present day kinematics of the mediterranean a comprehensive overview of gps results i combine recently published gps results to derive a geodetic horizontal velocity field consistent at the scale of the mediterranean and the surrounding alpine belts the velocity field is then used to discuss the boundary conditions around each major deforming area in the mediterranean to describe the main patterns of motion and deformation to critically review the existing kinematics models and to finally point out the main unresolved kinematics questions strain rate in europe north of the alpines belt is dominated by the signature of the glacial isostatic adjustment and tectonic strain remains below the current accuracy of gps results in the western mediterranean deformation is restricted to the betics the alboran and the morrocan rif with west to southwestward motion with respect to iberia which is part of stable europe shortening consistent with the relative nubia eurasia plate motion is found throughout the maghrebides but the distribution of deformation in northern africa remains largely unknown the central mediterranean is dominated by the counter clockwise rotation of the adriatic the junction between the southern adriatic domain and nubia has yet to be firmly established the deformation over a wide area east of the maghrebides in tunisia and the gulf of sirte in libya still remains to be quantified in the eastern mediterranean the velocity field is dominated by a general anti clockwise rotation and a general trend towards the hellenic trench with velocity magnitude increasing with decreasing distances from the trench this trend is observed not only in the aegean and anatolia but also in the southern balkans geodetic results emphasize that the convergence of the nubia and arabia plates towards eurasia directly controls the deformation across only very few segments along the plate boundary zone additional processes are therefore required to explain the observed velocity field and deformation pattern

changes in optical properties chemistry and micropore and mesopore characteristics of bituminous coal at the contact with dikes in the illinois basin abstract changes in high volatile bituminous coal pennsylvanian near contacts with two volcanic intrusions in illinois were investigated with respect to optical properties coal chemistry and coal pore structure vitrinite reflectance ro increases from 0 62 to 5 03 within a distance of 5 5 m from the larger dike and from 0 63 to 3 71 within 3 3 m from the small dike elemental chemistry of the coal shows distinct reductions in hydrogen and nitrogen content close to the intrusions no trend was observed for total sulfur content but decreases in sulfate content towards the dikes indicate thermochemical sulfate reduction tsr contact metamorphism has a dramatic effect on coal porosity and microporosity in particular around the large dike the micropore volume after a slight initial increase progressively decreases from 0 0417 cm3 g in coal situated 4 7 m from the intrusive contact to 0 0126 cm3 g at the contact strongly decreasing mesopore and micropore volumes in the altered zone together with frequent cleat and fracture filling by calcite indicate deteriorating conditions for both coalbed gas sorption and gas transmissibility

new data on mineralogy and geochemistry of high ge coals in the yimin coalfield inner mongolia china abstract the yimin ge coal deposit located in the yimin coalfield inner mongolia is the third largest ge rich coal deposit in china just after the lincang and wulantuga ge coal deposits based on the coal and non coal samples recently collected from the wumuchang coal mining district in the yimin ge coal deposit this paper reports some new data on the mineralogical and geochemical characteristics of the yimin high ge coals and provides some new evidence for the possible mode of ge enrichment in the yimin coals mineralogical analyses were performed by means of powder x ray diffraction xrd major and trace element concentrations were determined by inductively coupled plasma atomic emission spectrometry icp aes and inductively coupled plasma mass spectrometry icp ms respectively element affinities were determined by pearson s correlation analysis the studied coals fall within the coal rank between sub bituminous a and high volatile bituminous c with relatively high moisture content high volatile matter yield and low to medium ash yield quartz and kaolinite are the main mineral matters in the yimin coals with small amounts of pyrite and traces of microcline common pyrite and as bearing pyrite occurring in the yimin coals show an epigenetic origin the epigenetic precipitation of kaolinite quartz and as rich pyrite with ge and other trace elements in the yimin coal fractures may be caused by activities of both hydrothermal and low temperature fluids compared to common chinese and worldwide coals the yimin coals are markedly enriched in ge 43 mg kg as 155 mg kg and w 9 84 mg kg and slightly enriched in pb 22 mg kg and hg 0 24 mg kg most of the elements e g al k sc ti v cu ga sn th and rees in the studied coals present an aluminosilicate affinity as deduced from their obvious positive correlation with al and ash yields high correlation coefficients of as and hg with fe and s indicate a sulfide affinity of these elements in the yimin coals germanium b mo and w in the studied coals show an organic affinity and a partial sulfur affinity as deduced from their negative correlation with al and positive correlation with s respectively the preliminary and possible model for ge enrichment in the yimin ge coal deposit was that ge was carried by hydrothermal fluids and then these fluids were incorporated in the water existing in the upper porous conglomerates and percolate in the top of the coal seam where ge was trapped by organic matter and finally enriched in an early diagenetic stage humification gelification

mercury emissions and stable isotopic compositions at vulcano island italy abstract sampling and analyses methods for determining the stable isotopic compositions of hg in an active volcanic system were tested and optimized at the volcanic complex of vulcano aeolian islands italy condensed gaseous fumarole hg fum t plume gaseous elemental hg g 0 and plume particulate hg p ii were obtained at fumaroles f0 f5 f11 and fa the average total hg emissions based on hgt so2 in condensed fumarolic gases and plumes range from 2 5 to 10 1 kg y 1 in agreement with published values ferrara r mazzolai b lanzillotta e nucaro e pirrone n 2000 volcanoes as emission sources of atmospheric mercury in the mediterranean basin sci total environ 259 1 3 115 121 aiuppa a bagnato e witt m l i mather t a parello f pyle d m martin r s 2007 real time simultaneous detection of volcanic hg and so2 at la fossa crater vulcano aeolian islands sicily geophys res lett 34 l21307 plume hg p ii increases with distance from the fumarole vent at the expense of hg g 0 and indicates significant in plume oxidation and condensation of fumarole hg fum t relative to the nist srm 3133 hg standard the stable isotopic compositions of hg are 202hg fum t 0 74 0 18 2sd n 4 for condensed gaseous fumarole hg fum t 202hg g 0 1 74 0 36 2sd n 1 for plume gaseous elemental hg g 0 at the f0 fumarole and 202hg p ii 0 11 0 18 2sd n 4 for plume particulate hg p ii the enrichment of hg p ii in the heavy isotopes and hg g 0 in the light isotopes relative to the total condensed fumarolic hg fum t gas complements the speciation data and demonstrates a gas particle fractionation occurring after the gas expulsion in ambient t atmosphere a first order rayleigh equilibrium condensation isotope fractionation model yields a fractionation factor cond gas of 1 00135 0 00058

