holocene climate variability archived in the puruogangri ice cap on the central tibetan plateau two ice cores 118 4 and 214 7 m in length were collected in 2000 from the puruogangri ice cap in the center of the tibetan plateau tp in a joint us chinese collaborative project these cores yield paleoclimatic and environmental records extending through the middle holocene and complement previous ice core histories from the dunde and guliya ice caps in northeast and northwest tibet respectively and dasuopu glacier in the himalaya the high resolution puruogangri climate record since ad 1600 details regional temperature and moisture variability the post 1920 period is characterized by above average annual net balance contemporaneous with the greatest 18 o enrichment of the last 400 years consistent with the isotopically inferred warming observed in other tp ice core records on longer timescales the aerosol history reveals large and abrupt events one of which is dated 4 7 kyr bp and occurs close to the time of a drought that extended throughout the tropics and may have been associated with centuries long weakening of the asian indian african monsoon system the puruogangri climate history combined with the other tp ice core records has the potential to provide valuable information on variations in the strength of the monsoon across the tp during the holocene

soil aquifer stream interactions a reductionist attempt toward physical stochastic integration abstract the paper suggests an approach to describe the various interactions between soil aquifer and stream in a simplified but essentially physical and integrated manner for practical applications the complex hydrological processes cannot be thoroughly described at the smallest scale in time and space at which theoretical or empirical physical laws are known the successful passage from a smaller to a larger scale requires enlightened simplification integration in many senses that is 1 in time 2 in space 3 in an expectation sense and 4 in a process sense and finally enlightened coupling the paper illustrates in a simple manner this processus of multiple integration for the processes of infiltration moisture redistribution aquifer recharge and aquifer return flow with emphasis on the stream aquifer interaction the paper suggests that temporal patterns of rainfall spacial variation in soil properties temporal fluctuations in river stage sharp turns in flow directions e g from vertical to horizontal direction at the interface of two soil layers with contrasting hydraulic properties or in the vicinity of a water table etc can significantly affect the response of a watershed the paper also suggests that simple techniques can be devised that account to a large extent for these influences and will provide satisfactory tools for watershed modeling as a sort of parenthesis the paper shows that the purely statistical arma approach to hydrologic modeling will lead to incorrect identification of a perfectly stationary linear system as a nonstationary one the combined physical stochastic approach eliminates this potential error

element mobility during alteration of silicic ash to kaolinite a study of tonstein a laterally persistent kaolinitic mudstone parting tonstein occurring in a wyoming coal bed of eocene age was sampled to estimate the compositional contrast with a probable silicic ash precursor and to determine the compositional influence of leached ash on immediately adjacent coal with the exception of al and possibly ti the tonstein is highly to moderately leached of major elements relative to a range of compositions estimated for silicic ash of the region in agreement with the behaviour of geochemically similar major elements alkali trace elements rb cs are highly leached transition series metals moderately leached and ga is residual additional immobile trace elements are zr and hf but some other trace elements that are considered relatively immobile during low temperature alteration th ta nb ree y were apparently leached by the low eh low ph organic rich pore fluids of the coal forming swamp the migrational range of many of the leached elements is highly limited by the intimate association of tonstein with enclosing organic matter mixtures of coal minor tonstein that occur within 20 mm of contacts are consistently enriched in some elements relative to either tonstein or nearby coal u cu or relative to calculated mixtures of tonstein and coal in their measured proportions th y ree pb ba v ti direct observations by fission track radiography and electron microprobe indicate a preference of u and fe for the organic component of mixtures metal fixation is probably by adsorption on insoluble organic matter humic acids or by precipitation as minor sulphides in these low sulphur coals

the fate of nitrogen and sulfur in hard rock aquifers as shown by sulfate isotope tracing abstract stable so4 isotopes 34s so4 and 18o so4 and more occasionally 15n no3 were studied in groundwater from seven hard rock aquifer catchments the sites are located in brittany france and all are characterized by intensive agricultural activity the purpose of the study was to investigate the potential use of these isotopes for highlighting the fate of both so4 and no3 in the different aquifer compartments nitrate contaminated groundwater occurs in the regolith 34s fingerprints the origin of so4 such as atmospheric deposition and fertilizers and 18o so4 provides evidence of the cycling of s within soil the correlation between the 18o so4 of sulfates and the 15n no3 of nitrates suggests that s and n were both cycled in soil before being leached to groundwater autotrophic and heterotrophic denitrification was noted in fissured aquifers and in wetlands respectively the two processes being distinguished on the basis of stable so4 isotopes during autotrophic denitrification both 34s so4 and 18o so4 decrease due to the oxidation of pyrite and the incorporation of o from the no3 molecule in the newly formed so4 within wetlands fractionation occurs of o isotopes on so4 in favour of lighter isotopes probably through reductive assimilation processes fractionation of s isotopes is negligible as the redox conditions are not sufficiently reductive for dissimilatory reduction 34s so4 and 18o so4 data fingerprint the presence of a no3 free brackish groundwater in the deepest parts of the aquifer through mixing with present day denitrified groundwater this brackish groundwater can contribute to significantly increase the salinity of pumped water from the fissured aquifer

rare earth patterns with positive cerium anomaly in alkaline waters from lake van turkey abstract the distribution of rare earth elements has been studied for aerobic alkaline ph 9 6 carbonate rich waters from lake van turkey shale normalized ree ree sn patterns display an almost linear increase from the light to the heavy rees and strong positive ce sn anomalies there exist neither positive nor negative gd sn anomalies the ree sn patterns are consistent with domination of ree speciation in solution by poly carbonato complexes generating enrichment of the heavy rees that is even more pronounced than that seen in seawater this is the first report of positive ce sn anomalies observed in ree sn patterns of aerobic natural waters these anomalies apparently result from stabilization of penta carbonato ce iv complexes in solution leading to enhanced abundances of ce in comparison with its trivalent ree neighbours thus in remarkable contrast to seawater positive ce sn anomalies may be general features of alkaline carbonate rich and aerobic lake waters

recharge of aquifers by flood events in an arid region the process of aquifer recharge by flood events in an arid region was investigated as applied to the hazeva formation the karkom graben the wadi paran watershed israel the hydrological model was established as a complex system with due regard for groundwater and transmission losses of surface runoff it was based on a previously outlined hydrogeological model of the karkom graben and a model of transmission losses in arid watercourses under conditions of data deficiency proceeding from calculation of groundwater balances the contribution of surface runoff as a decisive balance component was confirmed the main characteristics of aquifer regimes such as changes in storage volume and groundwater level as well as lateral flow were all found to be dependent upon the net extraction rate i e pumpage discounting replenishment by flood events analysis and physical interpretation of model parameters enabled assessment of the influence of groundwater extraction on aquifer recharge this became apparent as increasing absorption capacity and recharge availability of the aquifer as a result of the groundwater abstraction copyright 2002 john wiley sons ltd

burial of organic carbon and pyrite sulfur in sediments over phanerozoic time a new theory in present day marine sediments almost all of which are deposited in normal oxygenated seawater rates of burial of organic carbon c and pyrite sulfur s correlate positively and bear a constant ratio to one another c s 3 on a weight basis by contrast calculations based on the isotopic model of garrels and lerman 1981 indicate that at various times during the phanerozoic the worldwide burial ratio must have been considerably different than the present day value this ratio change is caused by the requirement that increases in the worldwide mass of organic carbon must be accompanied by equivalent decreases in the mass of sedimentary pyrite sulfur in order to maintain a roughly constant level of o2 in the atmosphere such apparently contradictory behavior can be explained if the locus of major organic carbon burial has shifted over time from normal marine environments as at present to non marine freshwater or to euxinic environments in the geologic past a shift to predominantly freshwater burial can help explain predicted high c s ratios in permo carboniferous sediments and a shift to euxinic environments can help explain predicted low c s ratios during the early paleozoic it is demonstrated that the three environments today exhibit distinguishably different average c s ratios

provenance derived from the geochemistry of late paleozoic early mesozoic mudrocks of the pyeongan supergroup korea late carboniferous early triassic pyeongan supergroup korea was deposited in paralic to nonmarine environments developed disconformably on a lower paleozoic platformal sequence pyeongan supergroup mudrocks show progressive upsection changes in major trace and rare earth element compositions mudrocks in the lower and middle parts of the pyeongan supergroup are strongly depleted in cao and na2o while those in the upper part are enriched in these elements in parallel with cao and na2o the ratio of k2o al2o3 in the lower and middle sections is less than 0 3 while uppermost strata are enriched in k2o having k2o al2o3 ratios greater than 0 3 the index of compositional variability a measure of compositional maturity is less than 0 6 in the lower to middle section whereas in the uppermost strata it is greater than 0 7 similar trends are reflected in a cn k space compared to paas mudrocks of the pyeongan supergroup except for those in uppermost units they are depleted in mn ca and na and are slightly depleted in mg and p contrasting major oxide trends between the lower and middle parts of the pyeongan and the uppermost units are due to decreasing proportions of clay minerals and a concomitant increase in the proportion of nonclay silicate minerals due to increasing input of first cycle detritus excursions marked by increases in mgo na2o and cao reflect large scale input of nonclay first cycle minerals from crystalline source rocks due to large scale basement uplift incompatible elements are generally enriched in mudrocks of the pyeongan supergroup relative to paas while transition metals co ni cr and v are progressively depleted in younger parts of the section total rare earth element concentrations are higher than paas but chondrite normalized patterns display the typical lree enriched pattern of paas eu anomalies for most mudrocks are close to that of paas the youngest mudrocks in the pyeongan supergroup have the most negative values these trends can be explained by a sedimentary system dominated by detritus derived from recycled highly weathered granitic materials in the lower to middle pyeongan section with an increased proportion of less weathered detritus derived from fractionated granitic materials in uppermost strata such an interpretation is consistent with the results of studies on coarse grained sediments of the pyeongan supergroup

paleoclimate and paleoceanography over the past 20 000 yr in the mediterranean sea basins as indicated by sediment elemental proxies abstract marine sediments record paleoenvironmental changes over time through variations in major and trace element concentrations the main objective of this paper is to review such changes in the mediterranean sea basins over the last 20 ka using the inorganic chemistry and mineralogy of marine sediment records elemental ratio proxies that are mostly used are discussed and the uncertainties involved in using them for paleoclimate and paleoceanographic reconstructions are evaluated the focus on the mediterranean region is based on the sensitivity of this region to global climate changes due to its semi enclosed nature the elemental ratios that have been particularly useful for reconstructing terrigenous inputs into the mediterranean have been ti al and zr al ratios as proxies for eolian dust input and mg al k al and rb al ratios as proxies for fluvial input redox sensitive elements e g u mo v co ni cr have provided reliable reconstructions of oxygen conditions at the time of deposition some of these elements are also particularly susceptible to post depositional remobilization and record diagenetic processes instead of the original environmental signatures regarding productivity fluctuations most of the paleoproductivity reconstructions are based on the abundance of barite and ba excess algorithms the biogeochemistry of ba is however not fully understood and mechanisms for barite precipitation in the water column are not yet known two case studies are presented the eastern mediterranean sapropel s1 deposited between 10 8 and 6 1 cal ka bp and the westernmost mediterranean paleoclimate record over the last 20 ka

