sediment dispersal and quantitative stratigraphic architecture across an ancient shelf two large 200 to 300 km near continuous outcrop transects and extensive well log data ca 2800 wells allow analysis of sedimentological characteristics and stratigraphic architecture across a large area ca 60 000 km2 of the latest santonian to middle campanian shelf along the western margin of the western interior seaway in eastern utah and western colorado usa genetically linked depositional systems are mapped at high chronostratigraphic resolution ca 0 1 to 0 5 ma within their sequence stratigraphic context in the lower part of the studied interval sediment was dispersed via wave dominated deltaic systems with a compound clinoform geomorphology in which an inner wave dominated shoreface clinoform was separated by a muddy subaqueous topset from an outer clinoform containing sand poor gravity flow deposits these strata are characterized by relatively steep net regressive shoreline trajectories 0 1 with concave landward geometries narrow nearshore belts of storm reworked sandstones 2 to 22 km wide offshore mudstone belts 250 km and relatively high sediment accumulation rates ca 0 27 mm year 1 the middle and upper parts of the studied interval also contain wave dominated shorefaces but coeval offshore mudstones enclose abundant isolated tide influenced sandstones that were transported sub parallel to the regional palaeoshoreline by basinal hydrodynamic tidal circulation these strata are characterized by relatively shallow net regressive shoreline trajectories 190 km and relatively low sediment accumulation rates ca 0 11 mm year 1 the change in shelfal sediment dispersal and stratigraphic architecture from i compound clinoform deltas characterized by across shelf sediment transport to ii wave dominated shorelines with isolated tide influenced sandbodies characterized by along shelf sediment transport is interpreted as reflecting increased interaction with the hydrodynamic regime in the seaway as successive shelfal depositional systems advanced out of a sheltered embayment utah bight this advance was driven by a decreasing tectonic subsidence rate which also suppressed autogenic controls on stratigraphic architecture

coal maceral ratios as indicators of environment of deposition do they work for ombrogenous mires an example from the miocene of new zealand abstract maceral indices were applied to sub bituminous coals of the maryville coal measures as a means of interpreting environment of deposition very low amounts of inertinite and ubiquitous bituminite lead to difficulties in interpretation of the maceral ratios comparison with modern analogues suggests the theoretical basis for discrimination of mire type by maceral ratios is not well founded on the following grounds absence of well structured wood tissues does not imply the absence of arborescent vegetation inertinite formation may be unrelated to vegetation gelification is used in a geochemical sense and does not indicate groundwater table level as supposed for biochemical gelification detrital macerals often result from in situ fragmentation and not transportation

petrography palynology and depositional environments of the early miocene oberdorf lignite seam styrian basin austria abstract an early miocene ottnangian lignite seam up to 36 m thick occurs in the oberdorf trough at the northwestern margin of the styrian basin it forms part of the fluvial koflach voitsberg formation petrographic and palynologic data together with ash yield and sulphur content of samples from two boreholes and two surface profiles have been used to study vertical and horizontal coal facies variations numerous partings and a high ash yield show that the lignite originated in a topogenous mire petrographic indices and palynological data suggest a wet forest swamp paleo environment a fluvial main parting with channel sediments at the eastern margin of the oberdorf trough and overbank sediments in its central part splits the lignite into a lower and an upper seam the lower seam consists of a lower high ash part with frequent splittings and a higher low ash part the upward decrease in number and thickness of silty clayey partings interpreted as crevasse splay deposits reflects the withdrawal of the fluvial sediment source coal composition is characterized by an upward increase in detro xylitic coal and in tissue preservation a good correlation between tissue preservation and percentages of taxodiaceae cupressaceae pollen suggests that this is mainly a result of an increasing contribution of decay resistant gymnosperms conifers the upper seam is also ash rich abundant inertinite at the eastern margin of the oberdorf trough is related to fire episodes inside or outside the mire main features of the upper seam in the central basin are an upward increase in tissue preservation and in percentages of taxodiaceae cupressaceae pollen high sulphur contents in the fresh water lignite are a result of a concentration of sulphate rich waters above the impermeable floors of the lower and upper seams carbonate rich surface waters from the graz palaeozoic and raasberg sequence raised the ph value and controlled sulphur and ash contents in those parts of the lower seam which are uninfluenced by the basal sulphur enrichment palynomorph spectra are dominated by taxodiaceae cupressaceae pollen and pollen from plants living in a mixed mesophytic forest pollen from aquatic and reed plants are rare the ratio between arctotertiary and paleotropic pollen is close to one and supports the early miocene age of the lignite the detected pollen spectra point to warm temperate subtropic and humid conditions

