geochemical and mineralogical evidence for a coal hosted uranium deposit in the yili basin xinjiang northwestern china abstract the petrological geochemical and mineralogical compositions of the coal hosted jurassic uranium ore deposit in the yili basin of xinjiang province northwestern china were investigated using optical microscopy and field emission scanning electron microscopy in conjunction with an energy dispersive x ray spectrometer as well as x ray powder diffraction x ray fluorescence and inductively coupled plasma mass spectrometry the yili coal is of high volatile c b bituminous rank 0 51 0 59 vitrinite reflectance and has a medium sulfur content 1 32 on average fusinite and semifusinite generally dominate the maceral assemblage which exhibits forms suggesting fire driven formation of those macerals together with forms suggesting degradation of wood followed by burning the yili coals are characterized by high concentrations of u up to 7207 g g se up to 253 g g mo 1248 g g and re up to 34 g g as well as as up to 234 g g and hg up to 3858 ng g relative to the upper continental crust the rare earth elements rees in the coals are characterized by heavy or and medium ree enrichment the minerals in the yili coals are mainly quartz kaolinite illite and illite smectite as well as to a lesser extent k feldspar chlorite pyrite and trace amounts of calcite dolomite amphibole millerite chalcopyrite cattierite siegenite ferroselite krutaite eskebornite pitchblende coffinite silicorhabdophane and zircon the enrichment and modes of occurrence of the trace elements and also of the minerals in the coal are attributed to derivation from a sediment source region of felsic and intermediate petrological composition and to two different later stage solutions a u se mo re rich infiltrational and a hg as rich exfiltrational volcanogenic solution the main elements with high enrichment factors u se as and hg overall exhibit a mixed organic inorganic affinity the uranium minerals pitchblende and coffinite occur as cavity fillings in structured inertinite macerals selenium as and hg in high pyrite samples mainly show a sulfide affinity

laboratory experiments simulating the geomorphic response to tectonic uplift 1 we present the results of an experimental study of topography dynamics under conditions of constant precipitation and uplift rate the experiment is designed to develop a complete drainage network by the growth and propagation of erosion instabilities in response to tectonic perturbations the quantitative analysis of topographic evolution is made possible by using telemetric lasers that perform elevation measurements at an excellent level of precision we focus our study on the effect of initial surface organization and of uplift rate on both the transient dynamics and the steady state forms of topography we show that the transient phase is strongly dependent on the initial internally drained area which is found to decrease exponentially with time the topography always reaches a steady state whose mean elevation depends linearly on uplift rate with a strictly positive value when uplift is zero steady state surfaces are characterized by a well defined slope area power law with a constant exponent of 0 12 and an amplitude that depends linearly on uplift rate with a strictly positive value when uplift is zero these results are consistent with a stream power law erosion model that includes a nonnegligible threshold for particle detachment uncertainty regarding the sediment transport length is resolved by calibrating the transient dynamics with a surface process model reappraising published results on the linear dependency between mean elevation or relief and denudation rate we suggest that an erosion threshold is worth considering for large scale systems

petrology mineralogy and geochemistry of the permian and triassic coals in the leping area jiangxi province southeast china abstract permian and triassic coals from a series of mines in jiangxi province china exhibit a number of unusual geochemical mineralogical and petrographic characteristics the high volatile bituminous permian coals have high concentrations of the suberinite like maceral barkinite the origin and even the distinct character of barkinite are in dispute and consequently it has not been recognized as a distinct maceral by the international committee for coal and organic petrology iccp the permian bituminous coals have relatively high concentrations of pyrite and marcasite otherwise detrital minerals dominate their geochemistry the triassic coals all from one mine complex have higher rank a permian coal is also mined most samples straddle the low volatile bituminous semi anthracite boundary the one semi anthracite rank permian coal shows signs of incipient coking a triassic coal in the same fault block is coked by an igneous intrusions found in the mine the coals have in general been dolomitized aside from the geochemical imprint of the dolomitization trace element associations suggesting a contribution from a detrital mineral assemblage dominate the coals

geochemistry and mineralogy of coal in the recently explored zhundong large coal field in the junggar basin xinjiang province china abstract the zhundong coalfield is a very large coal deposit currently under exploration and promises to be an important coal mining resource in western china the coal reserves amount to 164 gt at xiheishan and wucaiwan the coal bearing units are the badaowan lower jurassic and especially the xishanyao formations middle jurassic these contain from one to 31 coal seams one to 10 workable coals reaching the rank of high volatile a bituminous with an accumulated workable coal thickness of 20 87 m these recently explored coal reserves are of a high quality and are characterized by low ash aluminum iron sulfur and trace element contents the minerals present in this coal are mainly quartz kaolinite siderite and pyrite the trace element contents in both xiheishan and wucaiwan coals are much lower when compared with the usual concentration ranges present in chinese coals with the exception of ba and sr thus ba contents in xiheishan coal are higher than swaine s worldwide concentration range a large number of elements have mainly aluminosilicate affinity and occur in clay and other detrital coal minerals ca and mn have mainly carbonate affinity fe and s have mainly sulphide affinity in wuchaiwan coal in xiheishan fe mn and mg have mainly carbonate affinity siderite and probably b co ni and s have an organic affinity thus the zhundong coalfield contains coal with a very high quality and very low levels of impurities the very low ash yields s fe and trace element contents may be attributed to the sedimentological setting with intensive peat bog aggradation in a very shallow lake environment with a low detrital supply the very low sulfur content the relatively high ba sulfate barite content and the high siderite occurrence in xiheishan coal in contrast to the pyrite occurrence in wucaiwan coal may be attributed to the rapid aggradation of peat with the consequent oxidation and leaching of minerals elements and degradation of organic components under this scenario sulfate is trapped by the continuous precipitation and accumulation of barium sulfate very low soluble

optical properties of pseudovitrinite implications for its origin a set of pennsylvanian coals from the north american coal basins ranging in vitrinite reflectance from 0 65 to 1 75 was examined with special emphasis on the optical properties of pseudovitrinite the results suggest that pseudovitrinite originates from the same material as telocollinite slits in the pseudovitrinite seem to have originated in situ due to low temperature oxidation of woody material their opening might have been facilitated by devolatilization during coalification the dominant orientation of the slits is perpendicular to bedding the intensity and orientation of the slits in pseudovitrinite could be important factors in predicting coalbed gas extraction from coal

variations in elemental composition of macerals with vitrinite reflectance and organic sulphur in the greta coal measures new south wales australia abstract the elemental composition of the individual macerals in the early permian greta coal measures of the northern sydney basin and adjoining cranky corner basin new south wales including some seams with high to very high organic sulphur contents have been analysed in polished sections using light element electron microprobe techniques and the results evaluated in the light of vitrinite reflectance and other characteristics of the coals concerned as with other australian coals the vitrinite macerals in each sample have the lowest proportions of carbon and highest proportions of oxygen and the inertodetrinite and fusinite macerals the highest c and lowest o contents semifusinite and the liptinite macerals have intermediate c and o percentages organic sulphur and organic nitrogen are also highest in the vitrinite macerals of the individual samples and lowest in the fusinite and inertodetrinite components the vitrinite macerals in the puxtrees seam of the greta coal measures on the muswellbrook anticline in the upper hunter valley have similar elemental compositions 78 c and similar reflectance values rv max around 0 7 to vitrinites in the late permian bituminous coals in other parts of the sydney bowen basin the vitrinites in the seams of the cranky corner basin also have similar carbon contents to the puxtrees seam material suggesting a similar rank level but have much lower vitrinite reflectance values rv max 0 4 0 5 probably due to marine influence associated with the depositional system the vitrinites in the greta seam on the lochinvar anticline in the lower hunter region have higher carbon contents 83 than the puxtrees material suggesting a higher rank level but similar to lower vitrinite reflectance values rv max 0 6 0 7 vitrinite carbon is also constant through the seam profile despite upwardly decreasing reflectance values in the seam due to progressive increases in marine influence the vitrinites in the upper greta seam and the cranky corner basin coals have high to very high organic sulphur contents again probably due to marine influence on the depositional process the vitrinites in the cranky corner basin coals which have particularly high organic sulphur contents also have somewhat lower oxygen contents in relation to their carbon percentages than those of other australian seams suggesting that the additional organic sulphur has replaced oxygen in the macerals molecular structure the macerals especially the vitrinites in the coals with high organic sulphur and anomalously low vitrinite reflectance also have up to 0 5 al and 1 ca intimately associated with the organic matter similar organically associated inorganic elements are commonly found in lower rank e g sub bituminous coals but are usually lost from the organic matter at higher rank levels the coals of the greta coal measures therefore have vitrinite carbon contents consistent with a high volatile bituminous rank but those seams or parts of seams with high organic sulphur due to substantial marine influence appear to have preserved the vitrinite reflectance values and organically associated inorganic elements more typical of lower rank sub bituminous materials

