response of late carboniferous and early permian plant communities to climate change abstract late carboniferous and early permian strata record the transition from a cold interval in earth history characterized by the repeated periods of glaciation and deglaciation of the south

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

evolution of caledonian deformation fabrics under eclogite and amphibolite facies at vardalsneset western gneiss region norway the vardalsneset eclogite situated in the western gneiss region sw norway is a well preserved tectonite giving information about the deformation regimes active in the lower crust during crustal thickening and subsequent exhumation the eclogite constitutes layers and lenses variably retrograded to amphibolite and is composed of garnet and omphacite with varying amounts of barroisite actinolite clinozoisite kyanite quartz paragonite phengite and rutile the rocks record a five stage evolution connected to caledonian burial and subsequent exhumation 1 a prograde evolution through amphibolite facies t 490 63 c is inferred from garnet cores with amphibole inclusions and bell shaped mn profile 2 formation of l s tectonite eclogite t 680 20 c p 16 2 kbar related to the subduction of conti nental crust during the caledonian orogeny lack of asymmetrical fabrics and orientation of eclogite facies extensional veins indicate that the deformation regime during formation of the l s fabric was coaxial 3 formation of sub horizontal eclogite facies foliation in which the finite stretching direction had changed by approximately 90 disruption of eclogite lenses and layers between symmetric shear zones characterizes the dominantly coaxial deformation regime of stage 3 locally occurring mylonitic eclogites t 690 20 c p 15 1 5 kbar with top w kinematics may indicate however that non coaxial deformation was also active at eclogite facies conditions 4 development of a widespread regional amphibolite facies foliation t 564 44 c p 10 3 8 1 kbar quartz veins and development of conju gate shear zones indicate that coaxial vertical shortening and sub horizontal stretching were active during exhumation from eclogite to amphibolite facies conditions 5 amphibolite facies mylonites mainly formed under non coaxial top w movement are related to large scale movement on the extensional detachments active during the late orogenic extension of the caledonides the structural and metamorphic evolution of the vardalsneset eclogite and related areas support the exhumation model including an extensional detachment in the upper crust and overall coaxial deformation in the lower crust

paleoecology of the fire clay coal bed in a portion of the eastern kentucky coal field vertically continuous increment samples of the fire clay coal bed mid middle pennsylvanian late westphalian b collected from a portion of the central appalachian basin were studied palynologically petrographically and geochemically in order to partially reconstruct the paleoecology and processes associated with peat formation in the ancient fire clay paleomire results indicate that four compositional groups can be identified they are 1 a lycospora vitrinite dominant group characterized by high percentages of lycospora and vitrinite macerals and generally low but variable ash yields and sulfur contents 2 a mixed palynoflora high vitrinite group that petrographically is similar to group 1 except that it contains a more diverse palynoflora 3 a mixed palynoflora moderate low vitrinite group characterized by various admixtures of lycopsid fern and calamite miospores increased percentages of liptinite and inertinite macerals and low ash yields and sulfur contents and 4 a mixed palynoflora high ash yield group characterized by high percentages of small lycopsid fern and occasionally calamite and cordaite miospores high liptinite and inertinite contents high ash yields and moderate to high sulfur contents the fire clay coal bed contains a distinctive flint clay parting of probable volcanic origin that naturally divides the bed into two benches these two benches upper and lower are highly disparte in occurrence appearance and composition in the study area the lower bench generally is thin 0 5 m laterally discontinuous and mainly composed of dull mainly durain coal lithotypes ash yields typically are high sulfur contents generally are moderate to high compositional group 4 the mixed palynoflora high ash yield group defines all of the increments examined from the lower bench in contrast the upper bench is thick 0 75 m laterally continous and mainly comprised of bright mainly clarain coal lithotypes overall ash yields and sulfur contents for this bench are generally low although vertical variation is apparent all of the compositional groups occur in the upper bench in some columns notably those that are thick and uninterrupted by clastic partings groups 1 and 4 often occupy basal coal layers and groups 2 and 3 occur in higher layers other columns especially those taken in areas of thin 0 5 m fire clay coal are dominated by groups 1 and 4

