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

maturation and bulk chemical properties of a suite of solid hydrocarbons abstract in this paper we present strong correlations of solid hydrocarbon reflectance shro to vitrinite reflectance vro and bulk chemical properties aromaticity tmax h c etc these correlations suggest that like kerogen in coals and sedimentary rocks solid hydrocarbons vary systematically during maturation as a consequence shro is especially useful as a maturity indicator in rocks lacking vitrinite such as pre devonian rocks and many organic rich marine rocks unlike other organic maturationv indicators the utility of solid hydrocarbons is not limited by botanical evolution but rather the generative potential of the petroleum system solid hydrocarbons also known as solid bitumen asphalt dead oil migrabitumen and pyrobitumen are genetically defined as solid phase accumulations of predominantly hydrocarbons produced by petroleum generation in source rocks they may occur over a range of concentrations in outcrop and well samples in all components of petroleum systems although accumulations of solid hydrocarbons from exhumed reservoirs are well reported the extent and utility of disseminated solid hydrocarbons in shales is less understood solid hydrocarbons are found in organic rich to very lean mature rocks as a residual product of generation disseminated solid hydrocarbons exhibit three optical forms anisotropic coked granular and relatively uniform homogenous only the homogenous solid hydrocarbons are recommended for correlation purposes with other thermal indicators

permian palynostratigraphy and palaeoclimate of lingala koyagudem coalbelt godavari graben andhra pradesh india abstract godavari graben one of the biggest basins among several gondwana basins of india holds a unique position not only because of its geographical location in south india but also due to the presence of almost complete succession from permian to cretaceous sediments the graben is traversed by many small faults due to which the dating and correlation of coal bearing horizons is difficult in this area as palynology is one of the most reliable parameter for dating correlation and characterization of continental deposits palynological studies have been carried out in order to date and correlate the coal bearing horizons of gundala mamakannu and kachinapalli areas from lingala koyagudem coalbelt of godavari graben the distributional pattern of various palynotaxa has suggested the occurrence of eight distinct palynozones in five borecores of gundala mlg 23 mlg 24 and mlg 28 mamakannu mmk 19 and kachinapalli mgk 6 areas these palynozones are comparable to talchir lower karharbari upper karharbari barakar and raniganj palynoflora of indian lower gondwana palynozone 1 is equivalent to parasaccites assemblage of talchir palynoflora palynozone 2 is correlatable with callumispora parasaccites assemblage of lower karharbari palynoflora palynozone 3 corresponds well with parasaccites scheuringipollenites assemblage of upper karharbari palynoflora palynozone 4 is comparable to scheuringipollenites assemblage of barakar palynoflora palynozone 5 is correlatable with faunipollenites striatopodocarpites assemblage of raniganj palynoflora palynozone 6 is comparable with striasulcites assemblage of raniganj palynoflora palynozone 7 shows its equivalence with parasaccites assemblage of raniganj palynoflora and palynozone 8 corresponds well with the crescentipollenites assemblage of raniganj palynoflora on the basis of palynofloral evidences it has been suggested that palaeoclimate during palynozone 1 3 was cool but humidity was more in palynozone 3 in comparison to palynozone 2 warmer phase started during palynozone 4 with thick coal deposits while palynozones 5 8 representing raniganj palynoflora indicate warm climate with very high humidity

fungal abundance spike and the permian triassic boundary in the karoo supergroup south africa the most severe mass extinction of marine species and terrestrial vertebrates and plants is associated with the permian triassic boundary 251 ma the extinction interval is also marked by the disappearance of most late permian gymnosperm palynomorphs at a layer containing solely the abundant remains of fungi this fungal spike apparently represents widespread devastation of arboreous vegetation stratigraphic and palynological study of the carlton heights section in the southern karoo basin of south africa revealed a 1 m thick fungal spike zone that occurs simultaneously with the last appearance of typically late permian gymnosperm pollen the plant extinction and fungal spike zone are found above the last occurrence of late permian mammal like reptiles of the dicynodont zone at other karoo sections using the fungal event as a time line in marine and non marine sections allows placement of the marine extinctions and the extinction of terrestrial plants and reptiles within a brief crisis interval of less than about 40 000 years at the end of the permian

geochemical attributes pore structures and fractal characteristics of barakar shale deposits of mand raigarh basin india abstract pore structures in the shale matrix are an essential factor affecting the storage capacity of gas of shale beds as well as production performance twenty organic rich shale samples at different depths were collected from barakar formation of mand raigarh basin to examine the pore structure and their fractal characteristic fractal dimension was calculated by following fhh theory to investigate the complexity of pore surfaces storage mechanism and the pore network system the complex pore system influenced by thermal cracking of organic matter pore dissolution during geochemical weathering and tectonics of the basins having surface area 5 56 23 94 m2 g avg 14 21 m2 g whereas the pore volume determined using the bjh model varying from 0 035 to 0 076 cc g avg 0 053 cc g ftir spectrum demonstrated that significant presence of aliphatic side chains and aromatic carbon structures existing in studied shale influencing the pore volume it is summarized that pores and matrix of shale are built by complex mixtures of organic and inorganic content further the pores are categorized into organic pores evolved during thermal cracking inter granular intra granular and inter crystalline due to the large content of altered clays and minerals showing fissile nature the sem edx derived facies indicating the involvement of different chemical constituents following the trend of alteration as well as carbon enrichment the d1 and d2 values obtained through fhh model range from 1 17 to 2 45 and 2 54 2 70 the fractal values particularly d2 are 3 demonstrating the pore surfaces and structure of studied shales beds are complex and heterogeneous this study helps to enhance the exploration and advancement in the shale gas resources from ib river of mand raigarh basin india

an autochthonous glossopterid flora with latest permian palynomorphs and its depositional setting in the dicynodon assemblage zone of the southern karoo basin south africa article i nfo the discovery of a plant fossil assemblage situated 70 m below the vertebrate defined permian triassic boundary allows for the characterization of part of the late permian landscape in the southern karoo basin the megafloral and microfloral assemblages are preserved in association with an o horizon above a weakly developed palaeosol exposed in both new and old wapadsberg pass eastern cape province south africa stable isotope geochemical evidence indicates that pedogenesis occurred under conditions of a high regional water table and the palaeosol was entombed by overbank or avulsion deposits in an aggradational landscape that includes tuffite the low diversity macroflora contains gymnospermous glossopteris and sphenopsid phyllotheca trizygia elements that include vegetative axial leaf and reproductive strobilar remains glossopteris leaves are microphyllous and may reflect the taxon s physiological response to purported climate perturbation or wetland edaphic conditions and exhibit a range of plant animal interactions palynological residues contain sphenophyllalean cuticles and the microfloral assemblage is consistent with a low diversity glossoperid dominated woodland with a sphenopsid understory extrabasinal elements include representa tives of peltasperms alisporites corystosperms falcisporites and conifers lueckisporites pollen conforming to lunatisporites pellucidus is present in the assemblage and is considered an indicator taxon for the latest permian to early triassic when compared to palynological assemblage zones in australia the wapadsberg pass flora is assigned a late changhsingian age and therefore represents the youngest autochthonous glossopteris dominated flora to be reported from gondwana these results extend a palynostratigraphic framework across the southern hemisphere that complements other zonations presently applied to the karoo basin succession

