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

geological controls on coal quality of the yili basin xinjiang northwest china abstract this study summarizes the results of geological petrographical geochemical and mineralogical analyses performed to determine the geological controls on coal quality of the yili basin in xinjiang province northwest china forty eight coal samples were collected from boreholes q12zk01 and z40zk1 and piliqing and musixiang coal mines the difference in base subsidence rate between the coal bearing strata badaowan and the xishanyao formations determines these differences of depositional environments swamp groundwater table and degree of terrigenous supply these factors may further cause the difference in coal quality the vitrinite contents ash yields volatile matter yields total mineral contents and most element contents are higher in coals of the badaowan formation from the q12zk01 and the musixiang mine than those of the xishanyao formation from the piliqing mine and the z40zk1 the high volatile matter yields of the coals in the badaowan formation relative to those in the xishanyao formation may be due to higher content of vitrinite that contains more volatile matters in comparison with the average concentrations for chinese and worldwide coals the yili coals are enriched mainly in ca na mg mn co sr ba and w but the other elements are depleted in the yili coals elements including si al k li ti cr cu rb zr pb and some ree la ce pr nd sm are predominantly associated with aluminosilicate minerals iron mg and mn in the coals of the musixiang mine and z40zk1 are associated mainly with carbonate minerals sulfur co and ni in the musixiang mine coals and b in the coals of q12zk01 and the z40zk1 mainly show an organic affinity sodium in the musixiang mine coals may occur in the brines

revisiting coos bay oregon a re examination of funginite huminite relationships in eocene subbituminous coals coal petrography has advanced significantly since reinhardt theissen and james schopf pioneered the use of thin sections to examine coals from coos bay oregon and to many coal petrographers the nomenclature used in that study is irrelevant the schopf 1947 study was a ground breaking examination of maceral relationships that need to be part of the working vocabulary of modern petrographers to support this a re examination of the coos bay thin section collection was undertaken using modern nomenclature for low rank coals under reflected light this particular collection was chosen in part because of the abundance of fungal material reported by schopf fungal material in coal and its association with huminite vitrinite macerals provides important information about the decompositional history of the coal and allows coal dominated by oxic processes to be differentiated from coal dominated by anoxic processes in the coos bay samples predominantly oxic intervals contain well preserved fungi including spores sclerotia and hyphae while anoxic intervals contain no fungi

mineralogical composition of late permian coal seams in the songzao coalfield southwestern china abstract coals from three seam sections in the songzao coalfield sw china are mainly high ash high sulphur semianthracites minerals within the songzao coals are mainly kaolinite pyrite or marcasite in some cases and quartz with various proportions of non kaolinite clay minerals carbonates feldspars and anatase the illite and mixed layer illite smectite i s are na rich in some of the datong coal samples the i s in the lower coals of the datong section is most likely an alteration product of dispersed volcanic ash due to the availability of necessary ions e g k na and mg in the marine influenced coal swamp organically bound na which was expelled from the organic matter with coal rank advance especially with anthracitization may have supplied additional na for the formation of na rich illite authigenic i s also occurs in a tonghua coal ply that is overlain by a mafic bentonite and underlain by an alkali tonstein potassium na and mg for the formation of such i s were probably derived from the leaching of the adjacent alkali tonstein and mafic bentonite although the marine water was also a possible supplier of the alkali elements authigenic i s is rare in coal plies that occur further away from the altered volcanic layer leaching of the volcanic claystones in the tonghua coal seam probably led to the formation of relatively abundant anatase and rhabdophane in the underlying coal ply fracture filling ree minerals probably ree hydroxides or oxyhydroxides also occurring in that coal ply crystallized from ascending ree rich hydrothermal fluids probably associated with contemporaneous volcanic activity

influence of localised igneous activity on cleat dawsonite formation in late permian coal measures upper hunter valley australia abstract stable 13 c and 18 o and radiogenic 87 sr 86 sr isotopic data have been used to investigate the origin of cleat dawsonite naalco 3 oh 2 in the late permian wittingham coal measures of the upper hunter region in the sydney basin new south wales the 13 c pdb values have a narrow range 1 7 to 2 4 with an average of 0 3 suggesting a magmatic source for the carbon in contrast 18 o smow values have a wide range 13 6 to 19 8 and decrease systematically with decreasing distance from a major intrusion this systematic variation reflects establishment of localised hydrothermal cells water rock interaction between fluids associated with these hydrothermal cells and rb poor volcaniclastic detritus in the coal measures produced mantle like 87 sr 86 sr 0 705032 to 0 706464 in the dawsonite

