petrology and thermal maturity of coals in the jharia basin implications for oil and gas origins abstract coals from the karharbari formation early permian the barakar formation early permian and the raniganj formation late permian of the jharia basin have distinctive petrographic characteristics the karharbari formation coals are dominated by inertinite whereas the barakar formation and the raniganj formation coals are vitrinite dominated the vitrinite and exinite content of the jharia basin coals generally increases towards the upper parts of the sequence coal facies analyses based on petrographic composition that the jharia coals were formed from woody peat facies in a fluvial environment the karharbari coals were formed in a predominantly forest swamp condition whereas the lower barakar coals were formed in mixed facies wet dry conditions the middle and upper barakar and the raniganj coals were formed under wet forest swamp conditions high rank permian coals r v max 0 93 1 27 occur near the surface in the jharia basin comparisons of the vitrinite reflectance versus depth profiles from the jharia basin samples with some known reflectance profiles indicate that 2 5 3 5 km of cover was lost in the jharia basin cover loss values extrapolated from a profile matching method show good correlation with those calculated from model temperatures the thermal history of the jharia basin suggests that the permian sections of the basin suffered a major permian triassic thermal event during this time a tensional tectonic regime probably prevailed in india possibly centred in the jharia basin this probably caused extensive subsidence and consequently a thicker sedimentary sequence was deposited in the jharia basin than in the other gondwana basins of india the early permian barakar formation is late mature to overmature this section has a high potential for oil condensate and gas generation although only condensate and gas are likely to be preserved the late permian raniganj formation is mature and the source potential for hydrocarbon generation of this section is assessed as very good however most structures within the jharia basin are probably fractured

cadalenes and norcadalenes in organic rich shales of the permian irati formation parana basin brazil tracers for terrestrial input or also indicators of temperature controlled organic inorganic interactions abstract cadalene isocadalene and a series of norcadalenes were identified in black shales of the permian irati formation in the northeastern and central eastern parana basin brazil the origin of their isomers with an isopropyl substituent is potentially related to higher plants and likely reflects the spreading of pteridophytes and gymnosperms after the glaciation of southern gondwana a general increase in the relative abundance of isocadalene 1 6 dimethyl 3 isopropylnaphthalene the isomer co occurs in with increasing thermal maturity at the base of the amaral machado quarry northeastern basin and refers to the acid catalyzed rearrangement of cadalene 1 6 dimethyl 4 isopropylnaphthalene the isomer due to the presence of montmorillonite via an organic inorganic interaction this localized and incipient maturation can be related to diabase sills of the serra geral formation similar maturation due to heating also affected the distribution of the norcadalenes by thermally stabilizing their isomers with an isopropyl substituent in addition to the formation of related compounds with an ethyl substituent based on this a norcadalene ratio is proposed which is the sum of the 1 6 dimethyl 4 ethylnaphthalene and 1 6 dimethyl 3 ethylnaphthalene over the sum of the 1 isopropyl 4 methylnaphthalene and 1 isopropyl 7 methylnaphthalene the results of this ratio and the established cadalene ratio resemble each other whereas samples from the sao mateus do sul quarry central eastern basin were not affected by thermal maturation and are characterized by a uniform distribution of the cadalenes and norcadalenes

properties origin and nomenclature of rodlets of the inertinite maceral group in coals of the central appalachian basin u s a abstract resin rodlets sclerenchyma strands and woody splinters which are collectively called rodlets were studied by chemical optical petrographic and scanning electron microscopic sem techniques a study was made of such rodlets from the bituminous coal beds of the central appalachian basin pennsylvanian upper carboniferous of the united states comparisons were made with rodlets from coal beds of the illinois basin the southern anthracite field of pennsylvania the st rose coal field of nova scotia and european and other coal fields in order to determine their physical and chemical properties a detailed study was made of the rodlets from the pomeroy coal bed high volatile a bituminous coal monongahela formation upper pennsylvanian of kanawha county west virginia the origin of the rodlets was determined by a comparative analysis of a medullosan seed fern stem from the herrin no 6 coal bed high volatile c bituminous coal carbondale formation from washington county illinois rodlets are commonly concentrated in fusain or carbominerite layers or lenses in bituminous coal beds of the central appalachian basin most of the rodlets examined in our study were probably derived from medullosan seed ferns the three types of rodlets are distinguished on the basis of cellularity morphology and fracture the resin rodlets studied by us are noncellular and appear to be similar in properties and origin to those found in coal beds of the middle and upper pennsylvanian of the illinois basin the resin rodlets extracted from the pomeroy coal bed exhibit high relief and high reflectance when polished and viewed in reflected light they are opaque in transmitted light in cross section the resin rodlets are oval to round and have diameters ranging from 60 to 450 m many are solid but some have vesicles canals or cavities which are commonly filled with clay probably kaolinite typically they have distinct fracture patterns kerfs in longitudinal and cross sections and many are characterized by dense probably oxidized rims the orientation and amounts of void space and mineralization of resin rodlets in coal have resulted in much confusion in their recognition and classification the resin rodlets are petrographically recognized as sclerotinites of the inertinite maceral group we here propose that resin rodlets be assigned to the maceral variety of sclerotinites termed resino sclerotinite because of their presumable resinous origin other investigators have confused some fusinitized resin rodlets with fungal masses which have different morphological properties and which probably have different chemical properties we here propose that such fungal masses be assigned to the maceral variety of sclerotinites termed fungo sclerotinite the sclerenchyma strands examined in our study are cellular thick walled and crescent shaped in cross section they exhibit high reflectance and high relief and belong to semifusinite and fusinite of the inertinite maceral group sclerenchyma strands are commonly associated with resin canals in medullosa and related seed fern genera which are common in coal balls of the illinois basin we here propose adoption of the maceral varietal terms sclerenchymo fusinite and sclerenchymo semifusinite for these bodies the woody splinters in the pomeroy coal bed are cellular and thin walled and have scattered pits as much as a few microns in diameter they are dark brown to black in transmitted light and commonly have a lower reflectance than the resino sclerotinite and sclerenchymo fusinite of the pomeroy coal the woody splinters belong to semifusinite and fusinite of the inertinite maceral group the maceral varietal terms xylemo semifusinite and xylemo fusinite are here proposed for these bodies elemental chemical data for the resin rodlets of the pomeroy coal bed of the central appalachian basin indicate that resin rodlets have significantly lower atomic h c and o c ratios than do sclerenchyma strands and woody splinters the lower atomic h c and o c ratios of the resin rodlets correlate with the highest reflectance in the coal ball medullosan seed fern stem from the herrin no 6 coal bed of the illinois basin the reflectances of the resin rodlets woody splinters and sclerenchyma strands are similar and comparable to those of associated vitrinite in the coal ball stem and in the attached coal however resin rodlets and sclerenchyma strands in the attached coal have significantly higher reflectances similar to those of the pomeroy coal

influence of soil cover on reducing the environmental impact of spontaneous coal combustion in coal waste gobs a review and new experimental data abstract the process of spontaneous combustion of coal and coal waste gobs including emitted gases condensation of inorganic and organic species in vents and leachable potential are examined in this study which encompasses a literature review and new experimental data furthermore the potential environmental benefits of cover soil reclamation for reduction of atmospheric and water leachable pollutant emissions are also considered the datong district shanxi province is one of the most important coal production areas in china the resulting large accumulations of mining waste are susceptible to spontaneous combustion three coal gangue dumps in the datong region subjected to a range of reclamation conditions were investigated to assess the influence on coal fires coal coal gangue and condensates from gaseous emissions were characterized in terms of chemical composition particle morphology mineralogy and leaching potential the condensates include tar like deposits elemental sulfur gypsum anhydrite ammonium and hg salts and a broad array of al k fe sulfates the latter may give rise to strongly acidic leachates with high metal loads which may pose a serious threat to the environment these findings led to the development of a proposed condensation sequence model for coal gangue fires the presence and distribution of organic compounds in the condensates deposited at vents were used as geothermometers in support of the proposed condensation model additionally the present study has also explored some feasible remediation measures it was found that covering these coal waste dumps with a layer of compacted soils appears to be an excellent cost effective method to reduce spontaneous combustion scavenge pollutants from gaseous emissions and minimize risks associated with the leaching of readily soluble salts condensed on the surface

association between atmospheric circulation patterns and firn ice core records from the inilchek glacierized area central tien shan asia 1 glacioclimatological research in the central tien shan was performed in the summers of 1998 and 1999 on the south inilchek glacier at 5100 5460 m a 14 36 m firn ice core and snow samples were collected and used for stratigraphic isotopic and chemical analyses the firn ice core and snow records were related to snow pit measurements at an event scale and to meteorological data and synoptic indices of atmospheric circulation at annual and seasonal scales linear relationships between the seasonal air temperature and seasonal isotopic composition in accumulated precipitation were established changes in the 18o air temperature relationship in major ion concentration and in the ratios between chemical species were used to identify different sources of moisture and investigate changes in atmospheric circulation patterns precipitation over the central tien shan is characterized by the lowest ionic content among the tien shan glaciers and indicates its mainly marine origin in seasons of minimum precipitation autumn and winter water vapor was derived from the arid and semiarid regions in central eurasia and contributed annual maximal solute content to snow accumulation in tien shan the lowest content of major ions was observed in spring and summer layers which represent maximum seasonal accumulation when moisture originates over the atlantic ocean and mediterranean and black seas

the lower permian coal seams from singrauli coalfield m p india petrochemical nature rank age and sedimentation abstract biopetrographic and chemical investigations carried out on the lower permian barakar formation coal seams encountered in two bore holes ncsm 3 and cmsa 111 from the singrauli coalfield son valley reveal that they are in general rich in inertinite and mineral matter towards the eastern part whereas towards the western part they are rich in vitrinite with subordinate amounts of inertinite and mineral matter the turra and purewa top seams in the eastern part consist chiefly of mixed and fusic coal types and the turra and purewa merged seams in the western part of the basin are characterized dominantly by vitric and mixed coal types the basin of deposition was shallower in its major part but deepened towards west consequently frequent oxic fluctuations are most common in the coal seams of the eastern part the rank of these coal seams ranges between subbituminous a to high volatile bituminous c stages they show normal increase in rank with depth the coal seams in the western part of the area are higher in rank than their counterparts in the east the purewa bottom seam ncsm 3 is petro palynologically correlatable with the turra seam cmsa 111 of the western part it has been presumed that glossopteridophyta a complex group of gymnospermous plants arthrophytes and ferns were the vegetal source for the formation of barakar coal seams these plants during the early permian grew as thick forests along river valleys and as upland and subaquatic vegetation and experienced a warm humid and windy temperate climate the coal seams were presumably deposited in backwater and lacustrine swamps in fluvial environment from hypoauchthonous source material an attempt has been made to explain reasons for the high incidence of mineral matter and its apparent relationship with inertinite content in the coal seams while also discussing the depositional history