comparison of the eastern and western kentucky coal fields pennsylvanian usa why are coal distribution patterns and sulfur contents so different in these coal fields abstract more than 130 mt of pennsylvanian coal is produced annually from two coal fields in kentucky the western kentucky coal field occurs in part of the illinois basin an intercratonic basin and the eastern kentucky coal field occurs in the central appalachian basin a foreland basin the basins are only separated by 140 km but mined western kentucky coal beds exhibit significantly higher sulfur values than eastern kentucky coals higher sulfur coal beds in western kentucky have generally been inferred to be caused by more marine influences than for eastern kentucky coals comparison of strata in the two coal fields shows that more strata and more coal beds accumulated in the eastern than western kentucky coal field in the early and middle pennsylvanian inferred to represent greater generation of tectonic accommodation in the foreland basin eastern kentucky coal beds exhibit a greater tendency toward splitting and occurring in zones than time equivalent western kentucky coal beds which is also inferred to represent foreland accommodation influences overprinted by autogenic sedimentation effects western kentucky coal beds exhibit higher sulfur values than their eastern counterparts but western kentucky coals occurring in langsettian through bolsovian strata can be low in sulfur content eastern kentucky coal beds may increase in sulfur content beneath marine zones but generally are still lower in sulfur than mined western kentucky coal beds indicating that controls other than purely marine influences must have influenced coal quality the bulk of production in the eastern kentucky coal field is from duckmantian and bolsovian coal beds whereas production in the western kentucky coal field is from westphalian d coals langsettian through bolsovian paleoclimates in eastern kentucky were favorable for peat doming so numerous low sulfur coals accumulated these coals tend to occur in zones and are prone to lateral splitting because of foreland tectonic and sedimentation influences in contrast westphalian d coal beds of western kentucky accumulated during low differential tectonic accommodation and therefore tend to be widespread and uniform in characteristics but exhibit higher sulfur values because they accumulated in seasonally drier paleoclimates that were unfavorable for peat doming hence basin analyses indicate that many differences between the mined coals of kentucky s two coal fields are related to temporal changes in paleoclimate and tectonic accommodation rather than solely being a function of marine influences

depositional history of the fire clay coal bed late duckmantian eastern kentucky usa more than 3800 coal thickness measurements proximate analyses from 97 localities and stratigraphic and sedimentological analyses from more than 300 outcrops and cores were used in conjunction with previously reported palynological and petrographic studies to map individual benches of the coal and document bench scale variability in the fire clay hazard no 4 coal bed across a 1860 km 2 area of the eastern kentucky coal field the bench architecture of the fire clay coal bed consists of uncommon leader benches a persistent but variable lower bench a widespread and generally thick upper bench and local variable rider benches rheotrophic conditions are inferred for the leader benches and lower bench based on sedimentological associations mixed palynomorph assemblages locally common cannel coal layers and generally high ash yields the lower bench consistently exhibits vertical variability in petrography and palynology that reflects changing trophic conditions as topographic depressions infilled infilling also led to unconfined flooding and ultimately the drowning of the lower bench mire the drowned mire was covered by an air fall volcanic ash deposit which produced the characteristic flint clay parting the extent and uniform thickness of the parting suggests that the ash layer was deposited in water on a relatively flat surface without a thick canopy or extensive standing vegetation across most of the study area ash deposits led to regional ponding and establishment of a second planar mire because the topography had become a broadly uniform nutrient rich surface upper bench peats became widespread with large areas of the mire distant to clastic sources vertical sections of thick 70 cm low ash yield upper coal bench show a common palynomorph change from arborescent lycopod dominance upward to fern and densospore produc ing small lycopod dominance inferred as a shift from planar to ombrotrophic mire phases domed mires appear to have been surrounded by wide areas of planar mires where the coal was thinner 70 cm higher in ash yield and dominated by arborescent lycopods rectangular

