elemental compositions and monazite age patterns of core sediments in the changjiang delta implications for sediment provenance and development history of the changjiang river core from a continuous borehole in the changjiang delta to a depth of 318 7 m dated back to the pliocene 3 58 ma and was selected for geochemical measurements and determinations of th u pb ages of monazite in order to investigate the changing sediment provenance and development history of the changjiang river geochemical proxies including fractionation parameters of rare earth elements cerium and europium anomalies and elemental ratios cr th nb co and th co suggest that the pliocene and quaternary sediments have remarkably different provenances six peak ages of monazite grains dated at 25 50 200 200 400 400 550 800 1000 and 1800 2000 ma are consistent with the main tectonic and magmatic events in the yangtze craton the data imply that the pliocene sediments were mostly derived from proximal and more silicic sources whereas the quaternary sediments were sourced from distal and more basic provenances including the emeishan basalt province in the upper changjiang valley we propose that during the pliocene the paleo changjiang or its eastern equivalent was a locally small river draining today s lower changjiang valley whereas during the early pleistocene not later than 1 18 ma it changed its drainage pattern and developed into a large river that originated from the eastern tibetan plateau this time matches well with many previous studies based upon geomorphologic geographic and tectonic observations in the jinshajiang valley and the three gorges

geology and characterisation of the pecket coal deposit magellan region chile abstract the geology petrography and chemical variation of the pecket coal sequence magellan region 52 57 s 71 10 w the only chilean coal used for electricity generation on a large scale has been studied in order to predict their combustion behaviour especially in coal blends the depositional environment of formation of the coal seams was a swamp rarely exposed to subaerial conditions and was associated with the development of the folded foreland of the magellan basin during the tertiary oligo miocene the general tectonic regime of the collision of the antarctic and south american plates is reflected by a system of joints with 40 n 50 w strike the maceral composition of all six seams studied indicates high contents of vitrinite 90 minor content of liptinite 4 7 and inertinite 2 al 2 o 3 and fe 2 o 3 cao ratios of the ashes diminish towards the lower seams with respect to the utilisation of pecket coals in combustion base acid ratios b a and silica ratios sr indicate potential fouling for seams 1 2 5 and 6i with high fouling indexes rf for seams 2 and 5 pecket coal is excellent for blend combustion due to its low sulphur content

time lapse 4 d seismic monitoring of primary production of turbidite reservoirs at south timbalier block 295 offshore louisiana gulf of mexico two seismic surveys acquired over south timbalier block 295 field offshore louisiana record significant differences in amplitude that are correlated to hydrocarbon production at multiple reservoir levels the k8 sand a solution gas drive reservoir shows increases in seismic amplitude associated with gas exsolution the k40 sand a water drive reservoir shows decreases in seismic amplitude associated with increases in water saturation a methodology is presented to optimize the correlation between two seismic surveys after they have been individually processed poststack this methodology includes rebinning crosscorrelation band pass filtering and cross equalization a statistical approach is developed to characterize the correlation between the seismic surveys this statistical analysis is used to discriminate seismic amplitude differences that record change in rock and fluid properties from those that could be the result of miscorrelation of the seismic data time lapse seismic analysis provides an important new approach to imaging hydrocarbon production it may be used to improve reservoir characterization and guide production decisions

new fossil evidence and diet analysis of gigantopithecus blacki and its distribution and extinction in south china the present paper reports the recently discovered fossil teeth of early pleistocene gigantopithecus blacki and associated mammalian fauna from baeryan cave bijie county in guizhou province and also reviews briefly the known fossil sites of gigantopithecus in south china of pleistocene in early pleistocene gigantopithecus had a wider distribution but withdrew southward in middle pleistocene to a limited area mainly in south china and it disappeared in the late pleistocene according to the present fossil records diet and habitat analysis from carbon isotope evidence is used to investigate the reasons for the extinction of gigantopithecus which fed on a pure c3 diet and lived in a forest habitat it was clearly different from early hominins in south and east africa such as australopithecus africanus paranthropus robustus and paranthropus boisei which had c4 diets the extinction of gigantopithecus was also related to the great changes of climate and environment of the pleistocene especially the last one million years during which homo became more and more prosperous and exerted great pressure on g blacki

weathering rates of sandstone in a semi arid environment hunter valley australia the rate of sandstone weathering in the semi arid climate of the hunter valley new south wales australia has been estimated from observations of gravestone weathering in the area the gravestone data points to two distinct stages in the weathering process the first stage covering the first century of exposure is characterised by a relatively low recession rate of 0 5 mm 100 years this is followed by a second stage in which the rate of weathering increases sharply to ca 2 5 mm 100 years the non linear nature of the weathering trends over time suggests that during the first century of exposure structural changes took place within the sandstone material which lay the foundation for accelerated weathering after further exposure laboratory trials were also conducted to identify the effectiveness of different weathering processes in the decay of sandstone in this region of the four processes examined only the freeze thaw cycle produced a significant degree of mass loss and is therefore most likely a strong contributor to the weathering of sandstone in this region

gassmann s fluid substitution and shear modulus variability in carbonates at laboratory seismic and ultrasonic frequencies carbonates have become important targets for rock property research in recent years because they represent many of themajoroilandgasreservoirsintheworld someareundergoing enhanced oil recovery most laboratory studies to understand fluid and pressure effects on reservoir rocks have been performed on sandstones but applying relations developed for sandstones to carbonates is problematic at best we measure in the laboratory nine carbonate samples from the same reservoir at seismic 3 3000 hz and ultrasonic 0 8 mhz frequencies samples are measured dry humidified and saturated with liquid butane and brine our carbonate samples showed typical changes in moduli as a function of porosity andfluid saturation however we explore the applicability of gassmann s theory on limestone and dolomite rocks in the context of shear and bulk modulus dispersion andgassmann stheoryassumptions forourcarbonatesetat high differential pressures and seismic frequencies the bulk modulus of rocks with high aspect ratio pores and dolomite mineralogy is predicted by gassmann s relation we also explore in detail some of the assumptions of gassmann s relation especiallyrock framesensitivitytofluidsaturation our carbonate samples show rock shear modulus change from dry to brine saturation conditions and we investigate several rock fluid mechanisms responsible for this change to our knowledge these are the first controlled laboratory experimentsoncarbonatesintheseismicfrequencyrange

dating plio pleistocene glacial sediments using the cosmic ray produced radionuclides 10be and 26al we use the cosmic ray produced radionuclides 26al and 10be to date plio pleistocene glacial sediment sequences these two nuclides are produced in quartz at a fixed ratio but have different decay constants if a sample is exposed at the surface for a time and then buried by overburden and thus removed from the cosmic ray flux the 26al 10be ratio is related to the duration of burial we first attempted to date pre wisconsinan tills by measuring 26al and 10be in fluvial sediments beneath them and applying the method of burial dating which previous authors have used to date river sediment carried into caves this method however requires simplifying assumptions about the 26al and 10be concentrations in the sediment at the time of burial we show that these assumptions are not valid for river sediment in glaciated regions 26al and 10be analyses of such sediment do not provide accurate ages for these tills although they do yield limiting ages in some cases we overcome this difficulty by instead measuring 26al and 10be in quartz from paleosols that are buried by tills we use a more general mathematical approach to determine the initial nuclide concentrations in the paleosol at the time it was buried as well as the duration of burial this technique provides a widely applicable improvement on other means of dating plio pleistocene terrestrial glacial sediments as well as a framework for applying cosmogenic nuclide dating techniques in complicated stratigraphic settings we apply it to pre wisconsinan glacial sediment sequences in southwest minnesota and eastern south dakota pre wisconsinan tills underlying the minnesota river valley were deposited 0 5 to 1 5 ma and tills beneath the prairie coteau in eastern south dakota and adjacent minnesota were deposited 1 to 2 ma

cosmogenic nuclide burial ages and provenance of the xigeda paleo lake implications for evolution of the middle yangtze river abstract hundred meter thick lacustrine sediments are widespread along the middle yangtze river the distribution of these sediments suggests that an event blocked the river forming a lake stretching 160 km from east to west and 110 km north to south with a depth of 500 m using the cosmogenic nuclides 10 be and 26 al we have dated the time of burial of the lacustrine sediments and fluvial gravels beneath the sediments our results indicate a deposition age for these sediments between 1 34 and 1 58 ma studies of zircon u pb age distributions within lacustrine sediments and fluvial sands related to the paleo lake formation show diverse provenances from the upper yangtze river and yalong river a major tributary of the yangtze river these deposits contain geologic fingerprints that allow identification of the source region of the lacustrine deposits and fluvial sands our results support the reversal of the middle yangtze river before the paleo lake formation we hypothesize that the geologic event that dammed the originally southward flow was the lateral movement of chenghai fault in the dali fault system initiated in early quaternary water eventually cut through the spillway and flowed to the east