lithostratigraphic subdivision of the karoo rocks of the luwegu basin tanzania and their biostratigraphic classification based on microfloras macrofloras fossil woods and vertebrates for the first time a comprehensive stratigraphic classification of the karoo deposits of the luwegu basin in southern tanzania is presented the karoo strata attain a total thickness of almost 6000 metres and are composed of deltaic lacustrine and fluvial deposits the sedimentary sequence has been subdivided into nine major lithostratigraphic units the results of biostratigraphic investigations microfloras macrofloras fossil woods vertebrates indicate that the karoo sequence ranges in age from upper permian to lower jurassic the palynological sequence comprises microfloras of the upper permian the upper triassic onslow and ipswich type and the lower jurassic their age is assessed from correlation with palynofloras of malagasy australia and zimbabwe resulting from this regional as well as intercontinental correlations with the karoo strata of east and south africa the karoo type strata of north africa and the gondwana sequences of australia and india can be proposed furthermore on the base of radiometric datings of hitherto unknown occurrences of volcanic rocks a karoo volcanism and an early tertiary volcanism can be distinguished

the geology petrology palynology and geochemistry of permian coal basins in tanzania 1 namwele mkomolo muze and galula coalfields abstract permian coal bearing strata occur in a number of intracratonic rift basins in tanzania this study examines coals shales and mudstones of the namwele mkomolo muze and galula coalfields rukwa basin by coal petrological palynological and rock eval techniques for the coals the focus was on the establishment of coal seam characteristics and related quality and utilization potentials whereas the shales and mudstones were examined for age relationships flora and related palaeodepositional environments and source rock potential the coal seams which have a thickness of up to 2 95 m are high in ash yields 25 63 wt and have calorific values ranging from 5344 to 18947 j g typical for many of the seams is their detrital nature as indicated by the high content in finely disseminated clay minerals quartz and detrital macerals pyrite content is variable 0 60 5 81 wt vitrinite reflectance ranges from 0 43 to 0 66 rrandom subbituminous to high volatile b bituminous use of the coals in small scale power generations and for domestic use would greatly reduce the dependency of rural tanzania on wood and wood derived charcoal as the main source of fuel palynomorph assemblages are characterized by the predominance of nontaeniate and taeniate pollen and trilete spores in the namwele mkomolo and muze coalfields at galula coalfield the palynomorph assemblages were poor rare trilete alete and monolete spores on the basis of age correlations with karoo basins to the south and the collie basin of western australia an artinskian to kungurian age is suggested for the coal measures in the rukwa basin the diversity of palynomorph assemblages suggests a variety of floras and contemporary depositional environments throughout deposition of the karoo strata this is consistent with coal petrographic parameter which would indicate that peat accumulation occurred in upper delta plain braided plain and lacustrine depositional environments rock eval parameters indicate kerogen type iii for all samples investigated and indicate very poor hydrocarbon source rock potential

geochemical application of tricyclic and tetracyclic terpanes biomarkers in crude oils of nw china composition and distribution of tricyclic terpanes tetracyclic terpanes and hopane in crude oils from tarim turpan ordos and qaidam basins nw china were investigated and some new source dependent parameters were developed and evaluated c 19 and c 20 tricyclic terpanes are more abundant in terrigenous oils with c 24 tetracyclic terpane dominant relatively higher carbon number tricyclic terpanes especially c 23 tricyclic terpane are often the dominant homologues in crude oils from saline lacustrine and marine sources on the whole the relative content of c 23 tricyclic terpane of crude oils follow the order of saline lacustrine oils marine oils freshwater lacustrine oils terrigenous oils for c19 23 tricyclic terpane some new parameters based on the tricyclic hopane and tetracyclic tricyclic terpane as well as tetracyclic hopane ratios could be used to distinguish the oils and source rocks with similar maturity deposited in different sedimentary environments c 2015 elsevier ltd all rights reserved

mass extinction of peat forming plants and the effect on fluvial styles across the permian triassic boundary northern bowen basin australia abstract the most spectacular extinction event in earth s history occurred across the permian triassic boundary in the northern bowen basin a major coal bearing sedimentary basin in eastern australia a long lived c 9 myr cold climate peat mire ecosystem collapsed at the permian triassic boundary when the vast majority c 95 of peat producing plants became extinct the environmental change marked by the permian triassic boundary is expressed as an abrupt and sharp change in sedimentary regime at the contact between the rangal coal measures and the sagittarius sandstone the stratigraphic record shows no diminution in the thickness lateral extent or spatial distribution of coal seams prior to the boundary event the abrupt ecological shift at the permian triassic boundary was coincident with and interrelated to a change in landscape attributes and fluvial style the boundary shift is considered to reflect a short period radical atmospheric change accompanied by an abrupt change in plant ecosystems however palynological data indicate that it was preceded by a more gradual gross taxonomic progression in the floral succession the boundary shift is unlikely to reflect change in the tectonic setting of the northern bowen basin because the detrital character of clastic sediment supply shows no provenance change within the boundary sequence the late permian fluvial style is characterised by large scale up to 1 km wide sandstone dominated low sinuosity trunk river channel deposits the trunk river channels were flanked by extensive levee composite crevasse splay systems channel tracts were relatively stationary in position over enduring periods and developed stacked sediment accumulations up to 30 m thick the constrained character of the late permian trunk river systems was most likely due to progressive compaction of thick tracts of peat substrate and the stabilising effect of vegetation adjacent to the channel complex the well developed crevasse splays coupled with the low sinuosity style of the fluvial channels might suggest a perennial fluvial system characterised by short discharge periods as common in high latitude settings the fluvial architecture of the sagittarius sandstone the basal formation of the lower triassic rewan group is characterised by sheet like elements suggestive of broad shallow channels in a deforested braid plain setting the channel deposits are considered to represent highly mobile sandy systems dominated by a flashy runoff regime the mass extinction of plants in the northern bowen basin at the permian triassic boundary thus had a significant impact on the early triassic landscape and fluvial architecture