enrichment of u se mo re v in coals preserved within marine carbonate successions geochemical and mineralogical data from the late permian guiding coalfield guizhou china we present multi element data on the super high organic sulfur shos 5 19 on average coals of late permian age from guiding in guizhou province china the coals formed on restricted carbonate platforms are all highly enriched in s u se mo re v and cr and to a lesser extent ni and cd although the guiding coals were subjected to seawater influence boron is very low and mainly occurs in tourmaline and mixed layer illite smectite uranium mo and v in the coal are mainly associated with the organic matter in addition a small proportion of the u occurs in coffinite and brannerite the major carrier of se is pyrite rather than marcasite rhenium probably occurs in secondary sulfate and carbonate minerals the u bearing coal deposits have the following characteristics the formation age is limited to late permian concentrations of sulfur and rare metals u se mo re v and in some cases rare earth elements and y are highly elevated the u bearing coal beds are intercalated with marine carbonate rocks organic sulfur and rare metals are uniformly distributed within the coal seams and the combustion products e g fly and bottom ash derived from the coal deposits may have potential economic significance for rare metals u se mo re v rare earth elements and y

impact of sulphur and trace element geochemistry on the utilization of a marine influenced coal case study from the south wales variscan foreland basin abstract incremental channel samples through two high volatile a bituminous coal seams the amman rider and bute seams below and above the vanderbeckei marine band at the westphalian a b boundary have been analysed using proximate petrographic inductively coupled plasma mass spectrometry icp ms x ray fluorescence xrf and scanning electron microscopy with energy dispersive x ray sem edx techniques the results show that both coals are vitrinite rich and indicate a similar history of palaeomire development with a period of falling water tables towards the middle plies of each seam mean sulphur contents in the coal with the marine roof the amman rider seam 4 19 wt are almost 4 times higher than in the coal with a non marine roof the bute seam 1 09 wt implying that high sulphur contents are derived from sea water sulphate in both coals sulphur is predominantly in the form of pyritic sulphur both syngenetic framboidal and euhedral crystals and epigenetic vein and cleat fill pyrite are present relatively constant levels of organic sulphur at around 2 have been recorded in the amman rider seam sulphur levels in the basal and top plies of each seam are at least twice that of the ply with the lowest sulphur content in the seam reflecting the stages in palaeomire development most strongly influenced by sulphate containing waters thorium uranium ratios are below 2 9 in the coal with a marine roof the amman rider seam indicating an enrichment of u from sea water most marked at the top and bottom of the seam the seam without a marine roof shows th u ratios between 2 5 and 4 9 indicating mild marine enrichment of u the concentrations of environmentally significant trace elements eses are correlated with either the ash or sulphur contents or both the correlation between s and pb as cu ni in the coal with a marine roof implies an origin of these eses from sea water and their mode of occurrence in sulphide minerals most eses in this coal are present at levels at least twice that of the global average in coals the exceptions being pb and zn which have concentrations less than half the global average by contrast the coal without a marine roof and with lower sulphur contents has most eses present at concentrations less than a third of the global average the exceptions being ni and cu diagenetic hydrothermal activity is documented in the middle ply of the coal with a marine roof this hydrothermal system redistributed the sulphur pb and as in this ply the principal utilization of bituminous coals in the south wales coalfield is as feed coals in power station boilers the resultant concentration of most eses in the solid residues from power plant coal combustion theoretically can be alleviated by careful blending of feed coals with low and high ese contents

sulfur in coals a review of geochemistry and origins geochemical studies of sulfur in coals comprise several major aspects relating to the nature and origin of sulfur in coals including the abundance and distribution of sulfur in coal seams abundance of sulfur in coal lithotypes and macerals characteristics and geochemical significance of sulfur containing organic compounds sulfur isotopic studies relating to the sources of sulfur in coals and sedimentary environments controlling the geochemistry of sulfur in coal a review of the evidence suggests that the variation of sulfur in coals is closely related to the depositional environments of coal seams for low sulfur coal 1 s sulfur is derived primarily from parent plant material for medium sulfur 1 to 3 s and high sulfur 3 s coals there are two major sources of sulfur 1 parent plant material and 2 sulfate in seawater that flooded peat swamps abundances of sulfur in coal are largely controlled by the degree of seawater influence during peat accumulation and by postdepositional changes diagenesis in high sulfur coals seawater sulfate diffuses into the peat which is subsequently reduced by bacteria into hydrogen sulfide polysulfides and elemental sulfur reaction of hydrogen sulfide with ferrous iron generates fine pyrite crystals and mackinawite fes0 9 mackinawite reacts with elemental sulfur to converts to greigite fe3s4 and then to framboidal pyrite the reduced sulfur species in the peat hydrogen sulfide elemental sulfur and polysulfides react with the organic matter to form organic sulfur compounds during coal diagenesis nodular pyrite forms permineralized peat was formed during diagenesis which contains appreciable fraction of pyrite after coal is solidified pyrite can deposit in the cleats from circulating groundwater epigenetic pyrite veins may be deposited from basinal fluids thus pyrite forms during various stages of coal formation from peat to coal as well as late epigenetic activity the relationships between sulfur abundance in coal seams and depositional environments of coals were reviewed for cases from the u s china u k germany hungary turkey indonesia and brazil in most cases low sulfur coals formed in a fluvial environment and high sulfur coals were deposited in seawater influenced environments there are exceptions for example turkish lignites formed in freshwater environments are high sulfur sulfur sources other than seawater are needed for these high sulfur coals the superhigh organic sulfur shos coals are highly enriched in organic sulfur but depleted in pyritic sulfur the shos coals were deposited in sulfur rich iron poor environments such as carbonate platforms or in an iron poor and clastic starved environment in which algae accumulate speciation of organic sulfur compounds in coal appears to be related to coal rank thiophenic compounds are more abundant in bituminous coal and anthracite than in low rank coals

elemental composition of coal macerals in relation to vitrinite reflectance gunnedah basin australia as determined by electron microprobe analysis abstract the elemental composition of macerals in high volatile bituminous coals from the gunnedah basin new south wales australia has been analysed by light element electron microprobe techniques the results have been evaluated in relation to maximum vitrinite reflectance trends in vertical section including the effects of marine influence and igneous intrusions on the coal bearing sequence mean maximum vitrinite telocollinite and desmocollinite reflectance for the analysed samples ranges from 0 63 to 0 99 and to 2 2 for coal affected by igneous intrusions the carbon content of the vitrinite as determined by electron microprobe ranges from 79 74 to 86 07 and up to 89 06 for the heat affected coal studied a simple relationship cannot be established between the reflectance of the vitrinite and its carbon content over this range of coal samples vitrinite in marine influenced coals with suppressed reflectance appears to have a slightly higher carbon content than vitrinite in isorank coals without marine influence the increase in carbon may be due to incorporation of carbon and sulphur rich lipoid material into the vitrinite component notwithstanding these differences the carbon content of vitrinite telocollinite seems to be affected only slightly by the depositional changes that cause suppression of vitrinite reflectance in marine influenced coals telocollinite carbon content may therefore be a useful alternative to vitrinite reflectance as a rank indicator in maturation studies the carbon content of whole coal samples determined by ultimate analysis shows in vertical section a trend intermediate between the carbon of the vitrinite determined by electron microprobe and that of the associated inertinite macerals whole coal analysis data in this range depend on the relative proportions of the different macerals present as well as the rank of the coal concerned coals affected by igneous intrusion show a different relationship between carbon and oxygen of vitrinite telocollinite relative to coals where the rank is determined by depth of burial alone the difference in c o relationships suggests that the short term heating associated with intrusions produces chemical changes in macerals that are not paralleled in more normal rank advance