facies development in the lower freeport coal bed west central pennsylvania u s a abstract the lower freeport coal bed in west central pennsylvania is interpreted to have formed within a lacustrine mire environment conditions of peat formation caused by the changing chemical and physical environments produced five coal facies and two mineral rich parting facies within the coal bed the coal bed facies are compositionally unique having developed under varying conditions and are manifested by megascopic petrographic palynologic and quality characteristics the initial environment of the lower freeport peat resulted in a coal facies that is relatively high in ash yield and contains large amounts of lycopod miospores and moderate abundances of cryptotelinite crypto gelocollinite inertinite and tree fern miospores this initial lower freeport peat is interpreted to have been a topogenous body that was low lying relatively nutrient rich mesotrophic to eutrophic and susceptible to ground water and to sediment influx from surface water the next facies to form was a ubiquitous clay rich durain parting which is attributed to a general rise in the water table accompanied by widespread flooding following formation of the parting peat accumulation resumed within an environment that inhibited clastic input development of doming in this facies restricted deposition of the upper shale parting to the margins of the mire and allowed low ash peat to form in the interior of the mire because this environment was conducive to preservation of cellular tissue this coal facies also contains large amounts of crypto telinite this facies development is interpreted to have been a transitional phase from topogenous planar peat formation to slightly domed oligotrophic nutrient poor peat formation as domed peat formation continued fluctuations in the water table enabled oxidation of the peat surface and produced high inertinite concentrations toward the top of the coal bed tree ferns became an increasingly important peat contributor in the e upper facies based on the palynoflora this floral change is interpreted to have resulted from the peat surface becoming less wet or better drained a condition that inhibited proliferation of lycopod trees accumulation of the peat continued until rising water levels formed a freshwater lake within which clays and silts were deposited the development of the lower freeport peat from a planar mire through transitional phases toward domed peat formation may be an example of the type of peat formation of other upper middle and upper pennsylvanian coal beds

paleoecological interpretation of a middle pennsylvanian coal bed in the central appalachian basin u s a abstract at least 180 small spore species assignable to 62 miospore genera have been identified from the middle pennsylvanian hernshaw coal bed in southern west virginia and its stratigraphic equivalent the fire clay coal bed in eastern kentucky the established natural affinities of a majority of these miospore taxa indicate that the hernshaw fire clay peat swamp supported a diverse flora consisting of arborescent and herbaceous lycopods ferns tree like and small varities calamities and cordaites four floral groupings are recognized in the hernshaw fire clay coal bed the inferred paleoecology and vertical stratification of each of these four floral groupings is similar in structure to the phasic floral communities found in modern domed peat systems suggesting that the ancient hernshaw fire clay peat swamp was a domed deposit compositional characteristics petrographic make up ash yield and sulfur content associated with the four groupings are consistent with and support this interpretation where uninterrupted by inorganic partings the hernshaw fire clay coal bed commonly contains basal coal layers dominated by lycospora bearing arborescent lycopods with successive increments showing a progression to a more fern and herbaceous lycopod dominant flora in younger layers these observations are corroborated by petrographic analyses which show the bed to be compositionally stratified increments dominated by lycospora have high vitrinite contents in contrast to increments containing increased percentages of fern and herbaceous lycopod affiliated taxa that are enriched in inertinite macerals the volcanic ash fall preserved as the flint clay parting in the hernshaw fire clay coal bed had a considerable effect on the development of the ancient hernshaw fire clay peat swamp besides interrupting peat formation the presence of an inorganic substrate represent a major change in edaphic conditions within the swamp this disruption is demonstrated by a change in palynflora and by the establishment and proliferation of some plant groups notably cordaites and calamites that may have been better adapted to growth on mineral soils these palynologic and petrographic relationships thought to be indicative of a domed peat swamp origin are not confined to the hernshaw fire clay coal bed but appear to be characteristic of many coal beds in the appalachian basin and also of coal beds in other basins