isotopic evidence for distinct sources of mercury in lake waters and sediments abstract lakes are important ecosystems where mercury hg may undergo extensive methylation and bioaccumulation in the aquatic food web it is thus crucial to understand the sources of hg in lake systems mercury isotope composition is a powerful tracer of its sources in the environment however previous studies on hg isotope compositions in lake systems mainly focus on the aquatic organism and sediments whereas lake water that provides the nutrients for the bottom of aquatic food chain has received much less attention here we report hg isotope compositions in surface water and sediments of 8 freshwater lakes in ontario canada we determined significantly positive 199hg and 200hg values in surface water of all lakes which are similar to previously reported isotope signature of local atmospheric precipitation in contrast the isotope compositions of lake sediments show predominantly negative 199hg and negligible 200hg values that are similar to atmospheric elemental hg 0 and terrestrial soils and plants we conclude that the source of hg in lake surface water is likely dominated by direct atmospheric precipitation while the hg in lake sediments is primarily derived from watershed inputs of terrestrial particles the concurrent odd hg isotope anomalies in surface waters suggest that methylmercury mehg from the watershed wetland together with hg ii derived from the catchment weathering is likely another hg source to lake waters besides atmospheric deposition we suggest that the different hg sources and isotope compositions between lake water and sediments would result in different isotope signatures for mehg that is produced in water column and in sediments therefore our study not only elucidates the sources of hg to lake systems but also has implications in distinguishing between different mehg sources and in tracing the bioaccumulation of mehg in aquatic organism

neotectonics and morphotectonics of the southern almeria region betic cordillera spain kinematic implications most previous studies related to the recent tectonic development of southeastern betic cordillera and in particular the south of almeria agree with the kinematic variety that can be observed in the post miocene structures at different scales this variety is difficult to explain if we consider only the regional stress field related to the convergence of the eurasian and african plates that remained relatively steady over the last 9 ma this work proposes a block tectonics with horizontal and vertical relative movements driven by strike slip movements of major faults to explain the variety of kinematics observed in the area from middle miocene to present the combined activity of the alpujarras fault zone dextral strike slip and the carboneras fault zone sinistral strike slip induces within the major block bounded by them the squeezing of minor pre existing fault bounded crustal blocks this process generates traction areas inside the escaping block which are linked with the existence of gradients of westward movement rate this tectonics can explain some of the structures related with the extensional tectonics predominant in the south of almeria province and the development of the minor and major morphostructures driven by faults with different kinematics the tectonics of blocks proposed is useful to give a coherent interpretation of apparently incoherent local structural data into a regional and homogeneous compressional stress field

environmental perturbations during the latest permian evidence from organic carbon and mercury isotopes of a coal bearing section in yunnan province southwestern china abstract the end permian mass extinction epme is sudden but prior to which the ecological resilience has diminished the late permian is an important geologic period for coal formation associated with extensive volcanic activities in south china and adjacent regions here we present a systematic analysis of organic carbon and mercury isotopes as well as elemental geochemistry and mineralogy of a coal bearing section from the lianying coalfield in yunnan province south china the data show that organic carbon 13c values are negatively shifted by 25 22 to 25 99 in pyroclastic tonstein partings which are near synchronous with the negative eu anomaly 0 48 0 52 significant hg enrichment 130 352 ppb and near zero 199hg 0 08 0 07 these c and hg isotope anomalies and associated geochemical signatures which are manifested by characteristic al2o3 tio2 zr tio2 and nb yb ratios are likely caused by subduction or collision related volcanism our study provides evidence for the occurrences of volcanism before the advent of epme which played a significant role in stressing the environment and consequently diminishing the ecological resilience in the latest permian

seismic transpressive basement faults and monocline development in a foreland basin eastern guadalquivir se spain 1 we examine the late tortonian to present day deformation of an active seismic sector of the eastern iberian foreland basement of the betic cordillera in southern spain transpressive faults affecting paleozoic basement offset up to triassic rocks late triassic clays and evaporites constitute a decollement level decoupling the basement rocks and a 100 m thick cover of jurassic carbonates monoclines trending ne sw to ene wsw deform the jurassic cover driven by the propagation of high angle transpressive right lateral basement faults they favor the migration of clays and evaporites toward the propagated fault tip i e the core of the anticline resulting in fluid overpressure fluid flow and precipitation of fibrous gypsum parallel to a vertical 3 the overall geometry of the studied monoclines as well as the intense deformation within the clays and evaporites reproduces three layer discrete element models entailing a weak middle unit sandwiched between strong layers late tortonian syn folding sediments recorded the initial stages of the fault propagation folding equivalent unexposed transpressive structures and associated monoclines reactivated under the present day nw se convergence are recognized and analyzed in the sabiote torreperogil region using seismic reflection gravity and borehole data a seismic series of more than 2100 low magnitude earthquakes was recorded within a very limited area of the basement of this sector from october 2012 to may 2013 seismic activity within a major ne sw trending transpressive basement fault plane stimulated rupture along a subsidiary e w n95 e strike slip relay fault the biggest event mblg 3 9 mw 3 7 occurred at the junction between them in a transpressive relay sector

zn fe and s isotope fractionation in a large hydrothermal system abstract the genesis of hydrothermal ore deposits is of crucial economic importance this study investigates the extent causes and consequences of zinc and iron isotope fractionation in a large hydrothermal system at the world class navan zn pb orebody ireland large variations in zn fe and s isotope compositions have been measured in microdrilled sphalerite zns at the millimetre scale 66 zn and 56 fe display a well defined positive correlation and both also correlate with 34 s these relationships represent the combined effects of kinetic zn and fe isotope fractionation during sphalerite precipitation and s isotope variation through mixing of hot metal rich hydrothermal fluids and cool bacteriogenic sulfide bearing brines combined with s isotope data 56 fe and 66 zn data on mine concentrates confirm that hydrothermal sulfide is a minor component of the overall deposit signature our data suggest that incoming pulses of metal rich hydrothermal fluid triggered sulfide mineralisation and that rapid precipitation of sphalerite from hydrothermal fluids will lead to strong kinetic fractionation of zn and fe isotopes at very short time and length scales thereby limiting the use of fe and zn isotopes as exploration tools within deposits but revealing the possibility of detecting new deposits from isotopically heavy zn fe geochemical halos

