization of coal a micro computed tomography study abstract a unique contrast agent technique using x ray micro computed tomography micro ct was developed for studying micrometer sized features in coal the technique allows for the visualization of coal fractures not visible with conventional imaging methods a late permian medium volatile bituminous coal from moura coal mine was imaged and the resulting three dimensional coal cleat system was extracted for fluid flow simulations the results demonstrate a direct relationship between coal lithotype and permeability i e bright coals offer more permeability than dull coals however there was no direct relationship between porosity and permeability for any given lithotype scanning electron microscope and energy dispersive spectrometry sem eds together with x ray diffraction xrd methods were used for identifying mineral matter at high resolution after segmentation of the micro ct image mineral phase was removed from the segmented data and it was found that permeability was significantly improved by increasing cleat void space and connectivity suggesting that enhanced recovery methods could target de mineralization techniques overall only the epigenetic mineral phases in the bright band influenced permeability while lithotype had a stronger impact on permeability than porosity coal lithotype and mineralization are important evaluation criteria when considering coal seam gas development sites

coastal staircase sequences reflecting sea level oscillations and tectonic uplift during the quaternary and neogene many coasts feature sequences of quaternary and neogene shorelines that are shaped by a combination of sea level oscillations and tectonics we compiled a global synthesis of sea level changes for the following highstands mis 1 mis 3 mis 5e and mis 11 also we date the apparent onset of sequences of paleoshorelines either from published data or tentatively extrapolating an age for the uppermost purported oldest shoreline in each sequence including the most documented mis 5e benchmark we identify 926 sequences out of which 185 also feature holocene shorelines six areas are identified where elevations of the mis 3 shorelines are known and 31 feature elevation data for mis 11 shorelines genetic relationships to regional geodynamics are further explored based on the elevations of the mis 5e benchmark mean apparent uplift rates range from 0 01 0 01 mm yr hotspots to 1 47 0 08 mm yr continental collision passive margins appear as ubiquitously uplifting while tectonic segmentation is more important on active margins from the literature and our extrapolations we infer ages for the onset of formation for 180 coastal sequences sea level fingerprinting on coastal sequences started at least during mid miocene and locally as early as eocene whether due to the changes in the bulk volume of seawater or to the temporal variations in the shape of ocean basins estimates of eustasy fail to explain the magnitude of the apparent sea level drop thus vertical ground motion is invoked and we interpret the long lasting development of those paleoshore sequences as the imprint of glacial cycles on globally uplifted margins in response to continental compression the geomorphological expression of the sequences matches the amplitude and frequency of glacial cyclicity from middle pleistocene to present day moderately fast 100 000 yrs oscillating sea levels favor the development of well identified strandlines that are distinct from one another pliocene and lower pleistocene strandlines associated with faster cyclicity 40 000 yrs are more compact and easily merge into rasas whereas older cenozoic low frequency eustatic changes generally led to widespread flat lying coastal plains

gis based approach for the measurement of variability in tectonomorphic signatures using dem s data a case study from the habo dome in the kachchh area india the kachchh region of western india is located in a plate interior region but falls under one of the highest seismic zones of india having very active crustal deformation and erosion the drainage system as well as the geomorphic evolution of the region under a semi arid climate zone with high to very high strength of rocks in areas with high relief is dominantly controlled by the seismic instability associated with continual tectonics in the present paper we have analysed a block close to the epicentre of the 2001 bhuj earthquake to understand the role of relative active tectonics in the evolution of domal landscape morphology shuttle radar topographic mission digital elevation model data were used to extract drainage network in the gis platform and evaluate active tectonics using different geomorphic indices of the habo hill the second largest domal structure situated in northern hill range of the kachchh region the average cumulative weightage of different geomorphic indices provides a quantitative tool index of relative active tectonics irat which shows significant variations in and around the habo dome activation of earlier lineaments and generation of new lineaments controlled the morphometric evolution of the fault bound block of the region to form the habo dome the undulating topography in addition to the domal shape of the study area resulted from the differential movements along several active transverse faults striking ne sw n s and nw se and the regional faults striking e w the kachchh mainland fault the kas fault and the jikadi fault stress propagations from the himalayan range in the northeast and suleiman range in the northwest are identified to be the causative factors for active tectonics and drainage anomalies in the area