the backpit seam sydney mines formation nova scotia a record of peat accumulation and drowning in a westphalian coastal mire abstract extensive westphalian d to stephanian coal seams divide the sydney mines formation of cape breton island into large scale repetitive sedimentary packages the backpit seam one of the most continuous seams within this formation was studied in detail to establish compositional trends and relate these to paleomire development within an overall transgressive setting the seam is of high volatile b to a bituminous rank and ranges in thickness from 0 6 to 1 5 m onshore agglutinated foraminifera occur in strata directly below and above the seam indicating a coastal setting for the mire ash and sulphur contents average 15 3 6 and 5 2 2 respectively sulphur predominantly in the form of pyrite increases near the roof of the seam consistent with a brackish influence in the roof strata the planar backpit mire was subjected to widespread periodic flooding marked by thin dull to coaly shale lithotype intervals some intervals can be correlated across the onshore portion of the basin for more than 45 km and this distribution suggests regional controls on their formation seam lithology changes frequently in vertical section and banded lithotypes predominate vitrinite macerals and vitrinite rich microlithotypes are abundant and thin discrete fusain bands the remains of ancient fires are also common coal facies patterns record a series of wetting upward pulses in the upper portion of the seam that culminated in the drowning and termination of the mire a broad relatively shallow embayment subsequently formed that supported a fresh to brackish water fauna

coal and oil shale of early carboniferous age in northern canada significance for paleoenvironmental and paleoclimatic interpretations abstract lower carboniferous mississippian coal beds and oil shale occur at several locations in northern canada in the northern yukon territory coal of semi anthracite anthracite rank r 0 max 2 72 4 03 occurs in the kayak formation in the british mountains and at hoidahl dome near the headwaters of blow river farther south in the liard basin northwest territories coals of high volatile bituminous rank r 0 max 0 67 0 80 are known to occur in the mattson formation in the arctic islands thicker beds of the emma fiord formation the oldest unit in the sverdrup basin contain thin coal seams and oil shale on devon island near the southern edge of the basin and on axel heiberg and ellesmere islands on the north side of the basin organic matter in the devon island section is at a low maturity level r 0 m 0 26 0 50 whereas that from ellesmere and axel heiberg has reached the level of meta anthracite r 0 max 5 0 depositional environments for these carbonaceous sediments were different the coal bearing kayak strata accumulated in a coastal plain setting overlain transgressively by younger marine beds the mattson coal beds appear to have formed in a prograding delta but coal and oil shale in the emma fiord were deposited in lacustrine environments in a rift basin these canadian occurrences resemble penecontemporaneous deposits in svalbard and elsewhere adjacent to the present day arctic ocean they formed at low latitudes where conditions were favourable for the preservation of carbonaceous matter prior to the opening of the arctic ocean basin in mesozoic times sites of the mainland were undoubtedly closer to sites in the arctic islands than they are today

δ2 triterpenes early intermediates in the diagenesis of terrigenous triterpenoids a series of 2 triterpenoids oleana 2 12 diene oleana 2 13 18 diene oleana 2 18 diene ursa 2 12 diene and taraxera 2 14 diene has been identified in holocene buried mangrove sediments florida usa by comparison of the mass spectra of and by co injections with authentic standards in the oligocene brandon lignite vermont usa oleana 2 12 diene and oleana 2 13 18 diene were also identified along with two a ring contracted amyrin derivatives by comparison with the sedimentary occurrence of related analogues of oxyallobetulin and betulin and the demonstrated diagenetic formation of lup 2 ene from lupan 3 one these novel terrigenous biological markers are considered diagenetic products formed by dehydration of precursor molecules such as and amyrin and taraxerol the identification of these early intermediates brings us one step closer to the full understanding of the diagenetic fate of terrigenous triterpenoids

the genesis of coal from the viewpoint of coal petrology abstract the genesis of the microscopic constituents of coal macerals and of maceral associations microlithotypes representing various coal facies is discussed in the light of recent advances that have been made in the study of coals and modern peats peat microscopy especially promoted the understanding of humification and biological gelification both of which are decisive for the genesis of huminites vitrinites in brown coals and hard coals respectively microbial activity during peatification has been documented by chemists microbiologists and petrologists and recently by electron microscopical observations in coals this activity leads to the incorporation of lipid substances into the humic matter and later influences the chemical physical and technological properties of vitrinites geochemical gelification transforms the huminites of brown coals into the vitrinites of bituminous coals and is probably caused by the onset of bitumen generation in coal in this process the hydrogel brown coal is transformed to the bitumogel bituminous coal coal as a source rock for oil has become an important research subject for coal petrologists and oil exploration the formation of more or less liquid bitumen and its later cracking to gaseous hydrocarbons leads to the coalification jumps of the macerals especially liptinites and vitrinites and to the generation of secondary macerals like exsudatinite bitumen and micrinite dead carbon bituminization in coal has been revealed by the use of fluorescence microscopy which also found the presence of new liptinite macerals bituminite fluorinite and exsudatinite and suggests a higher proportion of algal material in coals than was thought earlier the genesis of various types of inertinite macerals will probably become an increasingly important subject of research especially with regard to rank inertinites that seem to attain their high inertinitic reflectance initially during coalification besides the origin of macerals the origin of various coal facies in terms of maceral associations is considered in relation to the palaeogeographic depositional milieu the peat forming vegetation palaeoclimate water and nutrient supply acidity marine and calcareous influence and fire with examples from euramerican carboniferous coals gondwana coals and tertiary brown coals vegetation water and oxygen supply eh conditions are most important for the generation of coal facies vegetation has been reconstructed with the help of palaeobotany including palynology cuticular analysis and wood anatomy in brown coals and with the study of petrified permineralized peats preserved in coal balls the microscopical investigations of botanically recognizable plant remains isolated from coals or accompanying rocks has been especially informative however the results of palynological and cuticular analyses should be evaluated with caution considering the varying resistance of palynomorphs and cuticles and in the case of palynomorphs their possible extrapaludal origin microscopical studies of modern peats that were derived from different types of vegetation growing in different hydrological environments have been very helpful in interpreting coal facies especially in brown coals the much disputed origin of brown coal lithotypes is considered in detail for hard coals there seems to be agreement that coal layers rich in vitrites and liptinite poor clarite were deposited in wet forest swamps that microlayered liptinite rich clarites are sub aquatic humic muds and that inertinite rich durites represent oxidized peats the origin of liptinite rich durites is controversial either subaquatic muds or oxidized peats the latter perhaps from raised bogs a recent trend in the literature is the assumption that many if not all mineable coal seams have been deposited in raised bogs under ombrogenous oligotrophic conditions although raised bogs with a dense arborescent vegetation are known from borneo it seems not probable that most seams which were deposited in foredeeps or steadily sinking graben zones are of ombrogenous origin although a succession from relatively wet and eutrophic to relatively dry and oligotrophic conditions may be true for occasional seams but as in modern peats striking changes of coal facies are commonly caused by hydrological events e g inundations as a consequences of crevasses or of fires that burned the peat the origin of the inertinite rich gondwana coals is discussed in relation to their specific climatic conditions and a comparison with sub arctic peats is recommended coals influenced by marine and calcareous conditions are characterized by high contents of sulfur and pyrite as well as by hydrogen rich vitrinites with a relatively low reflectance and high fluorescence all due to a strong bacterial activity in peats of low acidity proposals for further research are made in the conclusions

spontaneous combustion of the upper paleocene cerrejon formation coal and generation of clinker in la guajira peninsula caribbean region of colombia abstract clinker referred here as red and brick looking burnt rocks found interbedded in the upper paleocene cerrejon formation is the result of spontaneous and natural combustion of coal seams in the recent geologic past these rocks have been mapped measured and characterized in the cerrejon coal mine at la guajira peninsula colombia these burnt rocks usually outcrop in irregular patterns as almost tabular bodies up to 100 m thick thinning and pinching out below ground surface to depths up to 448 m mapping revealed that clinker is usually found near deformed zones either faults or tight folds timing of spontaneous combustion seems to predate folding and faulting but seems to postdate the development of the cerrejon thrust fault and alluvial fan proceeding from the perija range clinker covers an area of around 2 9 10 6 m 2 with a volume of approximately 1 4 10 8 m 3 the calculation of the amount of heat released through coal burning indicates that complete combustion of 6 4 mt of 26 4 10 6 j kg coal would yield 17 10 13 j

variation in quartz arenite deformation mechanisms between a roof sequence and duplexes abstract microstructural abundances and histories in quartz arenite of the lower silurian tuscarora sandstone were used to determine the nature and role of microscale deformation in a cover sequence and underlying thrust system and to assess the degree to which the cover sequence accommodated emplacement of the thrust system sandstone samples are located across the transition from the central to southern appalachian foreland thrust system where the thrusts change from blind to emergent southwards and where southern deformation of early alleghanian age has been previously shown to be overprinted by central deformation of alleghanian age microstructures observed with transmitted light and cathodoluminescence microscopy indicate that grain scale deformation occurred by dislocation flow pressure solution and microfracturing with the last being generally the most important the sequence of deformation mechanisms is the same for the cover sequence and the thrust system pressure solution during sedimentary compaction dislocation flow during layer parallel shortening and localized microfracturing with limited pressure solution near major thrust ramps and in steep fold limbs a greater abundance of dislocation flow microstructures in the cover sequence from layer parallel shortening indicates grain scale accommodation in the tuscarora sandstone of some shortening associated with emplacement of the thrust system the transition zone between the central and southern appalachians contains the greatest occurrence of every microstructure which is consistent with the area having been affected by diachronous central and southern alleghanian deformations