sulfur isotope constraint on the provenance of salinity in a confined aquifer system of the southwestern nobi plain central japan abstract a combination of 34 s values and chemical compositions of brackish groundwater were used to examine the provenance of salinity in a confined aquifer system in the southwestern nobi plain central japan a tongue of brackish confined groundwater cl 1000 mg l which extends from the shoreline of ise bay inland has somewhat lower so 4 cl ratios and higher 34 s values 79 than those of the present seawater although the cation compositions of the brackish groundwater are consistent with values calculated for a mixture of fresh recharge water and seawater the anion compositions cannot be adequately interpreted as derived from such a mixing process alone using a rayleigh distillation model we found that the groundwater chemistry could be explained by sulfate reduction in combination with the mixing of two types of seawaters the present seawater and so 4 free seawater with the fresh recharge water the so 4 free seawater may consist mainly of fossil seawater that was trapped in an aquiclude for thousands of years model calculations based on cl and so 4 2 contents and 34 s values showed that the present and fossil seawaters compose at most 10 7 and 9 4 respectively of the brackish groundwater volume and the reduced so 4 2 content is up to 353 mg l in the confined aquifer the model s discrimination of the two seawaters is also in agreement with the spatial distribution patterns of groundwater composition from the west to the east in succession the main influence on the groundwater chemistry is fresh recharge water the present seawater and the fossil seawater moreover the area of intrusion of present seawater predicted by the model agrees well with the area of seawater intrusion determined from water quality data obtained a decade ago indicating that the model calculations can be reasonably used to discriminate quantitatively between present and fossil seawaters

contrasting patterns of early twenty first century glacier mass change in the himalayas glaciers are among the best terrestrial climate indicators an important water resource in mountains1 2 and a major contributor to global sea level rise3 4 in the hindu kush karakoram himalaya region hkkh a paucity of appropriate glacier data has prevented a comprehensive assessment of current regional mass balance5 however there are indirect evidences of a complex pattern of glacial responses5 8 in reaction to heterogeneous climate change signals9 here we provide the first coherent data set of detailed glacier thickness changes over the hkkh during 2003 2009 by combining satellite laser altimetry and a global elevation model in the eastern central and south western parts of the hkkh glacier wastage is widespread with regional thinning rates up to 0 66 0 09 m a 1 in the jammu kashmir region conversely in the karakoram glaciers are close to balance with only a slight thinning of 0 07 0 04 m a 1 regionally averaged thinning rates under debris mantled ice are similar to those of clean ice despite insulation by debris covers the 2003 2008 specific mass balance for our hkkh study region is 0 21 0 05 m a 1 water equivalent we significantly less negative than the global average of 0 7 m a 1 we for glaciers and ice caps4 10 this difference is mainly an effect of the balanced glacier mass budget in the karakoram the corresponding hkkh sea level contribution is 0 035 0 009 mm a 1 amounting to 1 of the present day sea level rise11 our 2003 2008 mass budget of 12 8 3 5 gt a 1 is more negative than recent satellite gravimetry based estimates of 5 6 gt a 1 over 2003 2010 ref 12 for the mountain catchments of the indus and ganges basins13 the glacier imbalance contributes 3 5 and 2 0 respectively to the annual average river discharge13 and up to 10 for the upper indus basin14

seasonal dynamics of elemental sulfur in two coastal sediments a spectrophotometric method for elemental sulfur s0 analysis without interference from other reduced sulfur compounds was adapted for the use in reducing sediments the s0 distribution in two coastal sediments was studied regularly from summer to winter and compared to factors regulating the s0 accumulation such as redox potentials the rate of bacterial sulfide production and the general sulfur chemistry dense coatings of sulfur bacteria developed on the sediment surface of a sulfuretum which had an s0 concentration of up to 41 mol s cm 3 the 2 5 mm thick bacterial coating contained 40 of all s0 in the sediment a more typical marine sediment with a few cm thick oxidized surface layer had an s0 maximum of 1 3 mol s cm 3 at 2 4 cm depth the s0 maximum in both sediments increased from summer to winter as the sediments gradually became more oxidized the deeper layers maintained a low s0 concentration most of the s0 in the upper few mm of a laboratory sulfuretum was present inside sulfur bacteria and actively migrated up and down with the bacteria depending upon the changing light and oxygen conditions

geological and geotechnical land zoning for potential hortonian overland flow in a basin in southern brazil abstract this paper presents a new procedure to perform geological and geotechnical land zoning at the 1 50 000 scale for potential hortonian overland flow rpot values the procedure was applied to the ribeirao do feijao basin sao paulo state brazil the zoning was conducted using a procedure that combines rainfall data engineering geological mapping infiltration modelling and anthropogenic and geomorphic aspects the association between the geological geotechnical units defined by the engineering geological mapping and the land use types generated 29 different infiltration condition categories which were used to divide the basin into 94 territorial units the in situ infiltration test and geotechnical data for each infiltration condition category combined with several rainfall event types were used as inputs to the philip model to obtain the values of the rpot and infiltration values the rpot and infiltration values estimated by the proposed procedure agreed well with the values estimated by the chu model the 94 territorial units were grouped into 4 classes based on the variability and magnitude of the potential hortonian overland flow the first class represents the areas where infiltration predominates 59 km2 for all selected rainfall events and the second class represents areas of infiltration and flooding 11 km2 infiltration is predominant in the third class however overland flow can be generated 133 km2 depending on the intensity and duration of the rainfall event the fourth class represents the main source areas of overland flow generation and runoff 40 km2 the areas considered in the third and fourth classes are affected by erosion processes due to the potential generation of hortonian overland flow the results indicated that the proposed procedure is adequate for identifying characterizing classifying and dividing a region into units with distinct geological and geotechnical zones that are associated with potential hortonian overland flow therefore the procedure is an appropriate tool for regional planning and water management at the 1 50 000 scale because the results define land units with specific environmental characteristics the application of the procedure is not expensive and uses common equipment but requires experienced or trained professionals to perform the field and laboratory work

review of the status and mass changes of himalayan karakoram glaciers we present a comprehensive review of the status and changes in glacier length since the 1850s area and mass since the 1960s along the himalayan karakoram hk region and their climate change context a quantitative reliability classification of the field based mass balance series is developed glaciological mass balances agree better with remotely sensed balances when we make an objective systematic exclusion of likely flawed mass balance series the himalayan mean glaciological mass budget was similar to the global average until 2000 and likely less negative after 2000 mass wastage in the himalaya resulted in increasing debris cover the growth of glacial lakes and possibly decreasing ice velocities geodetic measurements indicate nearly balanced mass budgets for karakoram glaciers since the 1970s consistent with the unchanged extent of supraglacial debris cover himalayan glaciers seem to be sensitive to precipitation partly through the albedo feedback on the short wave radiation balance melt contributions from hk glaciers should increase until 2050 and then decrease though a wide range of present day area and volume estimates propagates large uncertainties in the future runoff this review reflects an increasing understanding of hk glaciers and highlights the remaining challenges

illite smectite formation and potassium mass transfer during burial diagenesis of mudrocks a study from the texas gulf coast paleocene eocene abstract mudrock samples from a well penetrating eocene and paleocene strata 1235 4455 m of the texas gulf coast have been studied to assess geochemical redistribution in mudrocks during burial diagenesis and the mechanism by which detrital smectitic illite smectite i s is transformed into diagenetic illitic i s idealized smectite and illite end member compositions for interstratified i s are estimated to be k0 00x 10 56mg0 39fe0 57al1 13si3 90o10 oh 2 and k0 53x 10 18mg0 17fe0 16al2 28 si3 40o10 oh 2 respectively there is no obvious difference in the amount of k addition to i s in random and ordered interstratified i s aluminum substitution into both tetrahedral and octahedral sites suggests that the smectite to illite reaction is a complete dissolution precipitation reaction rather than a solid state k 1 al 3 for si 4 substitution reaction depth relat d mineral trends and mass balance calculations suggest that illitic i s may form from kaolinite and possibly illite or mica as well as from smectitic i s although most whole rock element abundances are invariant over the sampled depth interval k2o content increases from ca 2 0 weight percent at 1500 m of burial to ca 3 8 weight percent at 4000 m some of this increase is probably caused by import of k into the shale via fluids derived from interbedded sandstones implying that gulf coast mudrocks behave as open chemical systems during burial diagenesis if this is the case a minimum of 103 pore volumes of fluid must have passed through the most k enriched shales to have introduced the added potassium provided that the k content of present day formation water is representative of that of ancient formation water

geochemistry and tectonic setting of lewisian clastic metasediments from the early proterozoic loch maree group of gairloch nw scotland abstract the early proterozoic 2 0 ga loch maree group lmg of the lewisian complex consists of a supracrustal sequence of metasedimentary schists and associated tholeiitic metavolcanic amphibolites within the archaean basement the metasediments comprise three main mapped units the flowerdale schists kerrysdale schists and charlestown schists together with numerous narrower bands the dominant clastic metasediments within the schist units semipelites and psammites are chemically distinguished as a series of greywackes and lithic sandstones with variable lil and transition element abundances fractionated ree patterns and overall compositions similar to paas three chemical groups are recognized whose range of composition largely reflects the mixing between two main source components lewisian gneissose basement with an intermediate acid continental crust composition and local rift related amphibolites with a primitive tholeiitic composition which also incorporates components not preserved within the lmg the geochemistry of the clastic metasediments confirms a previous tectonic model for the lmg as an intracontinental extensional rift receiving clastic detritus from the adjacent uplifted basement as well as from internal volcanogenic sources

volcanic sources and diagenetic alteration of permian triassic boundary k bentonites in guizhou province south china abstract terrestrial permian triassic boundary ptb sequences in south china usually contain one to three ash beds k bentonites which provide evidence of a possible trigger for the terrestrial mass extinction and are useful as a distinct marker for correlation of the ptb boundary interval from terrestrial to marine areas here we investigate the clay mineralogy and geochemistry of ash beds in the zhejue and jiucaichong sections representing paludal and lacustrine environments respectively in order to better understand the source s and preservation of these ash beds the two zhejue k bentonites exhibit similar compositions that are distinctly different from that of the jiucaichong k bentonite the former contain mainly clay minerals with minor quartz anatase and lepidocrocite and the clay minerals in these layers are mainly r1 and r3 mixed layer illite smectite i s and well crystallized to poorly crystallized kaolinite whereas the latter consists mainly of r3 i s with minor quartz feldspars and anatase the former have higher cia values 92 2 and 93 8 than the latter 79 4 indicating more intense chemical weathering that may have been related to deposition in a paludal setting with high organic acid concentrations in pore fluids these k bentonites also exhibit differences in major element chemistry mgo and k2o contents are higher at jiucaichong due to lesser weathering intensity and possibly early diagenetic uptake from pore fluids ree chemistry jiucaichong exhibits a larger eu anomaly and nd isotopic compositions zhejue k bentonites have 143nd 144nd ratios of 0 512436 and 0 512400 higher than the 0 512190 ratio for jiucaichong although some of these compositional differences may be related to the dissimilar chemical environments in which diagenesis occurred i e paludal vs lacustrine the differences in eu anomalies and nd isotopic compositions imply heterogeneous volcanic ash sources the source of these k bentonites was probably a continental volcanic arc located on the paleo southern margin of the south china craton within which multiple volcanic vents may have been active concurrently