active shallow extension in central and eastern betic cordillera from cgps data abstract the betic cordillera is an alpine belt formed in the western mediterranean by the westward displacement of the alboran domain in between the eurasian and african convergent plates new cgps data from the central and eastern betic cordillera and its foreland obtained mainly from the topo iberia project allowed us to precisely determine the rate of tectonic deformation most of the displacements of the central and eastern betics are westward with a variable southwestward component in relation to the eurasian stable plate while in the iberian foreland the displacements are extremely low some deformation related to low compressional deformation occurs in the easternmost foreland basin and eastern betic cordillera the displacement increases substantially southwards and westwards in relation to present day extensional deformation major active discontinuities correspond to the nw se normal fault zones which dip westwards they are located in almeria tabernas balanegra and western sierra de gador whereas the padul fault zone located west of sierra nevada extends northwards to the granada basin nw se extensional faults are also observed to the north in the baza basin moreover the activity of dextral faults along the sorbas tabernas alpujarras guajares band generally considered as a transfer fault zone is evidenced by the displacement data these results come to demonstrate the low activity or inactivity of the large northern e w oriented folds of the central and eastern internal zone such as the sierra de los filabres antiform they also point to the possible residual activity of the northern part of the ne sw sierra nevada antiform where the maximum relief of the cordillera is found altogether our data support a heterogeneous present day westward extension that affects the upper crust of the betic cordillera and increases towards the thinned continental crust of the alboran sea and towards the west which is compatible with roll back subduction along the gibraltar arc

biogeochemical controls on mercury stable isotope compositions of world coal deposits a review abstract coal deposits were important natural hg sinks in the late paleozoic and middle late mesozoic coal combustion since the industrial revolution has emitted more than 35 000 t of hg into the atmosphere environmental geochemistry research on hg in coal is essential to understand the natural hg cycle throughout earth history and the present day hg cycle under human perturbation in this review we summarize the methods of hg isotope measurement in coals and compile recently published hg isotope data of 200 world coal samples according to their locations formation periods carboniferous permian jurassic cretaceous early middle cenozoic and ranks anthracite bituminous coal subbituminous coal lignite and illustrate the controls of sources and biogeochemical processes on hg isotope compositions in coal deposits up to 4 7 variation 3 90 to 0 77 in mass dependent fractionation mdf represented by 202 hg and 1 0 variation 0 63 to 0 34 in mass independent fractionation mif represented by 199 hg are observed in world coal deposit with an average value of 1 16 0 79 1sd and 0 11 0 18 1sd for 202 hg and 199 hg respectively we find that coal 202 hg and 199 hg are broadly controlled by two source materials terrestrial plants biogenic hg and crustal rocks geogenic hg accounting for 37 46 and 54 63 of hg in coals no clear trends are seen in neither 202 hg vs coal forming periods nor 202 hg vs coal ranks which we attribute to important overlapping of 202 hg in the source materials of different coal forming periods and the multidirectional hg mdf during coalification interestingly a step wise increase in total hg and a disappearance of 199 hg are observed along with increasing coal rank suggesting the addition of hydrothermal hg into high rank coals the hydrothermal fluids not only upgraded the coal ranks but also increased the hg concentrations and 199 hg of coals in addition the addition of hydrothermal hg into coal deposits was also partly responsible for the comparatively higher total hg and 199 hg in the late paleozoic coals relative to the mesozoic and cenozoic coals the co variation of atmospheric oxygen levels and 199 hg of coals at different coal forming time widows suggests that the removal of biogenic hg in response to widespread swamp fires may have increased the 199 hg in late paleozoic coals as well our study indicates that coal hg isotopes provide new insights into the biogeochemical cycle of hg in coal deposits and that 199 hg is a robust indicator to trace hg addition removal in coal deposits and biogeochemical processes magmatic intrusion hydrothermal fluids penetration burning of coal swamp occurring during coal deposition

the use of sequential extraction to determine the distribution and modes of occurrence of mercury in permian huaibei coal anhui province china sequential extraction tests using a flow injection mercury system fims were done on 34 samples collected from the number 3 4 5 7 and 10 coal seams in the huaibei coalfield average total mercury hg concentrations for the seams were 0 13 0 18 0 54 0 34 and 0 19 mg kg respectively the average value for all of the coal samples was 0 26 mg kg which is higher than most chinese and u s coals six modes of hg occurrence were recognized including water leachable ion exchangeable organic bound carbonate bound silicate bound and sulfide bound hg with rare exception little hg was found in water soluble ion exchangeable or carbonate bound forms sulfide bound hg and organic bound hg dominated seams 3 4 and 10 whereas silicate bound hg dominated seams 5 and 7 the relatively high hg values observed in seams 5 and 7 especially in parting samples are attributed to hg enrichment by magmatic intrusions

the alhama de murcia fault se spain a seismogenic fault in a diffuse plate boundary seismotectonic implications for the ibero magrebian region received 20 december 2002 revised 15 september 2003 accepted 26 september 2003 published 2 january 2004 1 the shortening between the african and the iberian plates is absorbed by a number of faults distributed over a very wide zone with very low slip rates and long periods of seismic loading thus a seismotectonic map based only on faults associated with seismicity or with expressive geomorphic features is incomplete it is possible to characterize seismogenic faults using paleoseismology first paleoseismological results based on trenching analysis in the eastern betics lorca totana segment of the alhama de murcia fault are presented the main paleoseismic parameters of this fault segment are 1 a minimum of two to three mw 6 5 7 earthquakes in the last 27 kyr shortly before 1650 a d between 830 and 2130 b c and shortly before 16 7 ka respectively with a mean recurrence period of 14 kyr and a very short elapsed time and 2 a net slip rate of 0 07 0 6 mm yr during the last 30 kyr these results were extrapolated to the rest of the known active faults in the eastern betics and were added to the slip rates of the active faults at the african margin the total slip rate of the transect which crosses de alhama de murcia fault in spain and reaches the cheliff basin algeria would represent 21 82 of the total shortening between africa and eurasia estimated from plate motion models and seismic moment summation a number of factors could account for this discrepancy 1 hidden seismogenic faults in the emerged areas 2 absence of correlation between current and late pleistocene slip rates 3 extensive small faults that are undetected and that absorb a significant amount of the deformation and 4 possible overestimation of the convergence rates index terms 7221 seismology paleoseismology 7230 seismology seismicity and seismotectonics 7215 seismology earthquake parameters 8150 tectonophysics plate boundary general 3040 keywords eastern betics alhama de murcia fault paleoseismology trenching seismotectonics plate boundary