distribution of arsenic selenium and other trace elements in high pyrite appalachian coals evidence for multiple episodes of pyrite formation abstract pennsylvanian coals in the appalachian basin host pyrite that is locally enriched in potentially toxic trace elements such as as se hg pb and ni a comparison of pyrite rich coals from northwestern alabama eastern kentucky and west virginia reveals differences in concentrations and mode of occurrence of trace elements in pyrite pyrite occurs as framboids dendrites or in massive crystalline form in cell lumens or crosscutting veins metal concentrations in pyrite vary over all scales from microscopic to mine to regional because trace elements are inhomogeneously distributed in the different morphological forms of pyrite and in the multiple generations of sulfide mineral precipitates early diagenetic framboidal pyrite is usually depleted in as se and hg and enriched in pb and ni compared to other pyrite forms in dendritic pyrite maps of as distribution show a chemical gradient from as rich centers to as poor distal branches whereas se concentrations are highest at the distal edges of the branches massive crystalline pyrite that fills veins is composed of several generations of sulfide minerals pyrite in late stage veins commonly exhibits as rich growth zones indicating a probable epigenetic hydrothermal origin selenium is concentrated at the distal edges of veins a positive correlation of as and se in pyrite veins from kentucky coals and of as and hg in pyrite filled veins from alabama coals suggests coprecipitation of these elements from the same fluid in the kentucky coal samples n 18 as and se contents in pyrite filled veins average 4200 ppm and 200 ppm respectively in alabama coal samples as in pyrite filled veins averages 2700 ppm n 34 whereas as in pyrite filled cellular structures averages 6470 ppm n 35 in these same alabama samples se averages 80 ppm in pyrite filled veins but was below the detection limit in cell structures in samples of west virginia massive pyrite as averages 1700 ppm and se averages 270 ppm n 24 the highest concentration of hg 102 ppm is in alabama pyrite veins improved detailed descriptions of sulfide morphology sulfide mineral paragenesis and trace element concentration and distribution allow more informed predictions of 1 the relative rate of release of trace elements during weathering of pyrite in coals and 2 the relative effectiveness of various coal cleaning procedures of removing pyrite for example trace element rich pyrite has been shown to be more soluble than stoichiometric pyrite and fragile fine grained pyrite forms such as dendrites and framboids are more susceptible to dissolution and disaggregation but less amenable to removal during coal cleaning

climate driven processes of hillslope weathering climate controls erosion and weathering on soil mantled landscapes through diverse processes that have remained diffi cult to disentangle due to their complex interactions we quantify denudation soil and saprolite weathering and soil transport near the base and crest of the western slope of the sierra nevada to examine how large differences in climate affect these processes depth profi les of fallout radionuclides and fi eld observations show relative differences in erosion and weathering processes at these two climatically diverse sites and our data suggest fundamentally different patterns of soil production and transport mechanisms biotically driven soil transport at low elevation and surface erosion driven by overland fl ow at high elevation soil production rates from cosmogenic 10 be decrease from 31 3 to 13 6 m ma with increasing soil depth at low elevation but show uncertain depth dependence at the high elevation site our data also show a positive correlation between physical erosion and saprolite weathering at both sites highly weathered saprolites are overlain by weakly weathered and rapidly eroding soils while chemically less depleted saprolites are overlain by slowly eroding more weathered soils our data are among the fi rst to quantify the critical role of saprolite weathering in the evolution of actively eroding upland landscapes and our results provide quantitative constraints on how different climates can shape hillslopes by driving processes of erosion and weathering

crustal scale pop up structure in cratonic lithosphere dobre deep seismic reflection study of the donbas fold belt ukraine the dobre project investigated the interplay of geologic and geodynamic processes that controlled the evolution of the donbas fold belt ukraine as an example of an inverted intracratonic rift basin a deep seismic reflection profile provides an excellent image of the structure of the donbas fold belt which is the uplifted and compressionally deformed part of the late paleozoic pripyat dniepr donets basin both the effects of rifting and those of later structural inversion are recognized in the seismic and geologic data the interpretation of the reflection data shows that the inversion of the donbas fold belt occurred at the crustal scale as a mega pop up which involved a major detachment fault through the entire crust and an associated back thrust the dobreflection image provides a simple concept of intracratortic basin inversion the crustal pop up being uplifted and internally deformed the association of such a structure with inverted intracratonic basins such as the donbas fold belt implies brittle deformation of relatively cold crust

experimental channel response to tectonic uplift 1 we have performed a series of experiments to investigate the relationship between channel geometry and tectonic forcing in steady state landscapes at various uplift rates the experimental setup consists of uniformly uplifted silica paste eroded by artificial rainfall in this setup erosional landscapes evolve by growth and amalgamation of incisions which organize into a drainage network whose dynamics are a function of the interaction between vertical channel cutting hillslope erosion and sediment transport high precision 0 5 mm pixel size digital elevation models were constructed using a stereogrammetric camera system from this data channel bed slope was found to be independent of discharge and position on the experimental surface and to increase linearly with uplift rate geometric parameters of the flow such as channel width or depth could not be observed directly during the experiments using laminar flow equations for the mean flow velocity these parameters were back calculated and relationships to the imposed substrate uplift rate were derived channel width cross sectional area and wetted perimeter decrease with increasing uplift rate to a limit value hydraulic radius and flow depth increase slightly and flow velocity increases approximately linearly with increasing uplift rate these results are qualitatively consistent with recent field surveys and highlight the importance of channel width and slope variations in accommodating channel response to variable rock uplift rates

light and trace element composition of carboniferous coals from the donets basin ukraine an electron microprobe study abstract the ukrainian donets basin donbas is one of the major coal mining provinces worldwide while the depositional setting of donbas coals is well studied information on modes of trace element occurrence and changes in element composition with increasing maturation is lacking within the frame of the present study both major light elements c o s and trace elements e g as cu hg mo pb were investigated using the electron microprobe epma which allows in situ determination of the chemical composition of a maceral or mineral phase deviating maturity trends in c o and s contents were found for different maceral groups in relatively immature samples 0 9 rr s contents of vitrinites and liptinites are comparable but lower in inertinite macerals vitrinites in a marine influenced coal host a higher amount of organic s whereas the trace element concentrations are lower than in the investigated non marine coals as expected a trend of increasing c and decreasing o contents was observed for vitrinite macerals within a maturity range from 0 5 to 1 4 rr referred to a decrease in volatile compounds during thermal maturation the light element composition generally tends to higher homogenity with increasing coal rank highly variable trace element concentrations of ash residues were determined for donbas coals with measured as contents up to several thousand ppm despite enrichment in epigenetic pyrite a clearly isolated inorganic source could not be identified suggesting that trace element storage in macerals is an important factor epma measurements revealed an organic matter affinity for at least part of the investigated elements e g hg mo pb

mineralogy and geochemistry of the coals from the chongqing and southeast hubei coal mining districts south china abstract this paper deals with the study of the late permian coal deposits from chongqing and south eastern hubei mining districts and of the late triassic coal deposits from chongqing mining district the late permian coals are characterized by relatively high amount of sulphide sulphate and carbonate minerals and by a high total content of trace elements with respect to the late triassic coals due to the marine influence on the depositional environment the late permian chongqing and the southeastern hubei coals showed similar geochemistry and mineralogy however there were some differences due to the different source rock and magmatic influence on hubei coals the concentrations of most trace elements in the late triassic coal were relatively low when compared with the usual range of the worldwide concentrations by contrast the contents of ta se nb sc hf tl bi cu v and zn in the late permian chongqing and southeastern hubei coals were higher than the usual range differences in occurrence of major and trace elements were found between late permian hubei and chongqing coals thus most of the trace elements investigated presented an aluminosilicate association followed by sulphide arsenide fe s as pb mo ni and co in most cases and carbonate ca and mg affinities in both areas however there was an important phosphate and zircon association in the chongqing coal whereas the carbonate association was significantly influenced by magma in the coals from hubei in the late triassic coal most of the major and trace elements investigated occur in aluminosilicate associations with the exception of s fe ca mn sr sn ba nb mo mg co and ta with carbonate sulphate and sulphide affinities

the donbas foldbelt its relationships with the uninverted donets segment of the dniepr donets basin ukraine abstract the donbas foldbelt df is a thrust faulted and folded inverted segment of the dniepr donets basin ddb it lies between the scythian and east european platforms north of the black sea and is conventionally thought to have formed in the early permian as part of the late palaeozoic hercynian uralian orogenic frame of cratonic europe the ddb itself formed as a result of late devonian intracratonic rifting and contains a thick up to 22 km late palaeozoic and mesozoic sedimentary succession the deformed strata preserved at the erosional surface of the df are mainly carboniferous the donets segment of the ddb displays mild inversion structures that are transitional to those in the df recently acquired regional seismic reflection data in the donets part of the ddb allow these structures to be imaged in the subsurface for the first time a widespread early permian unconformity occurring throughout the ddb is much more pronounced on its southern margin than on its northern one and appears to be related to profound uplift of the southern flank of the basin and the neighbouring ukrainian shield rather than to crustal shortening faults associated with the early permian unconformity are extensional in style gentle folds and other local structures in the southern flank and axis of the donets segment are mainly located in areas associated with early permian salt movements no significant development of compressional structures of early permian age can be seen in the seismic data where it is available in contrast there is ample evidence of latest cretaceous earliest tertiary compressional deformation in the ddb including the subsurface expression of structures along strike of the main folds of the df a review of geological evidence in the df also indicates that the main period of shortening that can be definitely constrained in time is latest cretaceous earliest tertiary the eastern part of the df records intense late triassic aged cimmerian deformation but none of clearly permian age it is tentatively concluded that the main phases of trans compressional tectonics forming the df were cimmerian and especially alpine rather than hercynian uralian

