classification of huminite iccp system 1994 abstract in the new classification iccp system 1994 the maceral group huminite has been revised from the previous classification iccp 1971 int handbook coal petr suppl to 2nd ed to accommodate the nomenclature to changes in the other maceral groups especially the changes in the vitrinite classification iccp 1998 the new vitrinite classification iccp system 1994 fuel 77 349 358 the vitrinite and huminite systems have been correlated so that down to the level of sub maceral groups the two systems can be used in parallel at the level of macerals and for finer classifications the analyst now has according to the nature of the coal and the purpose of the analysis a choice of using either of the two classification systems for huminite and vitrinite this is in accordance with the new iso coal classification that covers low rank coals as well and allows for the simultaneous use of the huminite and vitrinite nomenclature for low rank coals

the pre quaternary history of fire abstract although evidence for land vegetation comes from the silurian and maybe even earlier the first record of fossil charcoal fusain is from the late devonian for this period there are only one or two isolated records not until the early carboniferous is there a record of extensive charcoal deposits mainly preserved in near shore clastic sediments which provide evidence of significant and widespread wildfires by the late carboniferous charcoal was common or abundant in a wide range of facies including tropical wetland peats wildfire played an important role in shaping the environment at this time the latest palaeozoic and early mesozoic records of charcoal are fewer whereas important deposits of late mesozoic age are found worldwide the occurrence of charcoal at the cretaceous tertiary boundary has been highlighted as evidence for a global fire following a meteorite impact but this interpretation is questionable charcoal has been widely reported from tertiary sediments and its appearance in the quaternary and recent is not solely as a result of human impact through the past 400 million years there have been major changes in atmospheric oxygen levels that affected fire intensity and frequency fire systems thus have a long history and their impact on shaping the environment is assessed

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

observations and experiments on the origin and formation of inertinite group macerals the inertinite group macerals include fusinite semifusinite inertodetrinite macrinite micrinite and funginite and secretinite which together replace sclerotinite the macrolithotype fusain comprises fusinite and semifusinite and is now widely accepted as charcoal formed by wildfire activity however alternative origins for fusinite and semifusinite are still claimed this paper considers the use of the terms pyrofusinite degradofusinite rank fusinite and primary fusinite misleading while the definitions of the terms funginite and secretinite are also considered problematic observations made on modern wildfire derived and volcanogenic charcoal assemblages using reflectance and scanning electron microscopy together with experimental charcoalification studies demonstrate that most if not all inertinite macerals have acquired their optical and physical characteristics through the action of elevated temperatures the criteria for the identification of charcoals produced by wildfire and volcanic activity are outlined and the role of the petrographic nomenclature system is discussed

parameterization of centimeter scale sea ice surface roughness using terrestrial lidar microwave scattering from sea ice is partially controlled by the ice surface roughness in this paper we propose a technique for calculating 2 d centimeter scale surface roughness parameters including the rms height correlation length and form of autocorrelation function from 3 d terrestrial light detection and ranging data we demonstrate that a single scale of roughness can be extracted from complex sea ice surfaces incorporating multiple scales of topography after sophisticated 2 d detrending and calculate roughness parameters for a wide range of artificial and natural sea ice surface types the 2 d technique is shown to be considerably more precise than standard 1 d profiling techniques and can therefore characterize surface roughness as a stationary single scale process which a 1 d technique typically cannot do sea ice surfaces are generally found to have strongly anisotropic correlation lengths indicating that microwave scattering models for sea ice should include surface spectra that vary as a function of the azimuthal angle of incident radiation however our results demonstrate that there is no fundamental relationship between the rms height and correlation length for sea ice surfaces if the sampling area is above a threshold minimum size

observations on the nature and origin of fusain abstract evidence for a wildfire origin of fusain is examined charcoal produced by natural fires and artificial charring resembles fossil fusain both in physical size and shape and in optical reflectance artificially charred leaves and naturally burnt wood are illustrated using the sem reflectance studies on modern charcoals suggest that much semifusinite may be produced by pyrolysis the ecological implications of a wildfire origin of fusain are discussed and it is concluded that fires have been a feature of terrestrial ecosystems from at least the late devonian