fold axis parallel rotation within the laramide derby dome fold wind river basin wyoming usa abstract derby dome a doubly plunging anticline 7 3 km on the eastern flank of the wind river range wyoming trends nw se in response to the regional ne sw directed shortening of the cretaceous eocene laramide orogeny mesozoic sediments are exposed around the fold hinge above an east dipping thrust fault that offsets archean crystalline rocks at depth stress and strain ellipsoidal data were determined through the measurement of mechanically twinned calcite in limestones triassic alcova through j k morrison formation rocks 13 samples calcite cements 5 samples and synfolding calcite veins 16 samples around the northern half of the fold on the outer limbs of the fold the maximum shortening strain axis 3 5 15 nevs in the limestones and cements is sub horizontal layer parallel and normal ne sw to the fold hinge reflecting regional sevier laramide shortening this regional layer parallel strain fabric is rotated into a fold axis parallel orientation nw se near the fold hinge indicating that significant rotations occurred during folding synfolding calcite veins of varying orientations also preserve a local sub horizontal hinge parallel shortening strain 4 0 17 nevs suggesting that the regional laramide stress and strain field was locally rotated into parallelism with the fold during shortening and displacement on the underlying thrust fault in both the country rock cement and vein data sets the strain overprint noise nevs increases toward the fold hinge inferred differential stress magnitudes are also higher for the vein calcite than for the country rock limestones or cements and there is no interpretable pattern around the fold avg 560 bars range of 240 2000 bars fracture measurements n 74 in different lithologies have different orientations on each side of the adjacent dallas dome fold suggesting layer parallel rotation during folding or active fracturing occurred uniquely on each fold limb

burning of coal waste piles from douro coalfield portugal petrological geochemical and mineralogical characterization abstract in the douro coalfield anthracites were exploited for decades 1795 1994 besides many small mines douro coalfield had two principal mining areas s pedro da cova and pejao coal mining activities cause several impacts on the environment one of which is the amount of discard or waste which was disposed of all over douro coalfield resulting in one of the most significant and severe impacts on the environment over 20 waste piles exist in the old mining areas geographically dispersed and three of them are presently burning their ignition was caused by forest fires during the summer of 2005 samples from the burning and unburned zones of the waste piles were studied as were the gas from vents and the minerals resulting after combustion geochemical processes and mineralogical transformations in the burning coal waste pile were investigated microscopic analyses of the samples identified some particular aspects related with combustion oxidation of pyrite the presence of iron oxides organic particles with cracks and rims with lowered suppressed rr devolatilization vacuoles and some char structures the occurrence of vitreous glassy material as well as fe al spinels in the burning coal waste provide evidences that the combustion temperature could have reached values above 1000 c due to combustion and as expected the samples studied reported high ash yields samples taken from the burning zones reported an increase of as cr li nb ni pb rb sr and lree concentrations and a decrease in zr and hree concentrations enrichment in cs li and rb was noted when comparing with the geochemical composition of black shales and world coals composition that is related with the contribution of granitic rocks in the sediments that originated the main lithologies of the douro coalfield carbonaceous shale and lithic arenites cluster analyses r type and q type were performed to understand the trend between the unburned and burning samples and it seems that some chemical variations are responsible for this separation elemental sulphur and salammoniac ammonium salt are the coal fire gas minerals neoformed on the surface of piles near the burning zones they were identified by different techniques mainly sem edx xrd and ftir relatively high concentrations of several aromatic compounds were detected in the gas collected at the studied areas as well as aliphatic hydrocarbons the highest concentrations of aromatic hydrocarbons were measured in gas samples from s pedro da cova waste pile the exposure to hazardous compounds present in the gas is a serious risk to human health and the environment

a multiscale methodology for the analysis of velocity anisotropy in organic rich shale abstractchanges in the sources of velocity anisotropy and their relative magnitude as maturation progresses in organic rich shale are still incompletely characterized in the rock physics literature as a result of the increasing importance of organic rich shale as unconventional reservoirs a more thorough understanding of the elastic behavior of shale is needed we have formulated a comprehensive multiphysics multiscale experimental methodology for the characterization of the intrinsic syn lithification and extrinsic postlithification factors contributing to velocity anisotropy application of this methodology to unsaturated samples also enabled the characterization of the shale frame for fluid substitution modeling the methodological framework was then tested on a set of five naturally matured organic rich shale samples in this experimental methodology we combined classical rock physics measurements e g ultrasonic velocity and emergent high resolution imaging techniques such as x ray diffra

molecular characterization of fossil and extant dammar resin extracts insights into diagenetic fate of sesqui and triterpenoids abstract the composition of sesquiterpenoids and triterpenoids in the solvent extract of extant miocene and eocene dammar i e class ii resins has been determined and compared to investigate the vulnerability of these biomarkers to diagenesis molecular evidence e g absence of bicadinanes and low rock eval maturity values tmax

petrographic examination of low rank coals from saskatchewan and british columbia canada including reflected and fluorescent light microscopy sem and laboratory oxidation procedures the response to oxidation of eight coals of lignite and subbituminous rank from saskatchewan and hat creek british columbia was studied by means of maceral distribution fluorescence and scanning electron microscopy sem the oxidizing agent used was schulze s solution with some modification of reaction time from that normally employed in palynological maceration these eight samples were chosen to represent different macroscopically described lithotypes maceral analysis indicates that the huminite macerals behave differently when oxidized densinite seems to be the most susceptible to destruction along with gelinite humotelinite eu ulminite and texto ulminite is more resistant and in four of the eight samples shows a slight increase in concentration oxidation increases the relative content of liptinite along with some of the inertinite macerals fusinite and semifusinite among the liptinite macerals resinite appears to be preferentially concentrated suggesting that the modified oxidation pr

microfractures and their role in deformation of a quartz arenite from the central appalachian foreland abstract microfractures are pervasive in the massanutten sandstone a quartz arenite exposed in a doubly plunging synclinorium in the central appalachian foreland they are present as fluid inclusion planes fips and microveins parallel the fips fips occur in three orthogonal sets horizontal vertical and normal to the fold axis and vertical and parallel to the fold axis the geometry distribution and age of fips relative to other microstructures shows that microfractures developed during folding microfracturing followed layer parallel shortening by dislocation flow and was coeval with the peak of pressure solution that marked the final stages of folding microfracture densities are extremely high 160 mm 1 in many samples rapid closure of microfractures suppressed brecciation and prevented microfractures from propagating unstably to form joints microfracture opening accounts for significant finite strain with extensional strains of up to 11 1 and associated volume increases of over 16 0 the general lack of shortening microstructures indicates that a net volume increase is likely and that the massanutten sandstone may have served as a sink for dissolved phases from adjacent units undergoing volume loss deformation

strain paths of three small folds from the appalachian valley and ridge maryland structural analysis indicates that for a given set of conditions subtle differences in layer configuration and rheology can result in major differences in fold kinematics we studied three hand sample scale folds from the maryland valley and ridge province in an effort to understand the accommodation of folding on meso and microscopic scales and to constrain the deformation histories of the folds sampled two single layer folds and one multilayer fold were taken from two nearby outcrops of the wills mountain anticline and are therefore interpreted to have developed under virtually identical pressure and temperature conditions although all three folds are dominated by carbonate material structural fabrics are unique for each fold indicating rheological contributions to and local structural control of fabric development both single layer folds have asymmetric vein distributions that are consistent with strain directions expected from asymmetric flexural flow slickenlines on one sample and cleavage in an adjacent layer in the other sample support this interpretation the first of these folds appears to have undergone late stage hinge tightening as evidenced by the development of crosscutting bed normal stylolites in contrast veins stylolites and the intracrystalline deformation in the multilayer fold are suggestive of symmetric tangential longitudinal strain followed by heterogeneous sub horizontal flattening the three folds are interpreted to be buckle folds with differing mechanisms accommodating strain within the competent layers

petrological chemical and depositional aspects of eastern himalayan coals from elephant flat area kameng district arunachal pradesh india abstract the eastern himalayan coals of india associated with permian lower gondwana sediments in the kameng district of arunachal pradesh have petrographic and chemical properties differing from peninsular permian coals the coals are moderately to highly crushed and have reached a semianthracitic stage macerals are highly reflecting and homogenized vitrinite and inertinite exhibit a crushing effect in the form of criss cross fissures and cracks exinite is unidentifiable and has attained an inertinitic reflectivity the kameng coals are of high rank with average fixed carbon 88 75 and volatile matter 13 75 on d a f basis the reflectance values ro max 2 02 2 31 in oil of these coals are quite high with marked anisotropy it is inferred that these peculiar coal properties have been attained due to prolonged tectonic disturbance in the area during the later himalayan orogeny the coal characteristics suggest that these coals were formed in a humid tropical climate within a deltaic regime the depositional site experienced occasional marine influx due to tectonically controlled subsidence during peat accumulation

susceptibility to spontaneous combustion of indian coals and lignites an organic petrographic autopsy abstract a critical analysis of various genetic and physical factors associated with certain early and late permian and oligocene coal seams and early eocene lignite seams of india revealed that the high secondary porosity and small particle size irrespective of petrographic and rank properties in sub humid climate favour spontaneous combustion large particle size high rates of gas emission and highly wet or dry seams in combination with each other tend to inhibit spontaneous heating in sub humid per humid and semi arid conditions the susceptibility to auto ignition of a coal or lignite seam is not uniform throughout its lateral extent and a high inherent porosity at any given rank stage and a high content of susceptible or oxidizable constituents are not sufficient to cause auto ignition however coal seams having high contents of exceedingly porous inertinite macerals become prone to spontaneous combustion in sub humid climate even without secondary porosity a scheme for indexing spontaneous combustion susceptibility based on the present study has been proposed which is particularly suited to the indian context

calcite twin analysis in syntectonic calcite cape fold belt south africa implications for fold and cleavage formation within a shallow thrust front abstract lithologies of two formations in the frontal ranges of the cape fold belt south africa host synorogenic calcite precipitated at low metamorphic grade during the end permian deformation of this gondwana wide orogen the calcite crystals are mechanically twinned and this deformation is linked to both folding and the formation of an axial planar cleavage with associated extensional veins twinning strain analysis reveals a complex rotational synfolding history in the upper thin layered prince albert formation twinned calcite within the fold preserves two unique strain events the primary shortening strain fabric is layer parallel and transport parallel north south the shortening strain overprint 5 82 is layer normal and plunges steeply to the northeast these results are inconsistent with a flexural slip folding mechanism by contrast a homogeneous syn cleavage stress strain field is recorded in the underlying massive thick bedded dwyka tillite analyses of calcite twins in clast hosted syn cleavage fibrous calcite and rare limestone clasts define a sub horizontal n s shortening and sub horizontal e w extension the intermediate axis e 2 is vertical and preserves shortening 5 3 the extension axis e 3 is horizontal and parallel to the clast tension gash fracture plane these deformed syn cleavage calcite materials provide an independent constraint to the debate about contemporaneous stress strain fields associated with folding and formation of an axial planar cleavage