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

mercury as a proxy for volcanic activity during extreme environmental turnover the cretaceous paleogene transition abstract the usually low geological background concentrations of hg makes this trace element suitable for identifying accumulation pulses in sediments that can be tentatively related to weathering processes and thus to climatic changes intense volcanism has witnessed the cretaceous paleogene transition ktb and was perhaps responsible for dramatic climatic changes and decrease in biodiversity and mass extinction we have used hg concentrations as a proxy for volcanic activity and atmospheric hg and co2 buildup across the ktb at three localities in the salta basin argentina hg contents display several spikes across the ktb with a maximum value of 250 ng g 1 in three drill cores across the ktb in the paraiba basin northeastern brazil hg contents increase from the late maastrichtian to early danian and hg spikes predate the ktb perhaps as a record of volcanic activity before but very close to this transition at stevns klint denmark hg contents reached almost 250 ng g 1 within a 5 cm thick clay layer the fiskeler member fish clay that comprises the ktb some co variation between hg and al2o3 contents has been observed in all of the studied sections across the ktb suggesting that hg is probably adsorbed onto clays thermo desorption experiments in selected samples from the yacoraite formation showed hg 2 as the major species present which is in agreement with a volcanic origin combined hg and c isotope chemostratigraphy may become a powerful tool for the eventual assessment of the role of volcanic activity during extreme climatic and biotic events such as those during the ktb

mercury stable isotope compositions in magmatic affected coal deposits new insights to mercury sources migration and enrichment abstract mercury hg is commonly present at trace levels in coal deposits geological processes particularly magmatic intrusion and hydrothermal cycling in coal bearing strata can significantly increase hg levels in coals however the effects of thermal stress magmatic components magmatic hydrothermal fluids low temperature hydrothermal fluids on hg enrichment are confounded in a magmatic affected coal basin here we demonstrate the use of stable hg isotopes to understand the controlling factors on hg enrichment in two well known chinese coal deposits affected by magmatic activities wulantuga low temperature hydrothermal altered coal deposit and wolonghu magmatic intruded coal deposit the wulantuga no 6 coal seam is extremely enriched in hg varying from 0 37 g g in middle coal benches to 40 90 g g in the upper most and lowest coal benches approximately 2 5 variation in mass dependent fractionation mdf 3 07 to 0 58 in 202hg is observed 202hg vs 1 hg diagram suggests a mixture of three hg end members original hydrothermal fluids fractionated hydrothermal fluids and native coal forming materials in addition wulantuga coals all show positive mass independent fractionation mif of odd isotopes up to 0 87 in 199hg and 0 66 in 201hg the 199hg 201hg ratios range from 1 3 to 3 3 suggesting that a large fraction of photodegraded methylmercury was likely incorporated into the coal deposit the magmatic intruded wolonghu no 8 coal seam is only slightly to intermediately enriched in hg varying from 0 10 g g to 0 40 g g the coals near the contact sill 5 cm 1 81 to 1 52 have similar 202hg as the magmatic sill rocks 2 05 to 1 80 both with insignificant mif values coals far from the contact sill 15 cm have 202hg values varying from 3 40 to 1 61 and 199hg varying from 0 26 to 0 58 which are significantly enriched in light and odd hg isotopes compared to coals near the contact sill 199hg and 201hg in wolonghu coals far from the contact sill resemble those of meteoritic waters and seawater in both magnitude and 199hg 201hg ratio our two case studies show significant mdf and mif of hg isotopes which inform on hg migration and sequestration in the magmatic rocks and coal deposits and on the roles of meteoric water and hydrothermal fluid circulation

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

mercury isotopic composition of hydrothermal systems in the yellowstone plateau volcanic field and guaymas basin sea floor rift abstract to characterize mercury hg isotopes and isotopic fractionation in hydrothermal systems we analyzed fluid and precipitate samples from hot springs in the yellowstone plateau volcanic field and vent chimney samples from the guaymas basin sea floor rift these samples provide an initial indication of the variability in hg isotopic composition among marine and continental hydrothermal systems that are controlled predominantly by mantle derived magmas fluid samples from ojo caliente hot spring in yellowstone range in 202hg from 1 02 to 0 58 0 11 2sd and solid precipitate samples from guaymas basin range in 202hg from 0 37 to 0 01 0 14 2sd fluid samples from ojo caliente display mass dependent fractionation mdf of hg from the vent 202hg 0 10 0 11 2sd to the end of the outflow channel 202hg 0 58 0 11 2sd in conjunction with a decrease in hg concentration from 46 6 pg g to 20 0 pg g although a small amount of hg is lost from the fluids due to co precipitation with siliceous sinter we infer that the majority of the observed mdf and hg loss from waters in ojo caliente is due to volatilization of hg0 aq to hg0 g and the preferential loss of hg with a lower 202hg value to the atmosphere a small amount of mass independent fractionation mif was observed in all samples from ojo caliente 199hg 0 13 1 0 06 2sd but no significant mif was measured in the sea floor rift samples from guaymas basin this study demonstrates that several different hydrothermal processes fractionate hg isotopes and that hg isotopes may be used to better understand these processes

stress distribution at the transition from subduction to continental collision northwestern and central betic cordillera 1 we analyze focal mechanisms of shallow intermediate earthquakes in a nw se transect along the western betic cordillera and alboran sea and deep earthquakes located in the central betics to constrain the state of stress at the gibraltar arc slow convergence area shallow earthquakes 620 km show very similar focal mechanisms fitting the general slab behavior of resistance to further descent at the 660 km discontinuity seismicity features evidence the present day stress distribution in a context of transition from subduction to continental collision