arsenic and lead concentrations in the pond creek and fire clay coal beds eastern kentucky coal field abstract the middle pennsylvanian breathitt formation westphalian b pond creek and fire clay coal beds are the 2 largest producing coal beds in eastern kentucky single channel samples from 22 localities in the pond creek coal bed were obtained from active coal mines in pike and martin countries kentucky and a total of 18 fire clay coal bed channel samples were collected from localities in the central portion of the coal field the overall objective of this study was to investigate the concentration and distribution of potentially hazardous elements in the fire clay and pond creek coal beds with particular emphasis on as and pb 2 elements that are included in the 1990 clean air act amendments as potential air toxics the 2 coals are discussed individually as the depositional histories are distinct the fire clay coal bed having more sites where relatively high s lithologies are encountered in an effort to characterize these coals 40 whole channel samples excluding 1 cm partings were analyzed for major minor and trace elements by x ray fluorescence and proton induced x ray emission spectroscopy previously analyzed samples were added to provide additional geographic coverage and lithotype samples from one site were analyzed in order to provide detail of vertical elemental trends the as and pb levels in the fire clay coal bed tend to be higher than in the pond creek coal bed one whole channel sample of the fire clay coal bed contains 1156 ppm as ash basis with a single lithotype containing 4000 ppm as ash basis most of the as and pb appears to be associated with pyrite which potentially can be removed in beneficiation particularly coarser pyrite disseminated finer pyrite may not be completely removable by cleaning in the examination of pyrite conducted in this study it does not appear that significant concentration of as or pb occurs in the finer pyrite forms the biggest potential problem of as or pb enriched pyrite is therefore one of refuse disposal

petrography and geochemistry of oligocene bituminous coal from the jiu valley petrosani basin southern carpathian mountains romania abstract belt samples of oligocene chattian bituminous coal from 10 underground mines located in the jiu valley hunedoara county petrosani basin romania have been examined and analyzed for proximate and ultimate analysis major minor and trace element chemistry organic petrography and vitrinite reflectance the mineral chemistry and mode of occurrence of trace elements also have been investigated using sem and electron microprobe techniques twenty coal beds occur in the jiu valley and most of the samples are from bed no 3 the most productive bed of the dilja uricani formation of oligocene age the petrosani basin oriented sw ne is 48 km long 10 km wide at the eastern part and 2 km wide at the western part the coal mines are distributed along the center of the valley generally following the jiu de vest river reflectance measurements indicate that the rank of the coals ranges from high volatile b to high volatile a bituminous overall rank decreases from the southwest to the northeast in bed no 3 r max varies from 0 75 in the northeast to 0 93 in the southwest although most oligocene coals in romania and adjacent countries are lignite in rank the jiu valley bituminous coals have been affected by regional metamorphism and attending hydrothermal fluids related to the alpine orogenic event the coals are all dominated by vitrinite resinite and funginite are important minor macerals in most of the coals pyrite and carbonate generally dominate the mineral assemblages with carbonate more abundant in the northwest siderite occurs as nodules and masses within the macerals generally vitrinite dolomite and calcite occur as fracture fillings plant cell fillings and in other authigenic forms late stage fracture fillings are siderite dolomite calcite and ankerite in one instance two populations of siderite 35 and 45 wt feo plus ankerite fill a large fracture late stage pyrite framboid alteration is ni and cu bearing with ni rich pyrite hydrated ni fe sulfate chalcopyrite and rare pentlandite and clausthalite some of the mines sampled in 2001 have been closed as romania has undergone severe economic and environmental reforms in preparation for its 2007 entry into the european union eu romania s continued efforts to adapt to a market economy within the environmental and economic constraints of the eu make this collection of data valuable as the eventual fate of the other mines in jiu valley is unknown