geochemical and organic petrological study of bituminous sediments from dahomey basin sw nigeria abstract the dahomey basin sw nigeria hosts a 3000 m thick sedimentary succession of cretaceous and cenozoic age of which the turonian maastrichtian afowo formation includes sandstones arkoses shales shelly limestones unconsolidated sand clay and most importantly bituminous tar sand strata eighteen samples were picked up from outcrops exposed by streams and channels and were examined applying sedimentological mineralogical petrographical geochemical inorganic and organic and radiological techniques with the aim of assessing the origin and the thermal maturity of the organic facies the samples represent mostly coarse grained sands and subordinately shales referred usually as tar sands they consist of mainly quartz and kaolinite with variable amounts of mixed clay layers of illite montmorillonite mica and pyrite probably derived from weathering of the migmatite gneiss complex exposed to the north of the basin this can also explain the relative enrichment in the natural radionuclides 40k 238u 226ra and 232th for some samples although the radioactivity falls within the range for world values for soils the clastic material of afowo formation was deposited in a rather oxic shallow marine environment the particulate organic matter of the bituminous sediments comprises solid hydrocarbons coalified huminite and partially oxidized inertinite remnants of terrestrial plants and minor amounts of both terrestrial and marine liptinite macerals the random reflectance values of the indigenous huminite population ranges between 0 40 and 0 45 pointing to an immature stage for oil generation the respective reflectance of the migrabitumens ranges from 0 49 to 0 59 corresponding to vitrinite equivalent reflectance values of 0 70 0 76 falling well within the oil window this study concludes that the hydrocarbons contained in the afowo formation are upwards migrating from parts of the basin where afowo formation has subsided at depths corresponding well within the oil window the source rock corresponds to the middle shale horizon whereas the sandy horizons act as migration paths and or reservoirs

an upper paleozoic bio chronostratigraphic scheme for the western margin of gondwana abstract the carboniferous and permian fossiliferous sequences of the central western argentina contain abundant plant remains palynomorphs and invertebrates they include a continuous record of large distribution in the paganzo rio blanco calingasta uspallata and san rafael basins the most recent biostratigraphic schemes recognize a floristic succession represented by the biozones archaeosigillaria frenguellia af biozone frenguellia eximia nothorhacopteris kellaybelenensis cordaicarpus cesarii fnc biozone nothorhacopteris botrychiopsis ginkgophyllum nbg biozone interval biozone and gangamopteris biozone the associated palynological record is represented by the biozones reticulatisporites magnidictyus verrucosisporites quasigobbetti mq biozone raistrickia densa convolutispora muriornata dm biozone pakhapites fusus vittatina subsaccata fs biozone and lueckisporites weylandites lw biozone the precise age of the upper paleozoic western gondwanan biozones has been under discussion and remains controversial to date in some regions the main issue hampering an integrated comparison of the gondwanan biozones was its imprecise chronostratigraphic framework however new studies in some argentinian stratigraphic sections bearing floras and faunas have yielded several radiometric ages from these 206 pb 238 u zircon datings it is possible to determine the chronostratigraphic range of many fossiliferous assemblages in this sector of gondwana in this way the af and mq biozones are restricted to the late mississippian and they would be not younger than 335 ma according to radiometric ages 206 pb 238 u ages suggest that the nbg dma and dmb biozones characterize the late serpukhovian glacial deposits and persisted up to the late bashkirian beds containing the interval and dmc biozones have yielded 206 pb 238 u ages of 312 82 0 11 ma and 310 71 0 1 ma which would indicate that both zones characterize the moscovian the remains of gangamopteris biozone found in the paganzo basin overlie basalt levels ranging between 308 6 and 293 6 ma therefore the incoming of the first glossopterids was closely associated to the carboniferous permian boundary in this part of gondwana the data presented in this paper are used for establishing comparisons with other gondwanan biozones constrained by absolute ages

first record of marine bivalves from the talchir formation of the satpura gondwana basin india palaeobiogeographic implications abstract marine invertebrate fossils are rarely reported from the permian talchir formation of the intracontinental gondwana basins of peninsular india they are known to occur in umaria and manendragarh rewa basin daltonganj and rajhara daltonganj basin and dudhi nala bokaro basin the fossil assemblages include bivalves brachiopods gastropods polyplacophora crinoids bryozoans foraminifers ostracods conulariids etc the fossil localities define a roughly e w trending linear belt along the present day river valleys of son narmada damodar accordingly the existence of a marine embayment within the indian peninsula along this belt during permian time was inferred which extended westward up to the rewa basin this study reveals for the first time occurrence of marine invertebrate fossils within the hlchir formation of the satpura basin which is located further west of the presently known belt of marine fossils the fossil assemblage of the satpura basin includes bivalves ostracods and foraminifers along with floral remains in this present endeavor i describe two bivalve species praeundolornya subelongata dickins 1963 and eurydesrna sp juv this finding implies that the permian marine embayment of the indian peninsula extended further west than that was so far thought to be

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

δ13c and δ18o values of triassic brachiopods and carbonate rocks as proxies for coeval seawater and palaeotemperature abstract a dataset of 160 isotope 13c and 18o values from anisian ladinian carnian and rhaetian articulate brachiopod shells complemented by 158 carbon and oxygen isotope values from whole rock carbonates define the first continuous stable isotope baseline trends for the triassic seawater the carbon isotope data suggest the existence of several short term high amplitude excursions in the early triassic followed by a predominance of values around 0 5 1 during the middle triassic a rise to 3 5 during the carnian plateau at this level during the late carnian to early norian and a 1 5 decline in the middle norian to values around 2 during the late norian rhaetian interval the causation scenarios for these rapid oscillations are at present equivocal but may in part reflect a biological instability of the carbon cycle following the recovery from the end permian extinction event and or an input of mantle derived co2 from enhanced volcanic activity the 18o values from well preserved brachiopods from the tethyan realm range from 3 9 to 0 6 v pdb these values require open marine triassic seawater 18o values close to 0 v smow for the calculated temperatures to be within the range of tolerance of the coexisting reef building corals a 2 18o increase within the uppermost cordevolian and early julian suggests either a distinct temperature decline in the southern alps during that time interval an increase in seawater salinity or their combination oxygen isotope values for the muschelkalk brachiopods range between 6 2 and 2 0 and likely reflect a strong influx of meteoric waters into the germanic basin that shifted the oxygen isotopes to more negative values