variations in coal maceral chemistry with rank advance in the german creek and moranbah coal measures of the bowen basin australia using electron microprobe techniques abstract variations in the elemental composition of individual macerals in seams from the permian german creek and moranbah coal measures in the bowen basin of queensland have been studied over a wide range of coal ranks using light element electron microprobe techniques to establish the coalification tracks of key macerals in a single coal bearing interval from subbituminous through bituminous coal to anthracite vitrinite reflectance rv max in the seams studied increases from 0 39 in the western part of the basin to over 3 5 in the east apparently due to increases in burial depth the study extends significantly the rank range covered by previous work on elemental analysis of individual macerals in the gunnedah basin and provides a more useful basis than whole coal analysis to evaluate the performance of coals in different utilisation processes the microprobe results show that the carbon content of the telocollinite increases dramatically from 66 to 90 as the vitrinite reflectance of the coals rv max increases from 0 39 to around 1 75 but increases only slightly from 90 to 91 as rv max increases from 1 75 to 3 52 oxygen decreases from around 26 to approximately 5 as rv max increases from 0 39 to around 1 75 and then decreases only very slightly into the anthracite range the nitrogen content of the telocollinite in these coals also appears to decrease slightly with rank advance and appears moreover to display a relatively abrupt drop at around 2 rv max this may be associated with the development of ammonium illite in the mineral matter organic sulphur in the telocollinite on the other hand seems to remain essentially constant with rank advance at least in this particular succession in contrast to vitrinite fusinite and inertodetrinite have significantly higher but somewhat more constant carbon contents varying only from around 81 to 93 c over the rank range studied oxygen in these macerals decreases from around 12 to a little over 2 with the same degree of rank advance sulphur and possibly nitrogen also appear to be significantly lower in fusinite and inertodetrinite than in the vitrinite of the same coal samples semifusinite is somewhat more variable in composition with characteristics intermediate between those of the fusinite inertodetrinite and those of the vitrinite in the same coal over the rank range studied

shrinking and splitting of drainage basins in orogenic landscapes from the migration of the main drainage divide climate and in particular the spatial pattern of precipitation is thought to affect the topographic and tectonic evolution of mountain belts through erosion numerical model simulations of landscape erosion controlled by horizontal tectonic motion or orographic precipitation result in the asymmetric topography that characterizes most natural mountain belts and in a continuous migration of the main drainage divide the effects of such a migration have however been challenging to observe in natural settings here i document the effects of a lateral precipitation gradient on a landscape undergoing constant uplift in a laboratory modelling experiment in the experiment the drainage divide migrates towards the drier leeward side of the mountain range causing the drainage basins on the leeward side to shrink and split into smaller basins this mechanism results in a progressively increasing number of drainage basins on the leeward side of the mountain range as the divide migrates such that the expected relationship between the spacing of drainage basins and the location of the main drainage divide is maintained i propose that this mechanism could clarify the drainage divide migration and topographic asymmetry found in active orogenic mountain ranges as exemplified by the aconquija range of argentina

mercury and trace element contents of donbas coals and associated mine water in the vicinity of donetsk ukraine abstract mercury rich coals in the donets basin donbas region of ukraine were sampled in active underground mines to assess the levels of potentially harmful elements and the potential for dispersion of metals through use of this coal for 29 samples representing c 11 to m 3 carboniferous coals mercury contents range from 0 02 to 3 5 ppm whole coal dry basis mercury is well correlated with pyritic sulfur 0 01 to 3 2 wt with an r 2 of 0 614 one outlier excluded sulfides in these samples show enrichment of minor constituents in late stage pyrite formed as a result of interaction of coal with hydrothermal fluids mine water sampled at depth and at surface collection points does not show enrichment of trace metals at harmful levels indicating pyrite stability at subsurface conditions four samples of coal exposed in the defunct open cast nikitovka mercury mines in gorlovka have extreme mercury contents of 12 8 to 25 5 ppm this coal was formerly produced as a byproduct of extracting sandstone hosted cinnabar ore access to these workings is unrestricted and small amounts of extreme mercury rich coal are collected for domestic use posing a limited human health hazard more widespread hazards are posed by the abandoned nikitovka mercury processing plant the extensive mercury mine tailings and mercury enrichment of soils extending into residential areas of gorlovka

geochemistry petrology and palynology of the pond creek coal bed northern pike and southern martin counties kentucky abstract the geochemistry petrology and palynology of the duckmantian age pond creek coal bed were investigated in northern pike and southern martin counties eastern kentucky the coal bed exhibits significant vertical variation in the investigated geochemical parameters with many diagenetic overprints of the original geochemistry included in the range of geochemical signatures are the presence of elements particularly tio 2 and zr suggesting the detrital influences at the time of deposition of a low vitrinite durain a high cao zone with elevated b be both suggesting marine influence in a lithotype in the middle of the coal bed and the postdepositional emplacement of pyrite in the uppermost lithotype individual lithotypes each representing distinct depositional environments all complicated to some degree by diagentic overprints comprise the complex history of the coal bed

mineralogy and geochemistry of a superhigh organic sulfur coal yanshan coalfield yunnan china evidence for a volcanic ash component and influence by submarine exhalation abstract the mineralogy and geochemistry of a superhigh organic sulfur shos coal of late permian age from the yanshan coalfield yunnan province southwestern china have been studied using optical microscope low temperature ashing plus x ray diffraction analysis scanning electron microscope equipped with energy dispersive x ray spectrometer a sequential chemical extraction procedure and inductively coupled plasma mass spectrometry the m9 coal from the yanshan coalfield is a shos coal that has a total sulfur content of 10 12 11 30 and an organic sulfur content of 8 77 10 30 the minerals in the coal consist mainly of high temperature quartz sanidine albite muscovite illite pyrite and trace amounts of kaolinite plagioclase akermanite rutile and dawsonite as compared with ordinary worldwide bituminous coals and anthracite and chinese coals the m9 coal is remarkably enriched in b 268 g g f 841 g g v 567 g g cr 329 g g ni 73 9 g g mo 204 g g and u 153 g g in addition elements including se 25 2 g g zr 262 g g nb 20 1 g g cd 2 07 g g and tl 2 03 g g are also enriched in the coal occurrence of high temperature quartz sanidine muscovite and illite in the m9 coal is evidence that there is a volcanic ash component in the coal that was derived from acid volcanic ashes fallen into the swamp during peat accumulation occurrence of albite and dawsonite in the coal and strong enrichment of some elements including f s v cr ni mo and u are attributed to the influence by submarine exhalation which invaded along with seawater into the anoxic peat swamp abundances of lithophile elements including rare earth elements nb y zr and tio2 indicate that the silicate minerals in the coal were derived from the northern vietnam upland to the south of the basin

mineral matter in low rank coals and associated strata of the mae moh basin northern thailand abstract the mineral and other ash forming constituents in lignites of the mae moh basin in northern thailand have been identified and evaluated in relation to the minerals present in the associated interseam non coal strata and the intra seam non coal bands treatment of the coal with water ammonium acetate and hydrochloric acid shows that a considerable part of the ash forming inorganic matter occurs in water soluble acid soluble or ion exchangeable form although the distribution of elements may be modified by the effects of pyrite oxidation the mobile fraction of the fresh coal is dominated by water soluble ion exchangeable and acid soluble calcium water soluble and exchangeable magnesium water soluble sodium and sulphur and acid soluble iron and aluminium calcium is most abundant especially in coals where a low proportion of silicate minerals quartz clay etc is present it combines readily with the different sulphur forms on combustion to produce an ash with a distinctively high cao and so 3 content the main minerals in the coals are quartz pyrite and a clay fraction consisting of kaolinite illite and an expandable irregular mixed layer mineral the mixed layer clay appears to be more abundant in the coal and illite less so than in the mudrocks of the associated non coal strata the non coal partings within the main seams contain quartz pyrite and a similar clay mineral assemblage but they also contain an abundance of calcite and or aragonite and in some cases consist entirely of carbonate minerals shell fragments and possibly plant replacement structures are present in some of these materials gypsum bloedite hexahydrite and other sulphate minerals and calcite are deposited as fracture fillings and surface coatings on some exposed open cut mine faces