maceral distribution in garumnian coals and palaeoenvironmental implications in the central pyrenees spain abstract the organic content of garumnian coals in the central pyrenees of spain is heterogeneous and is formed of plant fragments with the fossil remains of botanic structures and secondary products resulting from thermal and biochemical transformation of macerals the maceral composition of the three areas studied berga tremp and ager is similar the berga and tremp zones include an upward decrease in organic materials and the top sequence is significantly richer in inorganic sediments in contrast in the ager zone only one level with organic matter is present the organic matter of the tremp formation is humic and five resinite groups have also been characterized the mineral phases determined mainly carbonates appear closely associated with macerals infilling cell lumens or replacing cell walls and in layers within the organic matter the maturity and source rock potential of the organic rich beds were investigated using reflected light and fluorescence microscopy the results are compared with other maturity parameters rock eval calorific value and diagenetic mineral matter the vitrinite reflectance r o 0 35 0 45 and the maximum temperature 430 c are low and homogeneous in the different areas these values indicate that the rank of the samples corresponds to an immature diagenetic state close to the lower oil window and allows classification of this coal as subbituminous the relationship between inorganic and organic phases indicates low grade transformation as a consequence of a low lithostatic pressure the macerals indicate that the coal forming peat was deposited in a predominantly forest moor swamp environment the liptinite assemblage suggests a subtropical and damp dlimate during peat deposition the amount of organic matter decreases upwards within the sedimentary sequences analyzed palaeoenvironments were similar in the three areas which could originally have been part of the same basin

finite element models of buckle folds in non linear materials abstract buckle fold development in single layers has been simulated by means of a two dimensional finite element model incorporating incompressible power law viscous fluids we have produced folds with the stiff layer initially parallel to and oblique to the bulk maximum shortening direction and investigated how fold growth rates and geometry vary as functions of viscosity ratio and power law exponent results for single layer buckling and the related instabilities of boudinage mullions and inverse folding closely match theoretical predictions in terms of initial growth rates which depend strongly on the power law exponent the results further show that the fold shape is sensitive to changes in the power law exponent of the stiff layer the most striking feature is that the fold hinges become sharper and the limbs become relatively longer and straighter as the exponent increases asymmetry of folding can arise in bulk pure shear models of asymmetric folds with inclinations of the stiff layer of up to 30 have been made the results indicate that initial growth rates are independent of the inclination of the stiff layer results of this work suggest that a number of geometrical properties of folds may be useful in providing information on the rheological behavior of rocks deformed under very slow natural conditions

comparison of the petrography palynology and paleobotany of the stockton coal bed west virginia and implications for paleoenvironmental interpretations abstract the stockton coal bed middle pennsylvanian is a relatively high ash coal composed primarily of moderately thin banded sparsely thin banded and nonbanded coal splint and cannel coal comparisons of petrographic palynologic and paleobotanic data gathered from the same sample sets from a single column of the stockton coal bed indicate that compositional correspondences among the sets exist regardless of coal type some correspondences are believed to exist because of original plant constituents and others because of the paleoenvironment of peat formation using some combination of these data is critical when interpreting paleoenvironmental conditions because 1 a direct correspondence is lacking between many of the data and 2 each of the three data sets provides a unique and important perspective on the paleomire the stockton paleomire in the area of this study supported a diverse flora that consisted of both small and arboreous lycopsids small ferns and tree ferns calamites cordaites and pteridosperms there appear to have been two successions of lycospora spore dominated vitrinite rich liptinite poor peat formation which were followed by inertinite rich peat formation marked by a tree fern dominant spore assemblage and abundant unidentifiable plant tissues these are interpreted to be two water laden or topogenous peat formational stages followed by slightly domed better drained peat formation

cyclic terpenoids of contemporary resinous plant detritus and of fossil woods ambers and coals abstract cyclic terpenoids present in the solvent extractable material of fossil woods ambers and brown coals have been analyzed the sample series chosen consisted of wood remains preserved in holocene to jurassic sediments and a set of of ambers from the philippines copalite israel canada and dominican republic the brown coals selected were from the fortuna garsdorf mine and miocene formations on fiji the fossil wood extracts contained dominant diterpenoid or sesquiterpenoid skeletons and aromatized species were present at high concentrations with a major amount of two ring aromatic compounds tricyclic diterpenoids were the predominant compounds in the ambers aromatized derivatives were the major components consisting of one or two aromatic ring species with the abietane and occasionally pimarane skeletons the saturated structures were comprised primarily of the abietane and pimarane skeletons having from three to five carbon c1 c2 etc substituents kaurane and phyllocladane isomers were present in only minor amounts bicyclic sesquiterpenoids as saturated and partial or fully aromatized forms were also common in these samples but only traces of sesterterpenoids and triterpenoid derivatives were found the brown coal extracts were composed of major amounts of one and two ring aromatized terpenoids with a greater proportion of triterpenoid derivatives than in the case of the woods and ambers this was especially noticeable for the german coal where the triterpenoids were predominant open c ring aromatized structures were also present in this coal steroid compounds were not detectable but some hopanes were found as minor components in the german brown coal an overview of the skeletal structure classes identified in each sample as well as the general mass spectrometric characteristics of the unknown compounds are included in the present paper it can be concluded from these structural distributions that aromatization is the main process for the transformation of terrestrial cyclic terpenoids during diagenesis constituting a general pathway for all terpenoids

occurrence of polycadinene in fossil and recent resins abstract dammars produced by dipterocarpaceae growing in southeast asia are partly composed of a macromolecule with a polycadinene structure this polymer is the precursor of many specific compounds encountered in crude oils and sediment extracts from south asia until recently there was no evidence for a more widespread geographical occurrence of this resinous polymer using different pyrolysis methods it is shown that the polymers present in a resinite from utah usa and in resins contained in resin canals of eocene fossil fruits from germany and england are also polycadinenes the fossil fruits were undoubtedly produced by ancient representatives of mastixioid cornaceae a group of plants which was widespread in the tertiary of europe and north america and which is not related to dipterocarpaceae these findings extend the known occurrence and origin of the sesquiterpenoid type resin polymer it is to be expected that catagenetic products of these resin polymers should be present in oils coals and sediment extracts from areas outside southeast asia

environmental characterization of burnt coal gangue banks at yangquan shanxi province china the environmental characteristics of coal gangue dumps in yangquan shanxi province china were investigated the amounts of coal gangue are very high in this coal region given the large coal production as a result widespread spontaneous coal gangue combustion gives rise to serious environmental problems coal gangue including bulk gangue and specific lithologies such as coal kaolinite rich material sandstone carbonate minerals and sulfide mineralizations fired coal gangue and condensate products from gas vents were fully characterized with respect to mineralogy chemistry and leaching potential the mineral paragenesis of the fired coal gangue cristobalite mullite hematite trydimite cordierite showed that the combustion temperature could reach 1200 c this was also corroborated by laboratory calcination tests during this combustion some elements such as c cl f s n as cd hg pb sn ge and se are emitted into the atmosphere however condensation processes accounted for the partial trapping of gaseous emissions of as s n hg and se thus condensate mineralizations of elemental sulfur and ammonium salts enriched in se as and other trace elements are frequent in the gas vents the leaching potential of trace elements in the fresh coal gangue was relatively low but the leaching of weathered coal gangue and the gas vents condensates could give rise to environmental problems as these materials produce acidic leachates and yield relatively high leachable levels of a number of elements

petrology palynology and organic geochemistry of eocene lignite of matanomadh kutch basin western india implications to depositional environment and hydrocarbon source potential abstract petrological palynological and organic geochemical investigations were undertaken to determine the source vegetation depositional conditions and hydrocarbon source potential of eocene matanomadh lignites from kutch basin western india the maceral study reveals that studied lignites are rich in huminite av 63 with sub ordinate amount of liptinite av 19 and low inertinite av 3 along with low to moderately high associated mineral matters av 15 the overall petrographic composition points to a lagoonal condition for the formation of these lignites the mean huminite reflectance values r r 0 28 0 34 av 0 31 as well as low rock eval t max av 417 c values for the seams suggest brown coal or lignitic stage rank for the studied lignites the palynological assemblages dominated by tropical angiospermic pollen suggest prevalence of warm humid tropical climate during the deposition of these lignites the total organic carbon toc content of lignites ranges between 26 and 58 wt whereas the toc content of the associated carbonaceous shales is around 4 wt the hydrogen index hi ranging from 23 to 452 mg hc g toc indicates that the lignite sequence has the potential to produce mixed oil and gaseous hydrocarbons on maturation the major pyrolysis products of lignites derived from curie point pyrolysis gc ms are straight chain aliphatics phenols and cadalene based c 15 bicyclic sesquiterpenoids the exclusive occurrence of c 15 bicyclic sesquiterpenoids suggests that these compounds are derived from dammar resin of angiosperm plants belonging to family dipterocarpaceae

terpenoids in surface soils from different ecosystems on the tibetan plateau abstract realizing the potential of terpenoid biomarkers as an unequivocal land ecosystem and floral diversity indicator calls for work to establish a direct link between the terpenoids extracted from the plants and those found in the underlying soils to this end we have characterized the triterpenoid profile of soils and vegetation along two altitudinal transects representing very different ecosystems the first transect comprising 31 sample sites was on the eastern slopes of mt gongga eastern tibetan plateau rising from 1230 m to 4500 m above sea level an area with a temperate monsoonal climate the second transect sampling 29 sites was on the northern slopes of mt west kunlun a region characterized by montane desert meadow and alpine steppe located between 1300 m and 5050 m above sea level the dominant terpenoid biomarkers polycyclic triterpenoids of the taraxerane oleanane friedelane ursane lupane glutinane and lanostane series identified in the soils were found to be consistent with the overlying vegetation however the discovery of some unusual triterpenoids including the pentacyclic triterpene 3 methyl ethers ptmes d a friedo 2 3 secoolean 2 3 dioic acid methyl 3 acetoxylup 20 29 en 28 oate 24 methylenecycloartan 3 one 9 19 cyclolanostan 3 yl 24 methylene acetate 3 methoxy 9 lanosta 7 24 dien 26 23 olide and 3 methoxy 9 lanost 7 en 26 23 olide in the gongga soils does not match the current vegetation and may be indicative of a long vanished forest type vegetation thus soil biomarkers may be a useful tool in the reconstruction of palaeo vegetation

