geochemistry and nano mineralogy of feed coals mine overburden and coal derived fly ashes from assam north east india a multi faceted analytical approach abstract in order to address the scarcity of information on the nature and mode of occurrence of minerals and elements in coal coal mine overburden and coal ashes from north east india and also the relations between coal mineralogy and ash chemistry the petrology mineralogy and nano mineralogy and ash chemistry of some industrially important high sulfur coals mine overburden materials and fly ash samples from assam india have been evaluated a combined approach using petrography low temperature ashing plus x ray diffraction lta xrd field emission scanning electron microscopy fe sem high resolution transmission electron microscope hr tem raman spectroscopy and inductively coupled plasma mass spectrometry icp ms has provided new information on the mineralogy and nano mineralogy of these sub bituminous coals and associated mine overburden the presence of rare earth elements and yttrium rey in northeast indian coal mine overburden and fly ash samples is also reported for the first time the identification of these components may be significant from an economic point of view some northeast indian fly ashes with ree oxides up to 1580 ppm on an ash basis might possibly represent sources for recovery of rare earth elements

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

prediction of rotational ground motion for mining induced seismicity case study from upper silesian coal basin poland abstract for decades coal mining in the upper silesian coal basin uscb in poland has been inducing annually more than 150 seismic events with local magnitude m 2 two sets of sensors were installed in the uscb in poland to measure angular velocities and translational accelerations from seismic events induced by underground coal mining in the period from december 2015 to november 2016 503 seismic events were recorded with local magnitude m between 1 1 and 3 5 analysis of measurement data for induced seismicity confirmed a strong linear correlation between peak ground acceleration of shear s waves pga and peak ground motion of angular velocity prv the observed correlation can be a result of previously observed coupling between the angular instantaneous velocity vector and the respective displacement vector at the ground surface three types of empirical equations for induced seismicity in upper silesia in poland were developed to predict the peak rotational ground motion of the vertical torsion horizontal rocking and instantaneous 3d xyz components the prediction values of horizontal peak angular velocity ground motion indicate that for strong mining induced seismic events in the uscb with a magnitude of m 3 5 we can expect that the mean values of prvh will reach 7 5 mrad s in the epicentral area r 500 m and with magnitude m 4 respectively will reach 19 7 mrad s such values of ground rotation may substantially contribute to the overall seismic response of civil infrastructure particularly for tall buildings the study of angular velocity ground motion is important not only from the cognitive point of view but also from practical significance for assessing the seismic impact on very high buildings chimneys and stability of slopes

coal characteristics elemental composition and modes of occurrence of some elements in the isaalan coal balikesir nw turkey abstract this study uses coal petrography micro ftir mineralogical and geochemical analyses to determine the coal characteristics and controlling factors of elemental enrichments in the isaalan coal nw turkey the obtained data show that this subbituminous coal has a relatively low ash yield avg 19 high hydrogen content avg 5 4 and total s content avg 2 4 on an air dry basis the maceral composition along with micro ftir data on ulminite suggests that lignin and resin rich vegetation was predominant the coal facies data imply the precursor peat was accumulating under mesotrophic anoxic conditions where water level was high and fluctuating the mineralogical composition of the bulk coal samples is composed mainly of quartz pyrite and clay minerals and lesser amounts of feldspars and carbonates the statistical analysis of the bulk compositional data shows the major elements including al fe k na mg p and the vast majority of trace elements have inorganic affinity whereas b presumably has organic affinity the trace element concentrations are variable and especially as and elements including b ba cr cs ni sb and v are enriched compared to most world coals the enrichments and distributions of cr cs ni and v were controlled by clastic inputs into a palaeomire whereas as enrichments were controlled mainly by epigenetic and to a lesser extent syngenetic factors introduced so42 and as rich surface and groundwater from the basin margin area along with anoxic conditions in the palaeomire resulted in syngenetic formation of as bearing pyrite the circulating intra seam solutions later liberated as from syngenetically formed pyrite which resulted in as and ni rich overgrowths around framboidal and massive pyrite crystals these solutions could also easily mobilize b that was absorbed by organic matter therefore b enrichment appears to be related to epigenetic factors tectonic activities during coalification allowed hydrothermal solutions from neighbouring epithermal mineralisation to penetrate and circulate along with underground waters that leached overlying volcanoclastic volcanic strata and supplied a number of elements to the studied coal thus infilling as bearing pyrite and silica were formed mainly during coalification all these results suggest that as enrichment in the study area is more likely a combination of epigenetic factors and syngenetic detrital rather than volcanogenic contributions as suggested earlier for some other turkish coal deposits

radioactivity heat flow and rifting of the indian continental crust the relationship between heat flow q and heat production a in india is quite different for the northern and southern parts of the peninsula in the north locations in a variety of tectonic settings including gondwana rifts show a linear relationship between q and a with a common reduced heat flow q about 40 mwm 2 in southern india the heat production of surface rocks is greater than is expected for the measured heat flow relative to other continental shields g is high in northern india and about average in the south apparently the indian crust evolved with a content of radioactive elements higher than in most shields and the southern part of the peninsula has undergone regional depletion in the lower crust and possibly upper mantle this depletion may coincide with a regional granulite event about 2 500 m y ago the high heat flow and heat production in northern india may explain several unique characteristics of the indian peninsula one feature is the continued reactivation of rif

erratum to observation and prediction of dynamic ground strains tilts and torsions caused by the mw 6 0 2004 parkfield california earthquake and aftershocks derived from upsar array observations online material corrected figures and strain rotation and displacement gradient time series

coal characteristics palynology and palaeoenvironmental interpretation of the yenikoy coal of late oligocene age in the thrace basin nw turkey abstract the yenikoy coal field is located in a narrow area between the black sea coast and the istranca standrja mountain in the thrace basin the aims of this study are to characterize coal petrographical mineralogical palynological geochemical and sedimentological properties of the yenikoy coal deposit and to reconstruct palaeoenvironmental conditions during peat accumulation a total of 9 coal samples collected from the coal seam section are almost entirely composed of xylite rich lithotype and are characterized by low ash yield 7 9 21 1 average 13 6 on dry basis and high total s contents 1 0 3 7 average 2 2 on dry basis the macroscopic features maceral composition and coal facies suggest that the peat was accumulated under mesotrophic anoxic conditions and the peat forming vegetation consisted mainly of arboreal species e g cupressaceae ulmus carya zelkova alnus pterocarya and quercus the low hi values of the analysed samples are presumably related to presence of xylite rich lithotype rather than the dominance of herbaceous plant and or low preservation of organic matter in the palaeomire even though relatively b enrichments high total s contents and weak anomalies of some rey e g y ce and gd in the analysed samples could refer possible sea water influence into palaeomire in the study area during late oligocene the sedimentological and palynological freshwater algaes pediastrum spirogyra and mougeotia data that indicate the palaeomire was located within a delta plain environment where small freshwater lakes and or ponds developed the statistical analysis and sem edx data show the vast majority of elements in the analysed coal samples have inorganic affinity the major elements al k and enriched elements like b v cr hg and u seem to be affiliated with aluminosilicate minerals whereas fe ni and as have probably sulphide affinity the detrital presences of apatite crystals as detected by sem edx analysis indicate that rey have mainly phosphate affinity in the analysed samples vertical distributions of the elements and ash yields suggest that the detrital input ratio was changeable and controlled some elemental enrichment during peat accumulation these variations could be related to development of and fluvial conditions in the study area which interrupted peat accumulation several times during late oligocene

sea99 a revised ground motion prediction relation for use in extensional tectonic regimes we present sea99 a revised predictive relation for geometric mean horizontal peak ground acceleration and 5 damped pseudovelocity response spec trum appropriate for estimating earthquake ground motions in extensional tectonic regimes which we demonstrate to have lower ground motions than other tectonic regimes sea99 replaces sea96 a relation originally derived by spudich et al 1996 1997 the data set used to develop sea99 is larger than that for sea96 and minor errors in the sea96 data set have been corrected in addition a one step regression method described by joyner and boore 1993 1994 was used rather than the two step method of joyner and boore 1981 sea99 has motions that are as much as 20 higher than those of sea96 at short distances 5 30 km and sea99 s motions are about 20 lower than sea96 at longer periods 1 0 2 0 sec and larger distance 40 100 km sea99 dispersions are significantly less than those of sea96 sea99 rock motions are on the average 20 lower than motions predicted by boore et al 1994 except for short distances at periods around 1 0 sec where sea99 motions exceed those predicted by boore et al 1994 by as much as 10 com parison of ground motions from normal faulting and strike slip events in our data set indicates that normal faulting horizontal ground motions are not significantly different from extensional regime strike slip ground motions

observation and prediction of dynamic ground strains tilts and torsions caused by the mw 6 0 2004 parkfield california earthquake and aftershocks derived from upsar array observationsdynamic ground strains tilts and torsions caused by the 2004 parkfield california earthquake