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

on the fundamental difference between coal rank and coal type abstract this article addresses the fundamental difference between coal rank and coal type while theoretically settled long ago as being different aspects of coal systems science the two concepts are still often confounded in recent years this has resulted in the publication of several works stating that coal type changes with coal rank coal type refers solely to coals depositional origin and the maceral mineral admixture resulting from that origin coal types typically fall in to two categories humic coals developed from peat and sapropelic coals developed from organic mud either type may be allocthonous or autochthonous and within types further refinement of depositional environment can be made coal rank refers to the changes in geochemistry and resultant changes in reflectance caused by increasing thermal maturity of the coal thus it provides an overprint of maturity on existing coal types with proper techniques such as use of crossed polars and etching maceral forms can be differentiated even at high ranks and the original coal type determined

an excellent fossil wood cell texture with primary uranium minerals at a sandstone hosted roll type uranium deposit nw china abstract a fossil wood cell texture with pitchblende and coffinite found at a sandstone hosted roll type uranium deposit xinjiang nw china is first reported here for the country in the mineralized sandstone detrital grains consisting of quartz feldspar rock fragments carbonaceous trashes mica and accessory minerals were deposited in early turassic time and were cemented by clays and minor authigenic calcite and quartz pitchblende and minor coffinite are principal ore minerals at the deposit and selectively replaced carbonized fossil wood remnants or filled fossil wood cells an excellent fossil wood cell texture with primary uranium minerals formed replacement of organic debris by primary uranium minerals may be due to a local reducing environment resulting from the production of ch 4 h 2 s or h 2 so 3 in its decomposition and a biochemical reaction indicated by the common presence of framboidal pyrite

distribution and origin of minerals in high rank coals of the south walker creek area bowen basin australia the coals of the south walker creek area in the northern bowen basin with a vitrinite reflectance rvmax of 1 7 to 1 95 are among the highest rank coals currently mined in australia x ray diffraction studies have identified an unusual mineral variation through the vertical sequence with kaolinite rich assemblages typical of other australian coals at the top and bottom of the seam section and an illite chlorite assemblage resembling a metamorphic association in the middle calcite and ankerite are also abundant in parts of the vertical sequence diaspore is abundant in the middle section of the seam in some areas and paragonite dickite or nacrite occurs in some locations as well the distribution of the non carbonate mineral assemblages cross cuts the seam stratigraphy and appears to be primarily controlled by faults and other structural features integration of the mineral distribution with optical and electron microscope data on the coal and non coal bands chemical data from coal ash analysis and information from x ray micro tomography suggests that the illite chlorite and diaspore bearing assemblages resulted from hydrothermal effects associated with fluid migration through the middle part of the coal seam this is further confirmed by the development of metamorphic textures in a tonstein band also altered to illite and chlorite in the illite rich part of the seam section in contrast to a tonstein with more normal sedimentary textures and a kaolinite composition in the kaolinite rich upper part of the seam detailed studies of cleat mineralisation suggest that fluids rich in ca mg and al were introduced relatively early in the seam s post depositional history associated with heat flow sufficient to alter the minerals in the coal and tonstein in the affected part of the seam section the relatively uniform vitrinite reflectance profile observed through the seam section may indicate that the coal was already of high rank before the fluids were introduced or that any localised heat effects on the organic matter associated with the changes in clay mineralogy were overprinted by subsequent wider ranging rank advance processes

notes on the origin of inertinite macerals in coals funginite associations with cutinite and suberinite abstract the association of fungus with plant leaves and roots is ubiquitous while many of these occurrences are considered to be pathogenic mycorrhizzal fungal associations with roots are essential for plant growth despite the common knowledge of such relationships in plant science with a few exceptions the fungus leaf root stem association as the macerals funginite cutinite and suberinite in coals has not been extensively studied in this work examples of funginite associations with cutinite and suberinite are discussed

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

notes on the origin of inertinite macerals in coals observations on the importance of fungi in the origin of macrinite macrinite is a generally rare inertinite maceral often incorporating remnants and fragments of other macerals including vitrinite liptinite and other inertinite the associated inertinites include multiple forms of funginite funginite is also commonly found in association with vitrinite of slightly elevated reflectance and with degraded varieties of vitrinite together with the highly degraded macrinite the latter two associations are here inferred to be part of a continuum of fungal and microbial degradation of peat in any case the origin of some macrinite is potentially distinct from that of inertinite generated by fire