eolian deposition in the alpine zone of the uinta mountains utah usa abstract field and laboratory investigations were conducted to determine the origin of a ubiquitous layer of silt that caps soil profiles in the alpine zone of the uinta mountains utah usa fine sediment isolated from snowbanks was studied to constrain the fraction of this material derived from allochthonous eolian additions lake sediments representing deposition over the past few centuries were analyzed to determine whether dust deposition in the uintas has been a long term process and if properties of the modern dust differ from dust which accumulated prior to european settlement results indicate that alpine soils have been strongly influenced by long term eolian deposition the loess cap in these soil profiles averages 18 cm thick and physical and chemical properties of soil horizons derived from the eolian parent material are significantly different than those of the subsurface horizons derived from in situ produced congelifractate fine sediment observed at the surface of snowbanks in the early summer is a mixture of silty exotic eolian material and sandy locally derived sediment snowbanks on ridgecrests and on slopes of blocky scree tend to accumulate the maximum amount of exotic dust with the minimum amount of local material the grain size distribution mineralogy and geochemistry of lake sediments indicate that dust has been accumulating in the uintas for at least the last few centuries modern lake sediments are significantly enriched in elements indicative of upwind mining and agricultural activity recording an anthropogenic change in dust composition following settlement of the surrounding lowland basins

chronology of lake bonneville 30 000 to 10 000 yr b p abstract 368 radiocarbon ages between 30 and 10 cal ka for samples collected from outcrops and shorelines from the lake bonneville basin have been compiled for this paper samples include 1 organic materials from sources outside the lake such as wood charcoal plant fragments from emergent aquatics and dispersed wetland organics and 2 carbonate materials deposited in the lake such as mollusk shells tufa charophyte debris ooids and marl in general organic materials provide rather than precise ages for lacustrine events but their interpretation is less complicated than interpretation of results from carbonate samples the data set shows evidence of contamination of different carbonate samples with both younger carbon and older carbon for example a radiocarbon reservoir at certain places within the lake during the middle transgressive phase accounts for ages of mollusk shells that are older than basal wood ages at similar altitudes the large number of ages permits an accurate reconstruction of the lake chronology conflicts between ages can be detected and reliable ages can be meaningfully integrated in interpretations if fewer ages were available the chronology might look simpler but its accuracy would be unknown

clay sized hf nd sr isotopic composition of mongolian dust as a fingerprint for regional to hemispherical transport hf nd sr isotopic fingerprinting has been employed as a powerful method for distinguishing dust sources however the hf and sr isotopic compositions of dust are highly dependent on particle size to accurately identify dust provenance here we compare the hf nd sr isotopic compositions of clay sized fractions from dust sources the mongolian plateau to sinks beijing and greenland our results document that clay sized hf nd sr isotopic compositions of mongolian dust are controlled by two isotopic geochemical provinces southern mongolian gobi smg and northern mongolian plateau nmp our data indicate that the smg is potentially an important dust source to the loess in beijing and hulun buir and could be a contributing source of dust to greenland whereas the nmp contributes little dust to the chinese loess and the greenland furthermore we demonstrate that the deserts of northwest china are one of the main dust contributors to beijing and greenland but not to hulun buir

contemporary geochemical composition and flux of aeolian dust to the san juan mountains colorado united states 1 dust deposition in the rocky mountains may be an important biogeochemical flux from upwind ecosystems seasonal winter spring dust mass fluxes to the san juan mountains during the period from 2004 to 2008 ranged from 5 to 10 g m 2 with individual deposition events reaching as high as 2 g m 2 dust deposited in the san juan mountains was primarily composed of silt and clay sized particles indicating a regional source area the concentrations of most major and minor elements in this dust were similar to or less than average upper continental crustal concentrations whereas trace element concentrations were often enriched in particular dust collected from the san juan mountain snowpack was characterized by enrichments of heavy metals including as cu cd mo pb and zn the mineral composition of dust partially explained dust geochemistry however based on results of a sequential leaching procedure it appeared that trace element enrichments were associated with the organic and not the mineral fraction of dust our observations show that the dust derived fluxes of several nutrients and trace metals are substantial and because many elements are deposited in a mobile form could be important controls of vegetation soil or surface water chemistry the flux measurements reported here are useful benchmarks for the characterization of ecosystem biogeochemical cycling in the rocky mountains