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

petrology mineralogy and geochemistry of the ge rich coal from the wulantuga ge ore deposit inner mongolia china new data and genetic implications abstract the early cretaceous wulantuga high ge coal deposit in inner mongolia is one of the major coal hosted ge deposits in china this paper reports new data on the petrological mineralogical and geochemical compositions of 13 bench samples of the high ge no 6 coal from the wulantuga deposit and provides new insight into the origin and modes of occurrence of the minerals and elements present the no 6 coal has a low rank ro max 0 45 and is a low ash coal 8 77 the total content of inertinite 52 5 vol on average in most coal benches is higher than that of huminite 46 8 vol on average the dominant huminite maceral is textinite averages 43 9 and the dominant inertinite macerals are mainly fusinite averages 33 and semifusinite 12 5 along with trace portions of intertodetrinite secretinite funginite and macrinite fungus seen as the maceral funginite played a role in the development of degraded maceral forms in the wulantuga coals funginite is present in samples examined in this study but is not easily extracted during palynological studies recovered fungal taxa are saprophytes indicating woody decomposition prior to incorporation in the mire palynology revealed a sparse flora that is consistent with the early cretaceous age minerals in the coal include quartz kaolinite illite and or illite smectite gypsum pyrite and traces of rutile and anatase a varying proportion of bassanite was observed in the low temperature ashes ltas bassanite in the ltas was derived both from the dehydration of gypsum in the raw coals and from the interaction between organically associated ca and s during the low temperature ashing in addition to a proportion of detrital quartz fine grained and cell filling quartz of authigenic origin is also present pyrite is of syngenetic origin and derived from sulfate rich hydrothermal fluids compared to common chinese and world low rank coals the no 6 coal is enriched in be 25 7 g g f 336 g g ge 274 g g as 499 g g sb 240 g g cs 5 29 g g w 115 g g hg 3 165 g g and tl 3 15 g g germanium in the coal is organically associated and its enrichment is attributed to hydrothermal fluids from the adjacent granitoids beryllium is probably associated with ca and mn bearing carbonate minerals and to a lesser extent with clay minerals rather than with organic matter fluorine largely occurs in clay minerals kaolinite and illite the elevated concentrations of tl hg as and sb are mainly distributed in pyrite and were derived from the same hydrothermal source the high w in the coal occurs in both the organic matter and the authigenic quartz illite is the major carrier of cs in the coal the accumulation of rare earth elements ree in the coals had a polygenetic and multistage nature including two syngenetic stages early hydrothermal and terrigenous and one diagenetic late hydrothermal stage the ree distribution patterns of the early hydrothermal and terrigenous stages were characterized by the enrichment of medium ree m type ree and light ree l type ree respectively a h type ree distribution pattern hree enrichment occurred in the late diagenetic hydrothermal stage the high ge wulantuga coals are also abnormally enriched in precious metals gold pt and pd in the coals calculated from their concentrations in the ltas are 3 5 25 8

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

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

ree geochemistry of the cretaceous lignite from wulantuga germanium deposit inner mongolia northeastern china 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 lower cretaceous bayanhua formation were collected and their ree compositions were analyzed by inductively coupled plasma mass spectrometry icp ms the modes of occurrence of ree in selected lignite samples were studied by scanning electron microscope with energy dispersive x ray spectrometer sem edx and statistical methods the distribution of ree and y in all 42 samples from wgd are in accordance with the log normal distribution the total rare earth element content ree of most lignite samples from wgd range from 9 02 to 118 ppm only four samples show relatively higher 149 533 ppm ree concentration the average ree contents of 42 lignite samples from wgd are slightly higher than those of the usa coals world wide coals sandstone from wgd and the contemporary ge barren lignite from hongqi coal mine the lignite samples from wgd have shale like chondrite or nasc normalized ree patterns similar to those of sandstone overburden and ge barren lignite from hongqi coal mine ree contents of most lignite samples are highly positive correlated with ash yields indicating a mainly detrital source and association with syngenetic mineral matter ree rich phosphates monazite were identified by sem edx in some medium to high ash ash yields range from 23 58 to 38 18 lignite samples with high ree y contents from wgd ree can be concentrated in the upper and lower proportions of the no 6 1 coal seam the vertical profiles of ree mainly follow that of tio 2 and the average ree tio 2 ratio of lignite sample in three sections is very close to that of the sandstone from wgd or lignite from hongqi coal mine it was determined that most ree in the lignite from wgd were derived from a detrital source and associated with syngenetic mineral matter however when normalized to the overlying sandstone some lignite samples from wgd display a small but distinct enrichment in middle to heavy ree indicating small quantity of middle to heavy ree may be added and or retained during epigenesis the lignite samples from wgd are characterized by higher ratios of lree hree and eu eu and horizontal nasc normalized ree patterns and distinguished from those of the ge bearing lignites from lincang germanium deposit yunnan china and ge deposits of russian far east there is no distinct correlations between ge and any individual ree or ree y content of lignite from wgd