provenance tectonic setting and age of the sediments of the upper disang formation in the phek district nagaland abstract integrated petrographic and geochemical studies of sandstones and geochemical studies of shales of turbidites from the upper disang formation phek district nagaland have been carried out to determine their provenance weathering conditions and tectonic setting paleomagnetic studies were carried out for magnetostratigraphic purposes studies indicate that most of these sediments were derived from felsic and mafic sources with minor contribution from low to medium grade metamorphic rocks most of the felsic components have been transported from distant sources as evidenced from extensive reworking of grains the most likely source rocks are the granite granite gneiss of the karbi anglong crystalline complex to the west of the study area however the bulk of the sediments have been contributed from nearby basic and ultrabasic sources this would correspond to the fast rising naga ophiolite which probably emerged above sea level during the mid eocene prevailing high temperatures and humid climate caused intense chemical weathering of the source rocks the sediments from the west were transported great distances by turbidity currents into an easterly deepening basin sediments from the nearby east were rapidly dumped on the seafloor causing rapid mixing leading to textural and chemical immaturity paleomagnetic studies endorse published paleontological evidence to indicate that most of the sediments of the upper disang formation were deposited during the late eocene deposition took place in a westward migrating accretionary prism complex in an active margin setting at the convergence of the indian and burma plates this was a rapidly closing basin where anoxic conditions prevailed towards the end of the eocene this basin closed completely with the destruction of the tethyan ocean

groundwater recharge estimation from ephemeral streams case study wadi tabalah saudi arabia estimation of groundwater recharge to an unconfined aquifer is studied using analytical and numerical techniques and results are compared with field observations there is an acute need for such estimation in water balance studies in arid climates and the case study in this paper is for such a region the wetting front movement in the unsaturated zone depends on antecedent soil moisture the ponded water depth and its duration and on the position of the water table and the hydraulic properties of the unsaturated zone a hydraulic connection between the recharge basin and the aquifer is not immediately established because the wetting front is unsaturated a numerical model is applied to estimate recharge in an arid zone wadi and its validity is tested by comparing it with an analytical solution of the equations the calculated recharge values matched the piezometric levels observed at a well site at the edge of the wadi channel the total recharge depths found by integration in the time domain provided a good estimate of the transmitted volume of water per unit length of wadi channel the findings were confirmed by runoff volume measurements at gauging stations located in the basin 1997 john wiley sons ltd

mineralogy geochemistry and genesis of clays interlayered coal seams succession in the neogene lacustrine seyitomer coal deposit kutahya western turkey abstract the seyitomer coal deposit is an important source of energy in turkey this study aims to determine mineralogical geochemical characteristics and genesis of clays associated with coal seams in order to identify their precipitation environment the late miocene pliocene units comprise organic rich shale organic rich marl marl coal seam siltstone and sandstone deposited in a fluvial and lacustrine environment with associated tuff and tuffite in the seyitomer coal deposit serpentinite sandstone organic rich shale and tuffaceous host rocks of the coal deposit are partly to completely argillized and partially carbonate cemented having also stockwork type silica in fill fissures smectite illite and kaolinite are associated with quartz feldspar olivine gypsum and pyrite oriented flaky illite with irregular outlined kaolinite and smectite flakes edging and coating relict feldspar and volcanic glass grains developed by a dissolution precipitation mechanism in an alkaline micro environment during deposition and diagenetic process the occurrence of subrounded microorganisms on resorbed feldspar and the coexistence of smectite illite flakes with organic matter pyrite and siderite indicates that degradation of feldspar and devitrification of volcanic glass is biologically mediated the slight enrichment of heavy rare earth elements hree compared to light rare earth elements lree with a positive eu and ce anomalies reflects fractional crystallization of feldspar and amphibole alteration of feldspar biotite serpentine and volcanic glass resulted in the concentration of al fe mg and k in a stagnant environment and precipitation of beidellitic smectite and illite in an alkaline environment kaolinite precipitated in an acidic open hydrological system an increase in ni co and v v ni ratios in altered units also suggest anoxic and anoxic to dysoxic conditions occurrence of pityosporites microalatus pinus laevigatosporites haardti pityosporites spp polyvestibulopollenites verus alnus compositae and graminae in the seyitomer coal deposit suggest subtropical to warm temperature humid climate during late oligocene middle miocene period association of argillization and silicification with coal microorganisms pyrite and gypsum indicates a swampy environment and partial hydrothermal processes this interpretation is corroborated by the calculated formation temperatures from stable isotope analysis of 30 463 c for smectite and 140 156 c for illite the high 34s isotope values 16 8 33 3 indicate a mixed diagenetic and hydrothermal origin for the sulphide and sulfate minerals

glacier mass balance in the qinghai tibet plateau and its surroundings from the mid 1970s to 2000 based on hexagon kh 9 and srtm dems abstract in the context of global warming glacier changes in the qinghai tibet plateau qtp and its surroundings have attracted a great amount of public attention to date there have been many studies of glacier mass balance across the qtp however given that most of the previous studies have focused on a short observation period 2000 2015 and that long term mass change measurements are available only for some local regions we utilized declassified kh 9 images and 1 arc second shuttle radar topography mission srtm digital elevation models dems to provide the region wide mass balance from the mid 1970s to 2000 for a larger scale including 11 sample regions across the qtp and its surroundings the final results indicate that the glaciers in the northwest of the qtp have shown a less negative or near zero mass balance ranging from 0 11 0 13 m w e a 1 to 0 02 0 10 m w e a 1 compared to those in the southeast part with a mass balance range of 0 30 0 12 m w e a 1 to 0 11 0 14 m w e a 1 the most serious mass loss has emerged in the central eastern himalaya integrating our results with the observations after 2000 suggests that over the past four decades mid 1970s to the mid 2010s the glaciers in the himalaya nyainqentanglha and tanggula mountains as a whole have exhibited accelerated mass loss and the most significant acceleration has occurred in the eastern nyainqentanglha moreover the hindu raj glaciers have shown a stable rate of continuous mass loss while a nearly stable or slight mass gain state in the western kunlun region can be dated back to at least as far as the mid 1970s

different isotopic evolutionary trends of δ34s and δ18o compositions of dissolved sulfate in an anaerobic deltaic aquifer system abstract concentration and isotope ratios 34sso4 and 18oso4 of dissolved sulfate of groundwater were analyzed in a very large anaerobic aquifer system under the lower central plain lcp 25 000 km2 in thailand groundwater samples were collected in two different kinds of aquifers type 1 with a saline water contribution and type 2 lateritic aquifers with no saline water contribution two different isotopic compositional trends were observed in type 1 aquifers sulfate isotope ratios range from low values 2 2 for 34sso4 and 8 0 for 18oso4 to high values 49 9 for 34sso4 and 17 9 for 18oso4 in type 2 aquifers sulfate isotope ratios range from low values 0 1 for 34sso4 and 12 2 for 18oso4 to high 18oso4 ratios 18 4 but with low 34sso4 ratios

model for prediction of organic carbon content in possible source rocks abstract a quantitative model has been developed to improve the prediction of the occurrence of marine siliciclastic source rocks and their likely organic carbon content the input parameters of this quantitative model are organic matter supply in the surface layer of the ocean photic zone water depth calculation of the carbon flux sedimentation rate and preservation conditions presence or absence of oxygen at the sediment water interface to handle the difficulties in the quantification of input parameters a probabilistic approach is applied depending on the available data or the interpretation of the kind of environment different risk distribution functions are used to describe the possible range of each input parameter the calculation is then carried out using the monte carlo simulation technique resulting in a probability distribution of the total organic carbon content which forms the basis of the analysis different scenarios currently under debate e g high primary productivity or the possible effects of enhanced preservation under anoxic bottom water conditions and the influence of varying water depth and sedimentation rate can be tested very quickly using examples of recent peru continental margin and ancient lower toarcian shale germany organic rich marine shales the potential of this tool is demonstrated firstly to quantify souce rock quality in this case total organic carbon content only secondly to assess quantitatively the uncertainties in source rock prediction e g evaluation of organic matter supply water depth and sedimentation rates and thirdly to determine source quality risk values to be used in the appraisal of sedimentary basins and prospects

controls on bacterial sulphate reduction in a dual porosity aquifer system the lincolnshire limestone aquifer england abstract chemical and sulphur isotopic analyses are presented of fissure waters and pore waters in the deep confined zone of a dual porosity carbonate aquifer some of the fissure waters show good evidence for bacterial sulphate reduction with low concentrations of sulphide present which is strongly to moderately depleted in 34 s relative to sulphate the sulphur geochemistry is best interpreted as mixing between i a reduced water with sulphide 60 depleted in 34 s relative to sulphate and ii a sulphate rich water from up dip in the aquifer in addition sulphide oxidation occurs where sufficiently oxidizing water is drawn in by abstractions the large isotope fractionation factor associated with the sulphidic waters is probably the result of redox cycling of sulphur with little net reduction rather than a true kinetic fractionation factor by contrast pore waters in the sulphate reducing zone show little or no evidence for the effects of sulphate reduction despite the fact that the pore waters represent a significant reservoir of sulphate for reduction some pore waters have been modified recognizably by diffusional exchange with the fissure waters but the aquifer matrix has not been colonized by sulphate reducing bacteria probably because porethroats in the limestone are too small for bacteria to pass physical exclusion of bacteria from the aquifer matrix and limited diffusional exchange are likely to exert fundamental controls on bacterial redox processes in dual porosity aquifer systems and other systems with low permeability due to small pore interconnections

using isotope fractionation of nitrate nitrogen and nitrate oxygen for evaluation of microbial denitrification in a sandy aquifer the nitrate input into the groundwater from forest and agricultural land in the fuhrberger feld catchment area is virtually completely degraded by microbial denitrification in the aquifer five multilevel groundwater sampling wells show characteristic depth functions of nitrate proving the denitrification process a series of 10 samples of arable land groundwater was taken from different depths at these multilevel wells and isotope ratios of 15n14n and 18o16o in the nitrate were measured the sampling was based on the two dimensional vertical plane groundwater flownet and on the knowledge of the landuse upgradient of the multilevel wells high nitrate concentrations are associated with low 15n and low 18o values and vice versa the 15n 18o ratio indicates a linear increase with a slope of 1 2 1 the microbial dentrification accords with a rayleigh process with calculated enrichment factors of e 15 9 for 15n and e 8 0 for 18o three samples taken from groundwater recharged under coniferous forest show deviating characteristics low nitrate concentrations with low 15n values 1 4 but very high 18o values 40 50 using the previously quantified enrichment factors for 15n and 18o an attempt was made to ascertain the significance of denitrification in specific depth sections at two other multilevel wells 7 samples in two cases quantitative assessments on the degree of nitrate concentration decrease owing to denitrification were possible however in other cases the specific nitrate isotope fractionation was masked by the variability of nitrate concentration and of nitrate isotope ratios in the corresponding groundwater recharge preventing definite interpretations