geochemistry of trace elements in coals from the zhuji mine huainan coalfield anhui china the abundances of nine major elements and thirty eight trace elements in 520 samples of low sulfur coals from the zhuji mine huainan coalfield anhui china were determined samples were mainly collected from 10 minable coal seams of 29 boreholes during exploration the b content in coals shows that the influence of brackish water decreased toward the top of coal seams marine transgression and regression occurred frequently in the lower shihezi formation a wide range of elemental abundances is found weighted means of na k fe p be b co ni cr se sb ba and bi abundances in zhuji coals are higher and the remainder elements are either lower or equal to the average values of elements in coals of northern china compared to the chinese coals the zhuji coals are higher in na k be b cr co se sn sb and bi but lower in ti p li v and zn the zhuji coals are lower only in s p v and zn than average u s and world coals potassium mg ca mn sr as se sb and light rare earth elements lree had a tendency to be enriched in thicker coal seams whereas fe ti p v co ni y mo pb and heavy rare earth elements hree were inclined to concentrate in thinner coal seams the enrichment of some elements in the shanxi or upper shihezi formations is related to their depositional environments the elements are classified into three groups based on their stratigraphic distributions from coal seams 3 to 11 2 and the characteristics of each group are discussed lateral distributions of selected elements are also investigated the correlation coefficients of elemental abundances with ash content show that the elements may be classified into four groups related to modes of occurrence of these elements

distribution of major minor and trace elements in hat creek deposit no 2 british columbia canada abstract the major minor and trace element contents of coals from hat creek no 2 deposit british columbia are determined using inaa and inductively coupled plasma emission spectrometry boron only al cr fe mn and na were found to be inorganically bound in the coal while as b and s are associated with the organic fraction of the coal the rare earth element concentrations in the coal are variable however the lree hree ratio decreases from base to the top of the deposits many elements show little variation in concentration with depth however the gradual increase of as and s with depth appears to be rank related and indicative of progressive decrease in porosity with increasing rank concentrations of b and cr are sensitive to the environment of coal deposition with coal deposited in a freshwater environment hat creek no 2 deposit having low b and high cr compared with more brackish coals

streamline based integration of time lapse seismic and production data into petroleum reservoir models abstractwe have developed an efficient approach of petroleum reservoir model calibration that integrates 4d seismic surveys together with well production data the approach is particularly well suited for the calibration of high resolution reservoir properties permeability because the field scale seismic data are areally dense whereas the production data are effectively averaged over interwell spacing the joint calibration procedure is performed using streamline based sensitivities derived from finite difference flow simulation the inverted seismic data i e changes in elastic impedance or fluid saturations are distributed as a 3d high resolution grid cell property the sensitivities of the seismic and production surveillance data to perturbations in absolute permeability at individual grid cells are efficiently computed via semianalytical streamline techniques we generalize previous formulations of streamline based seismic inversion to incorporate realistic field situations such as changing boun

geochemical data as indicators of palaeosalinity in coastal organic rich sediments abstract a geochemical study of extractable major minor and trace elements peatlands from e spain elucidated variations in salinity related to the interpretation of relative sea level change samples were taken from different peatlands from the subsiding valencia castellon quaternary basin e spain these correspond to back barrier marshes with brackish and freshwater influence containing carex juncus typha and phragmites samples from a highland sphagnum moss freshwater peat bog were also included for comparison this paper categorizes palaeosalinity indicators in this coastal peat deposits as follows b br i na s ge u this compares with low rank coal which shows the following relationship b br i s na ge u the formulation of an index for characterising the organic detrital content using k or al concentration is also proposed this resulted in the following salinity index for peat b k br k i k na k s k ge k u k and for low rank coal b k br k i k s k na k ge k u k

comparison of the geochemistry of lacustrine oil shales of mississippian age from nova scotia and new brunswick canada abstract the bulk elemental concentration of selected albert formation oil shale deposits of mississippian age from new brunswick was analyzed using icp ms and prompt gamma results compared to that of the big marsh oil shale of similar age from nova scotia reflected white and fluorescence light was used to determine the characteristic organic matter and rockeval analyses were used to determine the hydrocarbon potential of oil shale both albert and big marsh oil shales were deposited in lacustrine environments based on geological and sedimentological evidence the big marsh oil shale has low and stable b content 28 54 ppm which stays almost constant and with the range for freshwater with depth by contrast the oil shales from the albert formation from new brunswick have high and were for albert oil shale the big marsh deposit in contrast had stable discharge and recharge with higher aluminosilicate input and limited or no carbonate content the rate of sedimentation as determined by na k and th k ratios indicates that the albert oil shales deposited at a slower rate as compared to the big marsh oil shales the lower th u ratio for albert oil shale as compared to the big marsh is likely due to lower input of weathered and recycled sedimentary terrestrial flux and allochthonous u content into the lacustrine setting during their deposition albert oil shales deposited in oxic dysoxic conditions based on their cr and v cr ratio suggesting a well oxygenated and uniform warm temperature upper water level variation of ca sr versus ca mn ratios for the albert oil shale indicates low mn ca and relatively high sr ca ratio for most of the samples due to low terrigenous influx and warmer water which is supported by the mineralogy of the oil shales which contain low quartz and clay minerals the presence of higher authigenic u and mn ca ratio for albert oil shale indicates low terrestrial flux and therefore th as compared to big marsh oil shales the rare earth element rees content is higher for the big marsh oil shales owning to a higher input of aluminosilicate than the albert oil shale as supported by variation of y and la and that of hydrogen index hi and heavy rare earth hrees the albert oil shale displays a positive eu anomaly typical of a high carbonate environment by contrast big marsh which shows a negative eu anomaly which is typical of upper continental crust

cosmogenic burial ages reveal sediment reservoir dynamics along the yellow river china burial dating using cosmogenic al 26 and be 10 is an emerging technique for establishing chronologies of fluvial deposits ranging in age from ca 0 5 ma to 5 ma the determination of burial age however requires an assumption that sediment is buried with a known initial al 26 be 10 ratio using a sequence of well dated fluvial terraces along the yellow river in lanzhou china we demonstrate that this assumption may be violated when upstream sediment sources include neogene sedimentary basins samples of fluvial gravel from six terraces yield burial ages ranging from ca 0 83 ma to 2 81 ma comparison of these results to independent ages determined from magneto stratigraphic and loess paleosol studies demonstrates a high degree of correspondence between ages in the lower three terraces in the higher terraces however burial ages are systematically too old implying a previous burial history these results can be exploited to place quantitative constraints on the provenance of sediment in the terrace deposits our results reveal that rapid incision and excavation of late neogene sedimentary basins ca 1 7 ma led to injection of fluvial sediment with low initial al 26 be 10 ratios dilution of this source through time occurred as incision progressed into upstream bedrock ranges our results suggest that cosmogenic nuclides can illuminate the timing of long term storage and remobilization of sediment in continental scale river systems

the vertical distribution of minerals in coal zones a b c d hat creek british columbia abstract the four superimposed coal zones a b c d lie in the hat creek graben in folded and faulted eocene strata 76 consecutive samples from ddh 75 106 were analysed by xrd and examined in polished section kaolinite and quartz are the major minerals with kaolinite increasing with depth some upper samples grade into halloysite montmorillonite bentonite is virtually absent illite mostly in zone a varies irregularly with depth appears to be antipathetic to dolomite and between 160 and 306 m to be associated with tonstein pyrite occurs throughout the core only above 358 m is it detected by xrd pyrite and siderite occur in polished section but in xrd appear to be unrelated zone c shows a marked deficiency in mineral varieties cristobalite is found throughout zone a and in the lower half of d major gypsum in the upper part of a and in the lower part of d no correlation exists between minerals and palynomorphs

seismic monitoring of water floods a petrophysical study seismic velocities were measured in the laboratory on 67 samples as a function of pressure and temperature when saturated with gas and a 35 api 141 5 density at 1 atmosphere and 60 f 131 5 mineral oil and flooded with pentane and fresh water respectively using an ultrasonic pulse transmission method the rock samples consisted of 39 carbonate cores from eight reservoirs 22 sandstone cores from six formations and six unconsolidated samples from three origins the results show that water flooding increases the compressional velocity vp by more than 5 percent in most of the gas saturated cores at effective pressures overburden pressure minus pore pressure less than 20 mpa such vp increase is less than 5 percent in about half of the carbonate cores and some of the sandstone cores with normal pentane and in all the consolidated cores both carbonates and sandstones saturated with the 35 api oil however in unconsolidated samples saturated with gas pentane or oil water flooding increases th