basin evolution and coal geology of the donets basin ukraine russia an overview abstract the donets basin is a major coal mining district in eastern ukraine and adjacent portions of russia it comprises the donbas foldbelt which is the uplifted and compressionally deformed part of the pripyat dniepr donets pdd basin and the significantly less deformed western donbas region the pdd basin is a late devonian rift structure located within the east european craton thick coal measures formed during the post rift stage of the basin in serpukhovian to moscovian times when about 130 seams each with a thickness over 0 45 m have been deposited early serpukhovian coal accumulated in a relatively narrow shore zone it is rich in inertinite and liptinite and very low in ash bashkirian and moscovian coal have a significantly wider lateral extension and are generally rich in vitrinite bashkirian and moscovian coal seams usually have high ash yields 12 18 and high sulfur contents 2 5 3 5 but these data vary significantly depending on peat facies coal rank ranges from subbituminous to anthracite and is mainly controlled by the depth of the seams and the heat flow during maximum permian burial permo triassic thermal events locally overprinted the resulting coalification pattern coked coal occurs at the contact to presumed permian sills and dikes southwest of donetsk deep permian burial was followed by major permian and mesozoic uplift events the donets basin hosts proven reserves in the order of 60 gt at the exploitable depth the thickness of coal seams currently mined is in the range of 0 6 to 2 5 m production during 2009 was 68 7 mt in the ukrainian and 4 9 mt in the russian part of the basin coal mines in the donets basin are among the gassiest in the world the average methane content of coal is 14 7 m t but numerous seams have significantly higher gas content the high methane content presents a severe mine safety problem on the other hand it represents also a high potential for coal mine bed methane projects emissions of coal gas released by mining and related structurally induced underground hazards coal and gas outbursts are a major problem for safe and efficient coal exploitation in the basin

petrography and geochemistry of carboniferous coal seams in the donets basin ukraine implications for paleoecology abstract the carboniferous succession in the donets basin hosts about 130 seams each with a thickness over 0 45 m nine economically important seams from the south western donets basin are studied using organic petrographical inorganic geochemical and organic geochemical techniques the main aim of the study is the reconstruction of peat facies of serpukhovian mississippian and moscovian middle pennsylvanian coals formation of major coal seams commenced during serpukhovian times early serpukhovian coal accumulated in a relatively narrow shore zone and is rich in inertinite and liptinite very low ash yields low to moderate sulphur contents and upward increasing inertinite contents suggest coal deposition in raised mires moscovian coal has a significantly wider lateral extension and is generally rich in vitrinite coal properties vary widely in response to different peat facies low sulphur low ash k 7 coal was formed in a raised mire or in a low lying mire without detrital input l 1 and l 3 seams containing several fluvial partings were formed in low lying mires both seams are more than 2 m thick seams m 2 and m 3 contain high sulphur coal a consequence of deposition in a peat with marine influence in contrast syngenetic sulphur content is low in the m 5 1 upper seam which was formed in a lacustrine setting the late moscovian n 1 seam up to 2 4 m thick accumulated in a swamp with a vegetation rich in bryophytes and pteridophytes the properties of the n 1 seam are transitional between those of serpukhovian and other moscovian seams differences in maceral composition between serpukhovian and moscovian coals probably reflect changes in climate and vegetation type tuff layers are observed in the l 1 l 3 and m 3 seams the l 3 and m 3 seams contain abundant authigenic quartz trace element contents are high in many seams as contents are especially high in seams c 10 2 k 7 l 3 and m 3 ash in the l 3 seam contains up to 8000 ppm as co is enriched near the base of several seams maxima up to 2400 ppm occur in the ash of the k 7 and l 3 seams cd contents in ash are frequently as high as 30 or 40 ppm

variation in elemental composition of macerals an example of the application of electron microprobe to coal studies abstract elemental composition of macerals in lignite sub bituminous high volatile bituminous medium volatile bituminous and anthracitic rank coals have been investigated using the electron microprobe technique the concentration of c o n s fe si and al have been measured directly and hydrogen was calculated by difference the chemical composition was compared to reflectance values and whole coal chemistry in lignite the sequence ulminite 66 27 c porigelinite 67 32 c micrinite 67 92 c corpocollinite 68 21 c macrinite 70 24 c and fusinite 73 03 c represents a series with increasing carbon content sulphur concentration is the highest in porigelinite 2 95 and the lowest in fusinite 0 21 whereas nitrogen is the highest in corpocollinite 3 12 and the lowest in micrinite and porigelinite in sub bituminous coal the sequence of decreasing carbon content is as follows macrinite 80 01 c sporinite 73 00 c semifusinite 72 76 c and telocollinite 67 49 c sulphur content is the highest in telocollinite 3 29 in high volatile bituminous coal carbon content is highest in fusinite 93 68 and lowest in cutinite 82 82 vitrinite macerals have the highest sulphur content and fusinite has the lowest in medium volatile bituminous coal a sequence of decreasing carbon and increasing oxygen content fusinite 90 02 c semifusinite 89 73 c and vitrinite 88 56 c is detectable but differences in carbon and oxygen content between macerals are small in anthracite no statistical differences in carbon and oxygen content between vitrinite and inertinite macerals exist about 94 c and 1 o for both macerals comparison of reflectance values to carbon and oxygen contents for individual macerals demonstrates that vitrinite and sporinite enter a common coalification path at 88 5 c and a reflectance of 1 25 semifusinite joins the path at about 89 c and a reflectance of 1 8 2 0 more data are needed to determine the relationship between reflectance and elemental composition for other macerals

leaching of inorganics in the cretaceous greymouth coal beds south island new zealand abstract leaching processes are believed to be responsible for the unusually low ash content sometimes less than 1 of the thick up to 35 m cretaceous coals located in the greymouth coalfield south island new zealand although leaching of inorganics in peat is a generally accepted process little is known about leaching after burial the main and e seams in the greymouth coalfield show good correlation between low ash and bed thickness the ash content however is often less than 1 which is lower than most known modern analogues i e peat there are several lines of evidence that suggest that mineral matter may have been removed from the coal not only in the peat stage but also after burial for example etching features found in quartz grains and clay aggregates indicate that some leaching processes have taken place in addition liptinitic material e g bitumen in the cleat networks supports the conclusion that there has been some movement of solutions through the coal after burial these solutions may have helped to remove some of the inorganics originally within the greymouth coals

stratigraphic distribution of macerals and biomarkers in the donets basin implications for paleoecology paleoclimatology and eustacy abstract more than one hundred and thirty coal seams and coaly layers occur in the donets basin donbas twenty eight 52 samples of them ranging in age from serpukhovian late mississipian to gzhelian late pennsylvanian 33 clastics and three limestones were studied in terms of maceral composition sulphur contents and biomarker distribution diterpanes are used to estimate the contribution of different groups of plants and the height of the water table in the swamp hopanes are a measure of bacterial activity in the peat and steranes indicate the relative input of wood and algae stratigraphic trends in these parameters are discussed in relation to paleoenvironment climatic changes and eustacy a tropical climate prevailed in the donbas from serpukhovian to kasimovian times nevertheless periods with drier and wetter conditions can be distinguished based on maceral and biomarker data relatively dry conditions are observed during serpukhovian and vereian times whereas wetter climates with a maximum of coal deposition occurred during the late bashkirian most of the moscovian and the earliest kasimovian no economic coal seams are hosted in upper kasimovian and gzhelian deposits a result of a change to an arid climate our data also suggest climatic changes during sequences of different order for the second order third order and fourth order sequences relatively dry or wet conditions occurred during coal deposition in the lowstand systems tract an intermediate climate during the transgressive systems tract and the maximum flooding and a wet climate during the highstand systems tract the results for high frequency sequences support the cecil s paleoclimatic model an intermediate paleoclimate during lst sandstone and levee siltstone a wet climate during early tst coal and a dry climate during late tst limestone mfs claystone and hst deltaic siltstone coals deposited during maximum flooding periods are more enriched in c27 steranes derived from algae and contain lower proportions of c29 steranes derived from the wood of higher plants

coal deposits as potential alternative sources for lanthanides and yttrium abstract this paper presents data on widespread abnormal accumulations of lanthanides and yttrium rey in many coal deposits worldwide high rey contents 0 1 have been found in coal seams and coal ashes as well as in the host and basement rocks of some coal basins for a preliminary evaluation of coal ashes as an rey raw material not only the abundance but also the individual rey compositions were taken into account in this paper three rey distribution patterns for high rey coal ashes are fixed with lrey lan lun 1 mrey lan smn 1 and hrey lan lun

mineral matter in triassic and tertiary low rank coals from south australia abstract the minerals and non mineral inorganic constituents in triassic and tertiary low rank coals from various coal deposits in south australia were studied using selective chemical leaching and oxygen plasma ashing techniques although gypsum may be present in some samples most of the sodium calcium and magnesium as well as part of the sulphur appears to occur as a combination of dissolved ions in pore water and exchangeable ions attached to carboxylate groups significant concentrations of iron and aluminium occur in acid soluble form probably as organometallic complexes within the hydrocarbon structure quartz is the dominant mineral in the tertiary coal samples it appears to be mainly detrital but doubly terminated euhedral crystals suggest an authigenic origin in one of the deposits well crystallized kaolinite is common in the triassic coals while poorly crystallized kaolinite occurs in the tertiary samples siderite calcite and possibly collophane occur in the triassic coals sparse pyrite is present in both the tertiary and the triassic samples the differences in minerals and other inorganic constituents between the tertiary and triassic deposits can be explained partly by variations in the composition of the pore waters permeating the strata and partly by mobility of silica and alumina from different sources within the peat deposit the relative mobility of the different inorganic constituents is also significant in beneficiation of the coal for use in combustion processes