elemental and mineralogical anomalies in the coal hosted ge ore deposit of lincang yunnan southwestern china key role of n2 co2 mixed hydrothermal solutions abstract the lincang neogene high ge coal deposit in yunnan southwestern china is one of the major coal hosted ge deposits in the world this study reports new data on the petrological mineralogical and geochemical compositions of 57 samples including coal bench samples roofs floors partings and batholith granite of three high ge coal seams s3 z2 and x1 from the dazhai mine lincang ge ore deposit and provides new insights into the origin and modes of occurrence of the minerals and elements present the coals have huminite random reflectances in the 0 33 0 48 range on a mineral free basis the coal samples are dominated by huminite group macerals all having more than 88 5 total huminite ulminite and attrinite generally dominate the huminite macerals structured inertinite is rare with funginite being the most abundant inertinite form the minerals in the coals are mainly composed of quartz and to a lesser extent kaolinite illite and mica a hydrous beryllium sulfate phase beso 4 4h 2 o is present in the low temperature ashes of several coal samples compared to average values for world low rank coals beryllium up to 2000 g g and 343 g g on average ge up to 2176 g g and 1590 g g on average and w up to 339 g g and 170 g g on average are unusually enriched in the lincang coals with a concentration coefficient 100 cc ratio of element concentration in investigated coals vs world low rank coals elements as 156 g g on average sb 38 g g cs 25 2 g g and u 52 5 g g are significantly enriched 10 the biotite and two mica granites which served as both the basement for the coal bearing sequence and as a source of sediment input were also either hydrothermally altered or argillized the alteration appears to have taken place during or shortly after deposition of the coal bearing sequence two types of metasomatites of hydrothermal origin including quartz carbonate and carbonate were identified which occur as partings and as roof and floor strata these metasomatites were formed at the syngenetic or early diagenetic stages of coal deposition the rare earth elements in these hydrothermal rocks are characterized by a heavy ree enrichment type and by distinct positive eu anomalies compared to the upper continental crust hydrothermal solutions have played a significant role in producing the elemental and mineralogical anomalies in the lincang ge ore deposit the hydrothermal solutions leaching the batholith granite were a mixture of alkaline n 2 bearing and volcanogenic co 2 bearing fluids which led to the enrichment of trace elements not only including assemblages of ge w and be nb u both leached from granite and the deposited in the peat but also as sb from volcanogenic solution as well as the alteration and argillization of the batholith granites and the formation of carbonate and quartz carbonate metasomatites

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

mineral paragenesis and textures associated with sandstone hosted roll front uranium deposits nw china abstract we present a first paragenetic study of the wuyier wuyisan wuyiyi and shihongtan sandstone hosted roll front uranium deposits northwest china the mineralization is hosted by lower middle jurassic coarse to medium grained sandstones which are dark gray to black due to a mixture of ore minerals and carbonaceous debris the sandstone is alluvial fan braided river facies minerals associated with these deposits can be broadly categorized as detrital authigenic and ore stage mineralization ore minerals consist of uraninite and coffinite this is the first noted occurrence of coffinite in this type of deposit in china sulfide minerals associated with the uranium minerals are pyrite marcasite and less commonly sphalerite and galena the sulfide minerals are largely in textural equilibrium with the uranium minerals however these sulfide minerals occasionally appear to predate as well as postdate the uranium minerals this implies that there are multiple generations of sulfides associated with these deposits the ore minerals occur interstitially between fossilized wood cells in the sandstones as well as replace fossilized wood and biotite the deposits are generally low grade primary uranium minerals associated with the low grade deposits are generally too small ranging from 0 2 to 0 3 m in diameter to be observed by optical microscopy and are only observed by electron microscopy mineral paragenesis and textures indicate that these deposits formed under low temperature 30 50 c conditions

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

controls on boron and germanium distribution in the low sulfur amos coal bed western kentucky coalfield usa abstract the duckmantian aged amos coal bed is a thin geochemical analysis of the amos coal bed shows higher concentrations of b and ge than other western kentucky coal beds high total b concentrations as well as high b be both considered to be indicators of marine environments increase toward the top of the coal bed most of the b values for the amos samples range from 66 to 103 ppm whole coal basis indicating deposition in a brackish environment high ge concentrations in coals have been considered to be a function of seam thickness and proximity to the top and bottom of the coal bed thin coals such as the amos are dominated by the coal bed margins and therefore have a tendency to have relatively high ge concentrations in the case of the amos coal bed the lower bench has a higher ge content suggesting that the substrate was a more important source of ge than the roof rock