the role of fluids in low temperature fault related deformation of quartz arenite abstract the microstructural and fluid histories in quartz arenite deformed in a regional scale fault zone were investigated to determine the role of fluids in the selection of grain scale deformation mechanisms using cathodoluminescence fluid inclusion microthermometry and stable isotope geochemistry of quartz cements three chemically distinct aqueous fluids were identified that affected the rock at different times during deformation the earliest deformation microstructures are distributed cataclasites which were cemented by reddish brown luminescing quartz precipitated from an aqueous cacl 2 brine fluid i once cemented brittle deformation continued but localized along discrete shear surfaces in narrow zones 20 1000 m wide and on discrete microfractures microveins associated with this phase were cemented with bluish green luminescing quartz precipitated from an aqueous cacl 2 brine fluid ii water channelized along dissolution surfaces and in pervasive microfracture networks that formed at this time promoted hydrolytic weakening and crystal plastic deformation especially near fluid pathways temperatures during deformation associated with fluids i and ii were 225 235 c as determined from fluid inclusion data in the later stages of deformation an influx of iron bearing aqueous fluid fluid iii greatly accelerated the rate of quartz dissolution and filled fractures stylolites and vugs with goethite the progression of deformation mechanisms indicated by the microstructures and their relationship to the different fluids show that the selection of grain scale deformation processes is affected not only by the presence of fluids but also by their chemistry

characteristics of ionic concentration and δ18o and their variability in dry season and wet season snow on urumqi glacier no 1 eastern tien shan central asia to investigate the environmental and climatic significance of the ice core records from the tien shan central asia the characteristics of ionic concentration and oxygen isotopic ratio d 18 o as well as their variability are assessed from surface snow samples as well as old snow samples collected year round at weekly intervals from november 2002 to october 2005 on urumqi glacier no 1 eastern tien shan the results indicate that the d 18 o in surface snow samples is reversely coincident with air temperature and insignificantly affected by post depositional processes ionic concentrations in the wet season 1 november to 31 march snow are overall higher than those in dry season 1 april to 31 october snow while the variability of relative ionic composition between dry seasons is slightly less than that between wet seasons during dry seasons surface snow chemistry was mostly controlled by the chemical content entrained in some sporadic precipitations when precipitation is absent the effect of all post depositional processes together elevated the ionic concentrations in surface snow during wet seasons the snow chemistry is determined mainly by the input of aerosols entrained in precipitation and the elution process from percolation of meltwater

immature oil and condensate modification of hydrocarbon generation model for terrestrial organic matter petroleum has been found in canadian frontier basins in reservoirs which have undergone low levels of thermal alteration vitrinite reflectance 0 6 ro paraffin indices stable carbon and hydrogen isotope contents pristane to nc17 ratios and diterpenoid biologic markers have been used to assess the level of maturity of the hydrocarbons in the reservoir independently of the level of maturity of the reservoir itself and of the surrounding shale units in the tertiary of the beaufort mackenzie basin naphthenic oils and condensates have been generated from terrestrially derived organic matter in source rocks juxtaposed with the reservoir at reflectance levels of 0 4 to 0 6 ro however condensates discovered in reservoirs which are th rmally immature on the labrador shelf have undergone extensive vertical migration and can be classed as conventional mature to overmature condensates hydrocarbons discovered in the lower cretaceous of the beaufort mackenzie basin and also those of the scotian shelf are more or less in place in that they are at a level of thermal alteration about equivalent to that of the reservoirs in which they are trapped the source for the early oils and condensates is considered to be resinite occurring dispersed in coal fragments the proportion of resinite liptinite and vitrinite in the organic matter of terrestrial source rocks strongly controls both the level of thermal alteration necessary for the section to function as an effective source rock and the ultimate product gas oil or condensate which will be generated

petrology of some permian coals of india abstract in india permian coal deposits constitute approximately 99 of the total coal reserves of the country and occur in the early permian karharbari formation early permian barakar formation and the late permian raniganj formation in the present study petrographic analyses were carried out on coals from the pench kanhan valley son mahanadi valley and damodar valley basins the permian coals of india show a remarkable range in vitrinite content 13 79 seams with low vitrinite content are common the raniganj formation coals contain more vitrinite than the coals of the barakar and karharbari formation exinite liptinite content of many indian coals varies from 2 to 23 sporinite is generally dominant over cutinite and resinite exinite tends to be associated with vitrinite rich coal and most inertiniterich coals have relatively low exinite content inertinite is relatively abundant 10 67 in many permian coals of india and consists mainly of semifusinite inertodetrinite and fusinite coal facies analysis based on petrographic parameters indicate that the indian peats coals were deposited in dry and wet forest swamps a comparison of indian coals with some other coals of permian age from australia and south africa shows broad similarities even though the coals are from different basinal settings this suggests that palaeoclimate and floral assemblages outweighed basinal setting in determining the coal type being deposited in india outcrops of high rank coals r o max 0 85 1 30 are largely restricted to the damodar valley basin in this basin vertical rank gradients are higher and uplift and erosion have occurred to a greater extent than in other gondwana basins of india coals of other gondwana basins occur at shallow depth and are generally subituminous in rank r o max 0 40 0 65 the oil potential of the coals of the barakar and raniganj formations is very good except in the jharia basin in this basin the oil may have been released due to breaching of the structures

thermal response of a small ice cap to climatic forcing two dimensional finite element calculations of velocity and temperature fields have been applied to the energy balance of a cross section of barnes ice cap baffin island canada the flow plane currently is cooling near the ice divide and warming near the margin long term simula tions show a net warming trend followed by a cooling trend with a steady state average temperature similar to the present sensitivity studies on an idealized version of the flow plane show that the overall temperature responds less than surface temperature forcing because a negative feed back in temperature advection is substantially larger than a positive feed back in strain heating the response times of the flow plane by itself are somewhat faster but of the same magnitude as response times that would be estimated from one dimensional modeling when bedrock temperature calculations are included response times increase an order of magnitude but these do not substantially affect the short term response

microscale spatial variability of snowpack isotopic and chemical heterogeneity of a firn pack at qomolangma mount everest central himalaya for a better understanding of snow metamorphosing processes and more precise snow ice core interpretations it is necessary to know the extent of microscale spatial variability of isotopic and chemical distributions in a snowpack this work presents an investigation on the horizontal heterogeneity of the isotopic and chemical distributions in a firn pack on east rongbuk glacier at qomolangma mount everest central himalaya one pit wall of 1 2 1 2 m 2 at 6520 m a s l was sampled at intervals of 10 cm in a matrix pattern with a total of 144 samples collected all the samples were analyzed for d 18 o and ionic concentrations small horizontal isotopic and large chemical heterogeneities were found the averaged coefficient of variation cv of the twelve 10 cm thick layers for d 18 o is 0 052 and in the whole snow thickness of 120 cm it is 0 016 which is in the range of analytic precision and thus indicates complete homogeneity however the ionic distribution shows considerable heterogeneity the averaged cv values of the 10 cm thick layers for ionic concentrations vary in the range 0 628 1 477 depending on the ions based on these cv values the heterogeneity sequence is mg 2 ca 2 k na cl so4 2 po4 3 no3 nh4 the averaged cv values for all the ions except for nh4 decrease with increasing snow thickness although the decreasing rates and extents are different however the cv values of different ions are still large and in the range 0 183 1 116 when the snow thickness increases to 120 cm the heterogeneity sequence becomes k mg 2 ca 2 nh4 na cl po4 3 no3 so4 2 the cv average change with thickness is different for nh4 from 20 to 100 cm it increases slightly with increasing thickness but all the values are lower than the average of 10 cm thick layers

quantitative assessment of low temperature deformation mechanisms in a folded quartz arenite valley and ridge province west virginia abstract analysis of the grain scale deformation mechanisms in folded tuscarora sandstone from the western margin of the appalachian foreland near keyser wv reveals that deformation was accomplished by a combination of pressure solution microfracturing and crystal plastic mechanisms the finite strain was assessed using the normalized fry method and showed a predominant apparent flattening strain regime resulting from diagenetic compaction partitioning of the strain between operative deformation mechanisms revealed that layer normal shortening 25 and layer parallel shortening 10 by pressure solution were the greatest contributors to the finite strain followed by microfracturing and crystal plastic strains respectively although the crystal plastic contribution to the finite strain is small 1 0 layer normal shortening strain partitioning allowed detection of layer parallel extension consistent with the structural position of the samples on the outer arc of a fold the variation in inferred stress directions throughout the progressive deformation indicates that local stratigraphic and structural control on the stress field is important in the development of certain microstructures only the earliest stages of deformation record far field alleghanian compression whereas later stages reflect local stress fields controlled by bedding orientation and position on developing folds similarities in the microstructure evolution between the western and eastern margins of the appalachian foreland indicate that the entire belt underwent a similar deformation history

characteristics of upper cretaceous coals from enugu nigeria related to bitumen generation and mobilization abstract a set of nine upper cretaceous coals of sub bituminous rank were studied petrographically and geochemically the coals contain considerable amounts of various liptinites as well as fluorescent vitrinite some bitumen has been generated and mobilized in these low rank coals as evident by the presence of exsudatinite nevertheless no hydrocarbons have been expelled as the amount of bitumen generated is not considered to be sufficient to overcome the threshold saturation of the coals