permian phytogeography in gondwana abstract phytogeographic patterns based on multivariate techniques multidimensional scaling are proposed for the permian vegetation of gondwana this approach requires a data set with broad geographic coverage based on generic composition and with good time control in general strong phytogeographic differentiation can be observed throughout the permian in order to identify short term phytogeographic patterns the permian period was informally divided into five time slices in the permian stage i earliest permian the vegetation was strongly influenced by glacial conditions a very impoverished vegetation is seen except in patagonia and parts of south america four units were identified patagonia nothosouthamerica australia and indo africa by far patagonia was the most diverse and had the most favourable climatic conditions perhaps as a result of palaeogeographic separation from western gondwana nothosouthamerica which included plant assemblages from nw argentina and brazil perhaps as two subunits is a mid latitude area with glacial influence in the brazilian sector indo africa had a much lower diversity occupying high latitudes whereas australia had the lowest diversity of all the vegetational regions in stage i the early permian stage ii shows a more diversified and expanded plant cover vegetation of eastern and western gondwana was differentiated patagonia and south america including a brazilian and nw argentinean unit had the richest plant assemblages whereas africa indo australia and antarctica as separate units are less diverse probably due to late glacial influence by the late early permian stage iii gondwana shows much more ameliorated climatic conditions basically due to drifting into more temperate latitudes as well as increased moisture resulting in expansion of peat forming areas this is immediately reflected in the vegetation as shown by diversified plant assemblages even in antarctica nonetheless a differentiation is again observed between eastern gondwana patagonian and south american units and the western sector indo australian and antarctic units whereas africa would probably represent an ecotone beginning in the late permian stage iv there was a decrease in the number of plant assemblages and diversity indicating a deterioration in climate resulting from generally drier conditions latitudinal differentiation can be observed with antarctica as a polar unit afro australia at high latitudes whereas the south american indian and patagonian units are located in middle latitudes finally in permian stage v latest permian a south american unit can be differentiated clearly from the rest africa and indo australia antarctica is interpreted again as a discrete unit in the stage v time slice eastern gondwana returns to more humid climatic conditions allowing the formation of extended peat swamps whereas the western sector is affected by seasonal and strong droughtness this kind of phytogeographic approach has proven useful for detecting some palaeogeographic problems such as those involving the patagonian subcontinent in this regard palaeogeographic reconstructions and palaeoclimatic models should be tested against these phytogeographic patterns

δ18o and δ13c of permian brachiopods a record of seawater evolution and continental glaciation abstract two hundred sixty four 18 o and 13 c values of permian articulate brachiopod shells were analyzed and 81 of these values were characterized as well preserved and biostratigraphically well defined these were then utilized for construction of baseline oxygen and carbon isotope curves for the permian interval in addition 21 13 c whole rock values are reported for the wordian and capitanian the early permian asselian to artinskian times are characterized by 2 5 decrease in oxygen isotope values from 0 7 to 3 3 v pdb this is attributed to a 4 7 c increase in temperature in the southern urals concomitant with the retreat of the permo carboniferous ice sheets and return of the 18 o depleted melt water into the oceans the late permian samples from iran jolfa at kuh e ali bashi and china meishan yield 18 o values and presumably temperatures similar to those that followed the termination of the large scale glaciation in the lower permian in between the upper kungurian to capitanian samples from the delaware basin guadalupe mountains are enriched in 18 o at 1 5 to 3 we have no definitive explanation for these data but tentatively suggest that the anomaly can potentially be a result of evaporative enrichment of seawater in 18 o due to intracratonic arid setting of the basin the 18 o enriched nature of the zechstein samples 1 2 to 2 5 on the other hand is in all probability a reflection of the high evaporation rates in the zechstein sea the permian interval is characterized by a relatively constant 13 c at about 4 the exceptions are again the brachiopods from the delaware basin guadalupe mountains which show 1 6 increase in the guadalupian to values of up to 5 9 in the wordian a tentative explanation as in the case of oxygen is based on the proposition that the semi enclosed delaware basin was likely stratified with sequestration of the 13 c depleted carbon to the deeper water layers and a complementary 13 c enrichment in the upper oxygenated layer the coeval open ocean water dic may have been similar to that of the remainder of the permian interval at 4 as indicated by whole rock carbonate samples from oman sicily and iran in the latest permian the trend mimics the well known 13 c drop at the permian triassic boundary

carbon and conodont apatite oxygen isotope records of guadalupian lopingian boundary sections climatic or sea level signal abstract the guadalupian lopingian g l boundary 260 4 ma is one of the major extinction events in earth history that coincides with the emeishan large igneous province and palaeoclimatic changes carbon isotopes of whole rock samples were studied in order to document changes in the global carbon cycle in contrast to earlier studies we observe no major negative excursion in 13 c in the middle capitanian a positive 13 c excursion is observed in the latest capitanian with a 1 5 increase registered in the j xuanhanensis zone to c postbitteri hongshuiensis subzone followed by a decrease of 1 within the c postbitteri postbitteri subzone and a 2 decrease in the c dukouensis to c asymmetrica zone oxygen isotopes of conodonts from two g l boundary sections were measured in order to reconstruct conodont habitat and potential changes in water temperature oxygen isotope ratios of gondolellid conodonts are higher in comparison to oxygen isotope ratios measured on hindeodid conodonts suggesting that gondollelids lived in cooler and thus deeper waters compared with hindeodids the oxygen isotope record reconstructed from gondollelid conodonts suggests warming of water temperatures of about 4 c in the late capitanian j postserrata to j granti zone cooling of about 6 to 8 c across the g l boundary and in the earliest wuchiapingian and again significant warming in the wuchiapingian c dukouensis to c liangshanensis zone the temperature increase can be correlated with the main phase of emeishan volcanism suggesting that climatic warming may have resulted in an intensified hydrological cycle fertilisation of the oceans and enhanced primary productivity the latter documented in the positive late capitanian carbon isotope excursion however changes in sea level seem to parallel reconstructed water temperatures suggesting that changes in water depth in combination with superimposed climatic changes may be responsible for the observed temperature changes this study documents that oxygen isotope studies on permian conodonts should be performed on mono generic conodont samples and that oxygen isotopes not only provide valuable palaeoclimatic information but also may help to constrain the life habitat of conodonts

experimental protocols for the study of battered stone anvils from olduvai gorge tanzania abstract percussive activities are highly relevant in the economy of modern hunter gatherer societies and other primates and are likely to have been equally important during the palaeolithic despite the potential relevance of percussive activities in the early stone age attempts to study battered artefacts are still rare in order to establish protocols of analysis of battered tools this paper pursues an interdisciplinary approach combining techno typological refit use wear and gis studies of experimental anvils from olduvai gorge tanzania the main aim is to classify types of damage on battered artefacts according to the percussive task performed and hence identify patterns that can be used to interpret the oldowan and acheulean evidence our results indicate that abrasion marks on anvil surfaces are typical of nut cracking while bone breaking leaves characteristic scars and abrasion marks on the edges of anvils pounding of soft materials such as meat and plants also causes battering of anvils producing morphological and spatial patterns that can be discerned from the heavy breakage of anvils during bipolar flaking by integrating macroscopic microscopic and spatial analyses of experimental stone tools this paper contributes to create a referential framework in which early stone age battered artefacts can be interpreted