petrology and geochemistry of the high sulphur coals from the upper permian carbonate coal measures in the heshan coalfield southern china abstract the heshan coals with very high organic sulphur content are found in the upper permian marine carbonate successions heshan formation in the heshan coalfield central guangxi southern china the petrography mineralogy and geochemistry of coals and non coal partings from the suhe and lilan coal mines of the heshan coalfield have been investigated using proximate petrographic inductively coupled plasma mass spectrometry icp ms x ray fluorescence xrf x ray diffraction xrd and scanning electron microscopy with an energy dispersive x ray sem edx techniques the sulphur content in the coals with ash less than 50 ranges from 5 3 to 11 6 of which more than 90 is organic sulphur reflecting a strong marine water influence on the palaeomire the high vitrinite reflectance 1 89 2 18 romax indicates that the coals in the heshan coalfield are mainly low volatile bituminous coal microscopic observation has revealed that the coal is mainly composed of vitrinite and inertinite macerals with relatively low tpi and high gi values suggesting an unusual strongly alkaline palaeomire with high ph xrd analysis plus optical and scanning electron microscopy show that the minerals in these coals are mainly quartz calcite dolomite kaolinite illite and pyrite although marcasite strengite and feldspar as well as some oxidised weathering products such as gypsum are also present most trace elements in the heshan coals are enriched with respect to their world mean with mo u and w highly enriched more than 10 times their world means the trace elements are believed to be associated either with organic compounds mo and u or minerals such as aluminium iron silicates sc ge and bi aluminium silicates cs be th pb ga and ree iron phosphates zn rb and zr iron sulphides as cd cr cu ni tl and v and carbonates sr mn and w abnormally high organic sulphur content high ash yields relatively high gi values very low tpi values very high u contents and very low th u ratios suggest that the heshan coals accumulated in low lying marine influenced palaeomires developed on carbonate platforms many of these characteristics have also been recorded in the tertiary coals of the circum mediterranean coal basins where no marine influence is present the similarities are thought to be produced by strongly alkaline groundwater chemistry common to both environments

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

relationship between the hydrogeochemical environment and sandstone type uranium mineralization in the ili basin china this paper describes the occurrence and distribution of u within groundwater of the ili basin in xinjiang china dissolved major ions dissolved gases ph eh and salinity in groundwater were employed to distinguish different hydrogeochemical environments and associated processes affecting u transport within the aquifer the results show that dissolution and deposition of u by groundwater are closely related to reactions with organic c and minerals such as sulfides carbonates and silicates along groundwater flow paths different chemical reactions predominate and account for changes in the occurrence of u in the rock and water of the oxidized zone the redox transition zone and the reduced zone knowledge of these associations between u and hydrogeochemical environments could enhance the understanding of relationships of groundwater circulation and u mineralization and could have implications for prospecting for sandstone type u deposits

the sequence stratigraphy of fluvial depositional systems the role of floodplain sediment storage abstract the currently used model for alluvial sequence stratigraphy has been criticised miall 1991 and an alternative model is offered here in this model alluviation mainly takes place during transgressive and not highstand phases when accommodation space allows sediment storage the high capacity for some river systems to store floodplain sediments is a critical consideration the effects of climatic and intrinsic geomorphic changes during fluvial deposition are likely to greatly complicate simple base level controlled sequence models and recognising higher order fourth and fifth order cycles will be particularly difficult

mineralogical and geochemical compositions of the pennsylvanian coal in the hailiushu mine daqingshan coalfield inner mongolia china implications of sediment source region and acid hydrothermal solutions abstract this paper investigates the mineralogical and geochemical compositions of the pennsylvanian coal in the hailiushu mine daqingshan coalfield neighboring previously reported al ga ree ore deposits including the adaohai mine in the same coalfield and deposits in the jungar coalfield using optical microscopy field emission scanning electron microscopy x ray fluorescence and inductively coupled plasma mass spectrometry the mineralogical and geochemical compositions in the coal were primarily controlled by the sediment source region during peat accumulation and by epigenetic acid hydrothermal solutions the hailiushu coal was deposited in a sub depression intermontane basin in the inner part of the orogenic belt with a sediment source region composed mainly of cambrian ordovician strata and archaean metamorphic rocks the minerals in the coal from the hailiushu mine dominantly consist of kaolinite with minor amounts of quartz sulfide and selenide minerals including chalcopyrite selenian galena galena sphalerite clausthalite and siegenite aluminophosphates and rhabdophane the coal is enriched in sio2 17 05 on average tio2 0 60 al2o3 13 71 zr 289 g g hf 7 09 g g and to a lesser extent f sc v cu ga se y nb mo cd sn la ta w hg pb bi and th titanium largely occurs in the kaolinite elements such as cu se sn hg pb and bi in the coal mainly occur in sulfide and or selenide minerals zirconium hf and nb were largely derived from the sediment source region the substitution of ti for al in kaolinite the corrosion of previously formed zircon anatase and quartz and the enrichment of middle rare earth elements in the coal were caused by the epigenetic acid hydrothermal solutions