giant polygons in the triassic salt of cheshire england a thermal contraction model for their origin abstract the triassic salt in cheshire england has large polygonal patterns on bedding surfaces the polygons are bounded by deep v shaped fissures the fissures have a banded internal structure made up of individual units of pure secondary salt and clastic rich halite the salt was deposited from shallow brines in an arid environment a thermal contraction model is proposed here for the formation of the polygons calculations of the depth of penetration of thermal waves and the net contraction of salt beds indicate that annual temperature fluctuations would produce fissures of the observed depth and width it is suggested that thermal contraction is the most important factor in the initiation of all polygonal patterns on salt surfaces and that the polygon form that eventually develops is de endent on the thickness of the salt bed and the availability of brines to the salt surface

drainage basin responses to climate change recent investigations have shown that the extent of the channel network in some drainage basins is controlled by a threshold for overland flow erosion the sensitivity of such basins to climate change is analyzed using a physically based model of drainage basin evolution the golem model simulates basin evolution under the action of weathering processes hillslope transport and fluvial bedrock erosion and sediment transport results from perturbation analyses reveal that the nature and timescale of basin response depends on the direction of change an increase in runoff intensity or a decrease in vegetation cover will lead to a rapid expansion of the channel network with the resulting increase in sediment supply initially generating aggradation along the main network followed by downcutting as the sediment supply tapers off by contrast a decrease in runoff intensity or an increase in the erosion threshold will lead to a retraction of the active channel network and a much more gradual geomorphic response cyclic changes in runoff intensity are shown to produce aggradational degradational cycles that resemble those observed in the field cyclic variations in runoff also lead to highly punctuated denudation rates with denudation concentrated during periods of increasing runoff intensity and or decreasing vegetation cover the sediment yield from threshold dominated basins may therefore exhibit significant variability in response to relatively subtle environmental changes a finding which underscores the need for caution in interpreting modern sediment yield data

mercury and trace element distribution in density separates of a south african highveld 4 coal implications for mercury reduction and preparation of export coal abstract eight density separates of permian highveld 4 coal were investigated for partitioning of hg and trace elements the separates include float fractions obtained in heavy media having densities of 1 4 1 5 1 6 1 7 1 8 1 9 and 2 0 g cm 3 and the sink fraction for 2 0 g cm 3 bulk analysis of the separates shows strong r 2 0 80 positive correlations between pyritic sulfur and mercury and between ash yield and both pyritic sulfur and mercury laser ablation la icp ms analysis of individual pyrite grains in the separates confirms association of hg and as with pyrite as indicated by bulk analysis other elements detected in pyrite by la icp ms include mn co ni tl and pb results for the separates allow prediction of hg trace elements and ash yields expected in specific south african coal products these range from 0 06 ppm hg and an ash yield of 11 5 ash for the export fraction to 0 47 ppm hg and an ash yield of 60 9 for the discard stone fraction dry basis results show pronounced differences expected between coal used for domestic power generation and coal which is exported

determination of elemental affinities by density fractionation of bulk coal samples from the chongqing coal district southwestern china abstract the occurrence and distribution of major and trace elements have been investigated in two coal bearing units in the chonqing mining district south china the late permian and late triassic coals the late permian coals have higher s contents than the late triassic coals due to the fixation of pyrite in marine influenced coal forming environments the occurrence of pyrite accounts for the association of a large number of elements fe s as cd co cu mn mo ni pb sb se and zn with sulphides as deduced from the analysis of the density fractions the marine influence is probably also responsible for the organic association of b the rees zr nb and hf are enriched by a factor of 2 3 with respect to the highest levels fixed for the usual worldwide concentration ranges in coal for these elements the content of these elements in the late permian coal is higher by a factor of 5 10 with respect to the late triassic coal furthermore other elements such as cu p th u v and y are relatively enriched with respect to the common range values with maximum values higher than the usual range or close to the maximum levels in coal the content of these elements in the late permian coal is higher than the late triassic coal these geochemical enrichments are the consequence of the occurrence in relatively high levels of phosphate minerals such as apatite xenotime and monazite as deduced from the study of the density fractions obtained from the bulk coal the late triassic coal has a low sulphur content with a major organic affinity the trace element contents are low when compared with worldwide ranges for coal in this coal the trace element distribution is governed by clay minerals carbonate minerals and to a lesser extent by organic matter and sulphide minerals major differences found between late permian and triassic coals are probably related to the source rocks given that the main source rock of the late permian epicontinental marine basin is the emeishan basalt formation characterised by a high phosphate content

mineralogy and geochemistry of coal from the liupanshui mining district guizhou south china abstract this study focuses on the geochemistry and mineralogy of 23 coal seams from the shuicheng and luizhi coal fields from the late permian liupanshui coal mining district in the west of guizhou province in southern china coal rank ranges widely from high volatile bituminous to low volatile bituminous and anthracite major mineral phases present in the liupanshui coal are kaolinite quartz pyrite and calcite traces of other primary minerals are marcasite gypsum and dolomite the shuicheng coal usually has higher kaolinite and quartz contents than the luizhi coal marcasite occurs indiscriminately in the different coal seams without a clear distribution pattern the presence of other minerals such as rutile anatase tourmaline zircon and phosphates was also noted the total sulphur content of liupanshui coals is higher in the marine influenced coal seams up to 7 5 dry and lower in the nonmarine influenced coals as low as 0 3 in the luizhi coal field the coal is characterised by a high sulphur and iron content whereas in the shuicheng coal field contents varied from low to high depending on the coal seams an inverse geochemical distribution was detected for the mean contents of ca mn ge with lower contents in the luizhi coal field the liupanshui coals are characterised by relatively high contents of mn v cu li zr nb hf ta tl th and u when comparing with the usual concentration ranges in bituminous coals trace elements in coals from liupanshui showed narrow variations in their concentrations among coal seams and coal three major trace element affinities aluminium silicates sulphides and carbonates accounted for the occurrence and distribution of most of the elements studied were determined

geochemistry of trace elements in chinese coals a review of abundances genetic types impacts on human health and industrial utilization abstract china will continue to be one of the largest coal producers and users in the world the high volume of coal use in china has focused attention on the amounts of toxic trace elements released from coal combustions and also the valuable trace elements extracted or potentially utilized from coal ash compared to world coals chinese coals have normal background values for most trace elements with the exception of higher li 31 8 g g zr 89 5 g g nb 9 44 g g ta 0 62 g g hf 3 71 g g th 5 84 g g and rare earth elements la lu y 136 g g this is not only due to the higher ash yields of chinese coals but also to alkali volcanic ashes found in some southwestern coals the background values of toxic elements of hg 0 163 g g as 3 79 g g and f 130 g g in chinese coals are comparable to coals from most other countries the genetic types for trace element enrichment of chinese coals include source rock controlled marine environment controlled hydrothermal fluid controlled including magmatic low temperature hydrothermal fluid and submarine exhalation controlled subtypes groundwater controlled and volcanic ash controlled the background values of trace elements were dominated by sediment source regions low temperature hydrothermal fluid was one of the major factors for the local enrichment of trace elements in southwestern china serious human health problems caused by indoor combustion of coal in china include endemic fluorosis arsenosis selenosis and lung cancer endemic fluorosis mainly occurring in western guizhou was mostly attributed to the high fluorine in clay that was used as a briquette binder for fine coals in addition to a small quantity of fluorine from coal fluorine in the coal from endemic fluorosis areas of western guizhou is within the usual range found in china and the world endemic arsenosis in southwestern guizhou is attributed to indoor combustion of high as coal endemic selenosis in enshi of hubei was due to high se in carbonaceous siliceous rocks and carbonaceous shales fine particles of quartz released into air during coal combustion are hypothesized as a possible cause for the lung cancer epidemic in xuanwei yunnan china valuable elements including ge ga u ree rare earth element nb zr and re are concentrated to levels comparable to conventional economic deposits in several coals or coal bearing strata in china the ge deposits at lincang yunnan province and wulantuga inner mongolia have been exploited and industrially utilized the enrichment of ge in the two deposits was caused by hydrothermal fluids associated with adjacent granitoids the ga al ore deposit in the jungar coalfield inner mongolia was derived from the neighboring weathered and oxidized bauxite of the benxi formation pennsylvanian the nb ta zr hf ree ga deposits in the late permian coal bearing strata of eastern yunnan and chongqing of southwestern china were attributed to ashes of the alkali volcanic eruptions