high resolution non destructive measurement and characterization of fracture apertures abstract we measure at high resolution the fracture aperture of several consolidated materials and statistically characterize the aperture distribution for future studies on single and multiphase flow and transport through fractured porous media the images of the real fractures in granite and sandstone rocks are obtained with a computer aided tomography cat x ray scanner the minimum pixel size is 0 27 0 27 mm but fractures as small as 35 m can be accurately measured using a calibration standard for the variation in ct number due to the missing rock mass in a given pixel the distribution of fracture apertures is best described by a lognormal function this was also corroborated by comparing the theoretical to actual ratio of geometric mean to arithmetic mean apertures the mechanical roughness of the fractures ranged from 0 17 to 1 5 the variability in fracture aperture displayed only short range structure with correlation lengths of 0 8 to 7 mm at maximum which is at most one tenth of the minimum dimension width of the fracture plane fracture aperture distribution is rather heterogeneous potential flow channels can be deduced from the fracture aperture distribution

identifying spatial heterogeneity of coal resource quality in a multilayer coal deposit by multivariate geostatistics this study presents a new geostatistical approach to characterization of the geometry and quality of a multilayer coal deposit using the data of seam thickness as a geometric property and the contents of ash sodium total sulphur and the heating value as quality properties a coal deposit in east kalimantan borneo indonesia which has a synclinal geological structure was chosen as the study site semivariogram analysis clarified the strong dependence of heating value on ash content in the top and bottom parts of each seam and the existence of a strong correlation with sodium content over the sub seams in the same location the correlations between the geometry and quality of the seams were generally weak a linear coregionalization model was used to derive the spatial correlation coefficients of two variables at each scale component from the single and cross semivariogram matrices because the data were correlated spatially in the same seam or over different seams multivariate techniques ordinary cokriging and factorial cokriging were mainly used and the resultant spatial estimates were compared to those derived using a univariate technique ordinary kriging a factorial cokriging was effective to decompose the spatial correlation structures with different scales another important characteristic was that the sodium content shows distinct segregation the low zones are concentrated near the boundary of the sedimentary basin while the high zones are concentrated in the central part the main component of sodium originates from the abundance of saline water therefore it can be inferred that seawater had stronger effects on the coal depositional process in the central basin than in the border part the geostatistical modeling results suggest that the thicknesses of all the major seams were controlled by the syncline structure while the coal qualities chiefly were originated from the coal depositional and diagenetic processes

hydrocarbon prospects across narmada tapti rift in deccan trap central india inferences from integrated interpretation of magnetotelluric and geochemical prospecting studies abstract as the mesozoic sediments contribute most of the oil and gas reserves of the world we present an integrated interpretation approach using magnetotellurics mt and surface geochemical prospecting studies to demarcate hydrocarbon prospective gondwana mesozoic formations underneath the deccan flood basalts of late cretaceous age across narmada tapti rift between bhusawal and barwah in central india the mt interpretation shows deep 5 km basement structure between southern and central part of the mt profile however it gradually becomes shallower to either ends of the profile with a predominant basement depth reduction in the northern end compared to the southern end the geophysical results suggest thick 2 3 5 km mesozoic sediments in the area characterized by deep basement structure the geochemical analysis of the near surface soil samples indicate higher concentrations of light gaseous hydrocarbons constituents over the area marked with thick sub basalt mesozoic formations analyses of the geochemical data imply that these hydrocarbons are genetically related generated from a thermogenic source and these samples fall in the oil producing zone the temperature depth estimations in the region supports favorable temperature conditions 80 120 c for oil generation at basement depths

application of 3d inversion to magnetotelluric profile data from the deccan volcanic province of western india abstract using synthetic data siripunvaraporn et al 2005b demonstrated possible advantages of interpreting single profile mt data with a three dimensional 3d inversion program here we explore this idea further using real mt data from two profiles on the indian subcontinent the first profile 330 km long cuts across the deccan volcanic province of peninsular india the second 130 km long is in the narmada son lineament zone approximately 100 km further north using the data space occam inversion code of siripunvaraporn et al 2005a 3d inversion is carried out on each of these profiles independently and results are compared with previously published two dimensional 2d interpretations in addition to inversion of the full impedance tensor we consider 3d inversion of only the off diagonal components we also experiment with variants on the model covariance in particular allowing for longer smoothing length scales along the geoelectric strike not surprisingly the 3d inversion finds models that fit the data better than had been possible with the 2d programs many of the features inferred from these previous 2d interpretations are also present in the 3d inverse solutions but the positions and amplitudes of individual conductive features are in some cases changed the 3d models suggest substantial non uniqueness in the single profile data even without explicit or special treatment we find that the relatively modest near surface distortion effects in these datasets were well fit by the 3d inversion by inserting small scale conductive and resistive features in surface layers mostly off profile