diversity of the woody vegetation of gondwanan southern africa abstract the flora of gondwanan southern africa is represented in the rock record by micro fossils macro fossils and petrified woods all these types of fossils are seldom preserved together in any one particular facies because of taphonomic and preservational biases in order to obtain as accurate a picture as possible of the woody vegetation both the fossil woods and other macroplant fossils such as leaf impressions fructifications and cuticle of woody plants have been correlated this was done for each formation in the karoo supergroup in order to illustrate the changes in diversity of woody vegetation over time sediments of the karoo supergroup represent the terrestrial fossil record of the period upper carboniferous to the lower cretaceous when africa finally separated from south america in the upper carboniferous to lower permian dwyka formation there are at least five described genera of woods from south africa and namibia early to middle permian woods ecca group are a little more diverse with six genera representing the glossopterids cordaitaleans and possibly other seed fern groups late permian to early triassic beaufort group woods show very little change in diversity in spite of the major floral and biotic turnover evident from the rest of the fossil record although the late triassic molteno formation macro flora has been shown to be an example of explosive diversification the generally poorly preserved woods do not reflect this lower jurassic fossils clarens formation are also poorly preserved but have araucarian characteristics early cretaceous woods represent the araucariaceae cheirolepidiaceae and podocarpaceae with a number of species the diversity of the woods has not changed as much as the rest of the floral components in southern africa from the late carboniferous to the early cretaceous possible reasons for this apparent stasis are the conservative nature of wood functional restrictions limitations of suitable conditions for petrifications and the fact that very little research has been done on southern african woods

reflectance measurements of zooclasts and solid bitumen in lower paleozoic shales southern scandinavia correlation to vitrinite reflectance abstract reflectance measurements have been carried out on zooclasts graptolites chitinozoans and vase shaped microfossils and other organic particles vitrinite like particles porous granular vitrinite like particles and solid bitumen in middle cambrian to upper silurian shales from central and southern sweden and the danish island of bornholm baltic sea the most abundant organic components in all the shales are fragments of graptolites and vitrinite like particles the reflectance distribution of these two types of components is largely identical and it is suggested that the vitrinite like particles are fragments of graptolites without any recognizable morphology reflectance measurements of graptolites and vitrinite like particles yield well defined reflectance populations in samples with average r graptolite and average r vitrinite like of 0 75 r o the reflectance distributions are bimodal because of increasing bireflectance and the average reflectance value of the well defined lower reflecting population is arbitrarily used as maturity indicator our results suggest that with increasing thermal maturity the reflectance of graptolites increases faster than the predicted vitrinite reflectance the relationship between graptolite reflectance and equivalent vitrinite reflectance can be expressed by the equation vr eqv 0 73 r graptolite vitrinite like low 0 16 the gas generation window which normally is considered to begin at a vitrinite reflectance of 1 3 r o in post lower paleozoic rocks containing vitrinite starts accordingly at 1 56 r o graptolite reflectance porous granular vitrinite like particles occur in minor amounts and they may represent graptolite fragments with a non smooth surface they generally yield slightly higher reflectance than non granular vitrinite like particles and graptolite fragments the middle cambrian to furongian upper cambrian shales may contain sparse fragments of vase shaped microfossils vsm that seem to follow the maturation trend of chitinozoans in the present sample set the reflectance of chitinozoans and vsm is comparable to that of graptolites at the same level of maturity reflectance measurements of solid bitumen are a poor maturity indicator probably because bitumen can have various origins and morphologies and it may not be indigenous to the host rock

carboniferous permian facies and tectono stratigraphic successions of the glacially influenced and rifted carnarvon basin western australia abstract the carnarvon basin of western australia is a rift basin that contains a thick up to 5 km succession of late carboniferous early permian glacially influenced marine sedimentary strata these rocks accumulated in near polar paleolatitudes along the uplifted and glaciated margin of the west australian shield pilbara craton three stratigraphic successions i ii iii can be recognised each characterised by distinct facies associations that record different stages in the tectonic evolution of the basin and associated changes in the rate of basin subsidence and sediment accommodation a lowermost succession i comprises rapidly deposited 30 m ma glacially influenced marine strata lyons group containing palynomorphs of westphalian tastubian early sakmarian and possibly older age strata are dominated by subaqueously deposited sediment gravity flow facies succession ii is composed of richly fossiliferous cool water shales callythara and cordalia formations that record much reduced sedimentation rates 2 m ma in turn shales are overlain by an uppermost succession iii of shallow marine wave and storm influenced sandstone moogooloo sandstone comparison with other rift basin fills indicates that succession i likely records initial basin infilling where abundant coarse debris was produced by faulting and glaciation of the adjacent pilbara craton shales of succession ii mark a phase of sediment underfilling characterized by rapid tectonic subsidence an increase in relative sea level and reduced sediment supply shallow water sandstone facies of succession iii record a late stage in the tectonic cycle when subsidence rates had decreased and sediment supply outpaced accommodation such successions where found in other late paleozoic basins are widely interpreted in terms of glacioeustatically driven changes in sea level resulting from deglaciation events across gondwana instead the three successions within the carnarvon basin are argued to reflect a dominantly tectonic control on sedimentation and preservation

vegetation history across the permian triassic boundary in pakistan amb section salt range hypotheses about the permian triassic floral turnover range from a catastrophic extinction of terrestrial plant communities to a gradual change in floral composition punctuated by intervals indicating dramatic changes in the plant communities the shallow marine permian triassic succession in the amb valley salt range pakistan yields palynological suites together with well preserved cuticle fragments in a stratigraphically well constrained succession across the permian triassic boundary palynology and cuticle analysis indicate a mixed glossopteris dicroidium flora in the late permian for the first time dicroidium cuticles are documented from age constrained upper permian deposits on the indian subcontinent close to the permian triassic boundary several sporomorph taxa disappear however more than half of these taxa reappear in the overlying smithian to spathian succession the major floral change occurs towards the dienerian from the permian triassic boundary up to the middle dienerian a gradual increase of lycopod spore abundance and a decrease in pteridosperms and conifers are evident synchronously the generic richness of sporomorphs decreases the middle dienerian assemblages resemble the previously described spore spikes observed at the end permian norway and in the middle smithian pakistan and might reflect a similar ecological crisis

the permian triassic palynological transition in the guryul ravine section kashmir india implications for tethyan gondwanan correlations this first palynological study of the permian triassic succession in the guryul ravine kashmir india reveals impoverished latest permian spore pollen assemblages in the uppermost zewan formation a rich palynoassemblage from the basal khunamuh formation characteristic of the permian triassic transition zone and depleted triassic assemblages from higher in the khunamuh formation the collective assemblages can be broadly correlated to the densipollenites magnicorpus and klausipollenites decipiens palynozones of peninsular india and to palynofloras spanning the permian triassic boundary elsewhere in gondwana generally low spore pollen yields and poor preservational quality of the studied assemblages hinder more precise correlations and are inferred to be a function of an offshore marine depositional setting on the margin of the neotethys ocean and thermal alteration associated with cenozoic collisional tectonism between india and asia