chalcophile elements in western canadian coals abstract concentrations of chalcophile elements as co cu hg mo ni pb sb and zn in western canadian coals were determined using inaa and aas the concentrations of these elements in western canadian coals are within the range for most world coals however there are some high values for coals from outcrops and from areas which are not currently being mined arsenic content in the majority of western canadian coals particularly those currently being mined is low 0 2 3 ppm however there are coals with high arsenic content for example lignites from hat creek a zone contain between 4 0 and 14 0 ppm as in some samples from comox and suquash the as concentration is as high as 240 ppm and 1400 ppm respectively the enrichment of as in high arsenic coals is related to the geology and nature of country rocks associated with the coal seams the concentration of other elements for most western canadian coals particularly those being mined are within the range for most world coals in these coals the concentration ranges in ppm of chalcophile elements are 0 3 3 6 for sb 0 8 4 6 for co 7 35 for cu

geological controls on the sulphur distribution in british carboniferous coals a review and reappraisal abstract the very extensive literature on sulphur in peats and coals is reviewed and four case histories from british coalfields are considered in the parkgate seam langsettian from the nottinghamshire coalfield the variation in the total sulphur content is attributed to pyritic sulphur with organic sulphur also significant but showing a smaller variation sulphate sulphur is negligible there is a spatial variation in the sulphur concentrations in individual sections plies of the parkgate seam but this is unrelated to other sections of the seam and to identifiable post depositional controls thereby providing indirect evidence of a depositional control on sulphur incorporation in the main bright duckmantian north derbyshire coalfield and threequarters seams langsettian north derbyshire nottinghamshire coalfields the depositional control is shown to be related to contemporaneous channels there is a hierarchy of channels and it is concluded that these provided access of more saline waters into the peat mire coals associated with marine bands often show high sulphur contents but there are exceptions particularly in the scottish namurian as exemplified by the upper hirst seam where it is thought that there was no contemporary ingress of saline waters three westphalian depositional provinces are recognised on the basis of channel sandstone loci and there is the possibility that different source areas influenced the salinity sulphate content in the mires there is some evidence of regional differences in the sulphur content of british coals which is consistent with the distribution of the three provinces on the other hand there is irrefutable evidence that access of seawater leads to high sulphur coals and possibly the marine influence was more pervasive than is generally recognised there is supporting geochemical evidence of enrichment of trace elements in coals which is indicative of a seawater source

trace elements in the lower pliocene fossiliferous kangal lignites sivas turkey abstract the kangal lignite basin which is one of the most productive lignite basins in eastern anatolia turkey includes two lignite seams containing abundant gastropoda shells in the lower pliocene kalburcayiri formation the seams are currently exploited in an open cast mine in the kalburcayiri field and supply feed coal to a power plant with 300 mw capacity the average thickness of each of the two seams in this mine is about 10 m and they are separated by about 20 m of tuffaceous sedimentary rocks a 15 20 cm thick tuff bed occurs within the upper seam the purpose of the study was to understand mineralogy and trace element concentrations of the two lignite seams in the kalburcayiri formation which were affected by volcanic ashes fifty nine core samples of the lignites from seven boreholes across the basin and eight channel samples from the working lignite seams were collected and analysed by proximate analysis x ray powder diffraction xrd inductively coupled plasma mass spectrometry icp ms and scanning electron microscopy sem with energy dispersive x ray microanalysis techniques the samples show that the worked lignite seams on an as received basis contain high moisture contents 43 4 57 8 all the samples on an air dried basis have high ash yields from 19 5 to 81 7 and a broad range of total sulfur contents from 1 16 to 7 04 and calorific values 684 to 4621 kcal kg except for two samples with no temperature rise due to high ash yield the mineral matter of the studied samples is made up of calcite quartz feldspar pyrite opal ct clay minerals gypsum and traces of aragonite the trace element analyses on a whole coal dry basis indicate that most of the borehole samples showed enrichment in specific elements including zn 15 1394 g g mo 13 368 g g and u 5 5 131 g g when compared to the range of these elements for most coals in the world the contents of zn mo and u for the samples from the worked lignite seams are respectively 38 187 54 161 and 28 55 g g the sem studies show that zn is hosted mainly in micron sized zn bearing mineral sphalerite but no mo and u bearing minerals have been detected during these studies except for monazites containing th and u traces the mo and u concentrations are negatively correlated with the ash yields and these elements are contained mainly within organic matter

theoretical analysis of long offset time lapse frequency domain controlled source electromagnetic signals using the method of moments application to the monitoring of a land oil reservoir 1 we present a sensitivity study applied to water front monitoring of an onshore oil reservoir using a remote controlled source electromagnetic method csem with electric dipoles and a borehole to surface configuration we have developed an optimized and parallelized code based on the method of moments in order to study the influence of several static or time varying background uncertainties on the time lapse csem signal also called 4 d csem analysis of the relative and absolute variations in phase or quadrature of the time lapse signal induced by the fluid substitution process inside the reservoir has shown that the vertical electric dipole allows the shape of the water front to be monitored while remaining less sensitive compared to a horizontal electric source dipole to the total volume of substituted fluid we have examined the influence of missed anomalies 1 d 3 d with more or less conductive properties near to the ground surface or the reservoir and with or without time varying properties in most cases the 4 d signal behaves like a reliable filter canceling almost all response anomalies however it can also lead to strong local perturbations of the time lapse signal we have also shown that in the presence of steel cased boreholes at the source location or with outlying steel cased boreholes the recording of exploitable data does not present insurmountable difficulties at low frequencies 1 hz and for a dense array of surface receivers these positive results with csem monitoring suggest that minimal coarse time 3 d explorations should be used to ensure reliable interpretation of the monitored data

new evidence for the incision history of the liuchong river southwest china from cosmogenic 26al 10be burial ages in cave sediments cosmogenic nuclides be 10 and al 26 have been analyzed for sediments from the multilevel riverside caves along the liuchong river at the southeastern margin of the tibetan plateau the liuchong river is the northern origin of wujiang river which passes through the northwestern guizhou plateau and cuts down hundreds of meters into the bedrock leaving behind an abundance of multilevel caves the measured al 26 be 10 ratios produced the apparent burial ages in range of 0 49 2 85 ma taking into account of geomorphic and geological backgrounds the dashi cave located at the highest level along the liuchong river system formed around 0 75 ma ago which probably suggests the initial formation age of the modern wujiang river the resulted incision rate of similar to 480 m ma in guizhou in the last 0 75 ma is slightly higher than those in adjacent areas this feature implies an intensive downcutting history of the liuchong river during the quaternary which might be primarily caused by the uplift of tibetan plateau cut through of the three gorges and soluble carbonate bedrock c 2013 elsevier ltd all rights reserved

quaternary downcutting rate of the new river virginia measured from differential decay of cosmogenic 26al and 10be in cave deposited alluvium the concentrations of the cosmogenic radionuclides sup 26 al and sup 10 be in quartz can be used to date sediment burial here we use sup 26 al and sup 10 be in cave deposited river sediment to infer the time of sediment emplacement sediment burial dates from a vertical sequence of caves along the new river constrain its quaternary downcutting rate to 27 3 4 5 m m y and may provide evidence of regional tectonic tilt 32 refs 3 figs 1 tab

early pleistocene incision of the san juan river utah dated with 26al and 10be cosmogenic 26al and 10be in alluvial gravel on a strath 150 m above the san juan river utah reveal a depositional age of batchmode documentclass fleqn 10pt legalpaper article usepackage amssymb usepackage amsfonts usepackage amsmath pagestyle empty begin document 1 36 0 20 0 15 end document ma this gravel is correlative with a series of terraces that grade to glen canyon on the colorado river indicating a similar age for incision there the calculated incision rate 110 14 m m y is somewhat slower than that of the colorado river in the eastern grand canyon and suggests active steepening of the colorado river the cosmogenic nuclides also indicate rapid erosion in the sediment source area and are consistent with alluviation due to enhanced pleistocene erosion in the san juan mountains

a 900 k y record of strath terrace formation during glacial interglacial transitions in northwest china the timing of the development of strath terraces with respect to climatic variability remains equivocal previous studies attribute strath terrace formation to glacial or interglacial climates or to variations in sediment and water fluxes that cause lateral erosion followed by vertical incision a chronology of strath terrace formation spanning similar to900 k y has been generated on the basis of loess paleosol couplets and paleomagnetic thermoluminescence and radiocarbon dating of strath terraces in the qilian shan of northeastern tibet repetitive stratigraphic and geomorphic patterns on each terrace indicate that they formed during glacial interglacial transitions long term bedrock incision rates and inferred rock uplift rates appear steady and unrelated to strath formation over the past 900 k y