ge distribution in the wulantuga high germanium coal deposit in the shengli coalfield inner mongolia northeastern china abstract the geological and geochemical controls of the ge distribution in the cretaceous wulantuga high germanium coal deposit in the shengli coal field inner mongolia are investigated this paper focuses mainly on the spatial distribution of the ge contents in coal the high ge coals mainly occur in three splits of the 6 coal in the southwestern part of the shengli coal field mean germanium contents in the coal range from 32 to 820 g g with a mean value of 137 g g on a bulk coal basis mean of 939 coal samples from 75 boreholes in the 6 coal seam in an area of 2 2 km 2 the highest ge content occurs sw of 6 coal seam close to the margins of the coal basin decreasing with a fan shaped trend towards nw the direction of the coal basin there is an negative correlation between the mean ge content and the thickness of the coal seam different distribution patterns of ge content were found in vertical profiles high ge concentrations may occur in the middle parts of coal seams at the bottom and or the top of thick coal seams and inconspicuous variation a major organic affinity was determined for ge with a special enriched in the banded bright and semibright coal the high ge coals and the coalified wood in the sandstone overlaying the 6 1 coal highly enriched in ge as sb w cs tl be and hg the late jurassic silicified volcanic rocks in the nw of the ge coal deposit relatively high enriched in ge ga sb as cs be ge and hg the correlation coefficients among the elements enriched showed marked variations at close sites in this deposit suggesting a possible diagenetic origin of the geochemical anomaly the main ge anomaly was attributed to early cretaceous hydrothermal fluids circulating through the fault systems and porous volcanic rocs probably from the subjacent granitoid rocks the fault systems the porous coarse clastic rocks overlying coal seam and the lithotype of coal played an important role in the transport and trapping of ge a main diagenetic origin overlapping a slight synsedimentary accumulation is deduced for the ge anomaly

an investigation of wulantuga coal cretaceous inner mongolia macerals paleopathology of faunal and fungal invasions into wood and the recognizable clues for their activity coal macerals are the product of a complex series of decompositional and preservational pathways from living woody and herbaceous tissues to the variety of forms seen in coal the cretaceous wulantuga coal inner mongolia china offers an opportunity to observe a number of maceral forms resulting from these disparate pathways assemblages of coprolites within fusinite strongly suggest an origin related to arthropod ingestion and consequent in situ emplacement of the macrinitic coprolites within the damaged wood structure followed by combustion of the whole to achieve the observed reflectance

landscape response to strike slip faulting linked to collisional settings quaternary tectonics and basin formation in the eastern betics southeastern spain abstract neotectonic behaviour of the eastern betics southeastern spain has been controlled by the presence of a large left lateral shear zone this is an intraplate transcurrent zone probably decoupled by a mid crustal detachment horizon the morphological expression of this crustal structure is a sigmoidal corridor in which the main quaternary basins are located three types of morphostructural domains can be distinguished in the sigmoidal corridor the central segment and the northern and southern terminal splays the central segment is characterized by wrench tectonics whilst the southern and northern terminal splays are controlled by transtensional and transpressional tectonics respectively the quaternary morphostructural pattern is only the more recent picture of the tectonic processes that have controlled the late orogenic evolution of the eastern betics the indentation of the aguilas arc accompanied by thin skinned thrusting and tectonic escape in its easternmost sector and extensional collapse accompanied by thin skinned stretching in its westernmost sector

variations in the stable isotope composition of mercury in coal bearing sequences indications for its provenance and geochemical processes abstract mercury hg stable isotope variations provide a potential tool to better understand the provenance and geochemical processes that control hg occurrences in coal deposits in this study we explore the variations in hg isotope compositions in coal benches of a single coal seam no 3 1 coal seam daizhuang coal mine jining coalfield shandong province and in successive coals seams of a coal bearing sequence no 1 to no 11 2 coal seams zhuji coal mine huainan coalfield anhui province to assess hg isotopes as a hg biogeochemical tracer in coal deposits large variations in mass dependent hg isotope fractionation mdf were observed in both daizhuang and zhuji coal deposits with 202hg values ranging from 2 34 to 0 25 0 12 2 sd n 8 and from 1 62 to 0 44 0 12 2 sd n 18 respectively daizhuang coals showed insignificant mass independent hg isotope fractionation mif in most samples 0 04 to 0 12 0 08 for 199hg 2 sd n 8 whereas mif in the younger nos 7 11 coal seams of zhuji coals 0 06 to 0 22 0 08 for 199hg 2 sd n 7 were positive and significant increased trends in both hg concentrations and 202hg values going from older to younger zhuji coal seams were observed and were possibly related to variations in coal forming environment of different coal seams the significant negative correlations of 202hg vs 1 hg in the zhuji coals and of 202hg vs 199hg in the daizhuang coals suggest that hg isotopes can potentially be used to trace organic and inorganic hg end members in coal deposits natural coke a metamorphosed form of coal is on average two fold enriched in hg compared to coal indicating that hydrothermal fluids derived from magmatic intrusions bring hg into coal deposits in addition coke has either distinctly higher 0 70 to 0 91 0 12 2 sd n 2 or lower 202hg 4 00 to 3 47 0 12 2 sd n 3 than corresponding coals demonstrating that significant hg mdf occurred when coals were thermally contacted by intruded magmas

mercury distribution in coals influenced by magmatic intrusions and surface waters from the huaibei coal mining district anhui china the hg concentrations in 108 samples comprising 81 coal samples 1 igneous rock 2 parting rock samples and 24 water samples from the huaibei coal mining district china were determined by cold vapor atomic fluorescence spectrometry the abundance and distribution of hg in different coal mines and coal seams were studied the weighted average hg concentration for all coal samples in the huaibei coalfield is 0 42 mg kg which is about twice that of average chinese coals from southwestern to northeastern coalfield hg concentration shows a decreasing trend which is presumably related to magmatic activity and fault structures the relatively high hg levels are observed in coal seams nos 6 7 and 10 in the southwestern coal mines correlation analysis indicates that hg in the southwestern and southernmost coals with high hg concentrations is associated with pyrite the hg concentrations in surface waters in the huaibei coal mining district range from 10 to 60 ng l and display a decreasing trend with distance from a coal waste pile but are lower than the regulated levels for hg in drinking water