rotational motions for teleseismic surface waves 1 we report the findings for the first teleseismic six degree of freedom 6 dof measurements including three components of rotational motions recorded by a sensitive rotation rate sensor model r 1 made by eentec and three components of translational motions recorded by a traditional seismometer sts 2 at the nacb station in taiwan the consistent observations in waveforms of rotational motions and translational motions in sections of rayleigh and love waves are presented in reference to the analytical solution for these waves in a half space of poisson solid we show that additional information e g rayleigh wave phase velocity shear wave velocity of the surface layer might be exploited from six degree of freedom recordings of teleseismic events at only one station we also find significant errors in the translational records of these teleseismic surface waves due to the sensitivity of inertial translation sensors seismometers to rotational motions the result suggests that the effects of such errors need to be counted in surface wave inversions commonly used to derive earthquake source parameters and earth structure

gradiometry for polarized seismic waves 1 wave gradiometry for a generic point source wave model in cylindrical coordinates is developed to utilize the horizontal components of seismic wavefields attributes of p sv and sh waves such as horizontal slowness and its change the change in geometrical spreading the change in radiation pattern azimuth of propagation and wave polarization can be determined by measuring the horizontal strains and rotations of the wavefield along with three components of displacement gradiometer cells composed of an array of three component seismographs can be used to provide estimates of the wave gradients alternatively a single three component seismograph collocated with an areal strainmeter for p sv waves or a rotation sensor for sh waves can be used to estimate wave polarization and the slowness amplitude behavior of one aspect of the wavefield wave gradients are computed for the 1 april 2007 solomon island earthquake using data from the anza seismic network in southern california and show excellent consistency among stations of the network azimuth and slowness of various long period teleseismic waves are recovered using gradiometry analysis the consistency of strains computed from the broadband array suggests that they may be used to calibrate plate boundary observatory tensor strainmeters in the region

petrology and chemistry of permian coals from the parana basin 1 santa terezinha leao butia and candiota coalfields rio grande do sul brazil the current paper presents results on petrological and geochemical coal seam characterization in permian coal bearing strata from the parana basin southern brazil sequence stratigraphic analysis shows that peat accumulation in permian time was closely linked to transgressive regressive cycles with peat accumulation occurring in a predominantly back barrier lagoonal setting coal petrographic analysis indicates subbituminous coals at candiota and leao butia and high volatile bituminous coals at santa terezinha where locally the coal seams are thermally altered by volcanic intrusions petrographic composition is highly variable with seams at candiota and santa terezinha frequently enriched in inertinite chemical analyses indicate that all coals are mineral matter rich mean 49 09 wt with sio2 and al2o3 dominating as determined by icp aes quartz is also the predominant mineral detected by x ray diffraction where it is associated with feldspar kaolinite and hematite and iron rich carbonates the results from scanning electron microscopy are broadly consistent with the bulk chemical and mineralogical analysis quartz and clays are common in all samples analyzed other minerals observed were amongst others carbonates calcite siderite ankerite pyrite monazite kaolinite barite sphalerite rutile and quartz of volcanic origin the distribution of trace elements is well within the range typical for coal basins of other areas despite the fact that the parana basin coals are very high in ash yields the average concentrations for elements of environmental concern as b be cd co cr cu hg li mn mo ni pb sb se tl u v zn are similar to or less than the mean values for u s coal however considered on an equal energy basis parana basin coals will produce in combustion 5 to 10 times the amount of most elements compared to an equal weight us coal concentrations of major and trace elements such as fe b and s appear to be controlled by depositional setting with increasing values in coal seams overlain by brackish marine strata hierarchical cluster analysis identified three groups of major minerals and seven groups of trace elements based on similarity levels on a regional scale the coalfields can be separated by the differences in rank candiota and leao butia versus santa terezinha and by applying discriminant analysis based on 4 trace elements li as sr sb highest rb and sr values occur at candiota and are linked to syngenetic volcanism of the area whereas high y and sr values at santa terezinha can be related to the frequent diabase intrusions in that area

analysis origin and significance of mineral matter in coal an updated review abstract the material classed as mineral matter in coal embraces crystalline mineral materials as well as a range of inorganic elements that occur in non crystalline form this review outlines the methods that may be used to evaluate the percentage of mineral matter for a coal sample as opposed to the ash yield and to identify the minerals their individual percentages and their modes of occurrence within the coal the principal techniques include low temperature oxygen plasma ashing quantitative evaluation of x ray diffraction data observation using optical microscopy and a combination of observation chemical analysis and in some cases mapping based on scanning electron microscopy and related methods a range of other techniques may also be used to provide additional information on particular mineral matter components processes responsible for mineral matter formation include detrital input biogenic activity and authigenic precipitation at different stages of the coal s depositional and post depositional history differential migration of non mineral inorganic elements may also occur in lower rank coals and expulsion of non mineral inorganics may take place with rank advance knowledge of the mineral matter may be of assistance in understanding the modes of trace element occurrence with implications for assessing possible environmental impacts and also the potential for recovery of economic products from coal the behaviour of different mineral matter components at high temperatures is also discussed as well as methods for mineralogical analysis of ashes and other coal utilization products information from mineral matter studies may provide an improved basis for understanding coal formation and for evaluating the response of particular coals to different combustion gasification and coking processes

geological controls on mineralogy and geochemistry of the late permian coals in the liulong mine of the liuzhi coalfield guizhou province southwest china abstract this paper investigates the mineralogical and geochemical compositions of the late permian coals in the liulong mine liuzhi coalfield western guizhou province china by using xrd sem edx icp aes and icp ms both the no 3 and no 7 coals are classified as low volatile bituminous coal however the no 3 coal is a medium ash 29 8 on average and high sulfur 4 76 on average coal while the no 7 coal is a low ash 12 4 on average and medium sulfur 2 16 on average coal major minerals in both coal seams include quartz pyrite marcasite kaolinite calcite and to a lesser extent gypsum and anatase illite chlorite rectorite albite ankerite and siderotil are only present in the no 3 coal the no 3 coal contains higher elemental concentrations than the no 7 coal probably due to the higher mineral contents in the no 3 coal and is enriched in nb and ta and to a lesser extent in k ti li v co cu sr zr mo and ba the mineralogical and geochemical data presented in this study have shown that the no 3 coal was formed under a higher degree of marine influenced coal forming environment than the no 7 coal however the both coals have the kangdian upland made of mafic igneous rocks such as basalt rocks as sediment source region like other coals from guizhou province three geological factors control the geochemical patterns of the no 3 and no 7 coals namely 1 the high detrital input in the no 3 coal causing high ash yields 2 the sediment source region kangdian upland basalt causing high ti nb and ta contents and a minor proportion of co cr v and cu when combined with the high detrital input in the no 3 coal 3 the higher degree of marine influenced depositional environment in the no 3 coal causing a high s sr and ba contents

mapping ground movements caused by mining induced earthquakes applying satellite radar interferometry abstract anthropogenic activity related to the extraction of gas and oil raw materials or water pumping leads to slow or rapid ground deformation the ground motion rate is related to the type of the mined material geological conditions mining methods and other factors ground subsidence resulting from the collapse of underground post mining voids occurs gradually mining induced earthquakes and seismic earthquakes are largely unpredictable and have an adverse impact on the local inhabitants and buildings for this reason monitoring of this phenomenon is a challenge the application of interferometric sar for the evaluation of ground movement has brought satisfactory results over the past twenty years mainly in the regions where no other measurements were conducted during ground subsidence in this paper we have examined a mining induced earthquake with a magnitude 4 5 which occurred in an underground copper ore mine in poland on 29th november 2016 and caused eight fatalities it also had an impact on ground surface deformation in the vicinity of the mine tailings an assessment of the earthquake related impact on surface movement was carried out by sentinel 1 tops time series interferometry the velocity of ground movement and the scale of the phenomenon were investigated in addition the impact of the mining induced earthquake on zelazny most mine tailings site was analyzed moreover the process of dynamic ground compaction was also investigated in detail ground movement following the mine earthquake was explored two time phases of the movements were determined the first phase of dynamic ground displacement was rapid and 90 of total ground deformation appeared on the surface within 7 days the second phase of displacement was a vanishing one it lasted for approx 3 weeks and 10 of ground deformation appeared on the surface the study revealed that the maximum observed ground subsidence did not exceed 9 cm the presented results contribute to a better understanding of post earthquake ground deformations in the light of their spatial distribution in time