mineral matter and trace elements in coals of the gunnedah basin new south wales australia abstract the concentrations of major and trace inorganic elements in a succession of permian coals from the gunnedah basin new south wales have been determined by x ray fluorescence techniques applied to both whole coal and high temperature ash samples the results have been evaluated in the light of quantitative data on the minerals in the same coals determined from x ray diffraction study of whole coal samples using a rietveld based interpretation program siroquant to determine relationships of the trace elements in the coals to the mineral species present comparison of the chemical composition of the coal ash interpreted from the quantitative mineralogical study to the actual ash composition determined by xrf analysis shows a high degree of consistency confirming the validity of the xrd interpretations for the gunnedah basin materials quartz illite and other minerals of detrital origin dominate the coals in the upper part of the sequence whereas authigenic kaolinite is abundant in coals from the lower part of the permian succession these minerals are all reduced in abundance however and pyrite is a dominant constituent in coals formed under marine influence at several stratigraphic levels calcite and dolomite occur as cleat and fracture infillings mostly in seams near the top and bottom of the sequence the potassium bearing minerals in the detrital fraction are associated with significant concentrations of rubidium and the authigenic kaolinite with relatively high proportions of titanium zirconium is also abundant with associated p and hf in the gunnedah basin coal seams relationships exhibited by ti zr nd and y are consistent with derivation of the original sediment admixed with the seams from an acid volcanic source pyrite in the coals is associated with high concentrations of arsenic and minor proportions of thallium no other element commonly associated with sulphides in coals however appears to occur in significant proportions with the pyrite in the sample suite small concentrations of cl present in the coal are inversely related to the pyrite content and appear to represent ion exchange components associated with the organic matter strontium and barium are strongly associated with the cleat filling carbonate minerals ge and ga appear to be related to each other and to the coal s organic matter cr and v are also related to each other as are ce la nd and pr but none of these show any relationship to the organic matter or a particular mineral component

the guadalupian lopingian boundary mudstones at chaotian sw china are clastic rocks rather than acidic tuffs implication for a temporal coincidence between the end guadalupian mass extinction and the emeishan volcanism abstract previous studies on the temporal link between the end guadalupian mass extinction event and emeishan flood volcanism were mainly based on geochronological and bio and chemostratigraphic correlation techniques wignall et al 2009 the absence of material based hard evidence that directly links the extinction with the emeishan volcanism remains a major obstacle regardless of the indication of coincidence in timing isozaki et al 2007 the emeishan basalts overlie permian platform carbonates that may contain a record of the end guadalupian mass extinction and erosional product of this province this paper presents mineralogy and geochemistry of mudstones from the guadalupian lopingian boundary g lb at chaotian sw china results indicate that these g lb mudstones are not air fall acidic tuff as previously thought but likely represent clastic rocks derived from erosional deposits of the emeishan large igneous province elip mudstones of the lower part group 1 have a geochemical affinity to the emeishan felsic volcanic rocks whereas mudstones of the upper part group 2 are compositionally akin to mafic components of the emeishan traps this chemostratigraphic sequence resembles the xuanwei formation which sits on the emeishan basalts he et al 2007 these data therefore indicate that the lower part of the mudstones at the chaotian g lb section the lowermost part of xuanwei and longtan formations and the emeishan felsic extrusives broadly constitute an isochron horizon throughout the elip and adjacent region suggesting a short duration for the emeishan volcanism a temporal coincidence between emeishan volcanism and the end guadalupian mass extinction are therefore inferred thus providing support for a cause and effect relationship

enrichment of arsenic lead and antimony in balingian coal from sarawak malaysia modes of occurrence origin and partitioning behaviour during coal combustion abstract the concentrations of mineral forming elements and trace elements in coal and coal ashes from balingian coalfield sarawak malaysia were assayed and their modes of occurrence enrichment origin and partitioning behaviour during coal combustion were studied as well balingian coal is high in as cu pb sb th and zn of particular concern are as as high as 181 ppm pb 325 ppm and sb 96 ppm all of which are highly enriched in balingian coal relative to their respective coal clarke values arsenic pb and sb in the coal are mostly organic and to a lesser extent they are bound to discrete minerals in the form of aluminosilicates during coal combustion in the power plant a substantial portion of organically associated as pb and sb in the coal vaporize and are released into the atmosphere whereas ba and mn are highly enriched in the coal ashes as compared to the raw coal the as pb and sb anomalies observed in balingian coal may be related to a large sb as and probably pb mineralization in the vicinity of the coalfield with some localised epigenetic infiltration of these elements from the surrounding rocks by circulating groundwaters