organic petrology of hat creek coal deposit no 1 british columbia abstract the upper eocene hat creek coal deposits of british columbia canada are one of the thickest lignite to subbituminous coal deposits of the world and comprise 350 550 m of coal samples of sedimentary organic material were taken from a 560 m interval of interbedded shale siltstone and carbonate that was penetrated by corehole 75 106 in the centre of the coal basin and the reflectances of huminite eu ulminite from coal and kerogen from the organic material were determined and petrographical analyses were made the coal deposit contains many leaf and resinite rich horizons and the reflectance of huminite in these horizons in lower than in corresponding horizons containing less liptinite when compared with huminite in adjacent coal beds the reflectance of huminite in shale is lower that in siltstone is similar and huminite associated with carbonate rocks has slightly higher reflectance values the petrological variation in the coal is mainly within the huminite group of macerals the coal at the top of the deposits is lignite r o 0 38 and becomes subbituminous c r o 0 50 at the base the inertinite content is very low indicating a low level of peat fire or oxidation the early stages of transformation of gelinite to macrinite are described the paleoenvironment appeared to be lacustrine as determined by organic petrological analysis of coals and interbedded sediments four major zones each containing many subzones were found paleoenvironments were similar for the a and c zones and also for the b and d zones

geological factors influencing the concentration of trace elements in the philippi peatland eastern macedonia greece abstract six peat samples obtained from the holocene and the weichselian of the philippi peat deposit eastern macedonia greece were analyzed for 48 trace elements by inductively coupled plasma mass spectrometry icp ms the ash contents of these samples were also determined most of the trace elements are associated with the minerals in the peat while ge mo pb se ta tl u and w display a greater affinity with the organic matter compared with crustal averages clarke concentrations the philippi peat is enriched in some elements ag as au cd mo se te u and w because of the respective mineralizations in the area the philippi peat is also enriched in cr cu mo pb sc sn t v y and zn in comparison with typical fen peats as well as in as cr mo se and u in comparison with typical coals climatic and hydrogeological conditions strongly influenced the peat forming environment resulting in a differentiation between holocene and weichselian peat generally the holocene peat contains lower concentrations of trace elements in the northern and southern part of the fen than the weichselian one the opposite trend is observed in the fen area close to the western basin margins

time lapse seismic reservoir monitoring time lapse seismic reservoir monitoring has advanced rapidly over the past decade there are currently about 75 active projects worldwide and more than 100 cumulative projects in the past decade or so the present total annual expenditures on 4 d seismic projects are on the order of 50 100 million us this currently represents a much smaller market than 3 d seismic but the use of 4 d seismic has grown exponentially over the past decade and is expected to continue to do so

dating of pliocene colorado river sediments implications for cosmogenic burial dating and the evolution of the lower colorado river we applied cosmogenic 26 al 10 be burial dating to sedimentary deposits of the ancestral colorado river we compared cosmogenic burial ages of sediments to the age of an independently well dated overlying basalt flow at one site and also applied cosmogenic burial dating to sediments with less precise independent age constraints all dated gravels yielded old ages that suggest several episodes of sediment burial over the past 5 3 m y comparison of burial ages to the overlying 4 4 ma basalt yielded good agreement and suggests that under the most favorable conditions cosmogenic burial dating can extend back 4 5 m y in contrast results from other sites with more broadly independent age constraints highlight the complexities inherent in burial dating these complexities arise from unknown and complicated burial histories insufficient shielding postburial production of cosmogenic isotopes by muons and unknown initial 26 al 10 be ratios nevertheless and in spite of the large range of burial ages and large uncertainties we identify samples that provide reasonable burial age constraints on the depositional history of sediment along the lower ancestral colorado river these samples suggest possible sediment deposition and burial at ca 5 3 4 7 and 3 6 ma our calculated basinwide erosion rate for sediment transported by the modern colorado river 187 mm k y 1 is higher than the modern erosion rates inferred from the historic sediment load 80 100 mm k y 1 in contrast basinwide paleo erosion rates calculated from pliocene sediments are all under 40 mm k y 1 the comparatively lower denudation rates calculated for the pliocene sediment samples are surprising given that the sampled time intervals include significant pliocene aggradation and may include much incision of the grand canyon and its tributaries this conflict may arise from extensive storage of sediment along the route of the colorado river slower paleobedrock erosion or the inclusion of sediments that were derived preferentially from higher elevations in the watershed

vertical distribution of elements in deposit no 1 hat creek british columbia a preliminary study abstract four superimposed coal zones a b c d lie in the hat creek graben in folded and faulted eocene strata 65 samples from one central and representative drillhole are examined aa analyses show cu and zn as having an inorganic affinity and increasing upward reflecting either a change in environment of deposition or a more selective sorption srf analyses show six elements increasing in abundance with depth most pronounced first na ba si sr y mn with 12 decreasing rb cr k ni mg s ti fe ca zn p zr al does not vary the pronounced upward increase in rb might indicate the incorporation of increasingly silicic volcanic dust or sediment k rb ratios however show an upward zig zag variation while ba shows negative correlation with k sr ba ratios for zones a b d are similar to those for granite ti al na k ba sr rb sr and even the k rb ratios show that zones a and d appear to be structurally distinct of the 15 20 major stratigraphic coinciding highs and lows revealed in the element depth variograms 12 14 are in clean coal 5 6 in carbominerite the peaks may represent a the incorporation of volcanic ash or detrital sediment from different geological sources or b the concentration or removal of elements by groundwater aided by previously high geothermal gradients missing core may represent the position of former watertables drowned by repeated downward shifting of the graben more detailed collecting should permit cycles of deposition to be distinguished the coal zones can elementally be distinguished one from another but individually could be difficult to identify

occurrence and distribution of sulfur in peat forming environments of southern florida abstract cores and surface samples of peats from the everglades mangrove region of southern florida were analyzed for total sulfur and pyritic sulfur these values were compared with the petrographic botanical components of the peats as determined from point counts of oriented microtome sections pyrite occurs as individual euhedral crystals loosely packed framboids and lenses or crusts of minute crystals framboids and minute crystals are often associated with organic matter and sometimes with bacteria and fungi pyrite tends to selectively occur in void spaces in or between peat tissues in samples containing very small amounts of pyrite framboidal pyrite is the prevalent form marine to brackish peats contain the highest pyrite and total sulfur contents with brackish peats generally containing more pyrite than marine peats pyrite tends to be lower in all peats within 30 cm of the surface whether marine or brackish burial of freshwater peats beneath marine or brackish peats tends to increase the total sulfur and pyritic sulfur in the underlying peats burial beneath brackish water clay rich deposits such as splays tends to increase total sulfur and pyritic sulfur in the underlying deposits more than burial beneath less clay rich deposits

reconnaissance study of mineral matter and trace elements in greek lignites abstract mineral matter in low temperature ashes major oxides and trace elements were determined for twenty eight selected lignite samples and their respective 1000 c ashes from various locations in greece using x ray diffraction x ray fluorescence spectroscopy and inaa lignites ashed at lower temperature 150 c reveal the presence of quartz feldspars layer silicates pyrite gypsum bassanite and anhydrite in all samples in northwestern greece epirus kozani florina and ptolemais calcite siderite magnesite epsomite hexahydrite jarosite and meta aluminite coexist with the common occurring minerals large variation in the concentration of major constituents in the 1000 c ashes is observed sio 2 varies from 11 98 to 87 72 al 2 o 3 from 4 53 to 23 36 fe 2 o 3 from 3 01 to 39 72 cao from 0 55 to 43 05 mgo from 0 18 to 9 17 and so 3 from 0 02 to 32 72 smaller variations are exhibited by tio 2 na 2 o k 2 o and p 2 o 5 these variations are attributed to the depositional environment high concentrations of pb 548 ppm zn 2991 ppm ba 1520 ppm as 1131 and 1675 ppm mo 565 and 712 ppm w 191 420 ppm and sb 69 ppm are reported in the 1000 c ashes of the selected lignites from serres and drama northern greece samples from another location in northern greece serres yield 5000 ppm u while in drama dipotama u concentration reaches as high as 17 600 ppm the u enrichment of lignites in these locations is attributed to the leaching of this element from the superimposed u bearing volcanic rhyodacitic rocks of oligocene age in southern greece peloponnesus lignite samples from megalopolis xidias drossato and vounargo show high f ranging from 154 to 218 ppm present results indicate that not only the wide variety and combination of elements that can be used to fingerprint lignitic basins but also the possibility of extracting such valuable elements from lignites and their ashes whenever the concentration and economics warrants such an undertaking