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

mineralogical and geochemical anomalies of late permian coals from the fusui coalfield guangxi province southern china influences of terrigenous materials and hydrothermal fluids abstract the late permian coal in the fusui coalfield of southern china is characterized by high fe sulfide and organic sulfur contents 2 60 and 2 94 respectively trace elements including zr 354 g g on average hf 9 18 g g y and rare earth elements rey 302 g g li 97 9 g g and cs 7 02 g g are significantly enriched in these coals in addition to hg and se enrichment in the roof and floor of the coal fluorine mo and u are enriched in the roof the floor is rich in cl s fe pb and cd compared to the upper continental crust rey in the parting and coal bench samples are characterized by heavy rey and light rey enrichment respectively the coals partings and host rocks roof and floor have negative eu anomalies the coal benches have higher ratios of u th yb la nb ta and zr hf and more abundant heavy rare earth elements than their adjacent partings these geochemical anomalies are attributed to the composition of terrigenous materials derived from the yunkai upland multi stage syngenetic and epigenetic hydrothermal fluid activities and intensive leaching and re distribution of lithophile elements from partings to the underlying coal benches both the organic and sulfide sulfur are also derived mainly from the hydrothermal fluids rather than the marine influence the minerals in the samples studied including kaolinite quartz and ree bearing minerals are of both terrigenous and hydrothermal origin al oxyhydroxides crystalline feso 4 oh water bearing fe oxysulfate and goyazite were derived from the hydrothermal activity kaolinite quartz ree bearing minerals and apatite from the sediment source region were also subjected to destruction by hydrothermal fluid leaching

aseismic mining subsidence in an abandoned mine influence factors and consequences for post mining risk management in the lorraine area of eastern france decades of iron ore mining from 1850 to 1997 have left vast underground cavities beneath or in the vicinity of urban areas several major collapses occurred in the southern part of this iron ore basin in the 1990s after the mine closure and the flooding of underground mine workings following these large scale collapses the french government initiated a strategy of post mining risk management to prevent and control risks associated with these ground failures the high risk zones are secured either by reducing the vulnerability while the moderate risk zones are monitored for public safety purposes by using in situ monitoring this monitoring relies mainly on real time microseismic systems to detect precursors to a rapid large scale collapse after the progressive closing and then flooding of the northern iron basin ending in 2008 subsidence was observed in a town of the lorraine basin in autumn of 2009 however this local subsidence with a low velocity of few centimeters per month was not clearly detected by the borehole microseismic monitoring station located nearby only some microseismic events were recorded which could not be unambiguously related to the beginning of the subsidence event to better understand this lack of microseismic precursor a geophysical investigation was launched a calibration blast experiment was carried out from a remaining old underground access in order to answer to the following questions 1 what is the seismic wave attenuation field 2 what is the minimum source power that can be detected by the sensors 3 what is the impact of the geology the faults corridor and the integral pillar extraction zone on the wave propagation field the results of this study show strong anelastic attenuation of the seismic waves though the monitored overburden most likely related to the extensive fault system intersecting the study site strong attenuation might explain the lack of detected microseismicity during the subsidence event in order to clarify this issue a mobile gps monitoring system was designed and tested to address this type of situation in future

rotational motions observed during an earthquake swarm in april 1998 offshore ito japan abstract we observed six components of ground rotational and translational motions in a near field region during an earthquake swarm in april 1998 offshore ito izu peninsula japan to check the reliability of our observation using a motionpack sensor we installed an 8301f sensor which is an inertial angular displacement sensor with a higher sensitivity than motionpack the noise level of the motionpack is much higher than that of the 8301f but the waveforms of these signal components are quite similar to each other suggesting that the motionpack records rotational rate correctly but with higher noise our observation made known a linear correlation between the maximum rotational displacements around the vertical axis and the maximum translational velocities the waveforms of rotational motion around the vertical axis are analogous to those of translational horizontal velocities suggesting the linear correlation between maximum values these rotational motions are much larger than those calculated by array data at the san andreas fault this large discrepancy might be explained by one or more of the following effects the difference in the spatial scale of rotational motion by single gyro measurement and by array observation the effect of the precipitous topography at the station of the offshore ito swarm and the difference of the degree of maturation between the san andreas fault and the swarm regions of offshore ito

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

ground rotational motions of the 1999 chi chi taiwan earthquake as inferred from dense array observations 1 large rotational motions excited by the 1999 chi chi taiwan earthquake are inferred from a dense acceleration array near the northern end of the rupture fault where large surface slips along the fault are observed the estimated major frequency content is from 0 1 to 1 0 hz with a peak near 0 2 hz it is found that in the footwall region the observed strong rotational ground motions were most probably excited by the slip of the northern rupture ending segment of the chi chi earthquake fault and that its thrust slips induced a major rock motion in the radial component the analysis here indicates that during the chi chi earthquake significant rotation seismic energy was radiated from the bent northern end of the earthquake fault further analysis of rotational ground motions may provide useful constraints for its rupture mechanisms

quantification of crystalline mineral matter in some turkish coals using interactive rietveld based x ray diffractometry quantitative x ray diffractometry using a rietveld based computational method siroquant has been carried out for a series of coal samples from the various turkish mines standard proximate and ultimate analyses were carried out chemical compositions of the high temperature ash hta of coal samples were determined by x ray fluorescence xrf spectrometry technique crystalline mineral matter and amorphous content of raw coal samples were estimated the ca si al s and fe concentrations are higher than those of the other major elements ti mn mg na p k in the studied coal samples the percentage of crystalline mineral matter for each sample varies from 16 5 to 36 1 of the coal samples the minerals in the sampled coals consist mainly of quartz clay minerals calcite pyrite and gypsum percentages of crystalline mineral matter in ash content remarkably decrease for the elbistan orhaneli and tufanbeyli lower rank coals

coal mining seismicity and ground shaking hazard a case study in the trail mountain area emery county utah we describe a multipart study to quantify the potential ground shaking hazard to joes valley dam a 58 m high earthfill dam posed by mining induced seismicity mis from future underground coal mining which could approach as close as 1 km to the dam to characterize future mis close to the dam we studied mis located 3 7 km from the dam at the trail mountain coal mine a 12 station local seismic network 11 stations above ground one below combining eight triaxial accelerometers and varied velocity sensors was operated in the trail mountain area from late 2000 through mid 2001 for the dual purpose of 1 continuously monitoring and locating mis associated with longwall mining at a depth of 0 5 0 6 km and 2 recording high quality data to develop ground motion prediction equations for the shallow mis ground motion attenuation relationships and moment tensor results are reported in companion articles utilizing a data set of 1913 earthquakes m 2 2 we describe space time magnitude distributions of the observed mis and source mechanism information the mis was highly correlated with mining activity both in space and time most of the better located events have depths constrained within 0 6 km of mine level for the preponderance 98 of the 1913 located events only dilatational p wave first motions were observed consistent with other evidence for implosive or collapse type mechanisms associated with coal mining in this region we assess a probable maximum magnitude of m 3 9 84th percentile of a cumulative distribution for potential mis close to joes valley dam based on both the worldwide and regional record of coal mining related mis and the local geology and future mining scenarios

geochemistry and nano mineralogy of two medium sulfur northeast indian coals the petrology mineralogy and inorganic geochemistry of two contrasting high sulfur vitrinite rich subbituminous to bituminous coals from the north eastern region ner of india have been studied using a combination of optical microscopy quantitative x ray diffraction xrd field emission scanning electron microscopy fe sem high resolution transmission electron microscopy hr tem saed and chemical analysis techniques the study reveals that the fe nano particles are present in indian high sulfur tertiary coals including nano pyrite fe oxyhydroxides and a small amount of sphalerite the pyrite is present as framboids and unsymmetrical cubic crystals rhombohedral they contain potentially hazardous elements viz as pb and se measured by eds techniques mineral matter residues isolated from the coals by low temperature oxygen plasma ashing are dominated by carbonate minerals calcite dolomite ankerite pyrite and pyrite oxidation products jarosite and coquimbite kaolinite illite and quartz sulfate bearing phases such as tschermigite bassanite and gypsum are also present probably as artifacts of the plasma ashing process

the miocene coal seams in the soma basin w turkey insights from coal petrography mineralogy and geochemistry abstract the neogene soma basin western turkey hosts three coal seams km2 km3 and kp1 and several altered tuff layers within the miocene sequences this study focuses on the evaluation of coal petrography mineralogical and elemental compositions as well as the rock eval pyrolysis of the three coal seams from eynez isiklar and denis sectors and to identify the mineralogy of altered tuff layers within km2 and kp1 seams the routine coal quality analyses show that coal samples from the km2 seam are characterized by lower ash yields and total s contents and higher gross calorific values than km3 and kp1 seams the mineralogical composition of the bulk coal samples varies between all three seams the statistical treatment implies that major elements in bulk coal samples such as al fe k mg and na and the vast majority of minor and trace elements have inorganic affinity the trace element contents and elemental enrichments in the coal samples are generally changeable from seam to seam which could be related to differences in ash yield and mineralogy altered tuff layers or tonsteins were identified in km2 and kp1 seams the tonsteins are clay rich and certain trace elements e g as and zr are enriched in the coal layers beneath the tuff layers in the km2 seam this might be related to penetration of leached pore water into these layers and precipitation of epigenetic minerals the coal petrography composition and the coal facies diagrams show that the precursor peat of the km2 seam was accumulating under telmatic mesotrophic anoxic conditions whereas the water level was high and stable the relatively low ash yields and thicker coal beds suggest a lower clastic input from the basin margins and water table fluctuations resulted in calcareous intercalations in the km3 and kp1 seams these imply the development of limno telmatic conditions whereas fluvial activity affected during peat accumulation of both seams considering the maceral composition along with the coal thickness coal seams in the soma basin might display oil generation potential however the pyrolysis analysis shows that the studied coal seams are mainly gas prone and only certain coal beds have mixed hydrocarbon generation capacity all data presented in this study indicates that lithological features differences in coal qualities and elemental contents in the soma basin were mainly controlled by changes in the depositional conditions and the detrital input during miocene