mineralogy and geochemistry of the coals from the karmozd and kiasar coal mines mazandaran province iran abstract the karmozd and kiasar mines are two major coal producing areas in the central alborz coal bearing field northern iran this study focused on the mineralogy and geochemistry with respect to the mode of occurrence of elements in feed coals and element partitioning during coal preparation the low sulfur content in the coal seams indicates a non marine origin i e deposition in lacustrine and swamp environments detrital minerals in the coal seams are quartz feldspar albite and orthoclase mica muscovite and biotite amphibole hornblende and kaolinite authigenic minerals include pyrite calcite and chlorite the contents of most elements are within the general worldwide ranges with the exceptions of mn co and cr in some coal seams correlation coefficients between elements and the ash yield identified four separate groups of elements the sequential extraction results indicate that al na k zn cu and co principally occur in the silicates whereas pb and cr mainly occur in the organic fraction calcium and mg display strong affinities to the carbonate phase while cd mainly occurs in the water soluble and organic fractions the calculated removability index shows that the coal cleaning method in zirab not only removes mineral matter and pyritic sulfur but also reduces the content of most inorganic elements

quantification of mineral matter in the argonne premium coals using interactive rietveld based x ray diffraction abstract the mineral matter in the eight reference north american coal samples of the argonne premium coal series has been investigated on a quantitative basis using x ray diffraction xrd techniques x ray diffraction data obtained from electronic low temperature oxygen plasma ash lta residues from ashes produced by heating the coals in air at 370 c and also from the raw coals themselves were evaluated using an interactive data processing system siroquant based on rietveld interpretation methods the results from the three types of material lta 370 c ash and raw coal were compared for each sample this allowed the components present in the raw coals in crystalline form to be recognised separately from mineral artifacts produced particularly in the low rank coals from interaction of organically associated elements ca s etc during the two ashing processes after the allowance for the production of any artifacts the quantitative mineral assemblages identified from xrd of the raw coals were found to be consistent even for coals having a relatively low ash percentage around 5 with the results obtained from the respective mineral concentrates prepared by the ashing methods the effects of heating the coal to 370 c could also be distinguished relative to the raw coal or the lta through changes in components such as pyrite and the clay minerals although some areas of uncertainty exist particularly with magnesium in the low rank coals the calculated chemical compositions of the coal ash derived from the mineral mixtures identified for each coal were also found to be consistent with the results of direct chemical analysis of the respective coal ash materials

notes on the marginal enrichment of germanium in coal beds germanium distribution in coal has long been a topic of interest the enrichment of ge near margins of coals including the margins of partings within the coal has been noted in many coals from numerous coalfields throughout the world in this paper a summary of literature on ge geochemistry on the upper and lower margins of coal seams with special emphasis on the literature of russia and the former soviet union and japan is presented

concentration and distribution of trace elements in lignite from the shengli coalfield inner mongolia china implications on origin of the associated wulantuga germanium deposit abstract the wulantuga germanium deposit wgd hosted in coal seams with ge resources up to 1600 mt is located in the shengli coalfield in xilingol inner mongolia china forty two channel samples of ge bearing lignites of the no 6 1 coal seam in lower cretaceous bayanhua formation were collected and analyzed by inductively coupled plasma mass spectrometry icp ms the mode of occurrence of elements in selected lignite samples were studied by cluster analysis and scanning electron microscope with energy dispersive x ray spectrometer sem edx the lignite samples of wgd are distinctly enriched in be ge sb w and u and depleted in rb nb sn and ta compared with the average composition of upper continental crust the average concentrations of above enriched elements also are higher than those of overlying sandstone of wgd and contemporary ge barren lignite of hongqi coal mine in shenli coalfield as well as the average concentration of elements in the usa coals and worldwide coals with an exception of sr most trace elements and ash yields obey the log normal distribution in all 42 lignite samples collected from wgd the elements in these lignites may be classified into four groups the first group ge mo association contains elements with negative correlation coefficients with ash yields and they show mainly organic affinity the elements in the second group tl ga zn co association show negative to moderate correlation coefficients with ash yields and may also have an organic affinity but most of them are mainly related to mineral matter such as sphalerite the last two groups rb cs and w u cd y pb cu hf zr th sn nb ta tio 2 sb ba sr mno be associations contain elements with moderate to high correlation coefficients with ash yields much of them associated mainly with mineral matter such as anatase manganite zircon and barite as identified by sem edx analysis and show mainly aluminosilicate affinity silver bearing particles or native silver were identified by sem edx in the lignites from wgd and hongqi coal mine germanium and mo can concentrate in different proportion of coal seam in different sections while other elements more or less follow the distribution of ash yield the tio 2 normalized elemental profiles reveal that be tio 2 ge tio 2 w tio 2 u tio 2 mo tio 2 sb tio 2 tl tio 2 and sr tio 2 ratios of the lignite samples in three sections of wgd are generally one or two order of magnitude higher than the reference ratios of sandstone from wgd and lignite from hongqi coal mine much more than 90 of these elements be ge w u mo sb tl and sr may be transported into coal seam by solution the ge bearing lignites from wgd are distinctly characterized by lower rb cs ratios higher u th ratios different from those of the overlying sandstone from wgd and contemporary lignite from hongqi coal mine most trace elements in the ge bearing lignite of wgd may have been derived from a granitic source and the enrichment of be ge sb w and u may be attributed to an epigenetic lateral transferred ge bearing solution that leached these elements from the granitic source and transported them into the lignite