three dimensional modeling of clinoforms in shallow marine reservoirs part 2 impact on fluid flow and hydrocarbon recovery in fluvial dominated deltaic reservoirs permeability contrasts associated with clinoforms have been identified as an important control on fluid flow and hydrocarbon recovery in fluvial dominated deltaic parasequences however they are typically neglected in subsurface reservoir models or considered in isolation in reservoir simulation experiments because clinoforms are difficult to capture using current modeling tools a suite of three dimensional reservoir models constructed with a novel stochastic surface based clinoform modeling algorithm and outcrop analog data upper cretaceous ferron sandstone member utah have been used here to quantify the impact of clinoforms on fluid flow in the context of 1 uncertainties in reservoir characterization such as the presence of channelized fluvial sandbodies and the impact of bed scale heterogeneity on vertical permeability and 2 reservoir engineering decisions including oil production rate the proportion and distribution of barriers to flow along clinoforms exert the greatest influence on hydrocarbon recovery equivalent models that neglect these barriers overpredict recovery by up to 35 continuity of channelized sandbodies that cut across clinoform tops and vertical permeability within distal delta front facies influence sweep within clinothems bounded by barriers sweep efficiency is reduced when producing at higher rates over shorter periods because oil is bypassed at the toe of each clinothem clinoforms are difficult to detect using production data but our results indicate that they significantly influence hydrocarbon recovery and their impact is typically larger than that of other geologic heterogeneities regardless of reservoir engineering decisions clinoforms should therefore be included in models of fluvial dominated deltaic reservoirs to accurately predict hydrocarbon recovery and drainage patterns

mineralogy and petrography of the two lower eocene lacustrine coals sorgun and suluova turkey abstract coal reserves of lower eocene age are limited in turkey and the most important are situated in the sorgun and suluova basins a thick and laterally extensive coal seam occurs at the base of the celtek formation in the two basins the celtek formation was developed in a fluvial lacustrine facies and was unconformably overlain by transgressive units of middle upper eocene age the coal samples were studied mineralogically and petrographically and to define fluorescence emission spectra of sporinite and cutinite a total of 75 coal samples collected from the two basins are characterized on an air dried basis by relatively low moisture contents 0 69 9 31 wt av 3 90 wt a broad range of ash yields 2 4 67 8 wt av 19 9 wt total sulphur contents 0 55 7 60 wt av 2 15 wt and calorific values 1689 7480 kcal kg av 5458 kcal kg minerals of the coals from the two basins determined on an air dried basis by x ray diffraction method are mainly kaolinite quartz and pyrite kaolinite and pyrite contents of the sorgun coals are higher and quartz contents are lower than those of the suluova coals in addition a few samples in the sorgun coals contain epigenetic calcite whereas some samples in the suluova coals contain syngenetic siderite calcite and dolomite the coals in general are characterized by high contents of macerals of the huminite group av 69 0 vol and contain liptinite av 4 9 vol inertinite av 0 8 vol and mineral matter av 25 3 vol on the tpi and gi diagram the coals plot in the limno telmatic and telmatic areas in which the sorgun and suluova peats accumulated between the high and low water tables fluorescence emission spectra of sporinite and cutinite macerals are in general similar in the coals of both basins but the spectral maxima of sporinites and cutinites are between 594 658 nm and 592 671 nm respectively the values for the sporinites indicate a relatively broad range of coal rank however the range of values of the mean random ulminite mainly eu ulminite a reflectances 0 46 0 60 rr av 0 53 rr the proximate and ultimate analyses imply that the rank is a subbituminous a coal transitional to high volatile c bituminous coal according to the astm classification