rates of erosion and topographic evolution of the sierra nevada california inferred from cosmogenic26al and10be concentrations concentrations of cosmogenic 26 al and 10 be in cave sediments and bedrock surfaces combined with studies of landscape morphology elucidate the topographic history of the southern sierra nevada over the past 5 ma caves dated by 26 al 10 be in buried sediments reveal that river incision rates were moderate to slow between c 5 and 3 ma 0 07 mm a 1 accelerated between 3 and 1 5 ma c 0 3 mm a 1 and then have subsequently become much slower c 0 02 mm a 1 although the onset of accelerated incision coincides in time with both postulated pliocene tectonism and pronounced global climate change we argue that it primarily represents the response to a discrete tectonic event between 3 and 5 ma dated cave positions reveal that prior to 3 ma river canyons displayed up to 1 6 km of local relief suggesting that pliocene rock uplift elevated pre existing topography renewed incision beginning c 3 ma deepened canyons by up to 400 m creating narrow inner gorges tributary streams exhibit strong convexities indicating that the transient erosional response to pliocene uplift has not yet propagated into upland surfaces concentrations of 26 al and 10 be in bare bedrock show that upland surfaces are eroding at slow rates of c 0 01 mm a 1 over the past c 3 ma upland surfaces eroded slowly while adjacent rivers incised rapidly increasing local relief although relief production probably drove at least modest crestal uplift considerable prepliocene relief and low spatially averaged erosion rates suggest that climatically driven rock uplift is not sufficient to explain all uplift implied by tilted markers at the western edge of the range despite the recent pulse of erosion spatially averaged erosion rates are low and have probably acted to preserve the broad topographic form of the sierra nevada throughout much of the late cenozoic copyright 2005 john wiley sons ltd

the petrography mineralogy and geochemistry of a paleocene lignite from southern saskatchewan canada abstract the coal petrology mineralogy and elemental composition was determined on the 5 m thick lignite of the estevan seam bienfait mine southwest saskatchewan organic petrology reveals a dominance of huminite macerals 73 with minor liptinite 7 and inertinite 11 macerals the maceral assemblage and the banded nature of the coal suggests a forest moor depositional environment for the lignite optical and scanning electron microscopy and x ray diffraction reveals that the dominant mineralogy of the coal is quartz and carbonates with minor sulfates the roof parting and floor rock are dominated by quartz and clays with minor feldspars elemental concentration is rather uniform with depth most elements are associated with the mineral matter and increase with increasing ash content the elements b na sr and br are associated with the organic portion of the coal some elements show both a mineral and organic association as ba co fe mo ce dy lu w u the high concentrations of certain elements na b ca is attributed to groundwater circulation which can both introduce and remove elements from the porous lignite

lower pliocene hominid remains from sterkfontein cosmogenic aluminum 26 and beryllium 10 burial dates of low lying fossiliferous breccia in the caves at sterkfontein south africa show that associated hominid fossils accumulated in the lower pliocene these dates indicate that the skeleton stw 573 and newly discovered specimens from jacovec cavern have much the same age approximately 4 million years these specimens are thus of an age similar to australopithecus anamensis from east africa

geochemistry of coals from the elk valley coalfield british columbia canada abstract the elk valley coalfield of british columbia is one of the major coal producing areas in canada the coals are of cretaceous and jurassic cretaceous age and range in rank from high volatile to low volatile bituminous romax 0 8 1 6 coal seams from outcrops and active mines in this coalfield were analysed for rank and maceral composition using reflected light microscopy for geochemistry using aas inaa and icpes and also by proximate and ultimate analyses the elk valley coal seams contain low average concentrations of hazardous elements such as as mo pb and se however there are seams that contain relatively high concentrations of some of these elements such as 8 mg kg and 108 mg kg of arsenic when the geochemistry of coal seams is compared within the different parts of the coalfield the elemental composition amongst the seams from various sections located in the central area of the coalfield is similar coal seams in the northern area of the coalfield have different geochemistry than coal seams in other areas of the coalfield seams in the northern area have much higher as br cr cu fe k and na content but contain less ca

an isochron method for cosmogenic nuclide dating of buried soils and sediments we describe an improved method for dating buried paleosols using measurements of the cosmic ray produced radionuclides 10be and 26al in quartz grains and apply it to a sequence of intercalated tills and paleosols in central missouri usa that record plio pleistocene advances of the laurentide ice sheet a buried paleosol implies a period of surface exposure and nuclide accumulation followed by burial and a halt to nuclide production if the paleosol is formed in a sedimentary unit such as till this unit may also have been emplaced with unknown 26al and 10be concentrations inherited from past surface exposure if the inherited nuclide concentrations are the same at all depths in the soil as is true for well mixed sediments such as till then the 26al and 10be concentrations at different depths in the paleosol will show a linear relationship the slope of this line depends on the duration of burial of the paleosol but not on the inherited nuclide concentrations or on the sample depths thus one can date strata overlying buried paleosols by measuring 26al and 10be at multiple depths in the paleosol and calculating the burial age of the paleosol from the resulting isochron we focus on applying this approach to till paleosol sequences but the basic idea of forming an 26al 10be burial isochron with a set of samples that share the same burial age but differ in other aspects of their exposure history applies to other stratigraphic settings as well the method yields ages for four tills in missouri that are stratigraphically consistent agree with paleomagnetic age constraints and show that ice advanced into missouri near 1 25 ma near 0 8 ma and twice between ca 0 4 and 0 2 ma

organic petrology and geochemistry of intermontane coals from british columbia abstract rank maceral composition and elemental concentrations of coals volcanoclastics and sedimentary partings from coal bearing strata in the blakeburn opencast mine british columbia are determined using reflected light microscopy inaa and inductively coupled plasma emission spectrometry boron only petrologically the coal is similar to that from the hat creek coal deposits nos 1 and 2 of british columbia with vitrinite the dominant maceral group and inertinite macerals contributing only a small percentage three depositional cycles are observed each representing a particular sedimentological and petrological environment of deposition the coal in cycles i and ii was deposited in a freshwater environment with an almost uniform rate of subsidence the coal in cycle iii also formed in a freshwater environment but was subject to erratic subsidence rates distribution of certain elements is similar to that of the hat creek coals e g al br cr ca mo se ti w indicating a certain degree of regional lateral persistence of elemental distribution vertical variations of elemental concentrations are primarily related to the lithology organically bound elements are concentrated mainly in coal and inorganically bound elements are found in the volcanoclastic and sedimentary partings

aspects of the geochemistry of rare earth elements in coal an experimental approach abstract many coals worldwide are slightly enriched in heavy rare earth elements hree relative to light rare earth elements lree as compared with chondrites and shales a factor contributing to this fractionation could be the ability of the hree to form complexes with organic compounds which are more stable than those of the lree in order to test this hypothesis experiments on the sorption of several light and heavy rare earth elements la ce sm eu gd ho er lu on xylain and humic acids were performed the sorption on xylain was found to be ph and time dependent maximum quantity was sorbed in the range of ph 3 to 5 sorption equilibrium was reached in 5 to 7 days the shape of the sorption isotherms for all ree studied were similar the maximum content sorbed for each ree was about 0 2 meq 0 5 g xylain when all ree were present in equal concentration in the initial solution the quantity sorbed was also 0 2 meqv 0 5 g xylain nearly the same quantity of na k ca and mg were displaced from the sorbent these results suggest a cation exchange mechanism in which na k ca and mg bound to cooh and oh groups were replaced by the ree cations the capacity of humic acids leached from xylain was found to be about 0 05 meq ree on 0 250 mg humic acids ha the individual ree were sorbed in nearly equal quantities

geomorphic inheritance and the development of tower karst four genetic types of tower karst are identified the most typical consisting of residual hills protruding from a planed carbonate surface veneered by alluvium two extreme possibilities for tower karst evolution are recognized a direct development that is independent of any previous morphology and a sequential development that depends explicitly on the morphological characteristics of a previous cockpit karst phase examples of both are described although the latter appears the more common south china tower karst is examined in this light palaeomagnetic analysis of cave deposits in a tower near guilin indicate the feature to be a time transgressive landform four principal controls of tower development are discussed and a model of tower evolution is presented