geological geophysical and inherited tectonic imprints on the climate and contrasting coastal geomorphology of the indian peninsula abstract the indian subcontinent comprises accreted cratonic fragments that underwent subsequent rifting subduction collision processes along major mobile belts it is also a storehouse of a prolonged history of crustal evolution involving repeated episodes of magmatism volcanism sedimentation and metamorphism and the formation of intracratonic and foreland basins the geologic geomorphic evolution of the peninsula is recorded in relic faults suture zones that confine paleozoic mesozoic and cenozoic sedimentary basins and landforms in addition escarpments plateaus waterfalls deltas planation surfaces and strandlines are either aligned parallel and or formed over them asymmetric relief across the western eastern parts of the peninsula orographic effect on the precipitation pattern and climatic zones provide important constrains on the geologic and geomorphic evolution of the region though extensive continental and coastal deposition occurred during permo triassic and early cretaceous only the downwarped grabens of gondwana basins preserved the sedimentary records occurrences of extensive cenozoic deposits offshore and neogene holocene deltaic deposits along the entire east coast as opposed to the absence of comparable deltaic sequences in the west coast are linked to intense and recurrent episodes of denudation indicating first order control of basement structures over landscape evolution inheritance and continuum of basement structures over climate and landscape evolution of peninsular india can also be witnessed by the unique and diverse drainage patterns of major rivers while most of the major rivers follow a general easterly direction the landscape morphology of their catchments indicates youthful character and tectonically active nature the east flowing rivers show an asymmetry between the areal extents of drainage basin size and delta whereas the west flowing rivers are short and straight and their catchments are miniscule in comparison with the rivers flowing toward east the western ghats escarpment forms an orographic barrier and acts as the main divide between these two drainage systems there is a disparity between the quanta of sediment discharge as well in addition the eastern and western parts of india across the western ghats escarpment show significant differences in terms of climatic zones humid to per humid on the west while it is arid to subhumid on the east the west coast is characterized by 3000 mm year annual rainfall that often reaches 5000 mm year dominance of sw monsoon winds occurrence of narrow here we propose a conceptual tectono geomorphic model demonstrating the inheritance and continuum of gondwanan structural trends on the transient landscape of peninsular india

quantitative characterization of low rank coal reservoirs in the southern junggar basin nw china implications for pore structure evolution around the first coalification jump abstract the assessment of coalbed methane cbm reservoirs can provide insights into the evolution of the pore structure systems around the first coalification jump fcj the southern junggar basin a typical low rank coal bearing basin in northwestern china has been of interest to scientists and policy makers due to its abundance of cbm resources and favourable conditions for cbm enrichment a total of 28 coal samples from the middle jurassic xishanyao formation collected from 11 sampling sites in the central segment of the southern junggar basin were analyzed in this study these samples were quantitatively characterized and comprehensively evaluated using macroscopic to nanometer scale methods including macroscopic coal description proximate analysis vitrinite reflectance measurements maceral analysis low pressure nitrogen adsorption lpna scanning electron microscopy sem mercury intrusion porosimetry mip and nuclear magnetic resonance nmr the results show that the xishanyao low rank coals are characterized by low moisture contents low or low medium ash yields eastern and western parts high volatile matter contents moderate vitrinite contents and high inertinite contents the physical property of the xishanyao coals generally displays heterogeneity with the specific surface area the total pore volume the air permeability and the transverse relaxation time t2 ranging from 0 116 to 15 983 m2 g 0 461 10 3 to 13 37 10 3 cm3 g 0 001 to 151 66 md 0 987 10 6 to 0 149 m2 and 1 44 174 22 ms respectively a new parameter namely micropore volume proportion per unit nano meter is proposed micropore and transition pore volume per nm specific surface area total pore volume dn1 and dn2 lpna fractal dimension all first increase then decrease and finally increase with rising coal rank while the maximum and minimum values of the maximum vitrinite reflectance ro max occur at 0 58 0 59 and 0 65 0 66 the boundary of ro max corresponding to the fcj can be further defined from 0 5 0 6 to 0 58 0 59 based on the evolution of adsorption pore structures thus pore structure parameters related to adsorption capacity are controlled predominantly by coal rank in addition tectonic deformation has a strong impact on seepage pore structure but only a slight impact on that of adsorption pore which leads to an ambiguous correlation or a complex trend between mesopore macropore content dmip fractal dimension of mip and coal rank around the fcj this study reveals the complex variation of pore structure evolution of low rank coals and the significant influence of the fcj on physical properties of coalbed methane reservoirs