paleogeographic controls of coal accumulation cretaceous blackhawk formation and star point sandstone wasatch plateau utah analysis of sequences associations and relationships of facies in the upper cretaceous blackhawk formation and star point sandstone in the wasatch plateau utah leads to inferences regarding the paleogeographic controls affecting the accumulation of coals in delta barrier island complexes progradation lateral shifting and abandonment of these complexes created four major landward thinning tongues of the upper sandstone bed of the star point sandstone that extend into the lowermost blackhawk formation each tongue of the star point sandstone trends northwest to southeast subparallel to the general orientation of the late cretaceous paleoshoreline and represents accretion ridge distributary channel and mouth bar sandstones the accretion ridge or barrier island sandstones grade landward into coastwise lagoonal and back barrier swamp deposits which in turn merge with bayhead deposits of short headed streams these deposits grade laterally into delta plain deposits that consist of major distributary channels which crosscut the coastwise lagoons two coal populations were formed in this paleogeographic setting delta plain and back barrier coals delta plain coals formed as thin to thick discontinuous bodies back barrier coals are thicker and more laterally continuous they parallel depositional strike and accumulated in swamps on surfaces of infilled lagoons here the swamps were sites of accumulation of thick coals and were influenced by abandonment of associated deltaic barrier island complexes successive offlap events resulted in accumulation of the hiawatha coal not as a single continuous bed but as a series of discontinuous related coal bodies

petrographical palynological and geochemical analyses of the hub and harbour seams sydney coalfield nova scotia canada implications for facies development abstract benched channel samples and continuous block samples of the hub and harbour seams from the sydney basin nova scotia were studied to define the variations in petrography geochemistry and palynology of the seams and to interpret the depositional environments of the precursor mires petrographic compositions of the seams are very similar with high vitrinite content low inertinite moderate liptinite and negligible clastic mineral content pyrite content is moderate there is little variation in petrographic composition between benches in either seam there are marked variations in petrographic compositions at the lithotype scale petrographic facies parameters indicate deposition of the bulk of both seams under fairly uniform conditions in relatively wet mires unusually wet or dry periods were rare the palynological assemblages of both seams indicate a middle to late westphalian d age the common to abundant palynomorphs are derived from arborescent and herbaceous lycopsids tree ferns and other ferns and sphenopsids the palynological assemblages support the petrographic interpretation of relatively wet mires cordaites pollen florinites is rare suggesting that there was little contribution from plants growing in dry or upland areas the absence of the densospore miospore phase and the petrographic data indicate there were no periods in which domed mires occurred the distinctive dull bands occurring in the hub and harbour seams are characterised by low vitrinite contents high inertinite content high liptinite and common detrital minerals sporinite showing varying degrees of degradation is commonly highly concentrated in thin bands the geochemistry is marked by much higher hi values than normally reported for coals but other indices are typical for coals of this rank the palynological assemblages of the dull bands are dominated by tree fern spores and other ferns with only a minor contribution by sphenopsid spores the dull bands were deposited during periods of inundation of mires relatively low mineral content indicates that the distributary channels which flooded the mires were quite distant from the depositional sites of the samples