spatial gradient analysis for linear seismic arrays i incorporate the spatial gradient of the wave field recorded from one dimensional arrays into a processing method that yields the horizontal wave slowness and the change of geometrical spreading with distance in general the model for seismic wave propagation is enough to be appropriate for body and surface waves propagating from nearby seismic sources but can be simplified into a plane wave model although computation of the spatial gradient requires that array elements be closer than 10 of the horizontal wavelength seismic array apertures in the usual sense may extend over many horizontal wavelengths and illuminate changes within the wave field array images of horizontal slowness and the relative geometrical spreading changes of seismic waves are derived using filter theory and used to interpret observed array wave fields errors in computing finite difference spatial gradients from array nodes are explicitly considered to avoid spatial aliasing in the estimates i apply the method to interpret waves in strong ground motion and small scale refraction data sets use of the wave spatial gradient accentuates spatial differences in the wave field that can be theoretically exploited in fine scale tomographic studies of structure and is complementary to frequency wavenumber or beam forming array processing techniques

palaeoenvironment of seam i in the marathousa lignite mine megalopolis basin southern greece the present study aims to elucidate the depositional environment of seam i in the megalopolis basin southern greece using existing geological data supported by maceral and mineralogical analyses as well as by natural radioactivity determinations very high pyrite and uranium contents and a very low tissue preservation index usually suggest a marine influence during deposition in seam i however these features are most probably the result of a karstic aquifer supplying the palaeomire with sulphate rich neutral to weakly alkaline water the pyrite formation and the u precipitation are attributed to the anaerobic conditions which prevailed during peat accumulation the petrographic mineralogical and geochemical data of the studied profile point to several changes in the surface runoff and the supply of clastic material during deposition

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

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

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

the rupture process of the 1989 offshore ito earthquakes preceding a submarine volcanic eruption an earthquake swarm at the eastern offshore region of ito the izu peninsula started on june 30 1989 and became more active on and after july 4 the largest earthquake among the swarm mjma 5 5 occurred at 1109 jst 0209 ut on july 9 1989 and a second significant event followed 45 s later a remarkable volcanic tremor started on july 11 and a submarine eruption occurred just above the source region of the largest earthquake on july 13 in this paper we present a new inversion method to derive the source time function of rupture process the source time function is divided into several sections following an automatic algorithm and is interpolated with a cubic spline function the parameters which are the values and first derivatives at knots of the spline function are determined by minimizing a squared error between the observed and synthetic seismograms to demonstrate the performance of this method some numerical experiments simulations are carried out on near field seismic records applying this method to analysis of the two large earthquakes the detailed rupture processes are obtained a heterogeneous crustal structure near the volcanic area affects the rupture processes of these earthquakes the large stress drop due to the largest earthquake just beneath the submarine eruption point would assist a magma ascending and may have triggered the eruption 4 days after these earthquakes

moment tensors and other source parameters of mining induced earthquakes in tautona mine south africa abstract induced seismicity exhibits diverse source mechanisms that are often difficult to constrain for small events here we use data from the in mine seismic network the natural earthquake laboratory in south african mines network and a temporary program for the array seismic studies of the continental lithosphere deployment in tautona mine south africa to determine full moment tensors of 100 mining induced earthquakes in the magnitude range 2 7 m w f test to determine the need for including an isotropic component with an extra degree of freedom in the solution the results indicate 82 of the events have well constrained solutions and 45 of the well constrained events require an isotropic source term throughout the magnitude range both deviatoric and implosive mechanisms are observed with implosive ratios of volume change to shear deformation v of 1 03 to 0 15 two explosive events are observed at m w 0 5 and 0 2 with v 0 15 and 0 51 respectively for the largest events we determine maximum slip and apparent stress a and find values consistent with those of natural tectonic earthquakes with 0 1 a 9 2 mpa our results support previous speculation on the nature of isotropic components of mining induced earthquakes in which events of all sizes begin as shear failure that may intersect a void tunnel or stope and cause collapse whereas only small events result in explosive sources

development of ground motion prediction equations relevant to shallow mining induced seismicity in the trail mountain area emery county utah to provide a basis for assessing the seismic hazard to the joes valley dam due to future coal mining in the nearby cottonwood tract central utah we developed ground motion prediction relations using data recorded by a seismic network established and operated by the university of utah seismograph stations the network was centered on the trail mountain coal mine located adjacent to the cottonwood tract from late 2000 until early 2001 this network recorded numerous mining induced events with magnitudes as large as 2 17 the ground motion from these events recorded at hypocentral distances ranging from about 500 m to approximately 10 km were well suited to developing new ground motion prediction relations especially when augmented by data from a m 4 2 earthquake in the willow creek mine about 50 km north of trail mountain using a two stage regression analysis we determined prediction relations for peak acceleration peak velocity and pseudovelocity response spectra at 5 damping for periods of 0 1 0 2 0 5 1 0 and 2 0 s to illustrate the potential seismic hazard at the joes valley dam we used these ground motion relations to predict a peak velocity of 6 8 cm s due to an earthquake with the probable maximum magnitude of 3 9 at a hypocentral distance of 1 km recorded at a rock site typical for this region this result does not take into account the site response at the dam

predicting the sliding behavior of rotational landslides based on the tilting measurement of the slope surface abstract the surface displacements of slopes have been considered as a significant indicator in landslide investigations in last several decades while in recent years the tilting of slope surfaces is also being recognized as an important index in landslide monitoring however the slope surface tilting has been rarely examined so far and requires detailed investigations in this paper a series of laboratory tests and a field test were performed to investigate the surface tilting in rotational landslides as well as the correlation between tilt angles and displacements of slope surfaces in the laboratory tests slope models were constructed with different shapes of pre designed slip surfaces and tested under varying test conditions the tilting behavior of the slope surfaces in laboratory tests was measured using tilt sensors embedded into the slopes while the surface displacement was obtained by tracing the movement of marked points set on the slope surfaces near to the tilt sensors the test results revealed a linear relationship between the tilt angles and displacements of slope surfaces in the process of slope failure and this linear relationship was validated by a field test in which the slope failure was triggered by artificial rainfall the test results also indicated that the coefficient of the linear relation is consistent with the value of real distance between the locations of tilt sensors and the centers of slip surfaces an equation that relates the slope surface tilting and displacements was proposed in this study furthermore a method to estimate the geometry of the slip surface was also developed which was deduced from the observation that the path of the sliding masses was parallel to the slip surface according to the results of laboratory tests additionally an acceleration stage of surface tilting was observed in slope failure induced by artificial rainfall which implies that the surface tilting measurement can be used to predict the potential development of a rotational landslide or its reactivation

mineralogical and compositional characteristics of late permian coals from an area of high lung cancer rate in xuan wei yunnan china occurrence and origin of quartz and chamosite abstract some townships in xuan wei county yunnan province have one of the highest lung cancer mortality rates in china and the epidemic disease in the area has generally been attributed to the polycyclic aromatic hydrocarbons pahs released from domestic coal burning however the cancer causing culprit is not settled as tian tian l 2005 coal combustion emissions and lung cancer in xuan wei china ph d thesis university of california berkeley found nanometer quartz in these coals soot emissions and lung cancer tissues we have conducted mineralogical and geochemical studies of the coals from xuan wei for the purpose of shedding light on the minerals which may be related to the epidemic lung cancer in this paper abundances modes of occurrence and origins of minerals and elements in the coals from two mines in xuan wei have been studied using optical microscope low temperature ashing x ray diffraction analysis scanning electron microscope equipped with energy dispersive x ray spectrometer and inductively coupled plasma mass spectrometry the minerals in the coals are mainly composed of quartz chamosite kaolinite and calcite the particle size of quartz is rather small mostly less than 20 m and it is of authigenic origin chamosite occurs mainly as cell fillings the occurrence of quartz and chamosite indicates that they were derived from the hydrothermal fluids epigenetic calcite is derived from calcic fluids kaolinite is derived mainly from sediment source region of kangdian oldland to the west of coal basin the composition of xuan wei coal is high in sio2 fe2o3 tio2 cao mno v co ni cu and zn the high sio2 content is attributed to quartz and the fe2o3 content to chamosite the high mn and low mg contents in the coal indicate the inputs of hydrothermal fluids cao occurs mainly in epigenetic calcite elements ti co ni cu zn and rare earth elements were derived from the basaltic rocks at sediment source region