mineral matter and potentially hazardous trace elements in coals from qianxi fault depression area in southwestern guizhou china mineralogy coal chemistry and 21 potentially hazardous trace elements phtes of 44 coal samples from the qianxi fault depression area qfda in southwestern guizhou province china have been systematically studied the major minerals in coals studied are quartz kaolinite illite pyrite calcite smectite marcasite and accessory minerals including rutile dolomite siderite gypsum chlorite melanterite apatite collophane and florencite the sio2 content shows a broad variation 0 8 30 7 a high sio2 content in late permian coals reflects their enrichment in quartz the al2o3 content varies from 0 8 to 13 4 fe2o3 from 0 2 to 14 6 cao from al k ti na mg ca fe s a comparison with world coal averages shows that the late permian coals in qfda are highly enriched in as hg f and u and are slightly enriched in mo se th v and zn the late triassic coals in qfda are highly enriched in as and hg and are slightly enriched in mo th and u the concentrations of as hg mo se tl and zn in the qfda coal are higher than other guizhou coal and liupanshui coal nearby the qfda is an area strongly affected by the low temperature hydrothermal activity during its geologic history yanshanian age about 189 ma the coals in qfda are enriched in volatile phtes including as hg se sb mo among others the regions where the coals are enriched in as hg and f have been mapped the regions of coals enriched in volatile phtes overlap with the regions of noble metal ore deposits these coals are located in the cores of anticline and anticlinorium which are connected with the profound faults through the normal faults coals are enriched in volatile phtes as a result of the low temperature hydrothermal activity associated with tectonic faulting

on pollution of the biosphere in industrial areas the example of the donets coal basin abstract the distribution of heavy metals nitrates and other elements and compounds was studied in the donets basin biosphere the neomineralization processes in burning coal waste heaps were investigated more than 10 minerals were found for the first time in the donets basin the most frequently occurring are native sulphur and ammonium chloride in the process of geochemical mapping 30 000 soil samples were collected and analyzed the soil content of hg as pb zn cd and other elements was determined these concentrations often exceed the permissible level of concentration plc the soil mercury content is high in 90 of the donetsk city territory in some places it is 7 5 9 0 mg kg several times higher than the plc a high mercury concentration up to 19 mg kg was found in the soils of the central donbas area where the large coke chemical mercury and metallurgical plants are situated the air mercury content is about 25 30 pg l 1 pg 10 12 g in donetsk city and it is 300 1000 pg l or more near the nikitovsky mercury plant the background level is 1 6 1 8 pg l geochemical anomalies of arsenic mercury nitrates and other toxic elements and compounds were detected in 6000 donbas subsurface water samples near donetsk the arsenic content is up to 24 times and the mercury content is up to 3 10 times higher than the plc nitrate pollution of the donbas subsurface water covers 80 of the territory the nitrate content is as high as 500 1000 mg l and more plc is 45 mg l the sources of biosphere pollution by heavy metals and nitrates are coal waste heaps coal mines coke chemical plants metallurgical plants and other enterprises toxic pollution of the donbas biosphere negatively influences human health further systematic investigations of the donbas biosphere need to be conducted involving cooperation between scientists of different countries under joint programs

chemical composition of macerals in bituminous coals of the gunnedah basin australia using electron microprobe analysis techniques abstract the chemical composition of the organic matter in the principal macerals of high volatile bituminous coals from the gunnedah basin new south wales rvmax of telocollinite between 0 6 and 1 1 has been evaluated from polished section specimens using an electron microprobe technique highest proportions of carbon occur in the inertinite macerals especially fusinite and secretinite formerly resino sclerotinite as well as in sporinite lowest proportions of carbon occur in the different macerals of the vitrinite group oxygen shows the reverse trend being most abundant in vitrinite and least abundant in the inertinite components whereas sulphur is lowest in the inertinites and highest in the liptinite mainly sporinite present evaluations of maceral composition using the carbon content of telocollinite as a rank indicator show that carbon is more abundant in both sporinite and semifusinite relative to vitrinite in low rank high volatile bituminous coals the difference decreases with increasing rank and the proportion of carbon in telocollinite becomes essentially the same as that in sporinite and semifusinite at carbon contents of about 89 and 91 respectively the carbon content of fusinite and secretinite on the other hand does not seem to vary appreciably with rank advance no significant difference in composition occurs in the rank range studied between the three vitrinite varieties present desmocollinite telocollinite and a more highly reflecting telocollinite resembling pseudovitrinite no evidence was found to indicate a higher hydrogen content relative to telocollinite for the vitrinite matrix of desmocollinite

controls on the spacing of first order valleys 1 many landscapes are composed of ridges and valleys that are uniformly spaced even where valley locations are not controlled by bedrock structure models of long term landscape evolution have reproduced this phenomenon yet the process by which uniformly spaced valleys develop is not well understood and there is no quantitative framework for predicting valley spacing here we use a numerical landscape evolution model to investigate the development of uniform valley spacing we find that evenly spaced valleys arise from a competition between adjacent drainage basins for drainage area a proxy for water flux and that the spacing becomes more uniform as the landscape approaches a topographic equilibrium valley spacing is most sensitive to the relative rates of advective erosion processes such as stream incision and diffusion like mass transport such as soil creep and less sensitive to the magnitude of a threshold that limits the spatial extent of stream incision analysis of a large number of numerical solutions reveals that valley spacing scales with a ratio of characteristic diffusion and advection timescales that is analogous to a peclet number we use this result to derive expressions for equilibrium valley spacing and drainage basin relief as a function of the rates of advective and diffusive processes and the spatial extent of the landscape the observed scaling relationships also provide insight into the cause of transitions from rill like drainage networks to branching networks the spatial scale of first order drainage basins the contributing area at which hillslopes transition into valleys and the narrow range of width to length ratios of first order basins

shaping post orogenic landscapes by climate and chemical weathering the spacing of hills and valleys reflects the competition between disturbance driven or diffusive transport on hillslopes and concentrative or advective transport in valleys although the underlying lithologic tectonic and climatic controls have not been untangled here we measure geochemical and geomorphic properties of catchments in kruger national park south africa where granitic lithology and erosion rates are invariant enabling us to evaluate how varying mean annual precipitation map 470 mm 550 mm and 730 mm impacts hill valley spacing or landscape dissection catchment averaged erosion rates based on 10be concentrations in river sands are low 3 6 m m y and vary minimally across the three sites our lidar derived slope area analyses reveal that hillslopes in the dry site are gentle 3 and short such that the terrain is low relief and appears highly dissected with increasing rainfall hillslopes lengthen and increase in gradient 6 8 resulting in less dissected higher relief catchments the chemical depletion fraction of hilltop regoliths increases with rainfall from 0 3 to 0 7 reflecting a climate driven increase in chemical relative to physical erosion soil catenas also vary systematically with climate as we observe relatively uniform soil properties in the dry site that contrast with leached sandy crests and upper slopes coupled with downslope clay accumulation zones in the intermediate and wet sites the geomorphic texture of this slow eroding granitic landscape appears to be set by climate driven feedbacks among chemical weathering regolith fabric differentiation hydrological routing and sediment transport that enhance the vigor of hillslope sediment transport relative to valley forming processes for wetter climates 2013 geological society of america

trace and major element content and distribution in neogene lignite from the sofia basin bulgaria abstract lignite samples from the balsha seam in the sofia neogene basin were collected and ashed the coal ash was analysed for major and trace element contents the concentration of most of the elements in the coal ash was higher than the clarke value ag be cd co cr cu in mn mo ni p pb sc sn ti v and zn forty nine trace elements were determined aluminium si k ree bi zn ta tl sn sr cs u th rb au and hf have positive correlation coefficients with the ash content i e respectively high inorganic affinity but ti mn ga tb cu and cd have intermediate organic and inorganic affinity calcium mg fe s ge as be ag mo w in sb na p sc v cr ba pb ni co y and zr have high organic affinity some elements with organic affinity was also related with carbonate ca mg fe na ba p or sulphide fe s be as sb ge na mo in w ni ag tb minerals five groups of elements may be separated according to the form of occurrence in coal the first two la eu tb ce ta rb cs th sm u yb sr mn hf zn and al bi k au sn tl si associations contain elements with positive correlation with the ash content i e they show mainly inorganic affinity the elements which show negative correlation were separated in three other groups p sb ba na s mg ca as ge in w mo fe be zr y cd sc and pb ag cu cr co ni v ti associations four types of distribution of the elements along the balsha seam profile were recognised 1 elements concentrated in the low part of the seam 2 elements which have maximum concentration in the middle part of the seam 3 elements which tend to concentrate in the upper part of the coal seam 4 irregular distribution of the element contents it is established that most of the elements show high concentrations near the bottom the top or at the clay layers of the balsha seam