geochemistry of sulfur and elements in coals from the antaibao surface mine pingshuo shanxi province china abstract coal bearing strata in the antaibao surface mine pingshuo mining district shanxi china occur in the taiyuan formation upper carboniferous and shanxi formation lower permian the most productive coal seams in the mine are the nos 11 9 and 4 twenty five samples of coals partings and roof shales from the nos 11 10 9 5 taiyuan formation and 4 shanxi formation seams in the antaibao mine were analyzed for ash and total sulfur contents and forms of sulfur the no 11 seam is a medium to high sulfur coal 1 3 3 1 s a coal sample 14 1 ash from the no 10 seam contains 3 4 and high ash coal 37 4 ash from the same seam contains only 0 4 total sulfur the no 9 seam is a low to medium sulfur coal 0 6 1 3 s the highest sulfur content among the samples is 5 8 total sulfur from a coal sample of the no 5 seam the no 4 seam is low sulfur coal 0 29 0 54 s the remarkable variation in sulfur content among the coal seams in the taiyuan and shanxi formations could reflect different depositional environments from coastal to lower deltaic plain for the taiyuan and from upper deltaic plain to fluvial basin for the shanxi formation the sulfate sulfur comes mainly from the oxidation of pyrite sixteen samples were analyzed for 26 major minor and trace elements by x ray fluorescence spectrometry the sr content is significantly higher in coals from the no 4 seam in the shanxi formation than those from nos 11 to 5 seams chlorine sr ca and p are elements bound organically while si al ti fe k na mg cr v ni rb ba and nb are mainly associated with minerals

abrupt glacial valley incision at 0 8 ma dated from cave deposits in switzerland glacial erosion dramatically alters mountain landscapes but the pace at which glaciers carve a previously fluvial landscape remains poorly defined because long term valley incision rates are difficult to measure here we reconstruct the lowering history of the aare valley switzerland over the past 4 m y by dating cave sediments with cosmogenic 26al and 10be incision accelerated from 120 m m y to 1200 m m y at 0 8 1 0 ma at least 1 m y after the onset of local glaciation rapid incision may have been triggered by lowering of the equilibrium line altitude at the mid pleistocene climate transition

geochemistry of rare earth elements in a marine influenced coal and its organic solvent extracts from the antaibao mining district shanxi china twenty six samples including roof bottom and coal plies of a marine influenced coal bed were collected from the antaibao mining district shanxi china the rare earth elements rees were determined in solids and organic solvent extracts the distribution pattern showed three distinct patterns shale like lree rich and hree rich this is attributed to the variable microenvironment of peat forming swamp the degree of marine influences and different ree sources rees in the coal are mainly controlled by detrital minerals but also affected by seawater the chondrite normalized ree patterns of the organic solvent extracts are distinctly different from those of corresponding original coal samples which show a negative eu anomaly a depletion of middle rees and an enrichment of hrees the lrees in coal extracts are likely adsorbed by hydrogen containing functional groups and hrees are likely bonded to carbon atoms

mineralogical speciation of elements in an eastern canadian feed coal and their combustion residues from a canadian power plant systematic changes in mineralogy enrichment and depletion of selected elements and mineralogical speciation of selected elements in fly ash and bottom ash samples from the lingan power plant were compared to run of mine and pulverized feed coal from the sydney coalfield nova scotia eastern canada the analytical techniques used were an electron microprobe equipped with energy and wavelength x ray dispersive spectrometers x ray diffraction neutron activation scanning electron microscopy with energy dispersive x ray and incident light petrography three types of glasses feo rich fe al si o rich and or al si o rich were identified in the combustion residues they were formed as a result of the interaction of melted pyrite and clay minerals compared to the feed coal most elements were enriched 10 to20 times in the fly ash the concentration of the elements in both the fly ash and bottom ash are comparable to coal ash that is generated by the low temperature asher in the laboratory some chalcophile elements such as arsenic and lead occurred as a solid solution in pyrite in the feed coal and were concentrated in the float fraction density 2 81 g cm3 of the fly ash with non crystalline fe oxides x ray mapping of arsenic in the fly ash and bottom ash indicates that arsenic was evenly distributed as oxide within the feo and fe al si o rich glass and crystalline phases in the fly ash possibly in solid solution arsenic is associated with feo and fes crystalline phases in the bottom ash

coals of greece a review of properties uses and future perspectives abstract greece relies heavily on lignites to satisfy its domestic needs for power generation and produces some of the cheapest and most cost effective kwh within the european community currently it mines 70 tons year of soft brown coal to cover over 70 of the country s domestic power needs brown coal in greece is found in 68 coal basins of various sizes generally it is of poor quality that is of low calorific values and relatively high ash content henceforth a detailed knowledge of maceral and ash composition is essential to appropriately construct boilers to avoid abrasion of mechanical parts fouling and corrosion of boilers and to take appropriate environmental measures though the composition of the maceral groups is relatively the same in almost all greek coal basins the composition of maceral subgroups especially that of huminite varies substantially this variation affects boiler s performance since the maximum heat release takes place at various heights inside the boiler humotelinitic brown coals rich in resinite release their thermal energy at lower temperatures than humocollinitic coals which have low resinite contents furthermore coal ash rich in gypsum anhydrite and other minerals with hardness less than 3 do not affect the mechanical parts of the boiler whereas coal ash rich in quartz feldspars and pyrites do finally greek brown coals have variable trace elemental composition coals from basins surrounded by carbonate rocks western greece do not exhibit high concentrations of heavy elements whereas coals from basins surrounded by mafic rocks north central greece are rich in cr ni cu and zn while coal basins surrounded by igneous rocks north eastern greece are rich in pb zn co hg as and u

the influence of geological factors on the concentration of boron in australian and canadian coals abstract the concentration of boron in australian and canadian coals determined using atomic emission spectrometry aes inductively coupled plasma spectrometry icp aes and prompt gamma ray spectrometry is summarized in order to assess the variation of b content in coal with respect to rank age geological setting in seam and stratigraphic and the degree of paleosalinity of the coal forming environment this study indicates that no or very complex relations exist between boron and rank subbituminous to anthracite variations of b with ash content for canadian coals of different age devonian to oligocene eocene indicate that the b content of coals is not governed by the age of the coal there is some evidence of variation of b with maceral content in canadian coals particularly as related to the inertinite and vitrinite content of coals the b content of coal seams is sensitive to the environment of deposition with b contents remaining relatively stable and within the range of values designated for each depositional setting however b values may show variation in the same seam laterally due to changes of the environment of deposition and or the enrichment of b by a secondary source the vertical variation of b in a coal bearing section or strata is related to depositional environment and lithology of rock there is often little variation in b content for coal layers as compared to the partings dirt bands the b content of partings in a coal bearing strata may vary greatly as compared to the coal seams after reappraising earlier work and on the basis of more recent studies on australian and canadian coals it is proposed that the following ranges of values for b in coal indicate the degree of marine influence during the early stages of coalification up to 50 ppm b freshwater influenced coals 50 110 ppm b mildly brackish water influenced coals 110 ppm b brackish water influenced coals using these criteria assessments are given for the degree of marine influence on canadian and australian coals

preliminary study of quaternary tectono climatic cycles in china major cycle ii this started in the middle part of the aggradation of early pleistocene lacustrine and fluviolacustrine beds nihewan yuanmou and qiangtant formations and ceased with the deposition of the top part of these strata during this cycle the second glacial stage corresponding to the shizishan glacial stage of the east kunlun mountains is essentially indicated by sporepollen assemblages and periglacial phenomena reflecting a cold climate until the second interglacial stage or the late part of it intense tectonic movements also named nihewan yuanmou and qiangtang movements occurred simultaneously all over the country and interrupted the development of early pleistocene lakes the timing is shown by magnetostratigraphy and began near the gauss matuyama boundary and ended after the olduvia event major cycle i this began about 3 4 ma ago when global climate became colder and continued to about 2 4 ma bp corresponding more or less with the entire gauss epoch the moraines and the fluvioglacial or periglacial sediments representing the first glaciation rest mostly unconformably on bedrock including pliocene sequences with partial conformity in places overlying fluviolacustrine beds are generally in overlapping or transitional relationship with them for example it can be seen that the sammen movement marking the end of major cycle i led to a break in the sedimentation in the ancient sanmen lake of the sanmenxia area on yellow river cao et al 1983 several boundaries between the various cyclothems stratigraphically and geomorphologically using magnetostratigraphy and climatostratigraphy the boundaries between three major cycles can be established as follows

late cenozoic uplift of southeastern tibet the age of surface uplift in southeastern tibet is currently unknown but the initiation of major river incision can be used as a proxy for the timing of initial uplift the topographically high eastern plateau and gently dipping southeastern plateau margin are mantled by an elevated low relief relict landscape that formed at a time of slow erosion at low elevation and low tectonic uplift rates prior to uplift of the eastern tibetan plateau thermochronology from deep river gorges that are cut into the relict landscape shows slow cooling between ca 100 and ca 10 20 ma and a change to rapid cooling after ca 13 ma with initiation of rapid river incision at 0 25 0 5 mm yr between 9 and 13 ma a rapid increase in mean elevation of eastern tibet beginning at this time supports tectonic climate models that correlate the lateral eastern expansion of high topography in tibet with the late miocene intensification of the indian and east asian monsoons