applications of inclusion behaviour models to a major shear zone system the nordfjord sogn detachment zone in western norway rigid inclusion models have reached a stage where one should be able to use them to obtain quantitative values from ductile shear zones we used natural data collected in three sites and combined analogue and theoretical modelling to assess vorticity strain nature of rigid inclusion matrix interface and confinement in the large scale ductile nordfjord sogn detachment zone nsdz of the caledonides of western norway our study shows that 1 the observed shape preferred orientation spo at higher structural levels of the nsdz at site 1 gjervika can be explained by simple shear pure shear simple shear ratio sr 0 associated with a slipping inclusion matrix interface 2 the observed spo at deeper structural levels of the nsdz at site 2 near sandane can be produced by simple shear associated with a significant amount of shortening across the shear zone sr z 1 acting upon rigid inclusions in slipping contact with the enclosing matrix 3 observed back rotated boudins deeper in the nsdz at site 3 biskjelneset can form in confined flow associated with a considerable amount of shortening across the shear zone sr 0 4 4 the observed tails of porphyroclasts indicate a minimum at least local strain of ca g z 20 5 the clasts in the studied shear zones strongly depart from jeffery s model jeffery g b 1922 the motion of ellipsoidal particles immersed in a viscous fluid proceedings of the royal society of london a102 161e179 the large scale extensional nsdz under investigation shows evidence of strain partitioning rocks vary from protomylonites to ultramylonites and the simple shear and pure shear components are heterogeneously distributed therefore we conclude that flow in the nsdz was very heterogeneous both at the kilometre and the metre scale however the present study suggests that the amount of shortening across the shear plane throughout the nsdz increases with depth and the flattening component contributes to exhumation of the eclogite facies rocks in its footwall 2007 elsevier ltd all rights reserved

factors controlling the vegetation distribution and coal forming environments in a strike slip basin the pennsylvanian penarroya belmez espiel basin southern spain

paleobotanical and paleoecological constraints on models of peat formation in the late carboniferous of euramerica abstract the dominant plants of the late carboniferous lowland tropics were taxonomically and structurally distinct from those of any later time periods dominance was distributed among lycopsids ferns sphenopsids pteridosperms and cordaites and each of these groups had distinctive and different ecological preferences and amplitudes peat forming habitats were dominated by lycopsids throughout the westphalian with a significant cordaitean element in the middle westphalian during the stephanian tree ferns were dominant following major extinctions near the westphalian stephanian transition each of the major plant groups had distinctive architectures and tissue composition trees contributed up to 95 of the peat biomass and tree forms of lycopsids psaronius and medullosa lack good modern analogues the cordaites were the only woody plant group to contribute significantly to peat and then only during the mid westphalian structurally wood like lycopsid bark is the major woody tissue encountered in most westphalian coals tree ferns and pteridosperms were largely parenchymatous in construction the stigmarian root systems of lycopsids also were largely parenchymatous the tissue structure of these dominant plant suggests the need for extreme caution in the inference of mire ecological conditions or vegetational structure from coal petrographic data peat formed under arborescent ferns or pteridosperms or peat repeatedly exposed to decay and rerooting by stigmarian root systems of lycopsids would have a distinctly non woody signature and yet would have formed in a forested environment a summary is presented of the autecology and synecology of mire plants emphazing the structural framework provided by lycopsids during the westphalian certain constraints in the links between peat biomass and miospore palynology are discussed in terms of over representation under representation and non representation the formulation of smith s four phase hydroseral model is discussed and compared with more recent data available from plant paleoecology the current debate over an ombrotrophic vs rheotrophic origin of late carboniferous peats relies in large part on paleobotanical data almost entirely palynological in combination with petrographic analyses ecological studies of miospores and of coal ball and compression macrofossils and the linkage of miospores to source plants permit the re evaluation of mire successional models evidence for tree lycopsids sphenopsids pteridosperms and cordaites suggests growth mainly in rheotrophic mires tree ferns are likely candidates for growth in domed mires although evidence is ambiguous and some tree ferns clearly grew under rheotrophic conditions densospores produced by at least sporangiostrobus lycopsid subtrees have been considered diagnostic of ombrotrophic conditions abundant evidence refutes this simplistic interpretation and suggests broad ecological amplitudes for densospore producers including growth under rheotrophic conditions although plant fossils alone can not resolve most of the major debates in modern coal geology paleobotany does contribute significantly to our understanding of ancient mires an approach combining paleobotanical data with petrography sedimentology and geochemistry on a case by case basis is most likely to produce a clear picture