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

parameters determining the carbon isotopic composition of coal and fossil wood in the early miocene oberdorf lignite seam styrian basin austria abstract petrographical and geochemical data of gelified and ungelified fossil wood from the early miocene oberdorf lignite seam styrian basin austria provide evidence that the early diagenetic aerobic degradation of wood by fungi may be followed by further decomposition under reducing conditions by the activity of anaerobic bacteria based on the molecular compositions of terpenoid hydrocarbons the wood fragments in the lignite are identified as gymnosperms this result is corroborated by the mean isotopic composition 13c 24 2 of the macrofossils the isotopic difference between fossil wood and extracted cellulose of most samples 3 9 2 5 is higher than in modern trees which can be explained by the smaller effect of 13c discrimination during decomposition of cellulose when compared with wood the mean carbon isotope values found for gymnosperms and coals 24 2 and 24 7 respectively confirm the results from biomarker analyses indicating that the peat forming vegetation of the oberdorf seam was dominated by gymnosperm taxa minor variation in the relative contributions of gymnosperms and angiosperms to coal deposition is of negligible influence on the isotopic composition of the coals cross correlations between 13c of the coals soluble organic matter yield and the proportions of liptinite macerals of higher plant origin imply that the carbon isotopic composition may be affected by the contents of plant lipids because of their 13c values ranging from 5 to 10 less than whole plant tissue values an isotopic shift of the coals towards more negative values due to the activity of prokaryotes i e anaerobic bacteria in organic matter degradation is proposed the results obtained from the early miocene oberdorf lignite indicate that the carbon isotope ratios of the coals are primarily affected by varying contributions of different parts of whole plant tissue due to their different isotopic and molecular compositions e g epicuticular leaf waxes resins wood and their different decay resistance against the early diagenetic changes involved in organic matter decomposition carbon cycling during anoxic decomposition of plant derived organic matter is assumed to affect the 13c values of coal 13c values of wood and extracted cellulose are affected only to a minor extent

a short report of the investigations made on the facies of german coal deposits in 1996 commission ii of the iccp set up a coal facies working group the first step was to collate literature on coal facies analysis for different countries this report provides an overview on the investigations made on the facies interpretations of german coal deposits over the last 50 years with an emphasis on tertiary coals it outlines the major deposits present in germany and gives the main facies interpretations of coals of lignite and bituminous rank furthermore it points out that there lies a certain ambiguity in the interpretation of specific maceral associations which could confuse facies analyses without the support of interdisciplinary studies and thus suggests that the working group should address this point for future work

coal petrological and xylotomical characterization of miocene lignites and in situ fossil tree stumps and trunks from lusatia region germany palaeoenvironment and taphonomy assessment abstract the present paper investigates rank and composition of coal as well as depositional and hydrogeological settings persisting during the stage of peat accumulation and evaluates taphonomy and conditions for the in situ preservation of outstanding fossilized stump and trunks using coal petrological and xylotomical analyses the obtained results are further interpreted and compared with existing literature records lignite samples and fossil wood specimens were collected from the 2nd mfh 2nd miocene seam horizon or its equivalent present at meuro piskowitz and welzow sud open cast mines located in lusatia germany the examined lignite samples indicate low rank coals at lignite or subbituminous rank stage and are characterised by slight dominance of attrinite over textinite ulminite suberinite cutinite porigelinite resinite and corpohuminite macerals waterlogged conditions prevailing in the mire are associated with peat accumulation under anoxic conditions accompanied by low decomposition rates the determined facies indicators suggest a moderate to high as well as low gelification of the organic matter for the meuro and piskowitz open cast mines respectively in meuro open cast mine the prevalence of herbaceous plant in a mire or a bacterial fungal degradation of woody plant tissues can be envisaged whereas in the piskowitz open cast mine it is suggested that peat formed in a wet forest mire environment with a limited oxygen supply and a relatively low bacterial fungal degradation the studied fossil wood specimens revealed the presence of quasisequoioxylon piskowitzense preserved as an in situ fossilized stump as well as taxodioxylon cryptomerioides and sciadopityoxylon wettsteinii species preserved as fossilized trunks the examined species belong to the families of cupressacea sciadopityaceae and cupressaceae li sensu lato the taphonomy of the in situ fossilized stump and trunks can be explained by nutrient and oxygen poor oligotrophic mires distinguished as raised bogs and suggesting generally anoxic conditions during middle to late miocene climate transition

new interpretations of the facies of the rhenish brown coal of west germany abstract new ideas concerning the understanding of the facies of the rhenish brown coal of west germany are discussed these new interpretations are based on a significantly larger number of samples and refined procedures for analysis within the field of paleobotany palynology coal petrology and organic geochemistry than were available to p w thomson and m teichmuller the light and dark bands in the coal are mainly the result of different degrees of plant decomposition the influence of the peat forming plant communities plays a subordinate role in the petrographical composition of these particular strata of the rhenish brown coal