dust emission from wet and dry playas in the mojave desert usa the interactions between playa hydrology and playa surface sediments are important factors that control the type and amount of dust emitted from playas as a result of wind erosion the production of evaporite minerals during evaporative loss of near surface ground water results in both the creation and maintenance of several centimeters or more of loose sediment on and near the surfaces of wet playas observations that characterize the texture mineralogic composition and hardness of playa surfaces at franklin lake soda lake and west cronese lake playas in the mojave desert california along with imaging of dust emission using automated digital photography indicate that these kinds of surface sediment are highly susceptible to dust emission the surfaces of wet playas are dynamic surface texture and sediment availability to wind erosion change rapidly primarily in response to fluctuations in water table depth rainfall and rates of evaporation in contrast dry playas are characterized by ground water at depth consequently dry playas commonly have hard surfaces that produce little or no dust if undisturbed except for transient silt and clay deposited on surfaces by wind and water although not the dominant type of global dust salt rich dusts from wet playas may be important with respect to radiative properties of dust plumes atmospheric chemistry windborne nutrients and human health published in 2007 by john wiley sons ltd

wind regimes and aeolian transport in the great basin u s a abstract the modern great basin of the interior western united states is characterized by surface winds with considerable spatial and temporal variabilities wind records from the second half of the 20th century for 12 great basin localities analyzed with standard aeolian sediment transport methods developed elsewhere in the world reflect this complexity the drift potential dp for aeolian deposits is generally moderate dp 200 400 in the western great basin and weak dp 300 at the eastern edge of the great basin where the dominant prevailing wind direction is south southwesterly both dp and resultant drift direction rdd are consistent with synoptic meteorological observations of the evolution of cold fronts in the great basin meteorological observations show that effective winds to produce dunes are most commonly the result of late winter early spring cyclogenesis there has been considerable temporal variability of dp in the latter half of the 20th century most of the great basin has experienced decreasing wind strength since 1973 consistent with recent studies of wind strength in north america and elsewhere dune morphology matches both localized rdd and temporal variations in dp reasonably well in the great basin the results demonstrate that local topography can have an important influence on wind directionality thus providing a cautionary note on the interpretation of dune morphology in the paleoclimatic and stratigraphic record

provenance of the various grain size fractions in the negev loess and potential changes in major dust sources to the eastern mediterranean abstract the isotopic composition of sr and nd and elemental concentrations e g na k ca mg al of three primary negev loess sequences trace the relative contributions of desert dust sources over the past 180 000 yr to the southeastern mediterranean we focused on the geochemical signature of the fine 20 m grain size modes of the loess to identify their respective provenances the isotopic composition of the coarse fraction falls on a mixing line of sources feeding the nile and its delta the chemical compositions of the coarse fraction and the sinai negev sand dunes are similar indicating that this fraction is the product of aeolian abrasion of the adjacent sinai negev sands in turn these sands are derived from the nile delta and transported inland the fine fraction has less negative end values and slightly deviates from the mixing line indicating an additional end member the higher end values and mg al ratios of the fine fraction are relatively well correlated r2 0 64 and point to arabian dust as an additional source temporal changes in the geochemical composition of loess over time reflect changes in climates of source areas and the eastern mediterranean shifts from saharan to arabian fine dust dominated intervals indicate wetter conditions in the southern sahara that weaken dust fluxes from this source relative to the arabian fluxes