sulfur and oxygen isotope studies of melt country rock interaction babbitt cu ni deposit duluth complex minnesota the babbitt cu ni deposit formerly known as minnamax occurs within troctolitic and gabbroic rocks of the precambrian duluth complex both massive and disseminated mineralizations are found in the deposit pyrrhotite cubanite chalcopyrite and minor pentlandite mineralization occurs near the basal contact with pelitic metasedimentary rocks of the virginia formation or higher in the igneous sequence associated with abundant country rock xenoliths cloud zones sulfur and oxygen isotope studies have been carried out to evaluate the importance of melt country rock interaction in localizing sulfide mineralization the delta 34 s values of pyrrhotite plus pyrite from the virginia formation located outside the contact aureole range from 5 6 to 13 7 per mil pyrrhotite from footwall virginia formation hornfels or inclusions in the basal zone exhibits delta 34 s values ranging from 1 5 to 6 2 per mil whereas delta 34 s values of pyrrhotite from xenoliths in cloud zones range from 2 6 to 21 4 per mil isotopic values of basal zone cu ni sulfides range from 6 0 to 13 0 per mil with a mode at 8 to 9 per mil two features highlight basal zone delta 34 s values first delta 34 s values of sulfide mineralization are higher than those of pyrrhotite in immediately adjacent virginia formation hornfels second higher grade ore areas 1 cu show 34 s enrichment with delta 34 s values in the range of 9 to 13 per mil sulfides in cloud zones show a wide range in delta 34 s values from 0 7 to 19 7 per mil sulfur isotope data suggest that most of the sulfur found in the deposit has been derived from sedimentary country rocks however an in situ process of sulfur derivation is not indicated sulfur in basal mineralized zones must have been derived at depth within an auxiliary magma chamber or during magma ascent and emplacement isotopic homogenization was not achieved during the sulfide forming process as evidenced by the spatial variability of delta 34 s values oxygen isotope values of both mildly metamorphosed virginia formation and footwall hornfels range from 8 2 to 14 0 per mil inclusions of virginia formation show pronounced isotopic effects due to interaction with melt xenolith margins may have values as low as 7 to 8 per mil and are depleted in 18 o with respect to xenolith interiors the delta 18 o values of igneous rocks from the babbitt deposit range from 3 9 to 12 2 per mil zones of 18 o depletion are rare and suggest that exchange with a low 18 o fluid phase was spatially restricted anomalous delta 18 o values in excess of 7 to 7 5 per mil are common throughout the deposit but are limited to within 3 m of virginia formation xenoliths a model of diffusion controlled 18 exchange between igneous material and xenoliths best describes the delta 18 o distribution devolatilization and desilicification of the xenoliths occurred early in their history when physical mixing in the host magma was possible addition of high 18 o material from these processes into a large volume of melt affected delta 18 o distributions only slightly continued exchange of oxygen after major cation transfer produced the observed delta 18 o profiles in the case of basal zone cu ni mineralization at babbitt isotopic evidence indicates that sulfide saturation was not caused by in situ addition of sulfur silica or oxygen sulfide saturation is thought to have been achieved at depth triggered by assimilation of large quantities of sulfide liberated through devolatilization reactions occurring in country rocks

alluvial sandstone composition and paleoclimate i framework mineralogy abstract systematic variations in compositional maturity of first cycle fluvial sandstones are found in the cutler formation permian and fountain formation permian pennsylvanian in colorado and in the gondwana supergroup permian triassic of peninsular india these variations reflect changing climate during deposition climate is considered to be the critical factor affecting maturity because source rocks granite granite gneiss and tectono environmental setting alluvial systems associated with basement cored block uplifts were similar and remained relatively unchanged throughout deposition of all three of the units the roughly 3 200 m thick gondwana succession consisting of five sandstone petrofacies is characterized by the following sequence of change oldest to youngest in compositional maturity expressed in q f r percentages 54 42 4 88 10 2 62 34 4 82 16 2 99 1 0 this sequence is a function of the changing paleoclimate glacial arid temperate humid warm semiarid warm semihumid warm humid associated with the overall global limatic change and the changing latitudinal location of india as it moved from a location close to the south pole northward during the interval of time represented by gondwana deposition lithologic and fossil evidence indicates that during deposition of the fountain formation climate gradually changed from relatively wet and warm to at least semiarid and warm this climatic change is the main factor responsible for the difference in compositional maturity of the older fountain sandstone q f r 65 26 9 relative to the younger q f r 54 36 10 cutler sandstone was deposited in an arid climate and has maximum compositional immaturity q f r 49 44 7 a log log plot of the ratio of total quartz to total feldspar plus rock fragments against the ratio of total polycrystalline quartz to to al feldspar plus rock fragments is a sensitive discriminator of first cycle sandstones with differing climatic heritage bulk chemical composition data support interpretation of climate from framework mineralogy but by themselves are not sensitive enough to be unequivocal indicators the same is true for the ztr index and observations of degree and abundance of solution pits embayments on detrital quartz results of this study support the conclusion of earlier empirical and theoretical analyses which suggest that the optimum conditions for the production and preservation of a distinctive climatic signature on sand composition are met in extensional plate tectonic settings such settings are characterized by coarse grained crystalline parent rocks short transport distances in low order streams deposition in nonroutine environments and shallow burial diagenesis however even in such optimum settings only rarely will climate be a more important determinant of sandstone composition than the tectonic setting itself

dominant control of the south asian monsoon by orographic insulation versus plateau heating heat emitted from the tibetan plateau as dry heat and water vapour has long been assumed to be the main driver of the south asian summer monsoon but new work suggests that in fact it is the neighbouring mountains that are the major influence william boos and zhiming kuang use an atmospheric model to show that flattening the tibetan plateau has little effect on the monsoon so long as the himalayas and surrounding mountain ranges remain the plateau does boost rainfall locally along its southern edge but it is the build up of hot moist air over india insulated from colder drier air by the himalayas that drives large scale monsoon circulation the elevation of the tibetan plateau is thought to cause its surface to serve as a heat source that drives the south asian summer monsoon potentially coupling uplift of the plateau to climate changes on geologic timescales here however an atmospheric model is used to show that flattening of the tibetan plateau has little effect on the monsoon provided that the narrow orography of the himalayas and adjacent mountain ranges is preserved the tibetan plateau like any landmass emits energy into the atmosphere in the form of dry heat and water vapour but its mean surface elevation is more than 5 km above sea level this elevation is widely held to cause the plateau to serve as a heat source that drives the south asian summer monsoon potentially coupling uplift of the plateau to climate changes on geologic timescales1 2 3 4 5 observations of the present climate however do not clearly establish the tibetan plateau as the dominant thermal forcing in the region peak upper tropospheric temperatures during boreal summer are located over continental india south of the plateau here we show that although tibetan plateau heating locally enhances rainfall along its southern edge in an atmospheric model the large scale south asian summer monsoon circulation is otherwise unaffected by removal of the plateau provided that the narrow orography of the himalayas and adjacent mountain ranges is preserved additional observational and model results suggest that these mountains produce a strong monsoon by insulating warm moist air over continental india from the cold and dry extratropics these results call for both a reinterpretation of how south asian climate may have responded to orographic uplift and a re evaluation of how this climate may respond to modified land surface and radiative forcings in coming decades

recharge from an ephemeral stream following wetting front arrival to water table after the infiltration wetting front from a river bed of an ephemeral stream in flood reaches the shallow water table the rate of recharge which is also that of infiltration is affected by the development of a groundwater mound the effect is practically immediate if the water content behind the wetting front is close to saturation an approximate analytical solution is developed in that case which predicts the time dependence of the recharge rate comparison with experimental results in the laboratory shows that the solution is excellent in spite of the assumptions necessary in the derivations as long as the ratio of river width over depth to water table exceeds 2 and as long as the ratio of initial saturated thickness over depth to the water table exceeds 2 5 the analytical solution is essentially exact under most field conditions these ratios are largely exceeded consequently the predictive equation for the time dependence of the recharge is both quite simple to use and adequately accurate for field applications

precipitation gradients during the miocene in western and central turkey as quantified from pollen data abstract in the present paper we have analyzed thirty five palynofloras covering the time span from the early miocene aquitanian to the late miocene middle tortonian in turkey the results obtained are presented in tables and maps showing temporal palaeoprecipitation values the mean annual precipitation map exceeds 1200 mm during the aquitanian and early middle serravallian it is suggested to have been between 1000 and 1300 mm in the latest serravallian earliest tortonian in western and central turkey in the early middle tortonian the lower boundary of map decreases to below 1000 mm in central and eastern turkey today maps are represented by lower values around 600 1000 mm in western and 400 600 mm in central turkey for the driest month lmp the rainfall was not distributed homogeneously in the aquitanian the calculations are between 36 and 48 mm with humid conditions in western and eastern turkey during the burdigalian and middle miocene the driest month precipitation varied with respect to locations however it is clear that there was a reduction in precipitation during the early middle tortonian with values around 26 27 mm in central and eastern turkey the same pattern is observed for the wettest month precipitation hmp with estimates higher than 200 mm during the aquitanian and earliest tortonian although some areas received low rainfall hmp was reduced between 130 and 140 mm in the early middle tortonian the warmest month precipitation wmp varied from 96 to 140 mm except for konya ilgin kirsehir hacibektas and manisa soma that received 88 mm during the early middle miocene in the early middle tortonian the amount of summer rainfall lay between 58 and 88 mm the reason of the decrease in all rainfall parameters during the early middle tortonian could be related to several factors such as climatic cooling altitude aridification palaeotopograhy or continentality however it is necessary to indicate that the tortonian cooling had previously been proposed by akgun et al 2007 as the explanation using a large number of palynological assemblages in turkey we also observe a decrease in precipitation parameters during the middle miocene this could be related to fact that either low species diversity can result in wide coexistence intervals or the monterey cooling event was related to a cooling during the langhian and serravallian