mineralogical and geochemical compositions of the pennsylvanian coal in the adaohai mine daqingshan coalfield inner mongolia china modes of occurrence and origin of diaspore gorceixite and ammonian illite abstract aluminum hydroxide boehmite rich pennsylvanian coals of high volatile a bituminous rank were found previously in the jungar coalfield inner mongolia china this paper reports new results on 48 bench samples of the cp2 coal from the adjacent adaohai mine daqingshan coalfield inner mongolia and provides new insights into the origin and modes of occurrence of the minerals and elements present in the cp2 coal compared to the same coal in the adjacent mines the cp2 coal in the adaohai mine has a higher rank ro ran 1 58 which is attributed to igneous intrusions during the late jurassic and early cretaceous epochs the proportion of inertinite 35 3 in the coal is higher than that in other late paleozoic coals in northern china but lower than that in the jungar coals minerals in the cp2 coal include diaspore boehmite gorceixite calcite dolomite siderite clay minerals kaolinite and ammonian illite and trace amounts of anatase fluorapatite quartz and pyrite based on mineral proportions in the coal bench samples the cp2 coal may be divided into four zones i to iv from bottom to top the major mineral in zones i and iv is kaolinite zones ii and iii are mainly composed of ammonian illite diaspore boehmite gorceixite calcite dolomite and siderite diaspore boehmite and gorceixite forming materials were derived from oxidized bauxite in the weathered crust of the benxi formation in the sediment source region during peat accumulation however gorceixite may have formed earlier than diaspore the diaspore was derived from gibbsite that was subjected to dehydration by the heat of the igneous intrusions the ammonian illite may have been formed at a relatively high temperature by interaction of kaolinite with nitrogen released from the organic matter in the coal during metamorphism caused by the igneous intrusion the calcite and dolomite occur as epigenetic cell and fracture fillings and were probably derived from the igneous fluids compared to the common chinese and world coals the cp2 coal is enriched in cao 1 69 mgo 0 32 p2o5 0 214 f 207 g g ga 16 3 g g zr 446 g g ba 276 g g hg 0 33 g g and th 12 4 g g but has a lower sio2 al2o3 ratio due to the higher proportions of diaspore boehmite and gorceixite in the coal the f occurs mainly in gorceixite and fluorapatite the major carriers of ga are diaspore and kaolinite but not gorceixite barium mainly occurs in gorceixite and barite mercury was probably derived from the igneous intrusion and is distributed in both the organic matter and the minerals the elements are classified into five associations by cluster analysis groups a b c d and e group a represents a ree be y se ga ge sc in pb bi nb ta tio2 w hg sb zr hf th u association most of the elements in group a are lithophile elements that occur in aluminosilicate minerals group b sn te zn cd v as cr cu mo ni re is weakly correlated with ash yield and is associated with unidentified trace sulfide minerals elements in group c ad na2o al2o3 sio2 li k2o rb cs tl association probably occur in the clay minerals and diaspore group d consists of p2o5 ba f sr s and cl and with the exception of s they occur in minerals gorceixite and fluorapatite oxides of fe2o3 mno cao mgo make up group e and mainly occur in the carbonate minerals the coals are enriched in light rees and the lrees hrees have been highly fractionated with an average la yb n of 8 71 the heavy rees in the coals have a stronger organic affinity than the lrees

some considerations concerning the use of correlation coefficients and cluster analysis in interpreting coal geochemistry data the mode of occurrence of trace elements in coal is important from both scientific and environmental viewpoints because the behavior of trace elements in coal utilization depends not only on their concentration but also on their chemical form or mode of occurrence statistical methods are one of the more commonly used indirect approaches for interpreting element modes of occurrence these methods include correlation coefficients between elements and ash as well among the elements themselves cluster and factor analysis using data sets derived from a suite of 75 samples from a bulgarian lignite deposit we demonstrate that statistical analysis of subsets with different ash ranges and with slightly different suites of elements can lead to substantially different conclusions concerning the element modes of occurrence in this example we assume that direct information on the element modes of occurrence such as mineralogy or selective leaching behavior is absent statistical methods however can provide useful insights into trace element modes of occurrence for properly constrained sample suites

charcoal reflectance as a proxy for the emplacement temperature of pyroclastic flow deposits hot pyroclastic flow deposits often entomb and preserve vegetation as charcoal when studied in polished section this charcoal is highly reflective novel data from experimentally charred woods demonstrate that reflectance increases with both temperature and time at temperatures above 250 c reflectance rises rapidly for the first hour effectively stabilizing after 4 h for temperatures below 400 c however for higher temperatures reflectance only stabilizes after 24 h charcoalified woods from block and ash flow deposits generated by the soufriere hills volcano in montserrat have yielded interpreted deposit temperatures based on reflectance data of 325 525 c these temperatures compare favorably with directly measured data 365 640 c from the same deposits indicating that charcoal reflectance is useful as a temperature proxy for ancient pyroclastic flow deposits particularly where magnetic or mineral data are absent for this purpose however caution should be exercised as only a minimum temperature can be inferred where the heating duration of the deposit is unknown unlike magnetic or mineral data temperature data from charcoalified woods can be obtained from reworked deposits providing a valuable means of validating observations made about the style of eruption of volcanoes in ancient settings

geochemistry and petrology of selected coal samples from sumatra kalimantan sulawesi and papua indonesia abstract indonesia has become the world s largest exporter of thermal coal and is a major supplier to the asian coal market particularly as the people s republic of china is now 2007 and perhaps may remain a net importer of coal indonesia has had a long history of coal production mainly in sumatra and kalimantan but only in the last two decades have government and commercial forces resulted in a remarkable coal boom a recent assessment of indonesian coal bed methane cbm potential has motivated active cbm exploration most of the coal is paleogene and neogene low to moderate rank and has low ash yield and sulfur generally