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

origin of cratonic basins tectonic subsidence curves show that the illinois michigan and williston basins formed by initial fault controlled mechanical subsidence during rifting and by subsequent thermal subsidence thermal subsidence began around 525 ma in the illinois basin 520 460 ma in the michigan basin and 530 500 ma in the williston basin in the illinois basin a second subsidence episode middle mississippian through early permian was caused by flexural foreland subsidence in response to the alleghanian hercynian orogeny resurgent permian rifting in the illinois basin is inferred because of intrusion of well dated permian alnoites such intrusive rocks are normally associated with rifting processes the process of formation of these cratonic basins remains controversial past workers have suggested mantle phase changes at the base of the crust mechanical subsidence in response to isostatically uncompensated excess mass following igneous intrusions intrusion of mantle plumes into the crust or regional thermal metamorphic events as causes of basin initiation cratonic basins of north america europe africa and south america share common ages of formation around 550 to 500 ma histories of sediment accumulation temporal volume changes of sediment fills and common dates of interregional unconformities their common date of formation suggests initiation of cratonic basins in response to breakup of a late precambrian super continent this supercontinent acted as a heat lens that caused partial melting of the lower crust and upper mantle followed by emplacement of anorogenic granites during extensional tectonics in response to supercontinent breakup intrusion of anorogenic granites and other partially melted intrusive rocks weakened continental lithosphere thus providing a zone of localized regional stretching and permitting formation of cratonic basins almost simultaneously over sites of intrusion of these anorogenic granites and other partially melted intrusive rocks

mineralogy of lignites and associated strata in the mavropigi field of the ptolemais basin northern greece the mineralogy of five lignite layers and the associated roof floor and intercalating strata has been analysed using low temperature oxygen plasma ashing and quantitative x ray diffraction techniques the lignite contains quartz kaolinite illite and smectite and in some cases small proportions of feldspar thought to represent mainly detrital minerals in the original peat deposits one sample also contains crystalline calcium oxalates with weddellite present in the raw lignite and whewellite in the low temperature ash lta of the same lignite sample minor proportions of gypsum are present in some of the raw lignite samples possibly in part derived from precipitation of dissolved ca and so4 in the pore waters on drying all the ltas however contain much higher proportions of bassanite and or gypsum compared to the other minerals present consistent with production of calcium sulphate artefacts from interaction of abundant organically associated ca and s in the lignite during the plasma ashing procedure the inorganic strata are mainly carbonate rocks consisting almost entirely of calcite with minor aragonite small proportions of illite traces of pyrite and in some cases siderite some non carbonate rocks are also associated with the lignite seams these are dominated by plagioclase feldspar and mica along with illite kaolinite and a relatively minor proportion of quartz the mineral assemblages can be related to the palaeoenvironmental conditions under which the various sediments including lignite were deposited comparison of the mineral abundances in the samples to the chemical composition of the materials shows that the quantitative xrd technique provides results consistent with ash analysis data although abundant in the associated rocks calcite does not occur in the lignite samples while part of the relatively abundant ca in the lignite occurs as either gypsum or weddellite most of it appears to be organically bound mine products that incorporate calcareous rocks of the type associated with the lignite may however contain separate calcite phases and display high carbonate co2 contents

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

lithospheric mantle deformation beneath the indian cratons abstract the nature of deformation of the deep continental roots beneath the archean early proterozoic terrains opens the question whether these ancient terrains have had stable roots since the precambrian or whether recent plate motions have deformed them in view of this we make an attempt to study the thermal structure beneath the cratonic regions of the indian shield which vary in lithospheric thickness from 65 km in the singhbhum craton to 148 km in the archean dharwars the average depth of 104 km to the top of the underlying asthenosphere is consistent with other termination methods and is in fact less than half the 200 400 km depth found in other stable areas of the earth similarly the average reduced heat flow of about 35 mw m2 and moho temperature of about 550 c range 400 730 c for the indian cratons are also much higher than their counterparts elsewhere our study indicates a large scale deformation of the cratonic mantle lithosphere beneath the indian shield since the mesoproterozoic c

transient stresses at parkfield california produced by the m 7 4 landers earthquake of june 28 1992 observations from the upsar dense seismograph array the m 7 4 landers earthquake triggered widespread seismicity in the western united states because the transient dynamic stresses induced at regional distances by the landers surface waves are much larger than the expected static stresses the magnitude and the characteristics of the dynamic stresses may bear upon the earthquake triggering mechanism the landers earthquake was recorded on the upsar u s geological survey parkfield small aperture array array a group of 14 triaxial accelerometers located within a 1 square km region 10 km southwest of the town of parkfield california 412 km northwest of the landers epicenter no triggered earthquakes were observed at parkfield multiple filter analysis shows that the displacements obtained by double integration are dominated by the fundamental mode love and rayleigh modes with some higher mode contributions for periods shorter than 10 s most of the surface waves propagated along the great circle path from landers but a late arriving surface wave appears to have been scattered from the sierra nevada mountains we used a standard geodetic inversion procedure to determine the surface strain and stress tensors as functions of time from the observed displacements peak dynamic strains and stresses at earth s surface are about 7 strain and 0 035 mpa respectively and they have a flat amplitude spectrum between 2 s and 15 s period these stresses agree well with stresses predicted from a simple equation using the ground velocity spectrum observed at a single station peak stresses ranged from about 0 035 mpa at the surface to about 0 12 mpa between 2 and 14 km depth with the sharp increase of stress away from the surface resulting from the rapid increase of rigidity with depth and from the influence of mode shapes because of the free surface boundary conditions the horizontal components of the stress tensor tend to dominate in the top 5 6 km of the crust which might cause triggered seismicity to have strike slip or normal mechanisms comparison of dynamic stresses induced by the landers loma prieta and petrolia earthquakes at a variety of sites indicates that the landers stresses were not spectacularly larger than those induced by the other sources landers dynamic stresses were comparable to coalinga static stresses at parkfield the effective strain caused by landers at parkfield where no earthquakes were triggered are the same amplitude as those at some sites in nevada where earthquakes were triggered comparing various authors observations of dynamic stresses there is no obvious characteristic of these stresses that correlates with the triggered seismicity

lithostratigraphy of the neoproterozoic chattisgarh sequence its bearing on the tectonics and palaeogeography abstract the neoproterozoic purana succession in the eastern part of chattisgarh basin around sarangarh has been classified into a conglomerate sandstone shale dominated proximal assemblage and a lithographic limestone shale dominated distal assemblage the proximal assemblage constitutes the chandarpur group and unconformably overlies the archean crystalline basement complex the chandarpur succession has been classified into three formations that were deposited in fan fan delta deep water prodelta and storm tide dominated prograding shelf environments the distal assemblage the raipur group conformably overlies the chandarpur group and may be subdivided into two shale dominated formations separated by a limestone dominated formation the limestone sequence the sarangarh limestone comprises a lower member of mixed carbonate siliciclastic succession deposited in a storm dominated shallow water platform and an upper member of pelagic limestone that grades upward into a deep water shale the gunderdehi shale the rapid transition from shallow water platformal succession to deep water pelagic limestone and shale points to abrupt deepening of the basin and drowning of the craton the peak of transgression is represented by a persistent horizon of black limestone a product of basin wide anoxia disposition of facies belts in proximal and distal assemblages and palaeocurrent directions measured from different facies belts point to a north northwesterly palaeoslope of the basin signatures of intense storm and tidal currents in different litho units collectively point to an open marine circulation condition it has been inferred that the basin was connected to a major seaway that skirted the northern and north western margin of the craton development of thick fan delta sequence at the base of the succession occurrence of felsic welded tuff within the gunderdehi shale thick sandstone mudstone cyclothems in the chandarpur group and abrupt drowning of the carbonate platform leading to pelagic sedimentation collectively point to major tectonic control on basin evolution the basin developed as a cratonic rift and evolved into a deeply subsiding one without any major stratigraphic hiatus through episodic tectonic pulses

review progress in rotational ground motion observations from explosions and local earthquakes in taiwan rotational motions generated by large earthquakes in the far field have been successfully measured and observations agree well with the classical elasticity theory however recent rotational measurements in the near field of earthquakes in japan and in taiwan indicate that rotational ground motions are 10 to 100 times larger than expected from the classical elasticity theory the near field strong motion records of the 1999 mw 7 6 chi chi taiwan earthquake suggest that the ground motions along the 100 km rupture are complex some rather arbitrary baseline corrections are necessary in order to obtain reasonable displacement values from double integra tion of the acceleration data because rotational motions can contaminate acceleration observations due to the induced perturbation of the earth s gravitational field we started a modest program to observe rotational ground motions in taiwan three papers have reported the rotational observations in taiwan 1 at the hgsd station liu et al 2009 2 at the n3 site from two taiwan integrated geodynamics research taiger explosions lin et al 2009 and 3 at the taiwan campus of the national chung cheng university nccu wuet al 2009 in addition langston et al 2009 reported the results of analyzing the taiger explosion data as noted by several authors before we found a linear relationship between peak rotational rate prr in mrad sec and peak ground acceleration pga in m sec 2 from local earthquakes in taiwan prr 0 002 1 301 pga with a correlation coefficient of 0 988

moment tensor inversion of ground motion from mining induced earthquakes trail mountain utah a seismic network was operated in the vicinity of the trail mountain mine central utah from the summer of 2000 to the spring of 2001 to investigate the seismic hazard to a local dam from mining induced events that we expect to be triggered by future coal mining in this area in support of efforts to develop ground motion prediction relations for this situation we inverted ground motion recordings for six mining induced events to determine seismic moment tensors and then to estimate moment magnitudes m for comparison with the network coda magnitudes m c six components of the tensor were determined for an assumed point source following the inversion method of mcgarr 1992a which uses key measurements of amplitude from obvious features of the displacement waveforms when the resulting moment tensors were decomposed into implosive and deviatoric components we found that four of the six events showed a substantial volume reduction presumably due to coseismic closure of the adjacent mine openings for these four events the volume reduction ranges from 27 to 55 of the shear component fault area times average slip radiated seismic energy computed from attenuation corrected body wave spectra ranged from 2 4 105 to 2 4 106 j for events with m from 1 3 to 1 8 yielding apparent stresses from 0 02 to 0 06 mpa the energy released for each event approximated as the product of volume reduction and overburden stress when compared with the corresponding seismic energies revealed seismic efficiencies ranging from 0 5 to 7 the low apparent stresses are consistent with the shallow focal depths of 0 2 to 0 6 km and rupture in a low stress low strength regime compared with typical earthquake source regions at midcrustal depths