young uplift in the non glaciated parts of the eastern alps abstract we report the first incision rates derived from burial ages of cave sediments from the mur river catchment at the eastern margin of the eastern alps at the transition zone between the alpine orogen and the pannonian basin this river passes through the paleozoic of graz a region of karstifiable rocks called the central styrian karst this river dissects the study area in a north south direction and has left behind an abundance of caves these caves can be grouped into several distinct levels according to their elevation above the present fluvial base level age estimates of abandoned cave levels are constrained by dating fluvial sediments washed into caves during the waning stages of speleogenesis with the terrestrial cosmogenic nuclide method these ages and the elevations of the cave levels relative to the current valley floor are used to infer a very complex history of 4 million years of water table position influenced by the entrenchment and aggradation of the mur river we observe rather low rates of bedrock incision over the last 4 ma in the order of 0 1 mm y with an e folding decrease in this trend to lower rates at younger times we relate this incision history to a tectonic setting where an increase of drainage area of the mur river due to stream piracy in late miocene to pliocene times is linked to surface uplift the later decrease in valley lowering rates is attributed to the rise of the base level related to aggradation of sediments within the valley sediment transport through the valley from the upstream section of the mur river limited the erosional potential of the river to a transport limited state at the later stages of the incision history

integration of geology rock physics logs and prestack seismic data for reservoir porosity estimation the main objective of this article is to obtain reservoir properties such as porosity both at the well locations and in the interwell regions from seismic data and well logs the seismic and well log data sets are from an oil field in eastern saudi arabia and the main target is a jurassic carbonate reservoir the geology of carbonate reservoirs in saudi arabia is well understood reservoir porosity estimation is essential and needs to be determined for flow simulation and reservoir management a major component of this study is establishing the relation between the p impedance and porosity using well log data an amplitude versus angle seismic inversion algorithm was used to invert the three dimensional impedance volumes i e p impedance and s impedance given partial angle stacks of seismic traces representing reflection amplitude variations with angle of incidence these impedance volumes were used to estimate porosity between the well locations the seismic and log data provided a priori information i e the initial starting model and source wavelet estimate necessary for obtaining geologically consistent results

chemistry of fresh and weathered resinites an infrared photoacoustic spectroscopic study abstract photoacoustic infrared spectroscopy has been used to examine the chemical structures of resinites collected from coals of western canada arctic canada and australia variations in the chemical structure of the resinites were examined from the point of view of location of the resinite within the coal bearing strata and coal bearing section and the effect of rank and age the effects of weathering were analyzed in terms of the structures determined by infrared spectroscopy of the more weathered exterior surface as compared to the less weathered unexposed interior surface the molecular structure of the less weathered interior surfaces was found to be rather similar for resinites of similar rank the exterior weathered surfaces were usually quite different and these differences were related to rank and the degree of weathering influenced by the depositional environment

the partitioning behaviour of boron from tourmaline during ashing of coal abstract boron is an environmentally sensitive element that may be present in high concentrations in some coals three modes of occurrence for boron in coal are commonly recognised namely bound to the organic fraction locked into clay minerals mainly illite and bound within the crystal lattice of tourmaline the organically bound mode is generally considered to be the most likely following combustion in a pulverised fuel utility boron is generally enriched in the fine fly ash waste but in some cases it may also escape with the flue gas suggesting variable partitioning behaviour there is concern that boron may be leached from fly ash disposal impounds at concentrations toxic to higher land plants a coal sample from the d seam of the strongman no 2 mine west coast south island new zealand has been used to test the hypothesis that boron present in tourmaline is less volatile in coal combustion implying that mode of occurrence is a key control on the partitioning behaviour of this element six sample subsets were doped with increasing amounts of ground tourmaline one subsample from each set was analysed by prompt gamma inaa to determine the concentration of boron in the coal two subsamples were ashed at 1000 c one ash sample from each set was analysed for boron while the other ash sample was leached according to australian standards it was found that the relationship between boron in the doped coal and boron in the ash is approximately linear with some losses noted during ashing indicating boron present in tourmaline was substantially retained in the ash furthermore no relationship was found between the boron content of the ash and boron leached from the ash samples by reagent water the results suggest boron present in coal as tourmaline is retained in the ash and is unavailable to the environment following fly ash disposal

seismic monitoring of fluid fronts an experimental study seismic signatures of time dependent reservoir processes necessary for the interpretation of 4 d seismic data are still insufficiently described this experiment was designed to monitor fluid front movements and saturation changes and to identify the related seismic signatures ultrasonic p and s wave transmission and reflection measurements were used to monitor the waterflooding of a porous sandstone the sandstone was flooded in steps by filling a tank in which the room dry cubic 50 cm side block of rock was placed waterflooding caused the velocity amplitude and frequency of the transmitted waves to diminish significantly however the changes were reversible by drying the maximum reduction of the velocities was 7 and 12 for p and s waves respectively the velocity and amplitude behavior can be explained by the biot gassmann s theory local fluid flow and grain surface effects the correct interpretation of seismic signatures of fluid processes in reservoirs thus involves a knowledge of rock

a study of coal facies in the korba sub basin mahanadi valley india abstract in the korba sub basin an effort has been made to study the coal facies with the help of maceral content microlithotypes chemical constituents of coal and by depositional milieu macerals like vitrinite when associated with sporinite strongly characterised freshwater conditions i e limnic and telmatic microlithotypes of this sub basin mostly reflect conditions of a high groundwater level in a swamp forest microlayering observed in clarites suggest a certain phase of stagnant water conditions in a subsiding sub basin durite indicates sub aquatic facies carbominerite is more useful in studying lateral facies and the decrease of carbominerite content towards the eastern part of the sub basin points to the existence of eutropic swamp conditions the low concentration of boron low sulphur content and the presence of germanium in all blocks of the sub basin reflects limnic and telmatic coal facies in freshwater swamps the depositional milieu favoured the existence of limnic and adjacent telmatic conditions

trace element contents in composited samples of three lignite seams from the central part of the drama lignite deposit macedonia greece abstract drill core samples of three lignite seams from the central part of the drama lignite deposit and their corresponding 1000 c ash samples were analyzed for their trace element contents by instrumental neutron activation inaa and inductively coupled plasma icp analyses compared to crustal abundances the lignite samples are enriched in as br mo and sb while ba co cr cs eu hf la lu rb sc sm tb yb zn zr and au are depleted while br is negatively correlated with the ash content of the lignite samples ce co cr la sc sm and yb are positively correlated elements from the sorrounding rocks and mineralizations of the drama basin have influenced the inorganic constituents of the lignite

nature and depositional environment of devonian coals from western melville island arctic canada abstract the petrology and depositional environment of a suite of middle to upper devonian coals and carbonaceous shales from melville island has been studied the majority of the coals and carbonaceous shales are cannel coal and canneloids the sporinite content of cannel coal ranges as high as 80 the reflectance of vitrinite in cannel coals is suppressed compared with the normal coal from the same area these coals were deposited in fresh to slightly brackish water in interdelta lobe bays and lacutrine complexes associated with lower delta plain settings as indicated by the boron content 4 71 ppm petrology cannel and canneloid and sedimentology

quaternary sediment in the yichang area implications for the formation of the three gorges of the yangtze river sediment data from the yichang area in the jianghan basin of hubei province in china suggest deposition in a lacustrine environment prior to 0 75 ma b p followed by incision of the yangtze river the earliest quaternary yunchi formation accumulated in an alluvial fan to fan delta environment the subsequent shanxiyao formation was deposited in an environment that changed from fan delta to lacustrine the distribution of sedimentary facies suggests the presence of a lake in the yichang area prior to 0 75 ma b p the lack of sediments contemporaneous with the yunchi and shanxiyao formations in other areas of the jianghan basin suggests that this ancient lake was limited to the yichang area this lake predates the present yangtze river in the yichang area and the jianghan basin provenance studies of gravels in the yunchi and shanxiyao formations as well as gravels in terraces and the channel of the yangtze river indicate a variety of sediment sources but suggest that no material from the area west of the three gorges had been carried into the yichang area prior to 0 75 ma b p the yangtze river cut through three gorges area only after 0 75 ma b p