controls on hinge parallel extension fracturing in single layer tangential longitudinal strain folds the stress history results from a published viscous layer folding solution are used as the basis for a fracture mechanics analysis of the factors that control hinge parallel extension fracturing in tangential longitudinal strain folds the analysis incorporates published results for the change in sedimentary rock mode i fracture toughness at increasing confining stress to examine the relationship between regional strain rate depth of burial pore fluid pressure initial crack size layer viscosity and the amount of fold shortening required for the propagation of a bed perpendicular hinge parallel extension fracture tangential longitudinal strain folding of layers can occur at all scales in a foreland thrust system and is the result of the buckling and bending of stratigraphic units during the development of decollement fault bend and fault propagation folds hinge parallel extension fractures oriented perpendicular to bedding are a common fracture set observed in tangential longitudinal strain folds the fractures propagate as a result of local tensile stresses that develop by the stretching of layers in the outer arc of fold hinges during bending we considered a range of geologically reasonable boundary conditions to show that at one extreme fracturing can occur as a result of only minor shortening by folding to the other extreme where a tight fold can form with no associated extension fracturing for folds formed at shallow depths where the confining stress on the system is less than the bending stresses in the layer and where the confining stress has not greatly increased the fracture toughness of the rock hinge parallel extension fractures can grow under hydrostatic fluid pressure conditions as depth increases however much higher pore fluid pressures are required to cause fracturing under similar strain rates the observed controls are used to hypothesize how hinge parallel extension fracturing in fault bend folds can vary spatially and temporally across a thrust belt as a function of strain thrusting rate the amount of bending at thrust ramps and the depth of folding

high amplitude folding of linear viscous multilayers abstract high amplitude folding of viscous multilayers during shortening can be analyzed with a theoretical solution motivated by first order theoretical analysis of folding by raymond fletcher and ronald smith the solution method can better match boundary conditions along irregular interfaces than the first order method so it increases the range of slopes over which linear viscous folding theory can be applied in our method rather than solving algebraically for a small number of constants in the flow equations we numerically solve for a large number of constants the values of which are chosen so that they minimize errors in matching conditions at the interfaces in a least squares sense a similar method has been applied to problems of density instability involving a single deformable interface with bonded contacts however we extend the method to include shortening parallel to interfaces and many deformable interfaces so that we can deal with problems of multilayer folding contacts between the layers can be firmly bonded slip freely or slip with viscous resistance we use the solution to produce high amplitude folds in single layers embedded in soft media and in simple repetitive multilayers confined above and below by stiff or soft media we show that the folding of linear viscous multilayers can largely reproduce the gross forms of some small folds in the huasna syncline in the central california coast range as well as the berry buffalo syncline in the central pennsylvania appalachians however the sharp chevron like forms in these natural examples are notably missing in the simulations based on linear viscous theory

chemical characteristics mineralogical composition and rank of high sulphur coking coals of middle miocene age in the gokler coal field gediz turkey

rheology of the lithosphere selected topics we review recent results concerning the rheology of the lithosphere with special attention to the following topics 1 the flexure of the oceanic lithosphere 2 deformation of the continental lithosphere resulting from vertical surface loads and forces applied at plate margins 3 the rheological stratification of the continents 4 strain localization and shear zone development and 5 strain induced crystallographic preferred orientations and anisotropies in body wave velocities we conclude with a section citing the 1983 1986 rock mechanics literature by category

finite element analysis of an overturned fold using a viscous fluid model abstract folding of a single viscous layer embedded in a less viscous medium is analyzed by using the finite element method in the euler coordinate system to simulate a natural overturned fold the constituent substances are assumed to be isotropic and incompressible and to behave as newtonian fluids the penalty function method is used to take care of incompressibility and the effect of gravity is ignored in simulating the deformation process of the huang yuan overturned fold the layer was first compressed to form a symmetric fold and then sheared along its upper surface the results of the finite element analysis are compared with data measured in the field the overturned fold geometry is well simulated this suggests that this is a possible mechanism for the overturned fold and it also explains fairly well the relative thickening of the folded layer at the hinge

volumetric strains in neutral surface folding neutral surface folding is a significant contributor to fold development this mechanism produces contrasting strains in the inner and outer arcs of the folded layer that arise from principal stress orientations that are approximately parallel and perpendicular to the layer we demonstrate that such stress patterns imply significant gradients of mean stress across the folding layer being more tensional on the outer arc and more compressive in the inner arc this could pump fluids towards the outer arc during folding and result in heterogeneous volume changes we conclude that the neutral surface folding model should be adapted to accommodate volumetric strains in order to explain dilatational structures e g open fractures veining on the extrados and volume loss structures e g pressure solution seams stylolitic cleavages on the intrados this dilatation has economic implications as it allows prediction of sites of mineralization and zones of secondary permeability in fold related hydrocarbon traps

mechanical problems in geodynamics and work done in china the subject of geodynamics concerns the dynamics of the global motion of the earth of the motion in the earth s interior and its interaction with surface features together with mechanical processes in the deformation and rupture of geological structures a brief historical review is given from sir i newton maclauwin jacobi poincare poisson lame darwin rayleigh and love who dealt with the homogeneous sphere to leibenson takeuchi and meinesz concentrating on layered spheres and after the advent of plate tectonics on the use of numerical simulation to the analyses of tectonic features earthquake mechanism the application of nonlinear dynamics by discussing the forward and inverse mechanical problems and the questions facing the inverse problems of searching for the structural parameters driving forces etc are raised in more detail thereafter some works accomplished in china on the global and regional stress fields analyses tectonic features analyses mantle flow studies experimental studies of rocks and their constitutive relations are presented finally the interdisciplinary nature of the subject is emphasized and the main mechanical problems that need special attention are then proposed

organic petrology of fukang permian lucaogou formation oil shales at the northern foot of bogda mountain junggar basin china abstract the fukang oil shale zone located in the northern bogda mountain on the southern margin of the junggar basin was deposited in a deep lacustrine environment permian lucaogou formation shale samples collected from six measured outcrop profiles were characterized using organic petrographic and geochemical techniques the macerals can be divided into four groups bituminite liptinite vitrinite and fusinite oil shales are different from coal by their lower content of vitrinite and fusinite but generally high content of bituminite and liptinite all samples containing sufficient hydrogen rich organic matter types i and ii are considered to have a high potential for oil generation the organic matter was deposited in a clastic algal dominated deep water environment and it mainly consists of unstructured bituminite and mineral bituminous groundmass the oil shales with a sapropelitic constituent content lower than 5 5 to 15 15 to 25 and over 25 correspond to non oil shale low quality medium quality and high quality oil shales in industrial grade respectively approximately 65 of the samples belong to sapropel containing shales with an oil yield between 3 5 and 10 which are low quality and medium quality oil shales the total maceral content can be used as an auxiliary index to classify the industrial grade of oil shales oil yields of 3 5 5 and 10 correspond to total organic matter contents of 7 8 9 8 and 17 5 respectively

petrographic and chemical properties of carboniferous resinite from the herrin no 6 coal seam abstract resinite is a naturally occurring substance found in coal and derived from original plant resins it is ubiquitous in north american coals and comprises 1 to 4 by volume of most illinois coals it has been commercially exploited in the western usa for use in adhesives varnishes and thermal setting inks the major objectives of this study were 1 to separate resinite macerals from the herrin no 6 coal seam and to carefully verify by petrographic and fluorescence microspectrophotometric methods that the separated material was indeed resinite 2 to characterize the chemical composition of the separated resinite by py gc ms techniques and 3 to confirm the earlier results that show that this carboniferous resinite was a much different chemical substance than the cretaceous and younger resinites an additional objective was to compare the separated resinite to the resinite being commercially exploited in the western usa high purity fractions of resinite concentrates were separated from the herrin no 6 coal by a combination of density gradient separation and sink float techniques the chemical structure of the resinite concentrate indicated by the py gc ms analysis is that of a straight chain aliphatic polymer much like common polyethylene this result confirms the earlier work of nip et al nip m de leeuw j w crelling j c 1992 chemical structure of bituminous coal and its constituent maceral fractions as revealed by flash pyrolysis energy fuels 6 125 136 the assumption that the resinites in the illinois basin were similar in nature to the commercial resinites of the younger coals of the western usa appears invalid in the case of the resinite in the herrin no 6 coal although the botanical function of the carboniferous resinite is at present unclear it is clear that the cutinite and resinite precursors had not yet evolved to the point where they had differentiated into significantly different chemical compounds

optical properties of some tertiary coals from northeastern india their depositional environment and hydrocarbon potential abstract in northeastern india the coalfields of arunachal pradesh assam and nagaland are disposed along a linear belt of overthrusts known as the belt of schuppen where tertiary strata have been folded and dispersed into a number of thrust slices the coal bearing sediments in this belt are associated with the baragolai and tikak parbat formations of the barail group oligocene in meghalaya the tertiary sediments were deposited on a stable shelf along the periphery of the shillong plateau they are almost undisturbed and sub horizontal in attitude the coal seams are associated with the sylhet tura formations palaeocene of the jaintia group the chemical properties of these coals show characteristics of both low on volatile matter content and high on moisture and calorific value ranks the coals have a low softening temperature and a high swelling index volatile matter hydrogen and sulphur contents besides having the highest tar yield among indian coals the syncrude produced from these coals shows similarities with the identical fraction of crude oil from nahorkatiya oilfield assam the coals from the belt of schuppen and meghalaya are non banded and bright in nature microscopically their humic components are strongly decomposed with a common to frequent association of framboidal pyrite and calcite concretions the coals are vitrinite rich 52 0 80 0 with moderate amounts of liptinite macerals 5 8 16 2 the inertinite content is low 4 6 11 0 to occasionally high 30 0 fluorescing vitrinite and liptinite macerals constitute 46 5 to 83 5 by volume m m f perhydrous vitrinite liptodetrinite and resinite are the most common fluorescing macerals the rank of the coal samples r 0 max 0 57 0 74 ranges between high volatile bituminous c and b stages the assam coals are higher in rank than those of nagaland and meghalaya in northeastern india during the palaeocene and oligocene epochs peat swamps formed in situ from tropical mangrove rich angiospermous forest vegetation the palaeocene coals in meghalaya were formed in estuaries or lagoons however the coal forming phase ceased shortly due to prolonged marine transgression the oligocene coals in the belt of schuppen were formed during a regressive phase in back water lagoons or brackish water swamps on a prograding delta complex the hydrocarbon potential mg ch g c org of the coal samples from northeastern india has been theoretically deduced on the basis of their kerogen types following mukhopadhyay et al 1985 the presumed hydrogen index varies from 250 to 430 and 300 to 470 mg ch g c org respectively for coals in the belt of schuppen and meghalaya evidence indicates that in arunachal pradesh assam and nagaland oil has been generated from kerogen types ii b and ii a in the oligocene mudstone siltstone shale association of the coal measures of barail group in meghalaya no oil is known so far nevertheless the predominance of kerogen types ii a and ii b in coals indicates a good oil potential in the palaeocene sediments of the jaintia group