crustal structure of the gujarat region india new constraints from the analysis of teleseismic receiver functions abstract in this study receiver function analysis is carried out at 32 broadband stations spread all over the gujarat region located in the western part of india to image the sedimentary structure and investigate the crustal composition for the entire region the powerful genetic algorithm technique is applied to the receiver functions to derive s velocity structure beneath each site a detail image in terms of basement depths and moho thickness for the entire gujarat region is obtained for the first time gujarat comprises of three distinct regions kachchh saurashtra and mainland in kachchh region depth of the basement varies from around 1 5 km in the eastern part to 6 km in the western part and around 2 3 km in the northern part to 4 5 km in the southern part in the saurashtra region there is not much variation in the depth of the basement and is between 3 km and 4 km in gujarat mainland part the basement depth is 5 8 km in the cambay basin and western edge of narmada basin in other parts of the mainland it is 3 4 km the depth of moho beneath each site is obtained using stacking algorithm approach the moho is at shallower depth 26 30 km in the western part of kachchh region in the eastern part and epicentral zone of the 2001 bhuj earthquake large variation in the moho depths is noticed 36 46 km in the saurashtra region the crust is more thick in the northern part it varies from 36 38 km in the southern part to 42 44 km in the northern part in the mainland region the crust is more thick 40 44 km in the northern and southern part and is shallow in cambay and narmada basins 32 36 km the large variations of poisson s ratio across gujarat region may be interpreted as heterogeneity in crustal composition high values of 0 30 at many sites in kachchh and few sites in saurashtra and mainland regions may be related to the existence of high velocity lower crust with a mafic ultramafic composition and locally to the presence of partial melt the existing tectono sedimentary models proposed by various researchers were also examined

stochastic modeling of coal fracture network by direct use of micro computed tomography images abstract characterization of coalbed methane reservoirs is a challenging task because of complex petrophysical properties of coal coal cleat system has a key role in permeability of gas through coalbed previous computational methods for characterization and modeling in coal formations do not account for the actual complexities in cleat systems as they commonly rely on simple statistical properties for describing the fractures in this study unlike the previous methods that try to extract some of the spatial statistical properties the 2d 3d micro computed tomography images are used directly without any simplifications and assumptions the generated models are compared to discrete fracture networks as one of the widely used method for the modeling of such complex systems of coal cleats results show that the utilized algorithm produces visually satisfactory realizations of both coal matrix and cleat system to quantify such similarities autocorrelation functions connectivity with two distinct indices average fracture length and orientation are computed moreover permeabilities and porosities of the reconstructed samples are calculated and compared with the original sample it is demonstrated that the proposed reconstruction method reproduces samples with similar statistical and petrophysical properties but with different patterns of both coal porous region and fracture system finally the proposed method and the dfn realizations are also compared extensively the results of this study can be used for characterization of coal samples with any degree of complexity and heterogeneity by producing several realistic stochastic models consequently petrophysical properties and their corresponding uncertainties can be evaluated more accurately

the present day state of tectonic stress in the offshore kutch saurashtra basin india abstract exploration activity in the kutch saurashtra area has drawn major attention and because of the recent hydrocarbon discoveries offshore kutch saurashtra basin is now moved from category iii to ii accurate understanding of the full present day stress tensor and pore pressure is critical for field development in this study pore pressure stress magnitudes and horizontal stress direction have been estimated from high resolution geophysical logs and various direct downhole measurements recorded in the studied offshore exploratory wells extensive availability of subsurface pressure measurements confirms hydrostatic pore pressure in the tertiary sediments magnitudes of vertical minimum and maximum horizontal stresses indicate a strike slip tectonic stress regime wellbore breakouts of a c qualities have been identified in density image logs and four arm caliper logs indicating a nne trend n10 e to n20 e of shmax maximum horizontal stress the same has been confirmed from shear wave anisotropy analysis as well the interpreted stress direction is in good agreement with the world stress map data available from the adjacent area this study is significant in understanding the subsurface behavior during drilling reservoir modeling future well stimulation and production optimization