sulfur isotopic studies of continental flood basalts in the noril sk region implications for the association between lavas and ore bearing intrusions previous studies of both ore and non ore bearing intrusives in the permo triassic flood basalts of the siberian platform in the noril sk area have shown that high grade ni cu platinum group elements pge mineralization is associated with anomalously high 34s values of 8 to 12 in addition several researchers have proposed that observed depletions in the cu ni and pge content of basaltic lavas of the nadezhdinsky nd formation are related to diffusional exchange with and upgrading in metal tenor of sulfides in the volcanic conduit system sulfur isotopic studies of the lavas at noril sk were initiated to determine if interaction with crustally derived sulfur in the conduit system was evident and if the nd lavas in particular were characterized by an anomalous isotopic signature 34s values of the lavas range from 4 5 to 8 7 vienna canon diablo troilite vcdt with s concentrations from 40 to 1373 ppm the majority of 34s values range from 0 to 4 and are similar to those from s poor intrusions in the noril sk area although textural data are not supportive of early sulfide saturation and the presence of immiscible sulfide droplets in the lavas recrystallization may have erased expected mineralogical and textural evidence mineralogical data indicate that hydrothermal alteration of the lavas has occurred but s redistribution has been restricted to localized areas and 34s values have not been affected the relatively low s concentrations of the lavas are thought to be due in large part to degassing of the lavas in the shallow conduit system and during eruption our calculations are consistent with the premise that degassing of basaltic magmas at temperatures in excess of 900 c at qfm leads to only minor 34s depletion of sulfur remaining in the melt and decreases in 34s values of less than 2 at 90 degassing for this reason all lavas with 34s values in excess of 2 require a contribution of 34s enriched country rock sulfur because of the high s content and 34s value 16 20 of evaporites in the country rocks at noril sk contamination of less than 0 5 is required to explain the most 34s enriched lavas the nd lavas have an average 34s of 2 9 but show no difference in s isotopic composition relative to the other lavas suggesting that metal depletion involved only limited s transfer or that exchange between mantle derived s and s of crustal origin buffered 34s values to less than 5 anomalously positive 34s values similar to those of the ore bearing intrusives in the noril sk region are not consistently found in low s rocks either lavas or intrusives although the mechanism for the derivation of sulfide in the ore bearing intrusions remain speculative it is clear that the formation of sulfide ores characterized by high metal tenors proceeded only in the presence of sulfur of crustal origin

a reconciled estimate of glacier contributions to sea level rise 2003 to 2009 glaciers distinct from the greenland and antarctic ice sheets are losing large amounts of water to the world s oceans however estimates of their contribution to sea level rise disagree we provide a consensus estimate by standardizing existing and creating new mass budget estimates from satellite gravimetry and altimetry and from local glaciological records in many regions local measurements are more negative than satellite based estimates all regions lost mass during 2003 2009 with the largest losses from arctic canada alaska coastal greenland the southern andes and high mountain asia but there was little loss from glaciers in antarctica over this period the global mass budget was 259 28 gigatons per year equivalent to the combined loss from both ice sheets and accounting for 29 13 of the observed sea level rise

stratigraphy and holocene evolution of the mud dominated chao phraya delta thailand abstract the central plain of thailand was formed over the last 8 7 kyr mainly by the deltaic processes of two major rivers the chao phraya and the mae klong the delta plain is the third largest delta plain in southeast asia after that of the mekong and the irrawaddy on the basis of sedimentological and paleontological analyses of samples from three boreholes and an open pit survey the evolution of the delta was clarified with high resolution 14 c dating after the maximum transgression at between 8 and 7 cal kyr bp the delta system migrated southward into the paleo gulf of ayutthaya a large mud shoal the sananivate mud shoal formed near the mouth of the paleo gulf between 7 and 3 cal kyr bp and facilitated its infilling as a result the delta has prograded rapidly particularly during the last 2 kyr deltaic sediment volume for the last 7 5 0 5 kyr shows that the average rate of sedimentation was 23 1 3 6 million t yr which is nearly the same as the present total sediment discharge from both rivers the comparatively wide delta plain relative to sediment discharge resulted from the stable sea level the shallow paleo gulf acting as a receiving basin and effective sediment trapping because of the mud shoal

geochemistry of rare elements in waters and sediments of alkaline lakes in the sasykkul depression east pamirs abstract the saline lakes tuzkul chukurkul sasykkul lakes of the sasykkul depression located in the semidesert part of the pamirs provide a prominent example of the evaporative concentration of alkaline waters in a closed basin under arid climate conditions chemical evolution of the lake waters has resulted in the development of residual na cl co3 so4 and na cl co3 brines the contents of a number of rare elements were determined in waters and sediments of the sasykkul depression lakes speciation modelling suggests that the main aqueous species of ag are chloride complexes cu pb zn mn are carbonate complexes be bi nb are hydroxocomplexes mo w as v are oxyanions it was established that the salt lake sediments are significantly enriched in b ba mo w u th high contents of trace elements are considered to be due to chemical weathering of rocks within the catchment basin significant contribution from thermal springs derived from the residual fluids associated with acid igneous and volcanic rocks and following evapoconcentration in a closed basin the processes of evaporative concentration solution complexation chemical precipitation and water sediment interaction lead to the partitioning of trace metals in the salt sediments

occurrence and genesis of tonsteins in the miocene lignite tuncbilek basin kutahya western turkey abstract abundant beige and white kaolinite claystone layers 2 50 cm thick from the tuncbilek basin have the characteristics of tonsteins the aim of this study was to determine the mode of formation of the tonsteins together with their mineralogical and geochemical characteristics in order to identify their environment of deposition the miocene lacustrine units in the tuncbilek lignite deposit associated with tuff and tuffite are comprised of organic rich shale organic rich marl marl claystone silty claystone siltstone sandstone coal seam and conglomerate deposited in a fluvial and lacustrine environment sanidine plagioclase biotite and chlorite are partly to completely argillized and enclosed in an authigenic clay matrix in the rhyolitic to rhyodacitic tuff tuffite sandstone organic rich shale and serpentinite host rocks of the clay deposit abundant kaolinite and quartz are associated with smectite illite feldspar calcite dolomite siderite pyrite barite and gypsum development of oriented 7 a halloysite tubes on in altered volcanogenic materials associated with kaolinite and the occurrence of vermiform kaolinite edging disordered kaolinite locally siderite and pyrite crystals may suggest formation of halloysite following kaolinite the reaction pathway is volcanic glass feldspar muscovite biotite 7 a halloysite kaolinite the slight enrichment of light rare earth elements lree compared to heavy rare earth elements hree with positive eu anomalies based on upper continental crust ucc normalized values reflects fractional crystallization of feldspar and amphibole in the parent volcanic rocks and organic rich shale alteration of feldspar biotite and volcanic glass resulted in the concentration of al si fe mg and k and precipitation of kaolinite in an acidic open hydrological system while in a stagnant and alkaline environment smectite and illite are the alteration products the al2o3 tio2 and low cr ni ratios suggest felsic parent rocks the trace elements ratios such as ni co v cr cu zn and u th among the basement complex source rocks units also suggest oxic suboxic and anoxic conditions the occurrence of pinus alnus quercus alnus carya taxodiaceae and myrica palymorphs reflect a subtropical to warm temperature humid climate low elevations and swamp vegetation condition during the early middle miocene period in the study area association of argillization and silicification with coal pyrite and gypsum indicates a swampy environment and hydrothermal processes this interpretation is corroborated by the calculated formation temperatures from stable isotope analysis of 148 8 168 c for kaolinite and 145 169 2 c for smectite the low s isotope values of pyrite 19 to 2 9 and high positive values of gypsum 11 5 21 7 indicate a mixed diagenetic and hydrothermal origin for the sulfide and sulfate mineral

ophiolitic source rocks for taconic age flysch trace element evidence flysch generated along the appalachian orogen during the ordovician taconic orogeny ranges in age from late arenig to early caradoc allochthonous flysch and from late llanvirn to ashgill autochthonous flysch sandstones in these units are dominantly lithic arenites with a heavy mineral suite containing common to abundant mg rich chromite north of the canada united states border the only reasonable sources for the chromite were the lower ultramafic units of obducted ophiolites trace element analyses cr ni v cu ti zr y of flysch sandstones indicate a striking increase in cr and ni concentrations from the united states appalachians to the canadian appalachians in the united states units cr is in the range of 10 to 50 ppm canadian flysch units average an order of magnitude more cr these results suggest that ophiolite obduction either did not occur or was of minor importance during the taconic orogeny in the united states appalachians the difference in ophiolite abundance between the canadian and united states appalachians suggests a fundamental difference in tectonic style along the orogen a feature that must be accommodated by plate tectonic models new models will probably need to consider both obliquity of subduction and geological complexity of the ordovician collision zone in order to explain the spatial distribution of obducted ophiolite sheets

tracing a confined groundwater flow system under the pressure of excessive groundwater use in the lower central plain thailand excessive groundwater pumping from deep wells in the bangkok metropolitan area bma since the 1950s has induced piezometric drawdown land subsidence and probably remarkable disturbance in confined groundwater flow to trace the large scale groundwater flow system in the lower central plain lcp of thailand and to detect its disturbance we carried out isotopic and hydro chemical investigations of surface subsurface waters as well as hydrometric measurements at 98 observation wells isotopic compositions of the water d and 18o reflected significant seawater mixing and evaporative enrichment the cl br mass ratio suggested that halite dissolution is negligible and spatial distributions of and cl concentration implied that saline water is mainly remnant seawater in addition the cl relationship indicated that the remnant seawater may have been concentrated in part by transpiration from mangrove forests during delta formation after a period of maximum transgression the original d of the source water was estimated by correcting for the effects of seawater mixing and evaporative enrichment using the cl concentration and 18o respectively and its three dimensional distribution revealed that the water originating from precipitation over the lcp during the post glacial age was drawn down to a maximum depth of 240 m by groundwater pumping at two large depressions in the east and west of the bma water recharged during the last glacial age and or originating at higher elevations outside the lcp is drawn from suburban areas laterally or through underlying aquifers in contrast in the central bma groundwater within major productive aquifers is mainly replenished by downward leakage across confining layers copyright 2011 john wiley sons ltd

s and o isotopic character of dissolved sulphate in the cover rock aquifers of a zechstein salt dome abstract sulfur and o isotope analyses of dissolved so4 were used to constrain a hydrogeological model for the area overlying the gorleben rambow salt structure northern germany samples were collected from 80 wells screened at different depth intervals the study area consists of a set of two vertically stacked aquifer systems generally the isotope data show a good spatial correlation outlining well defined groundwater zones containing so4 of characteristic isotopic composition highly saline waters from deeper parts of the lower aquifer system are characterized by rather constant so4 isotopic compositions which are typical of permian zechstein evaporites 34s 9 6 11 9 18o 9 5 12 1 above this is a transition zone containing ground waters of intermediate salinity and slightly higher isotopic values average 34s 16 6 18o 15 3 the confined groundwater horizon on the top of the lower aquifer system below the low permeable hamburg clays is low in total dissolved solids and is characterized by an extreme 34s enrichment average 34s 39 1 18o 18 4 suggesting that bacterially mediated so4 reduction is a dominant geochemical process in this zone two areas of distinct isotopic composition can be identified in the shallow ground water horizons of the upper hydrogeological system sulfate in groundwaters adjacent to the river elbe and locknitz has a typical meteoric isotopic signature 34s 5 2 18o 8 2 whereas the central part of the area is characterized by more elevated isotopic ratios 34s 12 7 18o 15 6 the two major so4 pools in the area are represented by permian seawater so4 and a so4 of meteoric origin that has been mixed with so4 resulting from the oxidation of pyrite it is suggested that the s isotope compositions observed reflect the nature of the so4 source that have been modified to various extent by bacterial so4 reduction groundwaters with transitional salinity have resulted from mixing between brines and low mineralized waters affected by bacterial so4 reduction