funginite resinite associations in coal abstract petrographic examination of a series of indian tertiary age coal seams some with 38 resinite mineral free basis showed that several had associations of funginite in resinite there are three primary mechanisms for incorporation of fungus into resinite 1 as an accidental inclusion for example as a fungal infection on an insect encapsulated in resin 2 infestation of fungus into tree whether into a wound or other point of entry with encapsulation by resin as a defense mechanism by the tree alternatively fungal hyphae could also be growing from another portion of the tree that is already infected and 3 resinicolous fungus using the resin as a food source in the coal samples examined while incidental fungal inclusion on invading insects cannot be eliminated we have seen no direct evidence for insects both encapsulation of invading fungus by resin and resinicolous relationships are among the associations observed

deformation mechanisms and strain history of a minor fold from the appalachian valley and ridge province abstract we have re examined a minor fold in the silurian mckenzie limestone collected from the cacapon mountain anticline where the anticline crosses the potomoc river the fold was originally studied by james conel 1962 we have determined the strain and deformation mechanisms in both the hinge and the limbs of one layer the layer is towards the inner arc of a multilayer containing one other bed of comparable thickness and numerous thinner beds all separated by thin shale beds and enclosed in shale intragranular deformation mechanisms related to folding include faults and replacement veins the faults represent a complex interrelationship between shear displacement pressure solution and extension veins containing fibrous calcite the faults are curved and have the effect of moving material into the inner arc of the hinge zone the replacement veins occur normal to bedding on the outer arc of the hinge pressure solution zones normal to bedding are absent and so is cleavage intragranular strain is measured on twinned calcite using the least squares strain gage technique based on all the data the maximum compressive strain 1 is everywhere subparallel to layering and approximately perpendicular to the fold axis the maximum extension strain is everywhere subparallel to the fold axis the largest 1 values 12 7 and 11 0 occur in the inner arc of the hinge the smallest 1 2 1 is in the outer arc of the hinge the limbs have intermediate values of 1 intragranular layer parallel shear strain on the limbs is small and indicates a relative motion of material away from the hinge in the inner arc with respect to the outer arc

resino inertinites of indian permian coals their origin genesis and classification abstract variously shaped discrete bodies with reflectance higher than the associated vitrinite occur in permian coals in india australia and africa and the carboniferous coals of the united states canada and europe these bodies have been variously named by different authors in the present paper they are described as resino inertinites as suggested by lyons et al 1982 based on available information and our observations on carboniferous and permian coals it is presumed that resino inertinites were formed mainly from the resinous resinite and to some extent from the phlobaphinitic or corpocollinitic substances various morphological patterns developed on resino inertinites have been interpreted to be governed by the chemical composition of their precursors and the degree of oxidation or fusinization during coalification influences of other vvariables viz paleoenvironmental paleodepositional tectonic set up etc on resino inertinites are not clearly recognizable probably because all the previous effects were masked by subsequent fusinization different morphological features of resino inertinites associated with early diagenetic and secondary mineralization have caused much confusion in their proper identification and classification in order to resolve this problem an attempt has been made to ascertain the source of resins in indian permian coals and their subsequent mode of transformation into resino inertinites during coalification further by critically evaluating morphological features of resino inertinites and keeping the chemical nature of their precursors in view a classification scheme has been proposed categorizing them into 3 types the classification proposed may prove as a useful means for coal seam correlation

petrofabric test of viscous folding theory abstract compression and extension axes are deduced from quartz deformation lamellae in a quartzite and a graywacke folded into an asymetrical syncline deformation lamellae fabrics in the two sandstones are distinctly different in the graywacke regardless of bedding orientation or position on the fold compression axes are normal or nearly normal to the axial planar rough cleavage extension axes generally lie in the cleavage plane parallel to dip in most quartzite samples compression axes are parallel or subparallel to bedding at high angles to the fold axis and extension axes are normal to bedding two samples from the very base of the formation indicate compression parallel to the fold axis with extension parallel to bedding at high angles to the fold axis one of these two shows both patterns the lamellae fabric geometry in these two samples suggests the presence of a neutral surface in the quartzite the lamellae derived compression and extension axes are in good agreement with the buckling behavior of a viscous layer quartzite embedded in a less viscous medium graywacke and shale below and shale and carbonate above

atmospheric pollution of a remote area of tianshan mountain ice core record 1 the influence of anthropogenic pollution on the region of tianshan mountain a remote area in arid central asia has been debated in the recent years an ice core covering the past 43 years retrieved from glacier 1 at urumqi river head in the east tianshan northwest china was analyzed to examine the problem ch3coo acetate and hcoo formate the chief tropospheric carboxylates that can originate from anthropogenic pollution average 389 4 336 3 ng g 1 n 489 and 61 1 89 0 ng g 1 n 541 respectively with a mean ratio hcoo ch3coo of 0 21 0 23 n 489 so42 the major inorganic anion in the core averages 232 9 279 9 ng g 1 n 542 the organic and inorganic records have covaried in the past four decades they originate principally from anthropogenic pollution coal combustion in particular of the local and regional atmosphere the ph values in the record range from 6 to 9 with an average of 6 9 0 5 n 541 the general trend of the ph data matches that of hcoo ch3coo and so42 indicating that the anthropogenic pollution has released considerable particulate material along with unsaturated hydrocarbons and so2 as a result the pollution has not been acidifying the environment but making it alkaline

the microconstituents of godavari coals south india abstract the present paper deals in detail with the coal typology rank and correlation of some indian coal seams petrological evaluation of several known coal seams reveals that there are two main seams the king lower seam and queen upper seam with distinctly different characteristics all the other seams locally known by different names elsewhere in the field are correlatable with either the king or queen seams the coals are of inferior quality because of the predominance of mixed coals types associated with dispersed mineral matter however some seams show characteristics which are amenable to quality improvement with suitable preparation methods the coals appear to have been formed rapidly in a fluctuating environment aerobic to anaerobic under relatively cold to gradually warming conditions

dynamic analysis of rough cleavage in the martinsburg formation maryland abstract deformation lamellae in detrital quartz and twin lamellae in vein calcite are common in greywacke beds in the upper portion of the martinsburg formation near williamsport maryland these features are a product of the same stresses that resulted in the formation of rough cleavage dynamic analysis of the deformation lamellae and the calcite twins indicates that the cleavage formed normal to the maximum principal stress in limb samples the intermediate principal stress is parallel to the fold axis and the least principal stress plunges steeply in the cleavage plane in most hinge samples the intermediate and least stress axes could not be differentiated and together define the cleavage plane the lamellae developed during a period of high differential stress that accompanied flattening of early formed buckle folds the abundance of deformation lamellae and their development synchronous with the cleavage demonstrates that intracrystalline deformation may be an important mechanism in the formation of rough cleavage

review and update of the applications of organic petrology part 2 geological and multidisciplinary applications abstract the present paper is focused on organic petrology applied to unconventional and multidisciplinary investigations and is the second part of a two part review that describes the geological applications and uses of this branch of earth sciences therefore this paper reviews the use of organic petrology in investigations of i ore genesis when organic matter occurs associated with mineralization ii the behavior of organic matter in coal fires self heating and self combustion iii environmental and anthropogenic impacts associated with the management and industrial utilization of coal iv archeology and the nature and geographical provenance of objects of organic nature such as jet amber other artifacts and coal from archeological sites and v forensic science connected with criminal behavior or disasters this second part of the review outlines the most recent research and applications of organic petrology in those fields

observations on indian permian gondwana coals under fluorescence microscopy an overview abstract macerals like sporinite cutinite suberinite and resinite of the liptinite group have been insufficiently recorded in indian permian gondwana coals until the fluorescence microscopy came into existence with the introduction of this technique macerals like bituminite fluorinite and exsudatinite were convincingly recognized and alginite and liptodetrinite normally mistaken for mineral matter under normal reflected light in routine coal petrographic analysis were identified with certainty thus fluorescence microscopy has added certain new macerals to the tally of the liptinite group and has increased their overall proportion in indian gondwana coals in addition to the liptinite group collodetrinite desmocollinite and a certain fraction of collotelinite telocollinite macerals of the vitrinite group were found to be fluorescing with dull reddish brown to dark brown colours certain semifusinite and inertodetrinite macerals of inertinite group were also found to fluoresce with almost identical intensity and colour as that of the associated perhydrous fluorescing vitrinite contributions of degraded resinite algal matter and bitumen in the formation of perhydrous vitrinite have been established the fluorescence behaviour of inertinite appears to be related with its genesis from partial oxidation of resin bitumen impregnated cell walls

strain partitioning and factorization in a quartz arenite abstract most rocks deform by multiple grain scale deformation mechanisms in order to assess completely the contributions of each mechanism the strain associated with that mechanism must be known and compared to the finite strain this study describes the partitioning of strain between three mechanisms pressure solution dislocation creep and microfracturing in a quartz arenite deformed at low temperatures pressure solution which occurred primarily during compaction dominates the finite strain with an average of 24 shortening normal to bedding dislocation creep which occurred during layer parallel shortening accounts for about 2 shortening parallel to bedding dip microfractures which occur in three orthogonal sets resulted in 2 4 extension normal to bedding parallel to bedding strike and parallel to bedding dip the validity of the mechanism strains was tested using strain factorization models were constructed using the mechanism strains in an order determined by their relative ages because porous well sorted quartz arenites such as the one studied are likely to undergo some mechanical compaction in the early stages of diagenesis variable amounts of mechanical compaction were included in factorization models models using the measured deformation mechanism strains with an initial 5 10 mechanical compaction yield finite strains in close agreement with the measured finite strains this suggests that the mechanisms identified the strain associated with each mechanism and the deformation sequence are plausible

early eocene equatorial vegetation and depositional environment biomarker and palynological evidences from a lignite bearing sequence of cambay basin western india abstract an investigation of palaeofloral distribution with depositional environment and palaeoclimatic condition of western indian subcontinent during early eocene period has been carried out from a lignite bearing succession of cambay basin western india the study of biomarkers palynological remains and petrography is taken as proxies for providing supportive evidence for our inference the petrographic results reveal that the sediments are thermally immature and coalification was extended up to the lignitic stage low rank b the palynological results show the dominance of angiosperms mainly members belonging to the arecaceae family throughout the studied section triterpenoids with oleanane ursane and lupane structure in extractable organic matter are derived from angiosperm wax pollen grains spinizonocolpites proxapertites dipterocarpuspollenites albertipollenites retipollenites arengapollenites lakiapollis and longapertites with pteridophyte spores and fungal fruiting bodies confirm the prevalence of tropical to subtropical climate during the deposition of the sediments sesquiterpenoids like longifolene 12 methanoazulene cadinane and selinene together with amyrin derivatives are the indicator of dipterocarpaceae family that grows in the extant tropical rain forests in se asia appearance of dinoflagellate cysts and the predominance of lower molecular weight part in n alkane series with the signature of submerged floating vegetation in the shale horizon indicate marine influence in the younger part of the mine section the presence of mangrove pollen such as spinizonocolpites proxapertites and acanthotricolpites further suggests that the lignite bearing sequence was deposited in marshy marginal marine environment