a review of the palynostratigraphy of gondwana sediments from the godavari graben india global comparison and correlation of the permian triassic palynoflora abstract the continental sequences of gondwana deposits from the chintalapudi sub basin of the godavari graben south india have been palynologically investigated to explore the permian triassic palynoflora total 11 distinct palynoassemblages belonging to the asselian sakmarian i ii artinskian iii iv guadalupian v vi lopingian vii viii ix induan x and olenekian xi age have been documented the palynological studies support the existence of the two coal bearing horizons in the chintalapudi sub basin one in the karharbari and barakar formations sakmarian artinskian while other in the raniganj formation guadalupian lopingian the lack of the upper barakar and barren measures roadian palynoflora indicates apparent discordance in stratigraphic sequence in this sub basin presently studied the permian triassic palynofloral transition has been found akin to the palynoflora of the salt range madagascar antarctica australia and south africa the palynofloral correlation supports the presence of guttulapollenites palaeophytogeographic province in the gondwana during the guadalupian lopingian the guttulapollenites palaeophytogeographic province co exists with the glossopteris megafloral province and extends from the salt range in the north to amery basin in the south mid zambesi luangwa basin in the west to satpura wardha godavari basin in the east

stratigraphy and morphotectonics of karoo deposits of the northern selous basin tanzania late permian karoo deposits of the northern selous basin in south central tanzania comprise conglomerates and diamictitic boulder beds of alluvial and scarp foot fan origin these merge with grey to greenish sandstones siltstones and black shales of deltaic and lacustrine environments microflora assemblages indicate a late permian age lateral changes and interfingering of various lithofacies units are common depositional development was controlled by syndepositional faulting and variations of gradients resulting from fault movements the position of the fault scarp separating the basin area from the elevated basement horst to the west roughly corresponded with the present boundary between the selous basin and the precambrian metamorphics of the uluguru mountains the late permian karoo succession of this part of the selous basin apparently overlaps older karoo deposits contained in the north northeast trending narrow graben structures it is therefore regarded as a new depositional event which was initiated by renewed tensional tectonism in late permian time during this tectonic episode the narrow early karoo graben structures were expanded into much broader rift basins material eroded from the rift shoulders and associated highlands was literally dumped across the fault scarps forming debris aprons and scarp foot fans rivers emanating from the highlands formed large alluvial fans and further afield deltas issued into freshwater lakes some of these late permian faults were rejuvenated by late cretaceous to early tertiary tectonism thermal waters circulating along fractures converted feldspars biotites and hornblendes to prehnite further tectonic adjustments in mid tertiary time led to the present day morphology

investigation on the lignite deposits of surkha mine saurashtra basin gujarat western india their depositional history and hydrocarbon generation potential abstract an integrated approach is adopted to study the lignite deposits of surkha mine associated with the khadsaliya clays formation eocene of saurashtra basin western india the compilation of detailed investigation includes organic petrographical palynofacies and geochemical analyses the type and amount of organic matter and its relation to palaeoenvironmental conditions have been determined and discussed along with its significance as hydrocarbon source the macerals of huminite group show dominance av 61 over the liptinite and inertinite groups the petrographical indices gi tpi gwi vi indicate wood dominated precursors of peat were deposited in limno telmatic to telmatic regime under mesotrophic hydrological conditions in palynofacies analysis it is observed that the particulate organic matter is dominated by the phytoclasts group av 69 followed by the amorphous organic matter aom and palynomorphs the biomarker signatures show angiosperm and gymnosperm source vegetation the presence of sesquiterpenoids indicate the occurrence of dipterocarpaceae flora suggesting the existence of rain forest vegetation in the vicinity of depositional site the kaurane type of diterpenoids suggest the presence of conifers among the source flora the extrapolation of organic matter data on tyson s app diagram along with the pr n c 17 vs ph n c 18 plot indicate that the deposition took place in dysoxic suboxic conditions with intermittent shifting of the environment in proximal settings the huminite reflectance values av 0 31 r r show a good correlation with gross calorific values av 3917 cal g and average t max value 416 c of the lignites furthermore the abundance of thermally unstable hop 17 21 ene and hopane indicate immature stage of lignites these lignites contain high toc av 35 wt and low ash yields the volatile matter carbon and oxygen contents are relatively high whereas sulphur content is moderate and hydrogen and nitrogen contents are comparatively low in all the lignite samples the hydrogen index values vary between 53 and 538 mg hc g toc the atomic values of h c range from 0 47 to 1 04 and of o c from 0 20 to 0 29 overall the lignite bearing sequence is characterized by type ii iii admixed kerogens organic matters and has potential to generate hydrocarbons upon maturation

late permian palynology and depositional environment of chintalapudi sub basin pranhita godavari basin andhra pradesh india abstract the present study deals with the palynological dating correlation and depositional setting of the sediments from bore cores mgp 11 and mgp 4 from gauridevipet area of chintalapudi sub basin of godavari master basin south india on the basis of palynological studies three palynoassemblages have been identified one in bore core mgp 11 a faunipollenites protohaploxypinus and striasulcites assemblage and two in bore core mgp 4 one is characterized by the dominance of striate bisaccates and densipollenites and the other by striatopodocarpites and cresentipollenites palynoassemblages the other stratigraphically significant taxa include guttulapollenites hannonicus lunatisporites noviaulensis lunatisporites pellucidus densoisporites contactus chordasporites australiensis goubinispora spp lundbladispora microconata lundbladispora raniganjensis and klausipollenites schaubergeri the recovered taxa suggest a late permian lopingian age for these rocks this interpretation is based on the correlation of the assemblages with similar assemblages from previous gondwana studies chiefly densipollenites magnicorpus zone of damodar basin india and late permian palynoassemblages from africa antarctica australia and south america on the basis of palaeobotanical affinity of the identified microflora it has been inferred that the peat forming plant community was composed mainly of gymnosperm pollen attributable to glossopterids that includes striate and non striate bisaccates and paucity of cordaites which includes monosaccates spores are subordinate and are derived from lycopsids lundbladispora densoisporites sphenopsids latosporites and filicopsids horriditriletes lophotriletes verrucosisporites osmundacidites leiotriletes callumispora brevitriletes and microbaculispora occurring in variable proportions the dominance of subarborescent arborescent vegetation suggests a development in a forest swamp probably in a small distant marginal part of the mire or periods of standing water this flooding environment favoured the growth of herbaceous lycopsids filicopsids and sphenopsids in the palaeomire more or less similar environments of deposition have been deduced for both the sedimentary sequences on the basis of palynofacies analysis anaerobic reducing water logged peat forming conditions have been inferred based on the abundance of phytoclasts the relative abundance of structured organic matter implies the existence of a fairly dense vegetation cover in the hinterland the charcoal fragments recovered from the present study area reflects a possible wildfire in the accumulated swamps or a wildfire in the hinterland after which the sediments were flushed by fluvial systems into the swamps