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

using hem surveys to evaluate disposal of by product water from cbng development in the powder river basin wyoming production of methane from thick extensive coal beds in the powder river basin of wyoming has created water management issues since development began in 1997 more than 650 billion liters of water have been produced from approximately 22 000 wells infiltration impoundments are used widely to dispose of by product water from coal bed natural gas cbng production but their hydrogeologic effects are poorly understood helicopter electromagnetic surveys hem were completed in july 2003 and july 2004 to characterize the hydrogeology of an alluvial aquifer along the powder river the aquifer is receiving cbng produced water discharge from infiltration impoundments hem data were subjected to occam s inversion algorithms to determine the aquifer bulk conductivity which was then correlated towater salinity using site specific sampling results the hem data provided high resolution images of salinity levels in the aquifer a result not attainable using traditional sampling methods interpretation of these i

effects of detrital influx in the pennsylvanian upper freeport peat swamp abstract quartz cathodoluminescence properties and mineralogy of three sets of samples and vegetal and or miospore data from two sets of samples from the upper freeport coal bed west central pennsylvania show that detrital influence from a penecontemporaneous channel is limited to an area less than three km from the channel the sets of samples examined include localities of the coal bed where 1 the coal is thin split by partings and near a penecontemporaneous fluvial channel 2 the coal is relatively thick and located approximately three km from the channel and 3 the coal is thick and located approximately 12 km from the channel samples from locality 1 nearest the channel have relatively high ash yields low temperature ash average 27 3 on a pyrite and calcite free basis and high proportions of quartz and clay minerals the quartz is primarily detrital as determined by cathodoluminescent properties and the ratio of kaolinite to illite is low in addition most of the plant remains and miospores indicate peat forming plants that required low nutrient levels for growth in contrast samples from localities 2 and 3 from the more interior parts of the bed contained predominantly authigenic quartz grains nd yielded low temperature ash values of less than 14 on a pyrite and calcite free basis the low temperature ash contains low concentrations of quartz and clay minerals and the ratio of kaolinite to illite is relatively high although intact core was not available for paleobotanical analyses another core collected within 1 km from locality 3 contained plant types interpreted to have required high nutrient levels for growth these data indicate that mineral formation is dominated by authigenic processes in interior parts of the coal body some of the authigenic quartz may have been derived from herbaceous ferns as indicated by patterns in the palynological and paleobotanical data in contrast detrital processes appeared to be limited to in areas directly adjacent to the penecontemporaneous channel where the coal bed is high in ash split by mineral rich partings and of little or no economic value

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

the geochemistry of tungsten in bulgarian coals abstract this paper discusses the tungsten geochemistry in coal based on the behavior of this element in 14 bulgarian deposits the w contents range from 0 5 4335 ppm in the ash and from 0 01 784 ppm in the coals in four of the deposits the tungsten content proved to be 16 to 100 times higher than the clarke value for sedimentary rocks no correlation has been found between the w concentration and either the age of the coal bearing strata or the coal rank the deposits were divided in three groups on the basis of the relationship between tungsten and ash content the role of sorption ash and terrigenous ash in tungsten binding was evaluated for each group the correlation between tungsten and organic matter is demonstrated by the increased contents of tungsten in the ash of the low ash coals its concentration in the lighter coal fractions its extraction from the coals by hf and naoh only and by model experiments sorption ash concentrates tungsten terrigenous ash is a carrier of tungsten of the petrographic constituents of coal vitrain was found to concentrate the largest amounts of tungsten in two of the deposits richest in tungsten there is a very distinct zonality in its vertical distribution tungsten concentration decreases from the bottom to the top of the coal bed this zonality might be explained by the diffusion syngenetic or diagenetic with respect to the coal forming process through the coal bed of aqueous solutions enriched in tungsten the wide range of variation of the tungsten concentrations the considerable differences in the mean contents and the dispersions between the individual deposits show that tungsten is very sensitive to the differences of the source area coal deposits enriched in tungsten may be expected in the following favourable environments 1 in areas with nitrogen bearing thermal waters containing increased amounts of tungsten 2 source areas with tungsten mineralizations and 3 country rocks consisting of acid granitoids whose clarke values of tungsten are the highest as compared to the other types of rocks