germanium isotopic systematics in ge rich coal from the lincang ge deposit yunnan southwestern china abstract organic matter plays an important role in the transport and precipitation of germanium ge in coal hosted ge deposits in this paper ge isotopes of coal samples and their combustion products were analyzed in order to investigate the potential use of ge isotopes as tracers of ge sources and enrichment mechanisms in coal germanium isotopic composition of various samples mainly ge rich lignite from the lincang ge deposit yunnan southwest china was analyzed using a continuous flow hydride generation system coupled to a multi collector inductively coupled plasma mass spectrometer mc icp ms and the standard sample bracketing approach variations of 74ge 70ge ratios are expressed as 74ge values relative to nist srm 3120a ge standard solution ge rich lignite samples show large ge isotopic fractionation 74ge values range from 2 59 to 4 72 and their 74ge values negatively correlate with ge concentrations lignite samples with low ge concentrations 1000 ppm are close to zero or negative along stratigraphic sections ge is mainly concentrated in the top or the bottom of the coal seam such that high values of 74ge are usually found in the middle part of the coal seam interlayered hydrothermal chert and limestone samples in ge rich coal seams also show moderate fractionation 74ge values range from 0 14 to 2 89 and from 0 55 to 1 87 respectively the overall variations of 74ge values of ge rich lignite and organic rich chert samples can be well described by a rayleigh fractionation model indicating that preferential enrichment of light ge isotopes in coal in an open system might be the main factor controlling ge fractionation in ge rich lignite the germanium isotopic composition of hydrothermal chert and possibly limestone might also record the competitive fractionation produced by precipitation of quartz and sorption of coal elevated ge concentrations and or 74ge values of some chert limestone sandstone and claystone samples may be attributed to the mixing with ge rich organic matter furthermore similar to the fractionation of zn cd and hg isotopes observed between refinery dust or gas and slag high temperature coal combustion also fractionates ge isotopes with the ge isotopic compositions of soot being distinctly lighter up to 2 25 per mil than those of cinder the distinct enrichment of potential hazardous elements i e pb cd and as and ge in soot after coal combustion as well as the common enrichment of ge in sulfide minerals e g sphalerite highlights the possibility of using ge isotopes as useful tracers of sources of heavy metal pollution caused by high temperature industrial processes coal combustion and pb zn refining in the environment

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

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

mercury isotope fractionation in fossil hydrothermal systems the hg isotopic compositions of samples throughout the vertical extent of two fossil hydrothermal systems were analyzed by multicollector inductively coupled plasma mass spectrometry results show 5 2 0 2 hg 1 9 8 hg relative to nist 3133 fractionation more than 50 times greater than the 0 1 2 external reproducibility of the analyses the hg isotope compositions from both hydrothermal systems can be grouped by dominant mineralogy and position 2 0 2 hg 1 9 8 hg values at the tops of the systems are 3 5 to 0 4 in cinnabar dominant sinter and 0 2 to 2 1 in metacinnabar dominant sinter and the underlying veins have 2 0 2 hg 1 9 8 hg values of 1 4 to 1 3 these differences probably resulted from the combination of boiling of the hydrothermal fluid oxidation near the surface and kinetic effects associated with mineral precipitation the natural variation in hg isotopic compositions observed in this study is higher than that expected from the trend of decreasing mass dependent fractionation with increasing mass extrapolated from stable isotope systems up to z 26 fe confirming that even the heaviest elements undergo significant stable isotope fractionation in hydrothermal systems

catastrophic dispersion of coal fly ash into oceans during the latest permian extinction the eruption of the siberian trap flood basalts resulted in the heating and combustion of coals and organic rich sediments at the time of the permian mass extinction the presence of char in distant lake sediments linked to the eruption suggests that fly ash could have been generated by the coal combustion and then dispersed globally creating toxic marine conditions

coal reservoir characteristics and coalbed methane resource assessment in huainan and huaibei coalfields southern north china abstract the huaibei and huainan coalfields in southern north china contain abundant coalbed methane cbm resources 1 1 10 12 m 3 net accumulated thicknesses of all minable coal seams are 18 32 m in huainan and 8 18 m in huaibei coalfields coal rank in the huainan coalfield high volatile a and b bituminous r o 0 65 0 85 is generally controlled by geothermal metamorphism in comparison coal rank in the huaibei coalfield varies from high volatile a bituminous to semi anthracites 0 8 to 2 8 r o and is controlled by the influence of the cretaceous yanshanian magmatic metamorphism in both coalfields coal reservoirs have low permeability values of 0 0013 0 224 md and porosity of 0 9 10 9 pores in coals are dominated by those with diameter 2 in both coalfields the abundance of microfractures in coals is related to the coal structures commonly more abundant in sheared coals 200 per 9 cm 2 than in the normally structured coals 2 the in place gas content is generally 8 16 m 3 t in huaibei and 10 30 m 3 t in huainan coalfields these data yield an estimated in place cbm resource of 375 247 10 9 m 3 for the huaibei and 722 677 10 9 m 3 for the huainan coalfields based on the cbm resource investigation and reservoir evaluation the most prospective target areas for cbm production are evaluated which include the nanping taoyuan mines of the southern suxian deep coal district and zhuxianzhuang and luling mines in eastern suxian area of the huaibei coalfield and the area around the panji 2 mine in panji xieqiao coal mining districts in the huainan coalfield

distribution of arsenic in coals of yunnan province china and its controlling factors abstract the as concentration and its distribution patterns in southwestern chinese coal beds of two of the most important coal forming periods late permian and neogene are analyzed more than 700 samples from 26 mining districts have been collected and tested for as concentration the as content and distribution in coal can be significantly changed by the combined effects of many factors including the geochemistry of the source region and the tectonic and depositional environment of the basin and surrounding paleo watershed the as distribution in neogene coals of yunnan province reflects to some extent their primary distribution patterns during peat accumulation because as is a sulphophile element two as distribution types can be distinguished based on the correlation coefficient between as and total s contents in the high rank permian coals especially those affected by hydrothermal and tectonic activities significant secondary as enrichment in coal is likely to occur thus to optimally utilize coal resources it is important to investigate the distribution occurrence and concentration of as in coal during resource exploration and evaluation to identify as rich zones in the coal beds