the geology mineralogy petrography and geochemistry of the miocene dursunbey coal within fluvio lacustrine deposits balikesir western turkey abstract the dursunbey coalfield a typical example of coalfields in the western anatolia hosts a mineable coal seam about 9 0 m coal thickness with altered tuff layers within early miocene fluvio lacustrine sequences the aim of this study is to identify peat accumulation conditions and factors controlling the mineralogy and geochemistry of this seam the standard coal features and petrographical mineralogical and elemental compositions display changes throughout the seam ash yields display decreasing trends towards to the upper parts of seam while total c contents and gross calorific values are increasing furthermore the coal facies patterns evidence changes of depositional conditions and vegetation in the palaeomires during initial stages of peat accumulation the contribution of herbaceous peat forming plants were more common and palaeomires were open to detrital inputs whereas woody peat forming were becoming predominant and the water table was stable and high which caused development of anoxic conditions during late stages therefore the content of detrital minerals such as quartz and clay minerals illite smectite and chlorite increases in the lower parts of seam while that of pyrite increases in the upper parts in addition the sem edx data show that matrices of clay mineral aggregates are illitic in composition in the lower parts of seam while those of smectite prevalence are more common below and above altered tuff layers interestingly authigenic rhomboid k feldspar grains are observed within smectite clay aggregates in the samples from the upper parts of seam framboidal pyrite grains and clusters were also commonly identified from these samples as well this data shows that synchronous volcanic inputs were altered within a hydrologically closed system under slight acidic to neutral conditions during late syngenetic stages the enriched elements such as cr ni cs and v display moderate to strong positive correlations with ash yields while al2o3 and k2o indicate an aluminosilicate affinity clay mineral and feldspar considering the presence of metamorphic and ophiolitic rocks in the basement and the adjacent areas clastic inputs into the palaeomire seems to be controlling aluminosilicate affiliated elements additionally the sem edx analyses denoted that ni and as are associated with pyrite the ni and as bearing epigenetic pyrite infillings are mostly identified in coal samples below altered tuff layers hence as and ni enrichments are controlled by precipitation of leached pore waters from altered tuff layers nevertheless as and ni bearing syngenetic pyrite grains and clusters are related with the development of anoxic conditions within palaeomires this could also favour a mo and u enrichment which is another testimony for synchronous volcanic inputs altered under anoxic conditions overall high detrital input ratios from adjacent areas during initial stages of peat accumulation in the study area controlled by enrichments of aluminosilicate affiliated elements whereas during late stages of peat accumulation the development of a hydrologically closed system and redox conditions within the palaeomire caused as ni mo and u enrichments and the formation of smectite and authigenic k feldspars

a 5 year record of surface energy and mass balance from the ablation zone of storbreen norway a 5 year record of data from an automatic weather station aws operating in the ablation zone of storbreen norway has been used to calculate the local surface energy and mass balance the aws observations cover five mass balance years with an unusually strong mass deficit on storbreen the average energy flux q contributing to melt for the period 2001 06 is 113wm 2 of this the net shortwave radiation flux is the dominant contributor 92wm 2 followed by the sensible heat flux 20 wm 2 and the latent heat flux 9 w m 2 the net longwave radiation 6w m 2 and the subsurface heat flux 2 w m 2 contribute negatively to the budget net radiation thus produces 76 of the melt while the turbulent fluxes and the subsurface heat flux produce 24 of the total melt the seasonal mean incoming shortwave radiation is remarkably constant between the years whereas variations in temperature and reflected shortwave radiation albedo explain most of the interannual variation in melt the modelled ablation compares well with the measured ablation from stake readings the sensitivity of the energy balance model was examined by varying the surface roughness length of momentum and the sensitivity of the calculated melt by perturbations of temperature wind speed and relative humidity

petrographic properties of major coal seams in turkey and their formation abstract most types of coal in turkey are generally low in rank lignite and subbituminous most of the coal was formed during the miocene eocene and pliocene ages there are only a few thin jurassic age coal occurrences in turkey pennsylvanian age bituminous coal is found on the black sea coast general implications of the petrographic properties of turkey s coal seams and coal deposits have not yet been taken into consideration comparatively or as a whole for this study about 190 channel samples were collected from different locales the composite profile samples of the seams were taken into considerations the content and depositional properties as well as some chemical and physical properties of the main coal seams are compared all coal samples tend to have similar coal petrographic properties and were deposited in intermontane lacustrine basins later they were affected by faulting and post depositional volcanic activity as a result there are variations in the properties and rank of the coal samples the most abundant coal maceral group is huminite and the most abundant maceral is gelinite the liptinite and inertinite contents of the coal are low and the maceral contents of the coals show great similarity the depositional environments of the all coals are lacustrine dominated

factors controlling the trace element distribution in fine grained rocks the albian kaolinite rich deposits of the oliete basin ne spain abstract this paper combines mineralogical data x ray diffraction petrographic and scanning electron microscopy techniques and geochemical analyses in order to investigate the composition of a set of samples claystones siltstones and sandstones which belong to the albian deposits of the oliete basin in spain the aims of the study are to characterize the distribution of major and trace elements in kaolinite rich rocks to infer the role played by accessory phases and clay minerals on the trace element distribution and to assess the source area composition of these materials mineralogical analyses show that these rocks are mainly composed of different proportions of quartz and clay minerals kaolinite and illite with minor feldspar micron accessory minerals such as monazite zircon pyrite marcasite fe oxides and ti oxides have also been detected the sandstone framework implies that the source area of these sediments was probably a granitoid source which underwent low rank metamorphism the major element distribution reflects the mineralogy of the rocks plots in the a cn k diagram as well as their cia values indicate that these sediments were generated from an intensely weathered source area this produced the development of relatively cation poor clays such as kaolinite and claystones with large rare earth elements ree contents the fact that transition element contents in claystones are greater than in siltstones and sandstones suggests that they are preferentially linked to clay minerals probably by surficial sorption in comparison with other lithologies the high abundances of high field strength elements in siltstones imply that accessory minerals such as zircon and nb bearing phases are mainly concentrated in siltstones it should be noted that siltstones are also the lithology which displays the highest ree abundances the statistical analysis of the geochemical data suggests that ree are mainly controlled by ti and nb bearing phases such as titanite and nb and ti oxides although clay minerals are not the main phases in the ree control they probably also have some influence as the analyses show in addition other accessory phases such as monazite secondary phosphates and zircon also contribute to the ree contents although much less than amorphous fe oxides in some samples according to the ree patterns and elemental ratios such as la sc th sc th co etc the source area of the studied outcrops was probably felsic and with intermediate composition between granite and granodiorite

seasonality and interannual variability of the westerly jet in the tibetan plateau region abstract in this study 40 yr ecmwf re analysis era 40 data are used for the description of the seasonal cycle and the interannual variability of the westerly jet in the tibetan plateau region to complement results based on the analysis of monthly mean horizontal wind speeds an occurrence based jet climatology is constructed by identifying the locations of the jet axes at 6 hourly intervals throughout 1958 2001 thus a dataset describing the highly transient and localized features of jet variability is obtained during winter and summer the westerly jet is located respectively to the south and north of the tibetan plateau during the spring and autumn seasons there are jet transitions from south to north and vice versa the median dates for these transitions are 28 april and 12 october the spring transition is associated with large interannual variations while the fall transition occurs more reliably within a 3 week period the strength of the jet exhibits a peculiar seasonal cycle during northw

use of isotope fractionation of sulfate sulfur and sulfate oxygen to assess bacterial desulfurication in a sandy aquifer abstract the unconfined aquifer of the fuhrberger feld consists of 20 30m sands and gravelly sands with unevenly distributed reduced sulfur compounds and small lignitic pebbles in vertical direction two hydrochemically different zones with specific solute transformations are present an upper portion with bacterial denitrification with reduced sulfur compounds as electron donors and a deeper portion with hydrochemical indications of reduction of the aqueous sulfate in the study area ten multilevel groundwater sampling wells were installed sampling and interpretation was based on a two dimensional vertical plane groundwater flownet and on the knowledge of the landuse upgradient of the multilevel wells the concentration and isotopic composition of the sulfate at the entrance into the zone of sulfate reduction is controlled by sulfate of groundwater recharge as well as sulfate formed during denitrification the recharge sulfate shows clear landuse specific differences in concentration and isotopic composition under arable land an average concentration of 60 mg so 4 l 1 with values of 34 s close to 3 cdt diablo meteorite standard canon and of 18 o about 8 standard mean ocean water smow was measured whereas under coniferous forest an average of 100 mg so 4 l 1 with 34 s 2 and 18 o 4 5 was found in the denitrification zone no significant sulfur isotope fractionation occurs during oxidation of reduced sulfur the oxygenisotopic composition of the newly formed sulfate denitrification sulfate depends on the 18 o content of nitrate acting as oxygen donor and on the 18 o content of groundwater in which the oxidation occurs under certain assumptions a 18 o 0 54 was calculated for the oxygen of the newly formed sulfate consequently with increasing sulfate concentrations i e with the admixture of denitrification sulfate a decrease of the 18 o values from about 8 to 2 was observed in the zone of sulfate reduction both the 34 s and 18 o values of the residual sulfate increase with decreasing sulfate concentrations thus proving the existence of bacterial reduction of the aqueous sulfate this sulfate reduction follows a rayleigh process with calculated enrichment factors of 34 9 7 for 34 s and 18 6 for 18 o respectively a plot of 34 s vs 18 o gives a good linear correlation with a slope close to 1 1 4 data on concentration and isotopic composition of sulfate and on the hydraulically derived groundwater age are used for kinetic considerations the results of a multilevel well for depths between 10 and 17m are given as an example the bacterial reduction can be considered as first order reaction with a half life between 75 and 100 years

properties of a lacustrine subbituminous k1 seam with special reference to the contact metamorphism soma turkey abstract the subbituminous k1 seam in the middle miocene soma formation of western turkey reaches a thickness of 24 m typical samples on an air dried basis have 9 5 14 2 moisture 4 3 13 8 ash and 0 57 2 54 total sulphur the coal rank parameters and non agglomerating behaviour show that the coals are of subbituminous a rank the k1 seam is huminite rich coal with a mean random ulminite reflectance rr between 0 46 and 0 49 fluorescence emission measurements show that the sporinite cutinite resinite and alginite present have typical fluorescence spectra between 460 and 700 nm the soma formation was intruded by an olivine basalt during the pliocene pleistocene which caused local contact metamorphism at the top of the k1 seam on the basis of proximate ultimate and petrographic analyses the intruded seam can be divided into normal coal transition zone and natural coke intervals each differing in their degree of metamorphism moisture volatile matter hydrogen and oxygen contents very rapidly decrease close to the contact point with the intrusion whilst calorific value carbon content and mean random reflectance value increase a diagram ofo c versus h c also shows a distinct increase in rank caused by the intrusion minor illite siderite and plagioclase feldspar are present in the natural coke samples butpyrrhotite is not observed mineralogical geochemical and reflectance studies indicate that the general temperature during formation of natural coke was probably relatively low