erosion thresholds and land surface morphology we propose a graphical technique to analyze the entirety of landforms in a catchment to define quantitatively the spatial variation in the dominance of different erosion processes high resolution digital elevation data of a 1 2 km2 hilly area where the channel network had been mapped in the field were used in the digital terrain model topog to test threshold theories for erosion the land surface was divided into 20 m2 elements whose shapes were then classified as convergent planar or divergent the entire landscape plotted on a graph of area per unit contour length against surface gradient shows each planform plotting as a separate field a simple steady state hydrologic model was used to predict zones of saturation and areas of high pore pressure to mimic the extreme hydrologic events responsible for erosive instability of the land surface the field observation that saturation overland flow is rare outside convergent zones provided a significant constraint on the hydrologic parameter in the model this model was used in threshold theories to predict areas of slope instability and areas subject to erosion by saturation overland flow both of which can contribute to channel initiation the proportion of convergent elements predicted to exceed the threshold varies greatly with relatively small changes in surface resistance demonstrating a high sensitivity to land use such as cattle grazing overall the landscape can be divided using erosion threshold lines into areas prone to channel instability due to runoff and stable areas where diffusive transport predominates

estimations of clarkes for carbonaceous biolithes world averages for trace element contents in black shales and coals abstract black shale and coal clarke values are the average trace element contents in the world black shales and coals these calculations are made in russian geochemistry but up to now are poorly known in the west modern tables of black shale and coal clarkes are presented based on comprehensive calculations using very large amount of information thousands analyses of black shales coals and coal ashes for trace elements in black shale geochemistry three figures were calculated for each main lithologies terrigenous tuff chert and carbonate two clarke estimations are presented named lithological k1 and lithostratigraphical k2 in coal geochemistry seven figures were calculated for each trace element average content in hard coals and their ashes average content in brown coals and their ashes average content in all coals and their ashes and coal affinity index or coalphile index average content in all ashes clarke values of sedimentary rocks the black shale and coal clarkes presented here provide an important scientific base for many geochemical comparisons and issues

experimental evidence for hillslope control of landscape scale landscape evolution theory suggests that climate sets the scale of landscape dissection by modulating the competition between diffusive processes that sculpt convex hillslopes and advective processes that carve concave valleys however the link between the relative dominance of hillslope and valley transport processes and landscape scale is difficult to demonstrate in natural landscapes due to the episodic nature of erosion here we report results from laboratory experiments combining diffusive and advective processes in an eroding landscape we demonstrate that rainsplash driven disturbances in our experiments are a robust proxy for hillslope transport such that increasing hillslope transport efficiency decreases drainage density our experimental results demonstrate how the coupling of climate driven hillslope and valley forming processes such as bioturbation and runoff dictates the scale of eroding landscapes

gopher bioturbation field evidence for non linear hillslope diffusion it has generally been assumed that diffusive sediment transport on soil mantled hillslopes is linearly dependent on hillslope gradient fieldwork was done near santa barbara california to develop a sediment transport equation for bioturbation by the pocket gopher thomomys bottae and to determine whether it supports linear diffusion the route taken by the sediment is divided into two parts a subsurface path followed by a surface path the first is the transport of soil through the burrow to the burrow opening the second is the discharge of sediment from the burrow opening onto the hillslope surface the total volumetric sediment flux as a function of hillslope gradient is found to be qs cm3 cm 1 a 1 176 dz dx 3 189 dz dx 2 68 dz dx 34 dz dx 0 4 this result does not support the use of linear diffusion for hillslopes where gopher bioturbation is the dominant mode of sediment transport a one dimensional hillslope evolution program was used to evolve hillslope profiles according to non linear and linear diffusion and to compare them to a typical hillslope the non linear case more closely resembles the actual profile with a convex cap at the divide leading into a straight midslope section copyright 2000 john wiley sons ltd

modes of occurrence of mercury and other trace elements in coals from the warrior field black warrior basin northwestern alabama abstract the mineralogic residence and abundance of trace metals is an important environmental issue data from the usgs coal quality database show that potentially toxic elements including hg as mo se cu and tl are enriched in a subset of coal samples in the black warrior basin of alabama usa although the coal as mined typically is low in these elements localized enrichments occur in high pyrite coals and near faults microscopic analyses demonstrate that the residence of these elements is dominantly in a late stage pyrite associated with structurally disrupted coal further our data suggest addition of hg to the coal matrix as well the source of these trace elements was hydrothermal fluids driven into the black warrior basin by alleghanian age tectonism

rain splash of dry sand revealed by high speed imaging and sticky paper splash targets 1 rain splash transport of sediment on a sloping surface arises from a downslope drift of grains displaced ballistically by raindrop impacts we use high speed imaging of drop impacts on dry sand to describe the drop to grain momentum transfer as this varies with drop size and grain size and to clarify ingredients of downslope grain drift the splash of many grains involves ejection of surface grains accelerated by grain to grain collisions ahead of the radially spreading front of a drop as it deforms into a saucer shape during impact for a given sand size splash distances are similar for different drop sizes but the number of displaced grains increases with drop size in proportion to the momentum of the drop not infiltrated within the first millisecond of impact we present a theoretical formulation for grain ejection which assumes that the proportion of ejected grains within any small azimuthal angular interval dq about the center of impact is proportional to the momentum density of the spreading drop within dq and that the momentum of ejected grains at angle q is on average proportional to the momentum of the spreading drop at q this formulation consistent with observed splash distances suggests that downslope grain transport involves an asymmetry in both quantity and distance more grains move downslope than upslope with increasing surface slope and on average grains move farther downslope this latter effect is primarily due to the radial variation in the surface parallel momentum of the spreading drop surface parallel transport increases approximately linearly with slope

geological and geochemical characteristics of high arsenic coals from endemic arsenosis areas in southwestern guizhou province china southwest guizhou province is one of the most important areas of disseminated sediment hosted type au deposits in china and is an important area of coal production the chemistry of most of the coals in sw guizhou is similar to those in other parts of china their as content is near the chinese coal average but some local small coal mines contain high as coals the highest as content is up to 3 5 wt in the coal the use of high as coals has caused in excess of 3000 cases of as poisoning in several villages the high as coals are in the longtan formation which is an alternating marine facies and terrestrial facies the coals are distributed on both sides of faults that parallel the regional anticlinal axis the as content of coal is higher closer to the fault plane the as content of coal changes greatly in different coal beds and different locations of the same bed geological structures such as anticlines faults and sedimentary strata control the distribution of high as coals small au deposits as well as sb hg and th mineralization are found near the high as coals although some as bearing minerals such as pyrite arsenopyrite realgar as bearing sulfate as bearing clays and phosphate are found in the high as coals their contents cannot account for the abundance of as in some coals analysis of the coal indicates that as mainly exists in the form of as5 and as3 perhaps combined with organic compounds the occurrence of such exceptionally high as contents in coal and the fact that the as is dominantly organically associated are unique observations

landscape response to climate change insights from experimental modeling and implications for tectonic versus climatic uplift of topography we present the results of an experimental investigation of the concurrent action of tectonic uplift and climate variation on relief evolution we designed an experimental apparatus that allows the study of erosion of laboratory scale topographies that evolve under given uplift and rainfall rates for constant uplift and rainfall rates the experimental topography evolves toward a statistical steady state defined by a mean elevation constant with time starting from such a steady state and keeping the input uplift rate constant a subsequent change in the rainfall rate yields a change in the mean elevation of the landscape to a new equilibrium elevation an increase in precipitation yields a lower mean steady state elevation whereas for a decrease in precipitation the surface is uplifted we define this phenomenon as a climatically induced surface uplift as opposed to a tectonically induced surface uplift the climatically and tectonically induced surface uplifts correspond to different dynamics of denudation so that it is theoretically possible to differentiate between the climatic or tectonic causes of surface uplift from records of output sediment fluxes

using hilltop curvature to derive the spatial distribution of erosion rates 1 erosion rates dictate the morphology of landscapes and therefore quantifying them is a critical part of many geomorphic studies methods to directly measure erosion rates are expensive and time consuming whereas topographic analysis facilitates prediction of erosion rates rapidly and over large spatial extents if hillslope sediment flux is nonlinearly dependent on slope then the curvature of hilltops will be linearly proportional to erosion rates in this contribution we develop new techniques to extract hilltop networks and sample their adjacent hillslopes in order to test the utility of hilltop curvature for estimating erosion rates using high resolution 1 m digital elevation data published and new cosmogenic radionuclide analyses in the feather river basin california suggest that erosion rates vary by over an order of magnitude 10 to 250 mm kyr 1 hilltop curvature increases with erosion rates allowing calibration of the hillslope sediment transport coefficient which controls the relationship between gradient and sediment flux having constraints on sediment transport efficiency allows estimation of erosion rates throughout the landscape by mapping the spatial distribution of hilltop curvature additionally we show that hilltop curvature continues to increase with rising erosion rates after gradient limited hillslopes have emerged hence hilltop curvature can potentially reflect higher erosion rates than can be predicted by hillslope gradient providing soil production on hilltops can keep pace with erosion finally hilltop curvature can be used to estimate erosion rates in landscapes undergoing a transient adjustment to changing boundary conditions if the response timescale of hillslopes is short relative to channels