influence of a basic intrusion on the vitrinite reflectance and chemistry of the springfield no 5 coal harrisburg illinois abstract the springfield no 5 coal a pennsylvanian age high volatile b bituminous rank coal in the carbondale formation is mined in the southeastern section of the illinois basin intruded into this coal is a 10 1 m wide basic dike that is near vertical through the extent of the mined coal bed and strikes n 22 w the intrusion and the effects it had on the coal were studied petrographically and geochemically using a published heat flow model by carslaw and jaeger 1959 carslaw h s jaeger j c 1959 conduction of heats in solids oxford university press in conjunction with thin section microscope analysis a contact temperature of 600 c was determined vitrinite reflectance was measured for a suite of coal samples collected distal to the intrusion vitrinite reflectance values rose uniformly from the ambient reflectance values of 0 69 at just greater than one dike thickness away to 5 at the dike coal contact the increase in reflectance values for samples within 1 2 times dike thickness is concordant with data published by bostick and pawlewicz 1984 bostick n h pawlewicz m j 1984 paleotemperatures based on vitrinite reflectance of shales and limestones in igneous dike aureoles in the upper cretaceous pierre shale walsenburg colorado in woodward j g meissner f f clayton j l eds hydrocarbon source rocks of the greater rocky mountain region rocky mountain association of geologists pp 387 392 on the effects of mafic intrusions into cretaceous age shales in walsenburg colorado comparison of colorado data with data from these sites indicates that despite differences in intrusion temperature timing or coal rank at time of the intrusion ambient mean vitrinite reflectance values remain unchanged at just greater than one dike width from an intrusion

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

recent and present day stresses in the granada basin betic cordilleras example of a late miocene present day extensional basin in a convergent plate boundary the diffuse convergent boundary between the eurasian and african plates in the western mediterranean is associated with a seismicity zone more than 300 km wide although the two plates are converging nw se the betic and rif cordilleras contain extensional structures that have been active since the miocene the extensional tectonics in the region which occurred simultaneously with the uplift of the cordillera have been analyzed in the southeastern sector of the late miocene to recent granada basin using earthquake focal mechanisms the determination of paleostresses from the study of the orientation and kinematics of microfaults and the study of the major structures both the geological surface data and the focal mechanisms indicate present day regional conditions of ne sw extension with triaxial to prolate stress ellipsoids however the stress field is heterogeneous with local variations in stress over time with different stresses sometimes even acting simultaneously in adjacent areas the most frequent changes consist of pluridirectional or ne sw extension favored by the prolate character of the stress ellipsoids and nw se subhorizontal compression favored by the regional tectonic setting strike slip faults are scarce even though they are the most likely structure to be expected in a region with sw ne extension and nw se compression seismicity is concentrated in the upper crust and may correspond to the activity of low to high angle normal faults similar to the surface faults although they can not be correlated with them the lower cutoff of this seismicity probably coincides with the 300 c isotherm and suggests a low thermal gradient for the region present day regional stresses have 1 vertical at the surface but in depth plunge toward the sw

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 and geochemical effects of sill intrusions on coal and their implications for gas outbursts in the wolonghu mine huaibei coalfield china abstract since the early 1980s fifteen outbursts have occurred in the huaibei coalfield of china these outbursts were reported to be associated with sills to study the effect of sill intrusions on coal seam and their relationship to methane outbursts eleven samples from the no 10 coal seam were taken from the wolonghu mine at various distances from a diorite sill comparisons were made between unaltered and heat affected coals using petrographic and chemical data micropore characteristics adsorption properties of coal and gas outburst indexes from field approaching the intrusion vitrinite reflectance levels increased from 2 74 to 5 03 and the thermal aureole of the sill 60 m from the sill boundary to sample 9 three zones along this gradient were identified as corresponding to 1 thermal evolution zone no 1 0 5 m from sill 2 thermal evolution zone no 2 5 60 m from sill and 3 unaltered zone the methane adsorption capacity of coal samples in the thermal evolution zone no 2 was generally higher than in the two other zones and the unaltered zone higher than the thermal evolution zone no 1 it is concluded that the contact metamorphism decreased the adsorption capacity of coal and the thermal evolution of sill increased it the trap effect of sill combined with the mudstone and siltstone roof and floor of the no 10 coal seam provided a seal for the formation of a gas pocket abnormally high formation pressures at the no 10 coal seam led to two outbursts

petrological geochemical and mineralogical compositions of the low ge coals from the shengli coalfield china a comparative study with ge rich coals and a formation model for coal hosted ge ore deposit abstract to better understand the formation mechanism of coal hosted ge ore deposits this paper reports on the petrological mineralogical and geochemical compositions of the low ge coals in the shengli coalfield inner mongolia china using optical microscopy field emission scanning electron microscopy x ray fluorescence x ray diffraction and inductively coupled plasma mass spectrometry the samples in the present study closely neighbor the previously reported wulantuga coal hosted ge ore deposit both no 6 coal in comparison with the wulantuga ge rich coals the low ge coals of the shengli field display higher moisture 27 59 on average and lower pyritic sulfur contents 0 53 both the low ge and ge rich coals are generally high in inertinite and have varying but relatively low huminite contents preservation of fecal pellets as macrinite is notable in both the low ge and ge rich coals and the position of the fecal pellets appears to be within tunnels or chambers within the wood quartz kaolinite pyrite and gypsum are the major crystalline phases identified in most of the ge rich and low ge coals but the low ge coals contain significantly less pyrite and are more abundant in non mineral ca and mg ca oxalate of authigenic origin is observed generally occurring as cell fillings in the low ge coals otherwise mineral free organic matter in the low ge coals would be expected to have an inherent ash yield of around 6 derived from the inorganic elements mainly non mineral ca and mg that occur either in the organic matter or as dissolved ions in the pore water and form the sulfate species in low temperature oxygen plasma ash residues the highly elevated trace elements including be ge as sb w hg and tl that occur in the ge rich coals of the wulantuga deposit are significantly depleted in the low ge coals lateral migration of ge w and as hg sb tl rich solutions through the original peat swamp for the wulantuga ge ore deposit has led to significant enrichment of ge on the margin of the coal basin but decreasing ge concentrations toward to the inner part of the basin such a migration direction is different to those in the previously reported for the hydrothermal solutions in the lincang yunnan of china and spetzugli russian far east ge ore deposits where the solutions migrated vertically from granite to peat along faults and led to a dome shaped ge distribution in the relevant coal seam