the origin and isotopic composition of dissolved sulfide in groundwater from carbonate aquifers in florida and texas the 34s values of dissolved sulfide and the sulfur isotope fractionations between dissolved sulfide and sulfate species in floridan ground water generally correlate with dissolved sulfate concentrations which are related to flow patterns and residence time within the aquifer the dissolved sulfide derives from the slow in situ biogenic reduction of sulfate dissolved from sedimentary gypsum in the aquifer in areas where the water is oldest the dissolved sulfide has apparently attained isotopic equilibrium with the dissolved sulfate 34s 65 per mil at the temperature 28 c of the system this approach to equilibrium reflects an extremely slow reduction rate of the dissolved sulfate by bacteria this slow rate probably results from very low concentrations of organic matter in the aquifer in the reducing part of the edwards aquifer texas there is a general down gradient increase in both dissolved sulfide and sulfate concentrations but neither the 34s values of sulfide nor the sulfide sulfate isotope fractionation correlates with the ground water flow pattern the dissolved sulfide species appear to be derived primarily from biogenic reduction of sulfate ions whose source is gypsum dissolution although upgradient diffusion of h2s gas from deeper oil field brines may be important in places the sulfur isotope fractionation for sulfide sulfate about 38 per mil is similar to that observed for modern oceanic sediments and probably reflects moderate sulfate reduction in the reducing part of the aquifer owing to the higher temperature and significant amount of organic matter present contributions of isotopically heavy h2s from oil field brines are also possible

glacier mass loss induced the rapid growth of linggo co on the central tibetan plateau remote sensing and gis techniques in conjunction with field investigations show how glacier mass loss has led to the rapid growth of linggo co a glacier fed lake on the central tibetan plateau which has expanded by 21 3 in area between 1974 and 2010 with a lake level rise of 11 2 m the lake volume of linggo co increased at a rate of 0 02 10 6 42 67 10 6 and 65 8 10 6 m 3 a 1 during the periods 1974 92 1992 99 and 1999 2010 respectively other non glacier fed lakes in the vicinity i e longwei co amur co and darngo co ngion shrank considerably from the early 1970s to 1992 and then expanded from 1992 to 2010 despite being in the same climate region linggo co and the non glacier fed lakes have differed in response to climate change the glaciers in the catchment of linggo co retreated by 2 4 in area between 1974 and 2007 and their mean thickness decreased by 6 19 1 91 m between 1974 and 2000 with an associated glacier meltwater runoff of 7 52 2 32 10 8 m 3 the results indicate that glacier mass loss had a significant impact on the growth of linggo co over the past 40 years

short paper ophiolitic detritus in the ordovician sediments of south mayo ireland sandstones from ordovician sediments of the south mayo trough western irish caledonides show marked stratigraphic variation in their major and trace element geochemistry high cr ni and mg concentrations of ultramafic derivation succeed high ti and fe concentrations of mafic provenance this sequence is interpreted as the result of the progressive unroofing of an ophiolite a possible sedimentary linkage with ophiolite lithologies in the clew bay domain to the north would indicate minimal post arenig transcurrent displacement the south mayo flysch with its ophiolitic detritus is typical of caledonian flysch sequences which pre date the mid ordovician taconic deformation but differs in character from those of late ordovician age

geochemical paleoredox indicators in devonian mississippian black shales central appalachian basin usa the degree of anoxia that existed during accumulation of devonian mississippian black shales in central kentucky has been debated widely in this study geochemical data were used to elucidate paleodepositional environments for these units using analyses from ten cores collected from the outcrop belt in central kentucky sulfur carbon and selected trace element relationships were compared the sunbury shale tournasian lower mississippian and the cleveland and huron members of the ohio new albany shale fammenian upper devonian show different relationships between carbon sulfur and trace elements c s fe relationships for the sunbury suggest anoxic possibly even euxinic conditions prevailed during sediment accumulation analysis of c s fe data suggests that the cleveland may have accumulated under anoxic conditions with intermittent dysoxia whereas the huron member may have accumulated under a relatively wide range of conditions from anoxic to dysoxic to possibly oxic these three units exhibit different degrees of trace element enrichment with the approximate order of enrichment relative to an average shale being mo pb zn v ni cu cr co the sunbury shows the highest levels of enrichment followed by the cleveland with the huron showing only slight enrichment for most of these trace elements differing degrees of enrichment may reflect differences in depositional environment during accumulation high mo concentrations in the sunbury generally 200 550 ppm may infer euxinic conditions prevailed during sediment accumulation the cleveland and the huron both show considerably lower mo contents averaging around 100 ppm geochemical ratios including ni co v cr and v v ni also indicate variable paleoredox conditions for these shales based on previously established thresholds v cr and ni co ratios infer at least anoxic conditions during accumulation of the sunbury anoxic to dysoxic conditions during cleveland accumulation and dysoxic to oxic conditions for the huron v v ni ratios tend to indicate consistently lower oxygen regimes than do other paleoredox indicators and this discrepancy is greatest for the huron member it is suggested that thresholds established for paleoredox indicators in previous studies should not be applied strictly but that relative differences in these indicators collectively can infer variations in the degree of anoxia in addition relationships between corg and redox elements may help elucidate the role of anoxia in om accumulation it may be concluded from this study that the devonian mississippian black shales of central kentucky accumulated under variable bottom water conditions at least anoxic conditions prevailed during accumulation of much of the sunbury shale and the upper part of the cleveland member and possibly euxinic conditions for the sunbury bottom water conditions may have been intermittently anoxic and dysoxic during deposition of the lower cleveland during accumulation of the huron member it is likely that conditions ranged from anoxic to dysoxic to marginally oxic possibly being close to normal marine conditions at times during accumulation of the lowermost huron sediments

vegetation dynamics angiosperm radiation and climatic changes in the lusitanian basin portugal during albian times abstract the mid cretaceous is characterised by significant evolutionary changes in terrestrial ecosystems during this period the typical vegetation consisting of ferns conifers and other gymnosperms was replaced by an angiosperm dominated flora long ranging and continuous records from the continental realm are mostly lacking due to the prevalence of sedimentary gaps here a comprehensive palynological and clay mineralogical dataset covering early albian to early cenomanian strata from the shallow marine sao juliao section lusitanian basin portugal is analysed to reconstruct the vegetation composition as well as climate and weathering conditions in the continental realm the palynological assemblage is dominated by non saccate classopollis and inaperturopollenites gymnosperm pollen with low abundances of spores and angiosperm pollen the clay mineralogical data is mainly composed of kaolinite and mica and shows two conspicuous intervals of high kaolinite abundances in the late albian based on the ecological preferences of the associated parent plants of the spore pollen assemblage a gradual relative temperature increase is inferred in the hinterland of the lusitanian basin during the early albian to early cenomanian interval the clay mineralogy and palynological record show that the climate in the continental hinterland of the lusitanian basin was semi arid to sub humid and punctuated by two distinct humid phases during the late albian multivariate statistical analyses and a comparison with the nearby guincho section demonstrate the significance and reproducibility of the spore pollen record furthermore the palynological assemblage implies that angiosperms and ferns occupied similar palaeo ecological habitats namely as understorey in cheirolepidaceae araucariaceae and cupressaceae conifer dominated forests

a review of anomalous rare earth elements and yttrium in coal abstract coal deposits have attracted much attention in recent years as promising alternative raw sources for rare earth elements and yttrium rey not only because the rey concentrations in many coals or coal ashes are equal to or higher than those found in conventional types of rey ores but also because of the world wide demand for rey in recent years has been greater than supply in addition to anomalies of enrichment or depletion of light medium and heavy rey in coal deposits normalized to upper continental crust post archean australian shale or north american shale composite anomalies of redox sensitive ce and eu and in some cases of non redox sensitive la gd and y could be used as geochemical indicators of the sediment source region sedimentary environment tectonic evolution and post depositional history of coal deposits factors controlling rey anomalies in coal deposits include the geochemistry of terrigenous source rocks ingress of hydrothermal fluids influence of marine environments percolating natural waters volcanic ashes and sedimentary environments of peat formation additionally the smoothness of a normalized rey distribution pattern provides a simple but reliable basis for testing the quality of rey chemical analyses for coal and other sedimentary rocks

geochemical characterisation of tithonian berriasian chia gara organic rich rocks in northern iraq with an emphasis on organic matter enrichment and the relationship to the bioproductivity and anoxia conditions abstract tithonian berriasian chia gara organic rich rocks located in kurdistan northern iraq were analysed based on inorganic and organic geochemistry to define the origin type of organic matter and the influencing factors of organic matter om enrichment including the om input and preservation and their relationship to the paleoenvironment conditions the 13 c org values of the chia gara rocks range from 29 99 to 26 93 with average values of approximately 28 8 indicating that the organic matter has a predominantly marine origin enhanced biological productivity within the photic zone of the water column during deposition of the chia gara fm is indicated by consistently high organic carbon content in most samples average 3 wt as well as by bulk geochemical and biomarker characteristics major contributions by aquatic algae and microorganisms with a minor terrigenous organic matter contribution are indicated by the n alkane distribution patterns and the composition of the hopanoids steroids and tricyclic terpenoids strongly reducing bottom water is indicated by low pristane phytane ratios homohopane distribution patterns and the redox sensitive trace elements geochemistry salinity stratification with alkaline bottom waters is indicated by high sr ba ratios and the presence of gammacerane in the analysed chia gara samples these data indicate that om enrichment in the tithonian berriasian chia gara rocks results from the combination of enhanced biological productivity and salinity stratification with anoxic bottom water conditions which favoured om preservation

barite accumulation ocean productivity and sr ba in barite across the paleocene eocene thermal maximum the paleocene eocene thermal maximum petm ca 55 ma was a period of extreme global warming caused by rapid emission of greenhouse gases it is unknown what ended this episode of greenhouse warming but high oceanic export productivity over thousands of years as indicated by high accumulation rates of barium ba may have been a factor in ending this warm period by carbon sequestration however ba has a short oceanic residence time 10 k y so a prolonged global increase in ba accumulation rates requires an increase in input of ba to the ocean increasing barite saturation we use a novel proxy for barite saturation sr ba in marine barite to demonstrate that the seawater saturation state with respect to barite did not change across the petm the observations of increased barite burial no change in saturation and the short residence time can be reconciled if ba burial decreased at continental margin and shelf sites due to widespread occurrence of suboxic conditions leading to ba release into the water column combined with increased biological export production at some pelagic sites resulting in ba sink reorganization