the neoproterozoic cratonic successions of peninsular india abstract the peninsular india hosts extensive record of mesoproterozoic and neoproterozoic successions in several mobile belts and cratonic basins the successions provide excellent opportunities for chronostratigraphic classification in tune with the chronometric classification adopted by iugs for inter regional correlation on a global scale major tectono thermal events at 1000 950 ma in the mobile belts correlatable with the grenville orogeny may be considered as the datum for meso neoproterozoic classification in india principles of chronostratigraphic classification however can not be applied yet to the cratonic successions of india because of inadequate radiometric data paucity of biostratigraphic studies and lack of regionally correlatable stratigraphic or palaeoclimatic datum the kimberlite magmatism which affected the peninsular india on a continental scale at about 1100 ma holds the key to the identification of neoproterozoic successions of the cratonic basins thus the stratigraphically confined diamond bearing conglomerates and or the tuffs associated with kimberlites may be considered as the datum to define the base of the neoproterozoic fixed at about 1000 ma accordingly the rewa and bhander groups in the vindhyan basin the kurnool group in the cuddapah basin the jagdalpur formation in the indravati basin and the sullavai group in the pranhita godavari basin are taken to represent the neoproterozoic successions in the peninsular india the chattisgarh group in the central india the lower part of the marwar supergroup in western rajasthan the badami group in the kaladgi basin and the bhima group are the other possible neoproterozoics in the peninsula the closing phase of the mesoproterozoic in all these basins are characterised by stable shelf lithologic associations attesting to high crustal stability the neoproterozoic basins by contrast mark a new phase of rifting and extension and the basin fills exhibit signatures of initial instability which evolved with time into a more stable platformal condition a major episode of sea level rise has been recorded in most of the basins the riftogenic origin and evolution of the basins are comparable with the history of neoproterozoic basins of australia though there is no unequivocal record of glaciation in the indian formations

quantitative mineralogical analysis of coals from the callide basin queensland australia using x ray diffractometry and normative interpretation abstract comparisons are presented between the results of quantitative x ray diffractometry using a rietveld based computational method siroquant on low temperature ash lta and normative calculation from chemical analysis of high temperature ash for a series of coal samples from the callide basin of queensland mineral percentages indicated by each method are also compared to the results of conventional x ray diffractometry on low temperature ash spiked with a known proportion of corundum evaluated in conjunction with detailed clay mineral analysis of the for species where direct comparison is possible the proportions of the different minerals in the crystalline fraction indicated by siroquant are similar to those indicated by normative analysis using a computational procedure referred to as sednorm more conventional xrd study of spiked lta materials with the samples studied seems to underestimate quartz and siderite content and by default overestimate kaolinite siroquant on the other hand tends to overestimate the proportion of ca bearing minerals relative to the ca content of the high temperature ash processed using the sednorm computation both the siroquant analysis and the normative evaluation of sednorm provide significantly more quantitative information on coal mineralogy than other more commonly used techniques

proterozoic felsic volcanism in the pranhita godavari valley india its implication on the origin of the basin abstract the proterozoic sedimentary rocks in the pranhita godavari valley pg valley south india were deposited in diverse environments ranging from continental shallow shelf to deep basin and occur as several unconformity bound sequences the sedimentary rocks also include felsic pyroclastics in different formations and at different stratigraphic levels repeated occurrences of intrabasinal pyroclastic rocks of similar composition suggest that the detritus might have been erupted from a common chamber which was activated at different times throughout the basin filling episode it is postulated that the mature proterozoic crust of indian craton acted as a heat lens resulting in extensive partial melting at the lower crustal levels localized stretching and rifting of the craton leading to the formation of the intracratonic basin the sedimentological attributes also support extensional setting and the hypothesis may be extended for several meso neoproterozoic cratonic basins in the indian shield the mechanism operated over the time span of 1 6 0 7 ga and overlaps with the age of development of an extensive granite rhyolite province in north america the process of accumulation of heat at the lower crustal levels generating a heat lens is typical of the stationary phase of supercontinental cycles and the origin of the cratonic basins the origin of the pg valley basin may be related to the fragmentation of a supercontinent of which the indian craton was a part

minerals in bituminous coals of the sydney basin australia and the illinois basin u s a although other forms of inorganic components may be significant in lower rank coals the mineral matter in most bituminous coals is dominated by silicates carbonates sulphides phosphates and other crystalline mineral groups these may be present in various forms including thin bands and laminae intimately associated with the organic matter as well as lenticles nodules crystal aggregates and cell infillings all of which indicate approximately contemporaneous formation with the peat bed other minerals however occur as veins or cleat and fracture fillings indicating precipitation after most of the compaction and presumably after most of the rank advance ome of the penecontemporaneous mineral matter is of detrital origin representing epiclastic or pyroclastic particles washed or blown into the peat swamp other mineral matter however including much of the pyrite quartz and siderite as well as abundant well crystallized kaolinite appears to have been formed by precipitation processes either within the swamp waters or in the pores of the peat deposit pyrite largely formed by bacterial reduction of dissolved sulphate ions seems to be related in abundance to marine transgressions which allowed permeation of sea water into the swamp and through the peat bed beneath siderite appears to form in the absence of sulphate rich sea water probably from co2 released by organic decay the clay fraction of the noncoal rocks in many coal bearing sequences is typically dominated by illite or interstratified clay minerals with kaolinite chlorite and possibly montmorillonite also present to a variable though typically minor extent although perhaps modified by chemical reactions or ion exchange mechanisms in the peat swamp these clay minerals may also be present in the coal as well especially near the base of top of the seam the kaolinite in the noncoal rocks is usually poorly crystallized and typically a minor constituent but well crystallized kaolinite is characteristically present and often the dominant component in the mineral fraction of bituminous coal beds as well as in some of the lutites including underclays intimately associated with the seams a progressive upward gradation to a particularly kaolinite dominated mineral assemblage occurs in some seams of the sydney basin australia this gradation is thought to be due to either increased blockage of detrital contaminants as the swamp developed or to in situ chemical or biological leaching of the mineral fraction and reconstitution of the residues in the upper parts of the peat bed superimposition of such cycles is also noted within the seam in some instances suggesting repetition of several phases of this type during major peat accumulations

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

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

syn and post depositional sand bodies in lignite the role of coal analysis in their recognition a study from the frimmersdorf seam garzweiler open cast mine western germany abstract the lower rhine basin is a cenozoic age rift basin at the nw end of the european cenozoic rift basin in middle miocene times fluctuating sea levels in the north sea and the repeated spreading of paralic mires resulted in the deposition of marine sand units frimmersdorf and neurath sands alternating with thick lignite beds morken frimmersdorf and garzweiler seams within the frimmersdorf seam the presence of sand bodies has been interpreted both in terms of syn depositional emplacement in an estuarine setting as well as post depositional sand injection and soft sediment deformation partly linked to tectonic activity within the lower rhine basin while understanding of the causal mechanisms has improved early recognition of sand concentrations in future mine area remains difficult therefore organic petrological and inorganic geochemical analyses of sand and lignite samples were carried out in order to assess their efficacy as proxies for such studies the results reflect the complexity of the depositional environment which was influenced by both fresh and marine waters ash yields of the lignite samples are variable and sulphur contents as well as ca mg ratios depend on the distance from the overlying marine neurath sand humic substance values of the lignites are dependent on the sampling position within the seam and may be related to sand body deposition moderate contents of gelified macerals and the small size of huminite particles reflect the depositional environment during peat formation but are not influenced by sand body deposition not even when in close proximity to the sands while the geochemical and petrological methods provide much information on the depositional environment of the miocene age lower rhine basin and also on marine versus freshwater deposition of the sands they do not facilitate the differentiation of syn and post depositional sand emplacement in the frimmersdorf seam

rotational motions induced by the m8 1 tokachi oki earthquake september 25 2003 1 we report the first consistent observations of rotational motions around a vertical axis induced by distant large earthquakes it is standard in seismology to observe three components up down n s e w of earthquake induced translational ground motions using inertial seismometers however only recently ring laser technology has provided the required sensitivity for observations of the theoretically predicted rotational part of ground motion generated by seismic waves in a wide distance range and frequency band here we show that the rotations observed are consistent in waveform and amplitude with collocated recordings of transverse accelerations recorded by a standard seismometer this suggests that rotations may become a new observable for seismology and related fields with the potential of providing complementary information on earthquake source processes structural properties and ground shaking