geochemistry of boron in bulgarian coals a set of 466 individual full channel samples coals coaly shales and partings of thirteen bulgarian coal deposits as well as vitrain lenses gagatite and coalified woods embedded in sedimentary rocks have been analyzed by atomic emission spectroscopy the deposits consist of lignites subbituminous and bituminous coals the average boron content ranges from 15 to 164 ppm in the coals the boron content of the individual coal samples ranges from 2 to 164 ppm about 86 of the samples have a b content from 2 to 110 ppm which corresponds to the most probable interval of concentration for coals worldwide the boron content is not related to rank the lignites have the lowest boron content some of the vitrain and xylain samples studied are enriched in boron in comparison with the whole coal samples boron occurs in both organic borg and inorganic binorg forms excluding one deposit the boron content in the ash correlates negatively with the ash content whereas in coals it usually slightly increases with increasing ash content organically associated b dominates in the low ash coals and in the deposits enriched in boron the coals of the burgas deposit have the highest b content which is in agreement with the geological evidence for marine influence during the early stages of coalification the distribution of b is also independent of other geological factors

concentration of elements in lacustrine coals from zone a hat creek deposit no 1 british columbia canada abstract coal samples from the 170 m thick a zone of the hat creek coal deposit no 1 in central british columbia were examined for major minor and trace element distribution the coal is lignite subbituminous in rank and of eocene age this study shows 1 as b br cl and s are the only elements organically associated in these samples 2 concentration of certain elements such as fe mn and co can be related to the presence or absence of carbonate and or sulphide minerals 3 distribution of certain elements i e al b br cl cr fe th u and zn follow similar patterns of concentration or depletion across the vertical thickness of zone a and suggest three depositional cycles 4 concentration of boron versus chromium sodium sulphur and uranium for these coals clearly placed them in a freshwater environment 5 rates of sedimentation using the na k ratio also suggest three depositional cycles 6 in resinite samples hand picked from these coals the concentrations of all elements except as and se were lower than their concentrations in the whole coals

a new chronology for the age of appalachian erosional surfaces determined by cosmogenic nuclides in cave sediments the relative chronology of landscape evolution across the unglaciated appalachian plateaus of kentucky and tennessee is well documented for more than a century geomorphologists have carefully mapped and correlated upland erosional surfaces inset by wide valley straths and smaller terraces constraining the timing of river incision into the appalachian uplands was difficult in the past due to unsuitable dating methods and poorly preserved surface materials today burial dating using the differential decay of cosmogenic 26al and 10be in clastic cave sediments reveals more than five million years of landscape evolution preserved underground multilevel caves linked hydrologically to the incision history of the cumberland river contain in situ sediments equivalent to fluvial deposits found scattered across the eastern highland rim erosional surface cave sediments correlate with 1 thick lafayette type gravels on the eastern highland rim deposited between c 5 7 and c 3 5 ma 2 initial incision of the cumberland river into the eastern highland rim after c 3 5 ma 3 formation of the parker strath between c 3 5 ma and c 2 0 ma 4 incision into the parker strath at c 2 ma 5 formation of a major terrace between c 2 0 ma and c 1 5 ma 6 shorter cycles of accelerated incision and base level stability beginning at c 1 5 ma and 7 regional aggradation at c 0 85 ma initial incision into the appalachian uplands is interpreted as a response to eustasy at 3 2 3 1 ma incision of the parker strath is interpreted as a response to eustasy at 2 5 2 4 ma a third incision event at c 1 5 ma corresponds with glacial reorganization of the ohio river basin widespread aggradation of cave passages at c 0 85 ma is interpreted as the beginning of intense glacial interglacial cycling associated with global climate change copyright 2006 john wiley sons ltd

pliocene pleistocene incision of the green river kentucky determined from radioactive decay of cosmogenic 26al and 10be in mammoth cave sediments cosmogenic 26al and 10be in sediments washed into mammoth cave kentucky record the history of 3 5 m y of water table position governed by incision and aggradation of the green river a tributary of the ohio river upper levels of the cave formed during a period of slow river incision and were later filled with sediment due to river aggradation at 2 3 2 4 ma a brief surge of river incision ca 2 ma was followed by river stability and cave passage formation at a lower level rapid incision through 15 m of bedrock ca 1 5 ma was prompted by repositioning of the ohio river to its present course along an ice sheet margin renewed incision ca 1 2 ma and aggradation at 0 7 0 8 ma correlate with major ice advances in the ohio river basin measurements of 26al and 10be also indicate that sandstone capped uplands have maintained slow erosion rates of 2 7 m m y for the past 3 5 m y despite accelerated pleistocene river incision rates of 30 m m y

sequence stratigraphy organic petrology and chemistry applied to the upper and lower coal seams in the candiota coalfield parana basin rs brazil abstract the permian age coal seams in the candiota coalfield represent the largest coal deposit of the country currently two seams are mined called camada candiota superior and camada candiota inferior the other coal seams of the coalfield seams s1 s9 upper seams and i1 i5 lower seams have as yet not been exploited the objective of this paper is to perform a detailed sequence stratigraphic petrologic and chemical study of the upper and lower coal seams thereby generating data for assisting in the development and better use of the coal bearing interval the methodology includes application of the concepts of sequence stratigraphy which includes the lithological interpretation of the core to establish the depositional environments and genetic correlation between facies associations to define parasequences and bounding surfaces coal petrology analysis of the reflectance of vitrinite determination of the petrographic composition of the coals by maceral analyses and chemical analyses such as sulphur determination proximate analyses ash moisture volatile matter and fixed carbon and elemental analyses three main depositional systems were so far identified alluvial fan fluvial system lagoonal estuary system this study shows that coal development was controlled by accommodation accumulation rates with coal seams with greater thickness and lateral continuity being formed within the transgressive systems tract lagoonal depositional system of parasequence 2 ps2 indicating that the accumulation rates of the peat and distribution of the coal seams were controlled by stratigraphic setting vitrinite reflectances for the upper and lower coal seams are indicative of subbituminous rank rrandom 0 36 0 47 with evidence that anomalously low reflectance values are related to high mineral matter contents maceral composition is highly variable with some coal seams being extremely rich in inertinite up to 65 vol the upper and lower coal seams are ash rich ranging from 22 4 to 62 3 wt with the majority being classified as carbonaceous rocks very low grade coal sulphur contents in the upper and lower seams range from 0 41 to 8 08 wt with the majority below 1 wt the high amounts of sulphur 3 wt in some of the coal seams may indicate coastal flooding during the lifetime of the mire or shortly after

elemental distribution in coal seams at the fording coal mine british columbia canada abstract elemental compositions of coals from fording southeastern british columbia were examined using inaa and icp spectrometry detailed elemental analyses were carried out for coal seams in two equivalent sections and also within selected coal seams elemental concentrations in coal bands within individual seams were compared with those of tonstein bands and other partings within coal seams there was an overall decrease in the concentration of al as lu sc and th for coal bands within a coal seam in contrast the concentration of these elements in partings in the same seam remained almost constant or increased from roof to floor concentrations of certain elements for example k mg mn na sb th u v and zn for coal samples occurring in the eagle mountain section follow similar trends regular variation in the concentration or depletion of some elements indicates the presence of three cycles at eagle mountain and two cycles in the greenhills section a good correlation was observed between b concentration and the environment of deposition of these coals particularly when the b contents of coals deposited in fresh water and a brackish environment are compared the coals in the eagle mountain section were deposited in a semi brackish environment with the exception of the four uppermost coal samples which were deposited in a freshwater to semi brackish environment correlations between b and s or b and the br cl ratio were clearly grouped according to the depositional environment of the coals concentration of cr was greater for coals deposited in fresh water in contrast the th was more abundant in brackish coals

comparison of u th paleomagnetism and cosmogenic burial methods for dating caves implications for landscape evolution studies caves are useful in landscape evolution studies because they often mark the level of previous water tables and when dated yield incision rates dating caves is problematic however because their ages are only constrained by the oldest deposits contained within which may be far younger than the cave itself we dated cave deposits in the sierra nevada using u th dating of speleothems paleomagnetic dating of fine sediment and cosmogenic 26 al 10 be burial dating of coarse sediment the sampled caves formed sequentially as the water table lowered providing an important stratigraphic test for the dating methods large discrepancies between deposit ages from similar cave levels demonstrate that even when accurately determined deposit ages can seriously underestimate the timing of cave development drip type speleothems are most prone to this minimum age bias because they can accumulate long after caves form and because the u th method is limited to 400 ka paleomagnetic dating requires correlation with the global reversal chronology and is hindered by a lack of continuous stratigraphy the fine sediment analyzed for paleomagnetism is also highly susceptible to remobilization and deposition in cave passages well above base level cosmogenic 26 al 10 be dates bedload material deposited when caves were at or very near river level and can date material as old as 5 ma in the sierra nevada speleothem u th ages and sediment burial ages from the same cave levels differ by as much as an order of magnitude these results suggest speleothem ages alone may significantly underestimate cave ages