a new index of glacier area change a tool for glacier monitoring since the mid 19th century most glaciers have been losing area and volume this loss of area has not been homogeneous in time and space and direct observations are sparse making regional and global estimates of glacier change difficult this paper focuses on developing a single index for monitoring glacier change one that would be particularly useful for remote sensing applications we combine the results of direct glacier mass balance observations b total glacier area s and accumulation area sc derived from maps or remotely sensed images using the accumulation area ratio aar sc s we note the differences between observed aar time averaged aar hi and the equilibrium state aar0 as determined by its value at b 0 from a regression of b aar we suggest that d aar hi aar0 aar0 quantifies the difference between the currently observed state of glaciers and their equilibrium state and measures the delay in the dynamic response of s relative to the climatic response of sc using all available observations for the period 1961 2004 d 65 for tropical glaciers which implies their rapid shrinkage as s continues to decrease and catch up with sc during the same period mid latitude and polar glaciers show less negative values of d of 86 glaciers from all latitudes and regions only 11 show positive d at any time between 1961 and 2004 averaged over 1961 2004 d is 15 1 2 2 and b hi is 360 42 mm a 1 w e values for aar0 range between about 40 and 80 but the bulk of the equilibrium values are between 50 and 60 the average aar0 is 57 9 0 9 and has remained stable over time the equilibrium aar has not changed with climate overall the observed negative d suggests a committed retreat of glaciers and their continuing contribution to sea level even if global temperature is held constant

estimation of ice sheet motion using satellite radar interferometry method and error analysis with application to humboldt glacier greenland satellite radar interferometry provides glaciologists with an important new tool for determining the motion and topography of large ice sheets we examine the sources of error in interferometrically derived ice motion measurements including those errors due to inaccurate estimates of the interferometric baseline several simulations are used to assess baseline accuracy in terms of tie point error and the number and distribution of tie points these results give insight into how best to select tie points and also demonstrate the level of accuracy that can be achieved examination of two representative cases likely to occur in mapping ice sheet motion leads to the conclusion that with adequate tie point information ice velocity can be measured accurately to within a few meters per year a method to correct horizontal velocity estimates for the effect of vertical displacement using surface slopes is also developed finally we estimate the single component velocity field for an area on humboldt glacier northern greenland using interferograms formed from ers i sar images we estimate that these velocity measurements are accurate to within 2 3 m year 1

short term glacier velocity changes at west kunlun shan northwest tibet detected by synthetic aperture radar data abstract seasonal glacier velocity changes across the high arctic including the greenland ice sheet have been observed and have attracted significant attention over the past decade however it remains uncertain how much short term variability exists in other polythermal glaciers particularly those in high asia here we report satellite radar image analyses that reveal diverse glacier surface velocities and their evolution in west kunlun shan wks nw tibet where little is known about glacier dynamics on the basis of radar images obtained from 2003 to 2011 we examined 36 glaciers and classified them into two classes according to their multi temporal velocity profiles 25 as normal flow type surface velocity reaches maxima around the middle part and gradually approaches zero toward downstream and upstream and four as surging type surface velocities are greater than 150 m yr and or the terminus advance is recognized from the radar images seven other glaciers do not fit the former two classes and reveal stagnant velocity profiles that are nearly zero in the lower part but are similar to those of the normal type in the upper part although these glaciers could be just stagnant tongues indicative of receding normal type glaciers given the temporal evolution at the zhongfeng glacier the stagnant type possibly represents a quiescent phase of the surging type glaciers while glacier surfaces are mostly clean with limited debris cover except near the termini surge type glaciers might be common in wks the observed short term velocity changes provide us with evidence for efficient basal slip even at the high elevation polythermal glaciers this study demonstrates that frequent radar image acquisitions are helpful to understand short term velocity changes at remote glaciers in detail

compositional variations of olivine and sulfur isotopes in the noril sk and talnakh intrusions siberia implications for ore forming processes in dynamic magma conduits olivine from the noril sk i main and northwestern talnakh ore bearing intrusions in the noril sk region occurs as inclusions discrete grains and poikilitic crystals the original compositions of olivine inclusions have been well preserved by their host oikocrysts from reaction with interstitial silicate and sulfide liquids in contrast the compositions of discrete and poikilitic olivine crystals have been variably modified by reequilibration with trapped silicate and sulfide liquids there are abrupt changes in the contents of nickel in olivine inclusions 500 1 500 ppm between different rock units in all three intrusions which indicates that the different rock units in these intrusions are not related to each other via in situ differentiation of a common parental magma but rather are consistent with separate pulses of magma with variable degrees of differentiation possibly involving olivine crystallization and assimilation of siliceous crustal material in a staging chamber the 34s values of the samples with high sulfur contents 800 ppm sulfur from all three ore bearing intrusions vary between 8 and 14 per mil two sulfur poor samples 600 ppm sulfur from the northwestern talnakh intrusion yield 34s values of 1 5 and 3 6 per mil these values are similar to the values of the sulfur poor rocks from the ore barren intrusions in the region and illustrate the fact that high sulfur contents couple with increasing 34s values such a relationship is consistent with the addition of crustally derived 34s enriched sulfur to the magma of the ore bearing intrusions in contrast to other models of sulfide segregation in closed systems we propose that sulfide segregation occurred in an open system and the magma involved was undersaturated in sulfur and undepleted in chalcophile elements we envision that the 34s enriched sulfur was introduced via circulating fluids that transported sulfur from evaporite in the underlying sedimentary sequence to the magma in a dynamic magma conduit the immiscible sulfide liquids that segregated during sulfur contamination settled down in the wider parts of the conduit as the magma continued to travel successive pulses of new magma entered the conduit reacted with the early sulfide and displaced much of the early magma in the conduit the ore bearing intrusions are thought to have crystallized within the wider parts of the conduits and their voluminous sulfide poor peripheral sills represent some if not all of the magma that flowed out of the conduits

isotopic composition of sulfate as a tracer of natural and anthropogenic influences on groundwater geochemistry in an urban sandstone aquifer birmingham uk abstract development and management of urban groundwater resources is limited in practice by a lack of knowledge of the nature distribution and sources of groundwater contamination in an urban aquifer that may have had complex land use and abstraction history sulfate is associated with many of the solute sources to urban groundwater and in this study the use of dual isotope 18o and 34s fingerprinting of so 4 2 in groundwater to assess the contribution of different sources to urban groundwater is investigated groundwater 70 locations and surface water samples from the city of birmingham on the triassic sherwood sandstone aquifer have been analyzed for inorganic chemical and so 4 2 isotopic composition isotopic compositions of so 4 2 associated with various solute sources have also been determined sulfate derived from pyrite oxidation during recharge through quaternary drift deposits is characteristically depleted in 18o and 34s compared to other sources and is ubiquitous in unconfined zone groundwater though the contribution from this source has increased markedly following draw down induced by abstraction from the aquifer in unpolluted groundwaters other so 4 2 sources are dissolution of evaporite minerals confined zone and rainfall unconfined zone unfortunately so 4 2 isotopic composition cannot distinguish between made ground i e artificial man made ground usually demolition waste and sewage sources of so 4 2 which constitute the major contributions to so 4 2 in polluted urban groundwater at most sites contributions of so 4 2 from spilt industrial acids do have a distinctive isotopic composition seen at many metal working and former metal working sites estimates of solute contributions derived from these sources derived in this way provide a useful check on the calibration of aquifer and pollutant flux recharge models for urban groundwater

sr ba in barite a proxy of barite preservation in marine sediments abstract the observation by bertram and cowen j mar res 55 1997 577 593 that the strontium content of marine barite decreased from the water column to the deep sea floor suggested that the sr ba ratio in barite was sensitive to barite dissolution following this observation we have investigated the potential of using the sr ba ratio in barite as a proxy of barite preservation by separating barite crystals from sediment cores collected at different water depths in the equatorial pacific and in the southern ocean our investigations do not reveal significant downcore variations in the sr ba ratios during the holocene period in the two basins and up to a few hundred thousand years in the equatorial pacific however a comparison of the mean sr ba ratios in individual cores suggests that the sr ba ratios in barite decrease with increasing water depth a feature that could be related to dissolution of barite crystals during settling to the deep sea floor and or at the sediment water interface if confirmed the sr ba ratios in barite could be used to infer the intensity of barite dissolution and the state of preservation of barite crystals in sediments such information could be employed usefully in paleoproductivity reconstructions for the purpose of distinguishing between productivity and dissolution signals affecting barite distributions in marine sediments

relationship between inferred redox potential of the depositional environment and geochemistry of the upper pennsylvanian missourian stark shale member of the dennis limestone wabaunsee county kansas u s a analyses of 21 samples collected from a core of the 52 8 cm thick stark shale member of the dennis limestone in wabaunsee county kansas demonstrate four cycles with two orders of magnitude variations in contents of cd mo p v and zn and order of magnitude variations in contents of organic carbon cr ni se and u the observed variability in amounts and or ratios of many metals and amounts and compositions of the organic matter appear related to the cause and degree of water column stratification and the resulting absence presence of dissolved o2 or h2s high cd mo u v zn and s contents a high degree of pyritization dop 0 75 0 88 and high high v v ni 0 84 0 89 indicate the presence of h2s in a strongly stratified water column intermediate contents of metals and s intermediate dop 0 67 0 75 and intermediate v v ni 054 0 82 indicate a less strongly stratified anoxic water column whereas low metal contents and low v v ni 0 46 0 60 indicate a weakly stratified dysoxic water column high p contents at the top of the organic matter rich intervals within the stark shale member indicate that phosphate precipitation was enhanced near the boundary between anoxic and dysoxic water compositions relatively abundant terrestrial organic matter in intervals deposited from the more strongly stratified h2s bearing water column indicates a combined halocline thermocline with the fresher near surface water the transport mode for the terrestrial organic matter the predominance of algal organic matter in intervals deposited from a less strongly stratified water column indicates the absence of the halocline and the presence of the more generally established thermocline relatively low amounts of degraded hydrogen poor organic matter characterize intervals deposited in a weakly stratified dysoxic water column the inferred variability in chemistry of the depositional environments may be related to climate variations and or minor changes in sea level during the general phase of deeper water deposition responsible for this widespread shale member

accelerated glacier mass loss 2011 2016 over the puruogangri ice field in the inner tibetan plateau revealed by bistatic insar measurements abstract the temporal variation of glacier mass balance during recent years remains poorly known for the mountain glaciers in the inner tibetan plateau itp due to the lack of field measurements in this study we retrieved the annual glacier mass balance of the puruogangri ice field which is the largest modern ice mass in the itp by differencing multi temporal digital elevation models dems generated with five pairs of tandem x bistatic interferometric synthetic aperture radar insar images acquired between april 2011 and january 2016 we compared the tandem x dems in january and april 2012 to estimate the x band radar penetration depth difference 0 61 0 06 m which enabled systematic bias correction in the estimation of annual glacier mass balance the observed mass balance reveals a glacier mass gain of 0 44 0 10 m w e yr 1 in 2011 12 which was followed by accelerated glacier mass loss in 2012 16 glacier mass balances of 0 13 0 03 0 34 0 06 and 0 52 0 10 m w e yr 1 were estimated for the periods of 2012 13 2013 14 and 2014 16 respectively this accelerating trend of glacier mass loss is likely caused by the continuous decrease in annual precipitation according to the climate data recorded by adjacent meteorological stations this study demonstrates that repeated bistatic insar measurement is a promising method for monitoring glacier elevation change and mass balance at regular intervals