characteristic trace fossil associations in oxygen poor sedimentary environments the sedimentologic record of oxygen poor depositional environments typically includes trace fossils produced by deposit feeding organisms we propose an oxygen controlled trace fossil model in which increasing oxygen concentration of interstitial water in sediment parallels a transition from fodinichnia dominated through pascichnia dominated to domichnia dominated trace fossil associations in certain places such as parts of the late paleozoic oquirrh basin in utah this model provides a reasonable alternative to the more traditional depth controlled model of trace fossil distribution

a late stephanian forest swamp with sporangiostrobus fossilized by volcanic ash fall in the puertollano basin central spain abstract about 600 m of coal measures and oil shales in the puertollano basin of castilla la mancha contain late stephanian floras an ash fall now a tuff band intercalated in the lower part of coal seam iii fossilized a swamp forest floor with abundant mature sporangiostrobus remains that are associated with vegetative bodeodendron the same lycophyte the pecopterid fern scolecopteris and the sphenophytes asterophyllites and annularia sphenophylloides the floral composition of this tuff band was analyzed and the various stages of the disarticulation process of sporangiostrobus were determined the fertile apices of these lycophyte trees fell onto the forest floor where flattening occurred as the result of decay of the wide cortical area and the central part of the siphonostele subsequently the long distal laminae of sporophylls were removed and afterwards the sporangia leaving only the short stubby horizontal proximal parts of the sporophylls attached to the hulk of these fertile apices of stems or major branches disarticulation was the means of dissemination of the sporangia of this heterosporous lycophyte that produced cristatisporites densosporites cingulizonates microspores and zonalesporites megaspores sporangiostrobus was an extremely prolific producer of densospores and there is a direct correlation between sporangiostrobus and the high densospore count and durite content of seam iii the stratigraphic succession associated with seam iii is described environmental conditions are discussed in relation to the numerous well over a thousand specimens large almost complete remains of sporangiostrobus found in the lower tuff band the detached fertile apices were lying on the forest floor when the volcanic ash fall took place and were preserved in situ where they were shed from the bodeodendron tree this implies an absence of water currents although the general environment must have been humid in view of the overall lacustrine setting it is noted that this is one of the rare examples in europe and north america palaeoequatorial belt where lycophytes continued to be the dominant peat forming element in late stephanian time the systematic position of sporangiostrobus is briefly discussed this lycophyte belonged to a conservative group that was widely distributed throughout the world its important role in latest carboniferous peat forming environments has not been realized until now because of the rarity of richly preserved sporangiostrobus remains

coal facies studies in the eastern united states coals in the eastern united states east of the mississippi river have been the subject of a number of coal facies studies going back to the 19th century such studies would not necessarily fall within a strict modern classification of coal facies studies but if a study encompassed some aspects of paleobotany palynology petrology geochemistry or sedimentology we assumed that some data and interpretations may be of use in evaluations of the facies references are presented as a guide for further research with annotation in the tables

transgressive channel filling in the breathitt formation upper carboniferous eastern kentucky coal field usa abstract carbonaceous shales of brackish or marine origin in the breathitt formation may exhibit sharp bases with local channel form scours minor channels at the bases of these shales exhibit three general types of fill 1 shale 2 bioturbated heterolithic strata and 3 coal overlain by shale or bioturbated heterolithic strata most of the scours at the bases of the channels were formed during a depositional hiatus that preceded transgression some may also have been formed by transgressive reworking of underlying estuarine and deltaic siliciclastics the channel fills are bioturbated and may contain crudely cyclical rhythmites subordinate and dominant siltstone laminae couplets wave ripples and bimodal current ripple trends the fills are interpreted to represent estuarine sedimentation during marine transgression channels are capped by sideritic bioturbated sandstones that separate the fills from the overlying dark shales deposited under brackish to marine water conditions some of these sandstones may represent local transgressive surfaces the occurrence of these types of channels in different parts of the coal bearing breathitt formation supports the hypothesis of multiple transgressions during the late carboniferous in the central appalachian basin