3d digital outcrop modelling of the lower cretaceous los santos formation sandstones mesa de los santos region colombia implications for structural analysis abstract the increasing development of the geological data acquisition and processing techniques for outcrops from photographs acquired with the unmanned aerial vehicles has had a great impact on various branches of geology such as structural geology when approaching structural analysis one of the main inputs is given by the fracture orientations therefore the use of unmanned aerial vehicles is a great benefit for acquiring in a very short time a large georeferenced dataset for fractures distribution and orientation even in normally non accessible outcrops access during the fieldwork as well as the ease of data processing and visualization constitute great advantages provided by the use of unmanned aerial vehicles in structural analysis and modelling in this study data were acquired from two outcrops from the lower cretaceous los santos formation sandstones mesa de los santos region colombia el duende and la mojarra outcrops the data was processed in photogrammetry software based on the structure from motion technique with which a dense point cloud was obtained for each outcrop the dense point cloud was processed with the discontinuity set extractor software obtaining the main families of discontinuities and their associated clusters later as a validation these orientations which obtained in a digital way were contrasted with field data previously acquired in the area obtaining a good consistency between both datasets finally the data was associated with the regional structural trends evidenced in the field data generating more data to improve the structural models of the area

sediment supply dominated stratal architectures in a regressively stacked succession of shoreline sand bodies campanian desert member to lower castlegate sandstone interval book cliffs utah colorado usa

characterization of controls on high resolution stratigraphic architecture in wave dominated shoreface shelf parasequences using inverse numerical modeling abstract a new inverse numerical modeling method is used to constrain the environmental parameters e g relative sea level sediment supply and wave climate histories that control stratigraphic architecture in wave dominated shallow marine deposits the method links a process response forward stratigraphic model that simulates wave and storm processes barsim to a combination of inverse methods formulated in a bayesian framework that allows full characterization of uncertainties this method is applied for the first time to a real geologic dataset collected at outcrop from two shoreface shelf parasequences in the aberdeen member blackhawk formation of the book cliffs east central utah usa the environmental parameters that controlled the observed stratigraphic architecture are quantified and key aspects of stratigraphic architecture are successfully predicted from limited data stratigraphic architecture at parasequence stacking and intra parasequence scales was driven principally by relative sea level varying by up to about 55 m and sediment supply varying by up to 70 m2 yr whose interplay determines the shoreline trajectory within zones of distinctive shoreline trajectory variations in wave climate of up to about 3 m in fairweather wave height controlled superimposed variations in sandstone and shale content e g the development of upward coarsening and upward fining bedsets the modeling results closely match the observed stratigraphic architecture but their quality is limited by 1 the formulation and assumptions of the forward modeling algorithms and 2 the observed data distribution and quality which provide poor age constraint

sea level changes an integrated approach sea level changes an integrated approach in october 1985 sepm sponsored a four day conference entitled sea level changes an integrated approach the purpose of the conference was to provide a forum for an interdisciplinary exchange of ideas on sea level changes and to provide an opportunity for integrating various types of evidence in approaching unresolved issues the conference was successful in bringing together scientists from industry academia and government representing all of the major geosciences disciplines presentations of many new papers plus significant releases of data that were previously held proprietary provided fertile ground for discussion this much cited volume represents the best of the material presented at the conference includes the early vail chart

lidar uav or compass clinometer accuracy coverage and the effects on structural models abstract light detection and ranging lidar and structure from motion sfm provide large amounts of digital data from which virtual outcrops can be created the accuracy of these surface reconstructions is critical for quantitative structural analysis assessment of lidar and sfm methodologies suggest that sfm results are comparable to high data density lidar on individual surfaces the effect of chosen acquisition technique on the full outcrop and the efficacy on its virtual form for quantitative structural analysis and prediction beyond single bedding surfaces however is less certain here we compare the accuracy of digital virtual outcrop analysis with traditional field data for structural measurements and along strike prediction of fold geometry from stackpole syncline in this case the sfm virtual outcrop derived from uav imagery yields better along strike predictions and a more reliable geological model in spite of lower accuracy surface reconstructions than lidar this outcome is attributed to greater coverage by uav and reliable reconstruction of a greater number of bedding planes than terrestrial lidar which suffers from the effects of occlusion irrespective of the chosen acquisition technique we find that workflows must incorporate careful survey planning data processing and quality checking of derived data if virtual outcrops are to be used for robust structural analysis and along strike prediction