the clay mineralogy of calcitic seat earth in the northern everglades of florida abstract the interface between peat and underlying limestone bedrock in the northern florida everglades is often occupied by an unlithified calcitic seat earth that is stratigraphically similar to coal basin seat rock and contains a complex mineral assemblage composed of 14 different minerals the distribution and characteristics of the clay size fraction were used to indicate sediment source areas depositional environment and the degree of alteration of the original mineral assemblage x ray diffraction analysis of 42 samples showed that a significant lateral variation exists in the clay mineral suite of seat earth with respect to location in the study area the clay minerals palygorskite sepiolite and illite were found primarily towards the center of the study area and were derived from sediments north of the everglades seat earth located along the basin flanks showed an increase in the abundance of mixed layer smectite kaolinite and chlorite the proposed source area for these minerals is from erosion of marginal marine bar deposits that rim the basin underlying limestone bedrock erosion contributed to the detrital mineral assemblage but was not as important as source areas outside the basin the study area seat earth is interpreted to have been deposited in an alkaline environment that allowed much of the original detrital mineral assemblage to be preserved the only exception to this was the occasional identification of well crystallized authigenic mixed layer chlorite smectite that occurred in samples located near the basin flanks which were presumably deposited under more acidic conditions

introduction to the special issue on rotational seismology and engineering applications rotational seismology is an emerging field for studying all aspects of ro tational ground motions induced by earthquakes explosions and ambient vibrations it is of interest to a wide range of geophysical disciplines including strong motion seismology broadband seismology earthquake engineering earthquake physics seis mic instrumentation seismic hazards seismotectonics and geodesy as well as to physicists using earth based observatories for detecting gravitational waves generated by astronomical sources predicted by einstein in 1916 in this introduction to the bssa special issue on rotational seismology and engineering applications we will include 1 some background information 2 a summary of the recent events that led to this special issue and 3 an overview of its 51 papers 27 articles 11 short notes 4 reviews 6 tutorials and 3 supplementary articles our comments on these 51 papers are very brief and give just a hint of what the papers are about papers in this special issue demonstrate that earthquake monitoring cannot be limited to measuring only the three components of translational motion we also need to simultaneously measure the three components of rotational motion and the many components of strains a golden opportunity to improve our understanding of earth quakes lies in the near field of large earthquakes within about 25 km of the earthquake ruptures where nonlinear rock and soil response influences ground motions in a com plicated way

developing an application specific ground motion model for induced seismicity abstract a key element of quantifying both the hazard and risk due to induced earthquakes is a suite of appropriate ground motion prediction equations gmpes that encompass the possible shaking levels due to such events induced earthquakes are likely to be of smaller magnitude and shallower focal depth than the tectonic earthquakes for which most gmpes are derived furthermore whereas gmpes for moderate to large magnitude earthquakes are usually derived to be transportable to different locations and applications taking advantage of the limited regional dependence observed for such events the characteristics of induced earthquakes warrant the development of application specific models a preliminary ground motion model for induced seismicity in the groningen gas field in the netherlands is presented as an illustration of a possible approach to the development of these equations the gmpe is calibrated to local recordings of small magnitude events and captures the epistemic uncertainty in the extrapolation to larger magnitude considered in the assessment of the resulting hazard and risk

late paleozoic to jurassic silicic magmatism at the gondwana margin analogy to the middle proterozoic in north america a vast region of upper paleozoic to middle jurassic 300 150 ma silicic magmatic rocks that erupted inboard of the gondwana margin is a possible phanerozoic analogue to the extensive middle proterozoic 1500 1350 ma silicic magmatic province that underlies much of the southern mid continent of north america like the north american rocks the gondwana silicic magmas appear to be melts of crust that formed about 200 300 m y earlier in the north american case this older crust formed and was accreted to the continent during a major period of crustal formation 1700 1900 ma whereas in the gondwana case the crust that melted consisted mainly of magmatic are terranes accreted to the continental margin during the paleozoic in both cases basic to intermediate magmatic rocks are extremely rare and magmatism is less abundant in regions that contain older and previously melted crust the similarities between the north american and gondwana silicic rocks suggest that both suites formed in extensional settings where basaltic magmas ponded at the base of the preheated crust caused extensive crustal melting that inhibited upward passage of the basalts in both cases silicic volcanism occurred after major assembly of a supercontinent by subduction and accretion processes and before breakup of the supercontinent by analogy with the polar wander curves for gondwana the granite rhyolite provinces may have formed during a period of very slow motion of the supercontinents relative to the poles

what can be learned from rotational motions excited by earthquakes summary one answer to the question posed in the title is that we will have more accurate data for arrival times of sh waves because the rotational component around the vertical axis is sensitive to sh waves although not to p sv waves importantly there is another answer related to seismic sources which will be discussed in this paper generally not only dislocations commonly used in earthquake models but also other kind of defects could contribute to producing seismic waves in particular rotational strains at earthquake sources directly generate rotational components in seismic waves employing the geometrical theory of defects we obtain a general expression for the rotational motion of seismic waves as a function of the parameters of source defects using this expression together with one for translational motion we can estimate the rotational strain tensor and the spatial variation of slip velocity in the source area of earthquakes these quantities will be large at the edges of a fault plane due to spatially rapid changes of slip on the fault and or a formation of tensile fractures

recovering coseismic point ground tilts from collocated high rate gps and accelerometers 1 rotational along with translational and strain measurements are essential for a complete description of the motion of a deformable body in a seismic event we propose a new seismogeodetic approach where collocated high rate gps and accelerometer measurements are combined to estimate permanent and dynamic coseismic ground tilts at a point whereas at present only dynamic tilts are measured with either a dense seismic array or an expensive ring laser gyroscope we estimate point tilts for a five story structure on a shake table subjected to 13 earthquake strong motion records of increasing intensity for the most intense record from the 2002 m7 9 denali earthquake we observe a peak to peak dynamic tilt of 0 12 and a permanent tilt of 0 16 for the structure s roof point tilts derived from networks of collocated gps and accelerometers can be used to estimate the rotational component of the seismic wavefield for improved earthquake source characterization

late oligocene recent stress evolution in rift basins of northern and central thailand implications for escape tectonics abstract the tertiary rift basins of thailand are known through sub surface seismic and borehole data collected for hydrocarbon and coal exploration outcrops in open cast coal mines and a few natural outcrops these data provide mixed perspectives on how the basins evolved some providing data on ages and structural geometries others palaeostress data in general the region evolved under approximately e w extension although the extension direction probably changed periodically within basins extension was episodically interrupted by inversion events associated with sub horizontal nw se to ne sw 1 direction there is no evidence to suggest that the string of rift basins running from n thailand and laos into the gulf of thailand evolved in a similar way on the contrary the evolution of each basin seems different although certain regional trends along the rift system are apparent as follows 1 oligocene lower miocene extension is widespread in the region 2 in central and northern thailand middle miocene extension is also important and extension persisted into the upper miocene pliocene 3 in the extreme south of the area w natuna basin penyu basin malay basin extension ceased in the earliest miocene 4 in the northern gulf of thailand extension ceased in the middle miocene 5 thermal subsidence is greatest up to 4 km in the south malay pattani w natuna and penyu basins and least in northern thailand a few tens to hundreds of metres 6 inversion in the southern gulf of thailand was intense and occurred during the lower and middle miocene in the northern gulf of thailand inversion is very mild and occurred during the lower and middle miocene onshore inversion is patchy during the miocene but is strongest in the northwestern rift basins particularly the li basin the most widespread inversion event that affects the north occurred during the plio pleistocene it might be associated with the change from left to right lateral motion on the red river fault the relationship between strike slip faults and rift basins in terms of timing of extensional and inversion events and palaeostress orientation and evolution is more complex than can be explained by simple escape tectonic models

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

metamorphism of mineral matter in coal from the bukit asam deposit south sumatra indonesia abstract the coal of the miocene bukit asam deposit in south sumatra is mostly sub bituminous in rank consistent with regional trends due to burial processes however effects associated with plio pleistocene igneous intrusions have produced coal with vitrinite reflectance up to at least 4 17 anthracite in different parts of the deposit the un metamorphosed to slightly metamorphosed coals with rvmax values of 0 45 0 65 contain a mineral assemblage made up almost entirely of well ordered kaolinite and quartz the more strongly heat affected coals with rvmax values of more than 1 0 are dominated by irregularly and regularly interstratified illite smectite poorly crystallized kaolinite and paragonite na mica with chlorite in some of the anthracite materials kaolinite is abundant in the partings of the lower rank coals but is absent from the partings in the higher rank areas even at similar horizons in the same coal seam regularly interstratified illite smectite which is totally absent from the partings in the lower rank coals dominates the mineralogy in the partings associated with the higher rank coal beds a number of reactions involving the alteration of silicate minerals appear to have occurred in both the coal and the associated non coal lithologies during the thermal metamorphism generated by the intrusions the most prominent involve the disappearance of kaolinite the appearance of irregularly interstratified illite smectite and the formation of regular i s paragonite and chlorite although regular i s is identified in all of the non coal partings associated with the higher rank coals illite smectite with an ordered structure is only recognised in the coal samples collected from near the bases of the seams the i s in the coal samples adjacent to the floor of the highest rank seam also appears to have a greater proportion of illitic components the availability of sodium and other non mineral inorganic elements in the original coal to interact with the kaolinite under different thermal and geochemical conditions appears to be the significant factor in the formation of these new minerals and distinguishes the mineralogical changes at bukit asam from those developed more generally with rank increases due to burial and from the effects of intrusions into coals that were already at higher rank levels