dips ramps and rolls evidence for paleotopographic and syn depositional fault control on the western kentucky no 4 coal bed tradewater formation bolsovian illinois basin abstract the western kentucky no 4 coal is a high volatile b to high volatile c bituminous coal that has been heavily mined along the southern margin of the western kentucky coal field the seam has a reputation for rolling floor elevation elongate trends of floor depressions are referred to as dips and rolls by miners some are relatively narrow and straight to slightly curvilinear in plan view with generally symmetric to slightly asymmetric cross sections others are broader and asymmetric in section with sharp dips on one limb and gradual ramp like dips on the other some limbs change laterally from gradual dip to sharp dip to offset of the coal lateral changes in the rate of floor elevation dip are often associated with changes in coal thickness and in underground mines changes in floor elevation are sometimes associated with roof falls and haulage problems in order to test if coal thickness changes within floor depressions were associated with changes in palynology petrography and coal quality the coal was sampled at a surface mine across a broad ramp like depression that showed down dip coal thickening increment samples of coal from a thick 150 cm down ramp and thinner 127 cm up ramp position at one surface mine correlate well between sample sites a distance of 60 m except for a single increment the anomalous increment 31 cm in the lower middle part of the thick coal bed contained 20 more lycospora orbicula spores the rolling floor elevations noted in the study mines are inferred to have been formed as a result of pre peat paleotopographic depressions syn depositional faulting fault controlled pre peat paleotopography and from compaction beneath post depositional channels and slumps although the association of thick coal with linear trends and inferred faults has been used in other basins to infer syn depositional faulting changes in palynology within increment samples of the seam along a structural ramp in this study provide subtle evidence of faulting within a specific increment of the coal itself the sudden increase in l orbicula produced by paralycopodites in a single increment of a down ramp sample of the western kentucky no 4 coal records the reestablishment of a rheotrophic mire following a sudden change in edaphic conditions paralycopodites was a colonizing lycopod which in this case became locally abundant after the peat was well established along a fault with obvious growth during peat accumulation because many coal mire plants were susceptible to sudden edaphic changes as might accompany faulting or flooding changes in palynology would be expected in coals affected by syn depositional faulting

multiple bench architecture and interpretations of original mire phases examples from the middle pennsylvanian of the central appalachian basin usa abstract coal seams often exhibit lateral and vertical variability in composition when sampled as a whole seam this variability is masked but if a seam is subdivided into correlateable components this variability can be tested and better understood herein an architectural approach is used to divide seams into intra seam components clastic splits and mineral partings as well as persistent fusain and durain layers can be used as intra seam bounding units to subdivide a seam into subdivisions called benches regional examination of lower and middle pennsylvanian age coal seams shows that many contain laterally persistent bounding surfaces that can be used to define multiple benches of coal within each seam inter bench analyses from some of the most extensively mined seams in the central appalachian basin show that individual benches often have different spatial and quality trends hence some component of whole seam variability is a function of changes in the relative contribution of these different benches to the seam as a whole many coal benches also exhibit intra bench variation in coal parameters intra bench variation can be analyzed in terms of parameters such as sulfur content and ash yield in order to address changes in coal quality for regional resource evaluation intra bench variation can also be analyzed in terms of a combination of palynologic petrographic and geochemical parameters termed compositional groups in order to better understand the development of the original mire systems compositional groups are defined by ranges of multiple criteria which are inferred to owe their origin to the mire type in which they formed vertical changes in compositional groups within coal benches can be used to infer paleo edaphic conditions during peat accumulation if seam thickness is a product of bench configuration and trends in compositional groups occur in benches then trends in quality can be marginally predicted based upon seam thickness and inferred bench architecture additionally changes in inter bench and intra bench thickness and compositional profiles can be used to infer original depositional controls such as paleotopography syndepositional structural movement and syndepositional clastic influx for more accurate reserve estimates