palynology and correlation of carboniferous permian glacigene rocks in oman yemen and pakistan palynological assemblages from sections in yemen and pakistan are similar enough to allow the application of biozones based on the pennsylvanian glacigene sediments of interior oman thirty four samples from the upper 84 m of a 125 m thick section of the tobra formation at zaluch nala western salt range pakistan yielded palynomorph taxa including microbaculispora tentula abundant monosaccate pollen including cannanoropollis janakii and plicatipollenites malabarensis converrucosisporites grandegranulatus horriditriletes ramosus and horriditriletes tereteangulatus indicating the late pennsylvanian oman 2165b biozone eleven samples from the yemen kuhlan formation and 22 samples from the underlying akbarah formation from approximately 300 m of a section near kuhlan in northwest yemen suggest a 2165a biozone age also late pennsylvanian this correlation indicates the widespread nature of glacial sediments of a narrow biostratigraphic late pennsylvanian age range the oman p5 unit in basins across part of the north gondwana margin new data from three samples from the tobra formation at the choa road section near khewra in the eastern salt range pakistan are assignable to the earliest permian 2141b biozone indicating a possible correlation between the tobra shale and the rahab shale member of oman which is considered to mark the final deglaciation sequence in oman

discovery of gondwana plant fossils and palynomorphs of late asselian early permian age in the karakoram block we report the discovery of early permian late asselian 280 275 ma plant fossils and associated palynomorphs from a marine sedimentary sequence of the eastern karakoram plate in northern india these specimens show affinities with those found in marine lower gondwana sediments of the indian subcontinent this supports the contention that during the early permian period the karakoram plate was peri gondwanan it is suggested to have had an intermediate position between the indian plate and the qiangtang lhasa microcontinents at a latitude of about 35 south

organic matter and palaeoenvironmental signals during the early triassic biotic recovery the salt range and surghar range records latest permian to the middle triassic mixed siliciclastic carbonate shelf deposits of the northern gondwana margin have been studied in four sections nammal chhidru chitta landu and narmia in the salt range and surghar range of pakistan sedimentological and palynofacies patterns combined with a high resolution ammonoid based age control have been used to assess environmental changes such as sea level change distance from the shore and oxygenation conditions of the sections in the aftermath of the end permian mass extinction the base and the top of the early triassic are marked by second order sequence boundaries srt1 srt8 within the early triassic two third order sequence boundaries could be delineated by means of palynofacies analysis and sedimentology one near the dienerian smithian srt2 and the second one near the smithian spathian boundary srt5 the extinction event at the smithian spathian boundary seems to be closely associated to the latter globally recorded sea level low stand five additional sequences of undetermined order srt3 srt 4 srt5 1 srt6 and srt7 are reflected in the sedimentological record of the studied sections the observed changes in the composition of the particulate organic matter pom indicate a general shallowing upward trend which is modulated by smaller transgressive regressive cycles supporting the sedimentologically defined sequences the pom is mostly dominated by terrestrial phytoclasts and sporomorphs the strongest marine signal is reflected by increased abundance of amorphous organic matter aom in the lower part of the ceratite marls at nammal late dienerian and chhidru earliest smithian and the lower ceratite limestone at chitta landu late dienerian aom of marine origin is characteristic for deeper distal basinal settings and is preferentially preserved under dysoxic and anoxic conditions indicating reduced oxygen conditions during these intervals up section transgressive events are reflected by increased numbers of acritarchs reaching up to 50 of the pom well oxygenated conditions and low total organic carbon contents toc continue up to the top of the early triassic mianwali formation the most pronounced terrestrial influx is expressed in the middle triassic organic carbon isotope data parallel the carbonate carbon isotope records from the tethyan realm therefore they reflect real global changes in the carbon cycle independent of the om composition the biomarker study of the apolar hydrocarbons of three samples from the nammal section indicates an enhanced bacterial productivity especially in the smithian and spathian reflected in high relative abundances of hopanes pom toc data and redox sensitive biomarkers together with high resolution biostratigraphy demonstrate that well oxygenated environmental conditions prevailed in the early triassic with the exception of the dienerian to earliest smithian interval the pom assemblages of late permian to late griesbachian age indicate well oxygenated conditions during this time interval there is no evidence in support of an anoxic event in the late griesbachian in these sections

oxygen isotope values from high latitudes clues for permian sea surface temperature gradients and late palaeozoic deglaciation abstract the permian was a period of waning large scale continental glaciations in the southern hemisphere the waning of these ice sheets during the early permian led to discharge of 18o depleted ice melt water into the oceans this coupled with rising seawater temperatures resulted in a concomitant decline of about 2 5 in the 18o of seawater as recorded by brachiopod shells from low latitude

new biostratigraphic age dates from the lake rukwa rift basin in western tanzania geologic note 1 the rukwa rift basin in western tanzania is a segment of the western branch of the east african rift system three major stratigraphic units have been recognized in the basin from oldest to youngest karroo supergroup the red sandstone and the lake beds these units have traditionally been assigned the following ages respectively based upon lithologic correlations permian triassic jurassic cretaceous and tertiary recently microfloral assemblages collected from sidewall cores and cuttings from two deep exploration wells drilled in the basin have provided new data on the age of these formations the biostratigraphic data suggest the formations should be assigned the following ages karroo supergroup late permian red sandstone neogene miocene late pliocene and the lake beds late pliocene holocene the new age dates indicate that the post karroo to pre miocene history of the basin is one of relative quiescence and the modern rift is a relatively young feature this interpretation is more consistent with the tectonic histories of the other basins of the western rift

the geology petrology palynology and geochemistry of permian coal basins in tanzania 2 songwe kiwira coalfield abstract this study provides coal quality petrological palynological and geochemical rock eval data on permian coal seams and associated shales and mudstones of the karoo supergroup of the songwe kiwira coalfield tanzania the coal seams which have a cumulative thickness of 6 80 m occur in the shale coal sandstone facies of the mchuchuma formation of artinskian to kungurian age coal quality data calorific values volatile matter contents and vitrinite reflectances indicate high volatile c bituminous to high volatile a bituminous coals having relatively high ash yields 22 49 wt and highly variable sulphur contents 0 17 9 2 wt they could be used to fuel small scale power generation units thereby providing electricity to nearby towns and villages also the coals could be used as a substitute for wood which is becoming increasingly scarce in rural tanzania charcoal is still the main energy source for cooking and wood is used extensively in brick kilns and for making roofing tiles petrological analysis indicated that the coals are dominated by dull to banded dull lithotypes with seams at the base of the mchuchuma formation enriched in inertinite macerals up to 83 vol whereas up section vitrinite contents increase palynological analyses indicated that the assemblage in the lower mchuchuma formation scheuringipollenites assemblage is dominated by trilete spores whereas in the remainder of the section non taeniate disaccates dominate scheuringipollenites protohaploxypinus assemblage facies critical macerals suggest for most seams a marsh wet forest swamp depositional setting which is consistent with the palynological data rock eval analyses indicate type ii iii kerogen with tmax c values ranging from 426 to 440 corresponding to the early stage of hydrocarbon generation thermal alteration indices 2 to 2 and vitrinite reflectance levels 0 60 0 83 ro support the rock eval maturity assessment and despite the predominance of terrestrial derived organic matter there is evidence of oil generation and expulsion in the form of cavity and fracture filling exsudatinite