petrographic geochemical and mycological aspects of miocene coals from the novaky and handlova mining districts slovakia abstract fungi have once again become a topic of interest to coal scientists in their roles as agents of maceral formation recent works have demonstrated that fungi occur in association with woody remains resins and cuticles in coalified materials of a variety of ages in addition to coal balls and compression impression fossils where they are already well known these forms however have only been viewed as cross sections along a polished plane assigning the fungi to family much less determining which fungi they represent is very difficult in this orientation fungal identifications are necessary to the continuance of this research into the origin of coal macerals because of the need to know if macrinite begins to form prior to incorporation into the peat which could be demonstrated by its association with symbiotic and parasitic rather than saprophytic fungi this study examines the fungal remains recovered from eight coal samples from miocene age coals in the novaky and handlova mining districts of slovakia with the aim of making this distinction these samples were collected in slovakia as part of the us geological survey s world coal quality inventory program and provided to the authors the samples were processed using the o keefe technique for subbituminous coals and mounted for observation in transmitted light forms were identified using published works and consultation with a modern mycologist forms recovered through palynologic processing were compared to and correlated with forms seen in cross section under reflected light

lanthanide yttrium and zirconium anomalies in the fire clay coal bed eastern kentucky abstract the fire clay coal bed in the central appalachian basin region contains a laterally persistent tonstein that is found in the coal throughout most of its areal extent the tonstein contains an array of minerals including sanidine quartz anatase and euhedral zircon that constitutes strong evidence for a volcanic origin of the parting for this study five samples of the tonstein and four sets of coal samples underlying the tonstein were collected from five sites in eastern kentucky inductively coupled plasma mass spectroscopy icp ms analysis of the tonstein and underlying coal collected from four sites in eastern kentucky show that although zr concentrations are high in the tonstein 570 1820 ppm on a coal ash basis cab they are highest in the coal directly underlying the tonstein 2870 4540 ppm cab a similar enrichment pattern is observed in the concentration of y plus the sum of the rare earth elements y ree total y ree concentrations in the five tonstein samples range from 511 to 565 ppm cab however y ree contents are highest in the coals directly underlying the tonsteins values range from 1965 to 4198 ppm cab scanning electron microscopy of samples from coal which directly underlies two of the tonstein samples show that ree rich phosphate tentatively identified as monazite commonly infills cracks in clays and cells in clarain and vitrain zircon is rare and commonly subhedral on the basis of coal chemistry and grain morphology we suggest that volcanic components in the tonstein were leached by ground water the leachate rich in y and ree precipitated as authigenic mineral phases in the underlying coal

evidence of uranium biomineralization in sandstone hosted roll front uranium deposits northwestern china we show evidence that the primary uranium minerals uraninite and coffinite from high grade ore samples u3o8 0 3 in the wuyiyi wuyier and wuyisan sandstone hosted roll front uranium deposits xinjiang northwestern china were biogenically precipitated and psuedomorphically replace fungi and bacteria uranium vi which was the sole electron acceptor was likely to have been enzymically reduced post mortem accumulation of uranium may have also occurred through physio chemical interaction between uranium and negatively charged cellular sites and inorganic adsorption or precipitation reactions these results suggest that microorganisms may have played a key role in formation of the sandstone or roll type uranium deposits which are among the most economically significant uranium deposits in the world

integrated geophysical techniques for subsurface imaging of active deformation across the himalayan frontal thrust in singhauli kala amb india abstract non invasive geophysical techniques employed across the himalayan frontal thrust hft at singhauli in the north western frontal himalaya to understand shallow subsurface geological structures and their nature in the context of active tectonics the combination of high resolution ground penetrating radar gpr electrical resistivity tomography ert and multi channel analysis of surface waves masw techniques with the different acquisition parameters found to be beneficial in gaining high resolution images of shallow subsurface geological structures the contact zone of resistivity obtained between 134 m suggests the juxtaposition of dissimilar lithological units explained as two faults dipping to the northwest related to the hft the average separation between fault 0 and fault i is 12m which in general agreement with the trench excavation survey the gpr radargram over a length of 45m show offset reflectors at a horizontal distance of 12 15m close to the active deformation zone the horizontal reflectors abruptly truncate across two northerly dipping planes the 2d vs section masw1 2 exhibited dipping attitude of the litho units with different velocity zones in the northeast direction which are also consistent with the local geological setting prominent liquefaction feature identified in the ert section specifically with the 1 and 1 5m electrode spacing show explicit expression of its existence due to contrasting resistivity ranging between 100 and 450 m a strong correlation has been established between the field based geological observations carried out earlier in this area through a trench excavation survey with the present work using geophysical techniques the integrated approach found to be highly beneficial in those areas where contrasting sub lithological units exist in terms of their physical properties this study argues for judicious use of the ert gpr and masw techniques to delineate shallow subsurface geology across various active faults in the himalayan terrain to comprehend the active deformation related to large magnitude paleoearthquakes and earthquake hazard assessment