channel fill coal beds along the western margin of the eastern kentucky coal field abstract four channel filling coal beds from the lower part of the breathitt formation lower middle pennsylvanian late westphalian a were examined palynologically petrographically and geochemically to determine the paleoenvironmental conditions under which these peats accumulated these results were then compared with detailed sedimentological analyses of the strata overlying the coal in the channels to see if any genetic relationship between coal composition and the origin of the overburden could be drawn all four of the coal beds used in this study are located in the western most part of the eastern kentucky coal field and occur at or near the early pennsylvanian unconformity 0 30 m lycospora and densosporites and related crassicingulate taxa e g cristatisporites cingulizonates and radiizonates dominate the studied assemblages with granulatisporites and related trilete sphaerotriangular genera e g leiotriletes and lophotriletes laevigatosporites and schulzospora being common accessory genera petrographically all four coals contain high percentages of vitrinite macerals avg 78 6 mineral matter free moderate amounts of liptinite or exinite macerals avg 14 9 mmf and low percentages of inertinite macerals avg 6 5 mmf strata above the coals consist of dark carbonaceous shales and heterolithic strata that exhibit varying degrees of bioturbation commonly occurring trace fossils include arenicolites monocraterion planolites and skolithos although marine influenced strata as determined from detailed sedimentology and ichnology the study of trace fossils covers all four coal beds they are not uniformly high in total total sulfur content as might be expected rather they are extremely variable ranging from 1 9 dry basis total sulfur ash yields are also variable ranging from 6 2 54 3 dry basis it is probable that the origin of the very first sediments covering the peat as well as the amount of brackish water influence during peat accumulation were important factors in determining the total sulfur content of the resultant coal initial sedimentation of fresh water clays and silts may have acted as a barrier to downward percolation diffusion of sulfate bearing waters or may have served as a site for sulfide formation thereby keeping the total sulfur content of the underlying coal low if initial sedimentation was of brackish or marine origin as indicated by bioturbated laminae directly above the coal or if the peat was subject to frequent brackish or marine water influence during accumulation then sulfide generation might proceed unchecked resulting in high sulfur coal

mining geology of the pond creek seam pikeville formation middle pennsylvanian in part of the eastern kentucky coal field usa abstract the pond creek seam is one of the leading producers of coal in the eastern kentucky coal field the geologic factors that affect mining were investigated in several underground mines and categorized in terms of coal thickness coal quality and roof control the limits of mining and thick coal are defined by splitting along the margin of the coal body within the coal body local thickness variation occurs because of 1 leader coal benches filling narrow elongated depressions 2 rider coal benches coming near to or merging with the main bench 3 overthrust coal benches being included along paleochannel margins 4 cutouts occurring beneath paleochannels and 5 very hard and unusual rock partings occurring along narrow elongated trends in the study area the coal is mostly mined as a compliance product sulfur contents are less than 1 and ash yields are less than 10 local increases in sulfur occur beneath sandstones and are inferred to represent post depositional migration of fluids through porous sands into the coal run of mine quality is also affected by several mine roof conditions and trends of densely concentrated rock partings which lead to increased in and out of seam dilution and overall ash content of the mined coal roof control is largely a function of a heterolithic facies mosaic of coastal estuarine origin regional fracture trends and unloading stress related to varying mine depth beneath the surface lateral variability of roof facies is the rule in most mines the largest falls occur beneath modern valleys and parallel fractures along paleochannel margins within tidally affected stackrock and beneath rider coals shale spalling kettlebottoms and falls within other more isolated facies also occur many of the lithofacies and falls related to bedding weaknesses within or between lithofacies occur along northeast southwest trends which can be projected in advance of mining fracture related falls occur independently of lithofacies trends along northwest southeast trends especially beneath modern valleys where overburden thickness decreases sharply differentiating roof falls related to these trends can aid in predicting roof quality in advance of mining