early triassic early olenekian life in the interior of east gondwana mixed marine terrestrial biota from the kockatea shale western australia abstract a new terrestrial marine assemblage from the lower beds of a thin outcrop section of the kockatea shale in the northern perth basin western australia contains a range of fossil groups most of which are rare or poorly known from the lower triassic of the region to date the collection includes spinose acritarchs organic cemented agglutinated foraminifera lingulids minute bivalves and gastropods ammonoids spinicaudatans insects austriocaridid crustaceans actinopterygians a temnospondyl like mandible plant remains and spores and pollen of these groups the insects crustaceans and macroplant remains are recorded for the first time from this unit palynomorphs permit correlation to nearby sections where conodonts indicate an early olenekian smithian age the locality likely represents the margin of an early triassic shallow interior sea with variable estuarine like water conditions at the southwestern end of an elongate embayment within the east gondwana interior rift sag system preserved along the western australian margin monospecific spinose acritarch assemblages intertwined with amorphous organic matter may represent phytoplankton blooms that accumulated as mats and suggest potentially eutrophic surface waters the assemblage represents a mixure of marine and terrestrial taxa suggesting variations in water conditions or that fresh brackish water and terrestrial organisms were transported from adjacent biotopes some of the lower dark shaly beds are dominated by spinicaudatans likely indicating periods when the depositional water body was ephemeral isolated or subjected to other difficult environmental conditions the biota of the kockatea shale is insufficiently known to estimate biotic diversity and relationships of individual taxa to their permian progenitors and triassic successors but provides a glimpse into a coastal zone from the interior of eastern gondwana specialist collecting is needed to clarify the taxonomy of many groups and comparisons to other lower triassic sites are required to provide insights into the pattern of biotic decline and recovery at the end permian crisis

global basin classification system a proposed system classifies sedimentary basins worldwide into specific as well as general categories the geologic history of each basin may be subdivided into cycles using three parameters basin forming tectonics depositional sequences and basin modifying tectonics sedimentary basins may be simple with one or two tectonic sedimentary cycles or they may be complex polyhistory basins with many different cycles and events there are eight simple cycle types in this classification which cover continental continental margin and oceanic areas the eight basic cycle types their depositional fills and tectonic modifiers have been given letter and number symbols so that the specific geologic history of each basin may be written as a formula these formulas may then e compared and similarities or differences between basins noted

coal seam correlation of an indian gondwana coalfield a palaeobotanical perspective abstract coal in india mainly belongs to gondwana coalfields of damodar koel son mahanadi wardha godavari narmada and satpura basins the associated carbonaceous shales and sandstones exposed in these coalfields contain a variety of plant fossil assemblages of glossopteris flora the name of the flora is derived from the dominant presence of glossopteris leaves having a tongue shape entire margin distinct midrib and reticulate venation pattern apart from the leaves of glossopteris the flora is known by related leaf types variety of male female fructifications seeds sporangia and spore pollen of the glossopterid group of plants the fossils of other groups of plants viz bryophytes lycophytes pteridophytes coniferophytes and ginkgophytes are also discovered in association with the flora the coal bearing sequence of the indian gondwana coalfields is subdivided into a number of geological formations of the permian period i e talchir karharbari barakar barren measures and raniganj each formation contains characteristic plant fossil assemblages the coal is being exploited from the workable coal seams of the karharbari barakar and raniganj formations the palaeobotanical investigation of plant fossils recovered from four different coal seams of pench kanhan and pathakhera coalfields of the satpura gondwana basin of central india indicates the presence of different types of assemblages in different coal seams the flora of lower barakar coal seams demonstrates the frequent occurrence of gangamopteris noeggerathiopsis buriadia botrychiopsis various types of fructification ottokaria arberia seeds and leaves of glossopteris in distinction the assemblage of the upper barakar seams show the homogeneity of flora with dominance of glossopteris species and different types of glossoptrid leaves e g rhabdotaenia maheshwariphyllum fructification plumsteadia partha scutum and fertile and sterile fronds of neomariopteris present study for the first time demonstrates the usefulness of plant fossil data in the correlation of coal seams in the gondwana coalfields of india the floristic analysis of the raniganj coalfield of eastern india also shows the evidence of specific distributions of plant fossils in different coal seams of early permian barakar formation

carboniferous permian palynostratigraphy of west australian marine rift basins resolving tectonic and eustatic controls during gondwanan glaciations abstract the longest interval of cold climate in earth s phanerozoic history spanned some 55 million years from the namurian late carboniferous to the kungurian early permian when glaciation affected much of high latitude gondwana uncertainty surrounds the timing of glaciation s and the frequency of interglacial episodes ice volumes and the location of ice centres this is because the glacial record is preserved predominantly within marine strata deposited in intracontinental rift basins marginal to onshore ice centres on uplifted basement highs the direct stratigraphic record of glaciation is meagre on adjoining basement highs and extremely difficult to date many basins contain broadly similar threefold lithostratigraphic successions of lowermost glaciomarine diamictite facies middle shales and uppermost carbonate and sandstone rich commonly coal bearing deltaic strata in the absence of absolute age control and infrequent presence of macrofossils such deglaciation sequences are widely assumed to be correlative from basin to basin recording gondwanan deglaciation s and a world wide glacioeustatic sea level rise a newly compiled biostratigraphic database for west australia using first appearance datums of spore pollen types allows correlation of late palaeozoic siliciclastic successions between seven basins bonaparte canning carnarvon collie gunbarrel northern and southern perth basins these extend some 3800 km along australia s western continental margin adjacent to the west australian shield all but the gunbarrel basin contain tripartite glacially influenced successions diamictite shale sandstone biostratigraphic data reveal sharp differences in ages and stratigraphic distributions and marked variations in the thickness of coeval units diamictite shale sandstone successions accumulated diachronously from basin to basin recording a dominant tectonic control on subsidence and relative sea level middle shale units are not exact correlatives between basins and thus are unlikely to simply represent widespread climatically controlled glacioeustatic events instead they are argued to record high relative sea levels during times of maximum synrift subsidence this tectonostratigraphic model can be applied to other intracontinental rift basin successions across gondwana