spectral fluorescence analysis of some liptinite macerals from panandhro lignite kutch gujarat india abstract spectrofluorimetric analyses of sporinite alginite and resinite macerals of eocene lignite from the panandhro lignite field indicate that they are distinguishable on the basis of their max and red green quotients sporinite fluorescing with bright yellow colour has an average max at 570 nm with red green quotient q 0 92 alginite botrycoccus with a bright yellow fluorescence colour has a peak average at 540 nm with q 0 71 resinite in the panandhro lignite has been categorized into five types resinite type 1 yellowish green to greenish yellow is characterized by average max at 510 nm with a q value of 0 29 in resinite type 2 bright yellow the average max occurs at 520 nm with q 0 49 resinite type 3 yellowish orange to orange shows a max average at 520 nm with a q value of 0 69 resinite type 4 has been subdivided into sub types a and b based on its mode of occurrence primary and in situ remobilized sub type 4a pale orange has a max average at 590 nm and q 0 99 whereas sub type 4b fluoresces with faint brownish orange to pale brown colours and shows an average max at 610 nm and q 1 43 the average max at 610 nm and q 2 30 with pale yellowish grey orangish brown and brown fluorescence colours characterize resinite type 5 the wavelength of maximum fluorescence intensities and red green quotients of the sporinite and alginite macerals show a very good correspondence with the rank r0 max of the panandhro lignites the spectral parameters of the maceral resinite on the other hand do not show such a relationship with rank resinite types 1 to 3 are primary in origin whereas types 4 and 5 occur both as primary and in situ remobilized resinites none of the resinite types have been observed as crack or fissure fillings the origin of the resinite types is probably related to lignite forming plant communities chiefly angiospermous vegetation as well as pre and post depositional conditions

analysis of microstructures in the meade plate of the idaho wyoming foreland thrust belt u s a abstract kinematic histories of several imbricate slices of the meade plate in the idaho wyoming foreland thrust belt were determined using analyses of e lamellae in calcite f lamellae in dolomite and sub basal i deformation lamellae in quartz supporting these data were analyses of stylolites strained fossils and other markers and vein filled extension fractures compression was always parallel or sub parallel to bedding on upright fold limbs and on overturned fold limbs was either sub parallel or more commonly at a high angle to bedding extension in both limbs was generally either perpendicular to bedding or parallel to the fold axes observations in the hinge zones of folds were inconsistent while near thrust faults the microstructures record compression at a high angle to the nearby thrust surface measurement of different minerals in the same sample as well as cross cutting stylolite vein relations indicate that early compression was parallel to bedding while later compression was at a high angle to bedding these data suggest that regional shortening and probably compressive stress was horizontal or sub horizontal throughout the deformation and that most of the strain within thrust plates is directly related to folding and not thrusting the following structural history is proposed 1 1 initial layer parallel compression 2 2 buckle folding soon yielding to more complex folding in a three dimensional strain field 3 3 locking of folds and 4 4 locking of thrusts the fold locking angle as well as fold geometry indicates that these structures might be characterized as kink folds but the asymmetry is not consistent with theoretical analyses of kink folds strain due to basal traction along the fault surface is only important within 50 200 m of that surface depending on lithology

pyrolysis induced p wave velocity anisotropy in organic rich shales abstractthe sources of elastic anisotropy in organic rich shale and their relative contribution therein remain poorly understood in the rock physics literature given the importance of organic rich shale as source rocks and unconventional reservoirs it is imperative that a thorough understanding of shale rock physics is developed we made a first attempt at establishing cause and effect relationships between geochemical parameters and microstructure rock physics as organic rich shales thermally mature to minimize auxiliary effects e g mineralogical variations among samples we studied the induced evolution of three pairs of vertical and horizontal shale plugs through dry pyrolysis experiments in lieu of traditional samples from a range of in situ thermal maturities the sensitivity of p wave velocity to pressure showed a significant increase post pyrolysis indicating the development of considerable soft porosity e g microcracks time lapse high resolution backscattered electron scanning electron

the neyveli lignite deposits cauvery basin india organic composition age and depositional pattern abstract the palynological particulate organic material palynodebris and biopetrological aspects of the main lignite seam encountered in nle 27 nle 35 and nle 36 borehole sections in mine iii of the neyveli lignite field of the cauvery basin were investigated the palynoflora is rich in angiospermic pollen 79 6 distributed in 33 genera and 86 species pteridophytic spores representation is only 20 4 with 5 genera and 9 species quantitatively palynofossil assemblage of the seam from mine iii resembles fairly well with those from the mines i and ii based on geological geophysical and palynological data the lignite seam has been assigned a miocene age the lignite seam has a very high proportion of structured terrestrial organic matter om with a subordinate amount of biodegraded terrestrial fungal and amorphous materials in addition to resin petrologically the seam is rich in the huminite group of macerals usually dominated by attrinite densinite humodetrinite macerals botryococcus is common as are framboidal pyrite and concretions the seam in mine iii is lower in rank ro max 0 39 than its counterpart in mine i ro max 0 47 from a critical assessment of the palynological palynodebris and biopetrological data together with published geological information it is assumed that the main lignite seam was formed from in situ mangrove mixed moist tropical forests vegetation probably in a lagoon on a prograding delta with freshwater inlets from the western and restricted seawater channels from the east

fluorescence spectral analysis of resinite macerals from coals of the hanna formation wyoming u s a abstract flourescence spectral analysis indicates that resinite macerals from tertiary hanna formation coals hanna coal field southcentral wyoming u s a can be separated into five distinct groups the first resinite group fluoresces a a medium green in blue light its average spectral maximum occurs at or below 440 mm with a red green quotient of 0 22 the second resinite group fluoresces yellow green with an average spectral maximum of 500 nm and a red green quotient of 0 53 the third resinite group displays a yellow fluorescence having an average spectral maximum of 580 nm and a red green quotient of 0 86 the fourth resinite group fluorescence orange brown having an average spectral maximum of 610 nm and a red green quotient of 1 20 these four groups mostly occur as primary globular resinites exhibiting scratches and fractures indicating that they are brittle solid substances primary cell filling and secondary fracture filling resinites also occur in these four groups the fifth group only occurs as a secondary void filling material and lacks evidence of br of brittle properties it fluoresces a reddish brown has a spectral maximum at 690 nm and a red green quotient of 1 54 the fifth group has properties resembling exsudatinite the five resinite groups can be separated on the basis of their nine spectral properties alone without qualitative petrographic interpretation the relative quantities of the five resinite groups vary among hanna formation coals the origins of these five resinite groups are probably related to their botanical properties and pre and post depossitional conditions overall hanna formation resinites have petrographic characteristics similar to other north american resinites however only four resinite groups have been distinguished in in certain coals from utah and new mexico u s a and western canada

terpenoid composition of fossil resins from western india new insights into the occurrence of resin producing trees in early paleogene equatorial rainforest of asia abstract the terpenoid composition of well preserved fresh and oxidized fossil resins ambers from early paleogene lignite bearing sequences of india have been examined using gas chromatography mass spectrometry for determining their botanical origin the samples were collected from two sedimentary basins viz barmer akli formation and bikaner nagaur palana formation western india the total extracts of the studied ambers are represented by hydronaphthalenes sesquiterpenoids and significant occurrence of diterpenoids such terpenoid distribution is typical for gymnosperm especially conifer derived sources the diterpenoids are comprised of majorly abietane phyllocladane kaurane pimarane isopimarane and podocarpane class compounds tertracyclic diterpenoids such as 18 norkauranes ent 16 h kaurane and 16 h phyllocladane and a rearranged tricyclic diterpenoid rosane are detected in the fossil resins from barmer basin the occurrence of tetracyclic diterpenoids and rosane together with 8 13 dimethyl 16 norpodocarpa 6 ene suggests that podocarpaceae family is the possible source of the ambers however chemotaxonomic assignment at family level for the fossil resin from bikaner nagaur basin is difficult due to the absence of source specific diterpenoids previous reports had documented the occurrence of angiosperm derived dammar resins from early paleogene sediments of india dutta et al 2009 rust et al 2010 the present study suggests that the early paleogene resins of the equatorial rainforests were not always represented by the dammar resins derived from dipterocarpaceae a family of angiosperm some of them were also contributed by the conifers

trace element emissions from spontaneous combustion of gob piles in coal mines shanxi china the emissions of potentially hazardous trace elements from spontaneous combustion of gob piles from coal mining in shanxi province china have been studied more than ninety samples of solid waste from gob piles in shanxi were collected and the contents of twenty potentially hazardous trace elements be f v cr mn co ni cu zn as se mo cd sn sb hg tl pb th and u in these samples were determined trace element contents in solid waste samples showed wide ranges as compared with the upper continental crust the solid waste samples are significantly enriched in se 20x and tl 12x and are moderately enriched in f as mo sn sb hg th and u 2 5x the solid waste samples are depleted in v cr mn co ni cu and zn the solid waste samples are enriched in f v mn cr co ni cu zn sb th and u as compared with the shanxi coals most trace elements are higher in the clinker than in the unburnt solid waste except f sn and hg trace element abundances are related to the ash content and composition of the samples the content of f is negatively correlated with the ash content while pb is positively correlated with the ash the concentrations of as mn zn and cd are highly positively correlated with fe2o3 in the solid waste the as content increases with increasing sulfur content in the solid waste the trace element emissions are calculated for mass balance the emission factors of trace elements during the spontaneous combustion of the gobs are determined and the trace element concentrations in the flue gas from the spontaneous combustion of solid waste are calculated more than a half of f se hg and pb are released to the atmosphere during spontaneous combustion some trace element concentrations in flue gas are higher than the national emission standards thus gob piles from coal mining pose a serious environmental problem