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

geological and geochemical constraints on the origin of the giant lincang coal seam hosted germanium deposit yunnan sw china a review abstract the lincang germanium deposit yunnan sw china contains at least 1000 tonnes of ge at an average grade of 850 ppm ge and is one of the largest ge deposits in the world the deposit is hosted within coal seams of the miocene bangmai formation deposited on top of a ge rich granite batholith the bangmai formation is divided into eight units among which three are coal bearing the ge bearing coal seams are inter layered with siliceous rocks and siliceous limestones in the basal coal bearing unit the coal seams of the other two coal bearing units are not interbedded with siliceous rocks and siliceous limestones and are also barren with respect to ge equant or elongate ge orebodies are generally located at fault intersections germanium is mainly associated with organic matter within the coal seams and is concentrated at the top and bottom of the coal seams where the latter are in contact with the layered siliceous rocks or siliceous limestones major and trace element contents and o and c isotopes of the siliceous rocks and siliceous limestones are similar to those of hydrothermal sediments indicating formation by hydrothermal sedimentation compared with barren coals ge rich coals are notably rich in nb li sb w bi and u and show substantial enrichment of hree which increase together with ge germanium rich coals contain disseminated pyrite with 34 s ranging from 17 2 to 51 4 similar to pyrite in barren coals and thin vein like pyrite with 34 s ranging from 5 4 to 1 9 similar to sulfides in granite related quartz veins we propose that circulating hydrothermal fluids leached abundant ge and other elements from ge rich granites in the basement and were then discharged into the basin mainly along fault intersections to form layer like siliceous rocks and siliceous limestones by depositing si and ca the deposit was formed via interaction between ge in the fluids and organic matter in the coal seams

isotope geochemistry of mercury in source rocks mineral deposits and spring deposits of the california coast ranges usa abstract we present here the first study of the isotopic composition of mercury in rocks ore deposits and active spring deposits from the california coast ranges a part of earth s crust with unusually extensive evidence of mercury mobility and enrichment the franciscan complex and great valley sequence which form the bedrock in the california coast ranges are intruded and overlain by tertiary volcanic rocks including the clear lake volcanic sequence these rocks contain two types of mercury deposits hot spring deposits that form at shallow depths the franciscan complex and great valley sequence contain clastic sedimentary rocks with higher concentrations of mercury than volcanic rocks of the clear lake volcanic field mean mercury isotopic compositions 202hg for all three rock units are similar although the range of values in franciscan complex rocks is greater than in either great valley or clear lake rocks hot spring and silica carbonate mercury deposits have similar average mercury isotopic compositions that are indistinguishable from averages for the three rock units although 202hg values for the mercury deposits have a greater variance than the country rocks precipitates from spring and geothermal waters in the area have similarly large variance and a mean 202hg value that is significantly lower than the ore deposits and rocks these observations indicate that there is little or no isotopic fractionation

effects of structural deformation on formation of coalbed methane reservoirs in huaibei coalfield china tectonically deformed coal is defined as coal formed by superimposed reformations from tectonic stress the huaibei coalfield is typically composed of various tectonically deformed coals containing rich coalbed methane resources however the occurrence of coal seam in this area is complicated largely by the structural deformation which has not yet been evaluated systematically for exploration and exploitation of coalbed methane in this study tectonism in huaibei coalfield is discussed by combining systematic analyses on the occurrence of coal seams and the formation of coalbed methane reservoirs the study shows that with structural deformation in the study area the coal seams in huaibei coalfield are distributed in north south tectonic blocks and east west tectonic zones north tectonic block of huaibei coalfield is not favourable for exploitation of coalbed methane because of low gas content or disadvantageous structural conditions within the south tectonic block the east suzhou syncline contains high gas content but coal permeability is very low this area is generally not suitable for exploitation of coalbed methane and is a dangerous mining area due to gas outburst because of the widely developed mylonitic coals south suzhou and nanping synclines in the middle part of the south tectonic block are exposed to relatively weak structural deformations these synclines contain coals with high gas content and moderate permeability which are beneficial for exploration and exploitation of coalbed methane linhuan mining area in the south tectonic block is generally not suitable for exploitation of coalbed methane mainly because of well developed normal faults and interlayer slip structure and presence of mylonitic coal resulting in low gas content and poor structural conditions for mining coalbed methane in contrast guoyang mining area in the west part of the south tectonic block where tectonically deformed coal was generally underdeveloped is a potential area for exploration and exploitation of coalbed methane because of moderate gas content and possibly higher permeability of its coal

three dimensional inversion modelling of a neoproterozoic basin in the southern prince charles mountains east antarctica abstract three dimensional inversion modelling of airborne magnetic data acquired in the prince charles mountains east antarctica provides an insight into the sub ice distribution and three dimensional geometry of a neoproterozoic sedimentary basin a three dimensional starting model was created from two two dimensional gm sys modelling and our current geological understanding of the study area three dimensional vpmg inversion modelling was performed on the aeromagnetic data to obtain an acceptable fit between the observed response collected in the field and the calculated response of the three dimensional model modelling suggests that the base of the basin undulates and is relatively unstructured however the margins of the basin thicken from north 4 km to south 11 km the volume of the sodruzhestvo group that in fills the sedimentary basin has been calculated at approximately 35 000 km3 modelling of banded iron formations at the southern margin of the basin and a sharp magnetic contrast in the north reveal that both contacts dip toward the south we interpret this asymmetric geometry of the sedimentary basin as having began as a set of half grabens bounded by an underlying listric fault that flattened at depth below the sedimentary basin subsequent early palaeozoic inversion of this structure resulted in reactivation along the low angle basal detachment but rather than taking its original course underneath the sedimentary basin the fault ramped up along the southern margin this process caused exhumation of the underlying banded iron formations which are now juxtaposed at similar crustal levels to the neoproterozoic cover rocks