depositional setting petrology and chemistry of permian coals from the parana basin 2 south santa catarina coalfield brazil abstract in brazil economically important coal deposits occur in the southern part of the parana basin where coal seams occur in the permian rio bonito formation with major coal development in the states of rio grande de sul and santa catarina the current paper presents results on sequence stratigraphic interpretation of the coal bearing strata and petrological and geochemical coal seam characterization from the south santa catarina coalfield parana basin in terms of sequence stratigraphic interpretation the precursor mires of the santa catarina coal seams formed in an estuarine barrier shoreface depositional environment with major peat accumulation in a high stand systems tract pre bonito and bonito seams a lowstand systems tract ponta alta seam seam a seam b and a transgressive systems tract irapua barro branco and treviso seams seam thicknesses range from 1 70 to 2 39 m but high proportions of impure coal coaly shale and shaley coal carbonaceous shale and partings reduce the net coal thickness significantly coal lithoypes are variable with banded coal predominant in the barro branco seam and banded dull and dull coal predominantly in bonito and irapua seams respectively results from petrographic analyses indicate a vitrinite reflectance range from 0 76 to 1 63 rrandom hvb a to lvb coal maceral group distribution varies significantly with the barro branco seam having the highest vitrinite content mean 67 5 vol whereas the irapua seam has the highest inertinite content 33 8 vol liptinite mean values range from 7 8 vol barro branco seam to 22 5 vol irapua seam results from proximate analyses indicate for the three seams high ash yields 50 2 64 2 wt considering the international classification of in seam coals all samples are in fact classified as carbonaceous rocks 50 wt ash sulfur contents range from 3 4 to 7 7 wt of which the major part occurs as pyritic sulfur results of x ray diffraction indicate the predominance of quartz and kaolinite also pyrite gypsum gibbsite jarosite and calcite were also identified in some samples feldspar was noted but is rare the major element distribution in the three seams coal basis is dominated by sio 2 31 3 wt mean value al 2 o 3 14 5 wt mean value and fe 2 o 3 6 9 wt mean value considering the concentrations of trace elements that are of potential environmental hazards the barro branco bonito and irapua seams coal base are significantly enriched in co 15 7 ppm cr 54 5 ppm li 59 3 ppm mn 150 4 ppm pb 58 0 ppm and v 99 6 ppm when compared to average trace elements contents reported for u s coals hierarchical cluster analysis identified based on similarity levels three groups of major elements and seven groups of trace elements applying discriminant analyses using trace and major element distribution it could be demonstrated that the three seams from santa catarina show distinct populations in the discriminant analyses plots and also differ from the coals of rio grande do sul analyzed in a previous study

mineralogy of the volcanic influenced great northern coal seam in the sydney basin australia abstract the mineralogy of the individual coal plies and intra seam claystone bands in the great northern seam of the sydney basin has been evaluated using optical and scanning electron microscopy and quantitative x ray diffraction techniques the uppermost two claystone bands are tonsteins consisting mainly of well ordered kaolinite with graupen to vermicular textures idiomorphic crystals of k feldspar within these tonsteins may represent members of the anorthoclase sanidine series or a sodic sanidine and indicate an acid to intermediate volcanic ash input in contrast the lowermost parting was largely derived from epiclastic sediment admixed with minor volcanic material such as high temperature quartz and a different type of k feldspar component the mineral fraction of the coals especially in the middle and upper parts of the seam is dominated by authigenic kaolinite with a very low abundance of quartz apart from the tonsteins authigenic processes therefore appear to be the dominant mechanism of mineral matter formation authigenic k feldspar also occurs in the lower few metres of the seam with a variety of modes of occurrence including cell and cleat infillings cross cutting veins and thin laminae parallel to the organic matter and detrital clay bands a late syngenetic low temperature hydrothermal fluid injection process is suggested for formation of the feldspar veins the origin of the fluid is uncertain but is most likely associated with contemporaneous volcanic activity

the dharwar craton and the assembly of peninsular india peninsular india can be separated into five discrete crustal areas the bhandara singhbhum and aravalli bundelkhand cratons the eastern ghats and a block in southern india containing the dharwar craton and adjoining granulite terrain these areas are separated by four major joins eastern ghats front godavari rift mahanadi rift sukinda thrust and narmada son lineament and associated thrusts all joins except the godavari rift are former orogenic belts where thrusts juxtapose rocks of different metamorphic grade these thrusts and the absence of clear correlation of suites among different cratons suggest that the indian shield formed by accretion of separate continental fragments epicontinental late archean early pro terozoic sediments throughout india however may indicate that the joins are intracontinental formed within a coherent block the term dravidian shield is used for the southernmost of the five crustal blocks including all of india south of the deccan basalts and godavari rift

clays and other minerals in coal seams of the moura baralaba area bowen basin australia abstract the clays and other minerals in a succession of late permian coals of high volatile bituminous to semi anthracite rank have been identified using low temperature oxygen plasma ashing and x ray diffraction and evaluated to identify the relative roles in mineral matter formation of detrital input early diagenesis in the peat swamp and late diagenesis associated with rank advance although well ordered kaolinite of probable early diagenetic origin is abundant throughout the succession the uppermost and lowermost seams of the sequence regardless of rank contain relatively abundant illite and or interstratified illite smectite along with a small but significant proportion of chlorite these clays are thought to be essentially of detrital origin washed or blown into the peat deposit in relative abundance during the establishment and subsequent overwhelming of an extensive and long lived swampy environment quartz is also abundant in the lower seams of the sequence especially close to the regional sediment source area illite is unusually abundant in the topmost seam in both high and low rank parts of the succession and thus appears to represent detrital input from a particular source material although significant changes are reported in the clays of the associated strata due to rank advance the principal effect of rank advance on the minerals in the coal itself appears to be the development of an ammonium illite and possibly some additional fine grained chlorite in the semi anthracite material isolation within the organic matter of the coal is thought to have inhibited access for ions such as k which might otherwise have become involved in metamorphic reactions and given rise to mineralogical changes commonly found in non coal sedimentary successions

ground motions induced by mining seismic events with different focal mechanisms abstract it is essential to quantify the ground motions induced by seismic events with different focal mechanisms in underground mine to quantitatively calculate the induced ground motions we expressed the motions as the convolution of the seismic source and the wave propagation path using seismological method firstly we investigated the theoretical ground motion patterns using four idealized focal mechanisms results show that the pure compressional failure source and the pure tensional failure source induced the same ground motion patterns the vibrations they induced attenuate extremely fast the pure shear failure source shows closely azimuth related pattern with four quadrants around the source the pure explosive failure source induces vibrations attenuating toward all directions away from the source but the vibrations are not attenuated gradually with the increasing distance then we investigated the ground motions under complicated focal mechanisms using recorded fault slip events cavity collapse events and tensional failure events the fault slip events show a four quadrants ground motion distribution in the horizontal plane and a two quadrants distribution in the vertical plan but the cavity collapse events show a two quadrants distribution in the horizontal plane and a four quadrants distribution in the vertical plane it is concluded that the induced ground motion at a certain location is controlled by the dual effects of the azimuth and the source focal mechanism as well as the distance and the source magnitude

ground rotational motions recorded in near source region of earthquakes large rotational motions excited by earthquakes are recorded during an earthquake swarm of march 1997 offshore ito in izu peninsula japan the largest rotational velocity recorded at kaw is 2 6 10 2 rad s around the north south axis during an earthquake of magnitude 5 2 at 14 09 gmt on march 3 the rotational motions around the vertical axis excited by the largest event is 3 3 10 3 rad s considering a spatial variation of slip velocity which directly relates to excitation of a rotational motion we apply a simple point source model to the largest event and succeed in explaining the observed rotational motion around the vertical axis

fine details of mining induced seismicity at the trail mountain coal mine using modified hypocentral relocation techniques abstract master event and double difference techniques were used to relocate mining induced seismicity mis at the trail mountain mine a longwall coal mine in central utah travel time data were collected by arabasz et al 2002 using a surface seismic network with stations at elevations both above and below mine level because of the topography and a single in mine station arabasz et al 2002 only used surface stations above mine level to determine locations using this network geometry they were only able to constrain focal depths for 321 of 1829 events in contrast we use all stations creating a 3d network hypocentral locations are improved by implementing a master event methodology to reduce the effects of uncertainties in the velocity structure though the resulting locations do not correspond with known structures or stratigraphy the mismatch between the locations and geology is likely due to fracturing of the rock mass by the mining process thereby decreasing the seismic velocity near mined out regions assuming a 10 velocity decrease places the mis in the roof of the mine a double difference procedure is used to mimic a time varying velocity structure the time varying velocity structure results in locations that approximate the dip of the coal seam by using all available stations and allowing for a time varying velocity structure we find the mis is located immediately above the coal seam and closely follows the position of the coalface the epicenters align with the roads along the longwall panel where stress concentrations are expected during mining online material animations of the progression of seismicity along the longwall panel