geomorphic and land cover identification of dust sources in the eastern great basin of utah u s a abstract this study identifies anthropogenically disturbed areas and barren playa surfaces as the two primary dust source types that repeatedly contribute to dust storm events in the eastern great basin of western utah u s a this semi arid desert region is an important contributor to dust production in north america with this study being the first to specifically identify and characterize regional dust sources from 2004 to 2010 a total of 51 dust event days deds affected the air quality in salt lake city ut modis satellite imagery during 16 of these deds was analyzed to identify dust plumes and assess the characteristics of dust source areas a total of 168 plumes were identified and showed mobilization of dust from quaternary deposits located within the bonneville basin this analysis identifies 4 major and 5 secondary source areas for dust in this region which produce dust primarily during the spring and fall months and during moderate or greater drought conditions with a palmer drought index pdi of 2 or less the largest number of observed dust plumes 60 of all plumes originated from playas ephemeral lakes and are classified as barren land cover with a silty clay soil sediment surface playa surfaces in this region undergo numerous recurrent anthropogenic disturbances including military operations and anthropogenic water withdrawal anthropogenic disturbance is necessary to produce dust from the vegetated landscape in the eastern great basin as evidenced by the new dust source active from 2008 to 2010 in the area burned by the 2007 milford flat fire this fire was the largest in utah s history due to extensive cover of invasive cheatgrass bromus tectorum along with drought conditions however dust mobilization from the milford flat burned area was limited to regions that had been significantly disturbed by post fire land management techniques that consisted of seeding followed by chaining or tilling of the soil dust storms in the eastern great basin negatively impact air quality and transportation in the populated regions of utah this study details an improved forecasting protocol for dust storm events that will benefit transportation planning and improve public health

the role of aeolian dust in ecosystems abstract the recent upsurge in research attention to aeolian dust has shown that dust transport systems operate on very large spatial and temporal scales and involve much larger quantities of sediment than was previously realized an inevitable consequence of this is that researchers from a range of neighbouring disciplines including ecology are beginning to realize that this new knowledge has important implications for their study areas in the present paper we examine the ecological implications real and potential of this expanding knowledge of dust transport systems with a particular emphasis upon the australian dust transport system we track these ecological effects from source to sink at source wind erosion soil vegetation relationships are often dominated by temporal changes in rainfall nine years of measurements in the channel country of the lake eyre basin australia show that vegetation and soils in dune fields can recover from drought whereas on inter fluve grasslands uni directional and negative successional vegetation changes can result from wind erosion during drought on floodplains both wind erosion and vegetation responses are complicated by flood frequency up to 1999 flooding of saline claypans did not increase vegetation but did increase wind erosion through the supply of alluvial fines however after three floods within as many months vegetation became established and wind erosion rates were dramatically reduced wind erosion research attention is now gradually turning from the physical to the organic content of eroded dusts in australia organic matter content can reach 65 by mass but this cannot be explained by removal of soil organic matter alone biological soil crusts not only stabilize soils against wind erosion but contribute to some of the organic dusts the role of dust as a vector for pathogens is an area which deserves greater research attention in the future downwind from source we show that dust contributions to soils are more widespread and more variable in time and space than earlier work on dust derived loess soils has suggested recent studies also show positive dust impacts upon nutrient budgets within distant forest ecosystems and significant contributions to river nutrient loads especially in the arid sectors of internally draining river basins the number of studies of dust impacts upon marine ecosystems is increasing dramatically studies of dust within antarctic ice cores combined with dust modelling provide compelling evidence that increased soluble iron rich dust inputs to the southern ocean have stimulated phytoplankton populations modern process studies are however yet to clearly demonstrate these relationships finally we examine the potential for major dust impacts upon global climates using its positive and negative effects upon solar radiation and precipitation as examples of the complexity and importance of this new research area

the palaeodelta of the proto vatrak and proto mahi rivers of northeastern gujarat india a remote sensing interpretation abstract detailed remote sensing studies carried out in northeastern gujarat india suggest that there has been a major change in the drainage system as evidenced by the presence of a large palaeo delta system the area is drained by two major rivers the mahi and vatrak originating from the aravalli hills to the east which discharge into the gulf of cambay in the indian ocean major lineaments palaeodrainage patterns and palaeodeltas of the vatrak and mahi rivers were delineated these were large rivers in the past with a high discharge and floodplains which were 5 10 km wide most of the palaeodrainage follows the ne sw precambrian lineaments faults indicating their structural control reactivation of these lineaments and differential uplift of the aravalli hills resulted in increased transportation of the eroded sediments and deposition of more than 5 km thick sediments into the tarapur block of the cambay basin the gulf of cambay extended up to the limbasi sojitra petlad area during the quaternary there are implications for petroleum exploration in the sense that the results when integrated with subsurface geological and geophysical data help to delineate the reservoir facies suitable for petroleum exploration along the eastern margin of the tarapur block