characterization of trace elements in sulphur rich late permian coals in the heshan coal field guangxi south china abstract the concentration of trace elements and their distribution in the late permian coal in the heshan coal field guangxi autonomous region were analysed in this paper the late permian coal of the heshan mining district was developed in a low energy and shallow confined carbonate platform heshan coal is a low volatile bituminous coal characterized by a high sulphur content ranging between 2 0 and 8 2 compared with the worldwide average content of the trace elements in coal the content of some trace element in the study coal is markedly high bi ce cr cs cu ga hf sr ta th u v w y zr la mo nb and sc the trace element associations were investigated by means of intracorrelation analysis some elements such as cl f and sr are found in coal in association with the carbonate minerals v cr zn mo ni and as contents in coal vary significantly amongst the coal samples they are mainly concentrated in the lower part of the coal 4 upper of suhe and lilan mines and the coal 4 lower of dong mine and these possibly occurring in minerals such as arsenide and sulphide the content of u in heshan coal is high and is mainly concentrated at the upper and the lower parts of the coal seam and it is associated with mineral assemblages with ba mo v ni zn rb and cr furthermore la and ce are highly correlated with those found in phosphate minerals and pb sc ga th y and sn to those in aluminosilicate minerals the enrichment of some elements such as v cr zn mo ni rb as well as total sulphur and iron in the lower part of most coal seams might be associated with the formation of soil horizon before the accumulation of peat in the basin some other elements such as cl f sr and ca are locally concentrated in the top of specific coal seams as a result of the leaching from overlying carbonates

gallium and germanium in selected indiana coals abstract the distribution of gallium ga and germanium ge was studied in two pennsylvanian high volatile bituminous coals of indiana the springfield coal member of the petersburg formation and the danville coal member of the dugger formation gallium in the springfield and danville coals shows similar ranges from 1 70 to 8 90 ppm averaging 5 06 ppm for the danville coal and 1 40 to 12 30 ppm with an average of 3 39 ppm for the springfield coal for ge these ranges are 2 50 to 26 70 ppm average 14 19 ppm for the danville coal and 1 54 to 38 0 average 9 40 ppm for the springfield coal in the vertical section ga shows a symmetric distribution with the lowest values in the middle part of the seam in the springfield coal and an asymmetric distribution increasing or decreasing upward in the danville coal gallium is dominantly associated with the mineral matter and clay minerals in particular germanium shows a symmetric distribution with the largest enrichment in the topmost and the basal benches of the coal it appears to be associated with either mineral matter dominantly clays occasionally pyrite or organic matter

sedimentological setting of sandstone type uranium deposits in coal measures on the southwest margin of the turpan hami basin china abstract sandstone type uranium deposits usually exist in coal measures this stratigraphy study found that the jurassic coal measures shuixigou group at the southwest margin of the turpan hami basin consist of the badaowan sangonghe and xishanyao formations which correspond to sequences a b and c respectively sequence c can be divided into the lowstand systems tract lst expanding lacustrine systems tract est and highstand systems tract hst uranium mineralization mainly develops in sequence c in which lst and hst are the main mineralization strata while est is the secondary mineralization stratum high resolution study of depositional systems tracts indicates that the fine sediments around the boundaries of parasequences can form the confining beds of uranium metallogenetic fluid systems within parasequences the braided channel sandstones and part large scale braided distributary channel sandstones have a close relationship with strong interlayer oxidation and uranium mineralization periodical development of parasequences conduces to the frequent growth of large skeletal sandstones and confining beds that is the essential reason for the complexity of uranium mineralization in depositional systems tracts the study also found that different depositional systems lead to obvious differences in the spatial distribution structures of skeletal sandstones and confining beds lst and hst mainly comprise braided stream depositional systems where uranium skeletal sandstones develop and are always located in the middle and lower parts of the parasequences while confining beds are always located in the upper part of parasequences while est mainly comprises braided delta depositional systems where uranium skeletal sandstones have a relatively small scale and are always located in the middle part of parasequences confining beds are always located in the lower and upper parts of parasequences thus the study of depositional systems tracts in sequence is only suitable for the primary exploration stage of sandstone type uranium deposits and parasequences are the best evaluation units in the advanced exploration stage