sequence stratigraphic analysis and the origins of tertiary brown coal lithotypes latrobe valley gippsland basin australia abstract the methods of sequence analysis have been applied to the onshore gippsland basin and in particular to the latrobe valley group coal measures which include up to five coal seams each exceeding 100 m in thickness the methods appear to provide new depositional concepts to the evolution of these seams and the development of coal lithotypes in the eastern half of the latrobe valley evidence for marine transgressions into the coal measures are recorded in most of the interseam sediment splits by the presence of contained foraminifera and dinoflagellates to the west inland these splits pinch out into continuous coal however they can be followed westwards as enhanced organic sulphur levels along sharply defined boundaries between light coal lithotypes below and dark coal lithotypes above the dark lithotype immediately overlying each of these boundaries contains the highest sulphur value and warmer climate pollen assemblages sluiter et al 1995 this volume colorimeter and lithotype logging strongly supports an upwards lightening cyclicity to coal colour at 12 20 m intervals through the approx 100 m thick seams with cycle boundaries defined at sharp planar to undulating surfaces the lightening upward lithotype cycles together with their unique boundary conditions i e enhanced organic sulphur levels warm climatic indicators and laterally equivalent marine clay splits are interpreted as parasequences and parasequence boundaries respectively each major coal seam can comprise up to five parasequences and is interpreted to represent deposition during an outbuilding high stand systems tract at one of several maximum periods of tertiary coastal onlap the top of each major seam shows evidence of truncation erosion on a regional scale and these surfaces are interpreted to represent the sequence boundaries the major seams are usually conformably underlain by marine clays and extensive aquifer sands being deposits of the late transgressive systems tracts the low stands and early parts of the transgressive systems tracts appear not to be represented in the latrobe valley due to its more basin margin location but are probably present down dip in the equivalent marine facies of the seaspray group stratigraphic correlation of the sequence boundaries identified in the coal measures to the adjacent internationally dated marine seaspray group provides a basis for chronostratigraphic correlation of the coal successions to the coastal onlap charts of haq et al exon mesozoic cenozoic chronostratigraphic chart version january 1988 and august 1989 from this dating it appears that each major seam is confined to high stands of third order eustatic cycles it therefore follows that the lithotype cycles parasequences that comprise each seam are related to fourth order eustatic cycles by analogy all the coal cycles may have developed under subtropical conditions as ombrogenous forested peat swamps in a similar manner to the holocene though tropical swamps of indonesia

lithotype sequences in the early miocene maryville coal measures new zealand abstract coals of the early miocene maryville coal measures show well developed dulling up trends defined by a decrease in the proportion of bright coal that culminate in sapropelic horizons field determination of lithotype is difficult but the use of polished surfaces enables classification by either the brightness or stopes heerlen systems during upwards dulling gross petrographic composition remains essentially constant at 80 90 huminite vitrinite 10 15 liptinite and 1 4 inertinite except in sapropelic types which are liptinite dominated dull bands are characterized petrographically by fragmentary macerals especially detrogelinite whereas bright bands are composed of intact plant fragments dulling up is related to the development of raised ombrogenous mires where growth and subsequent preservation of large intact plant fragments is favoured during early stages of mire development and around the mire margins

petrography and depositional environment of coal seams in the carboniferous morien group sydney coalfield nova scotia the morien group westphalian a stephanian of the sydney basin nova scotia contains numerous coal seams many of which can be traced across the onshore part of the basin depositional environments during coal formation range from proximal fluvially dominated to intercalated distal fluvial to restricted marine most of the coal samples analyzed in this study come from the bras d or section a near continuous coastal exposure of the sydney mines formation petrographic compositions of the samples are discussed in the context of the depositional setting of the enclosing strata the coal seams have a high vitrinite content 70 90 vol with moderate inertinite and low liptinite petrographic indices suggest that most coals of the sydney mines formation are similar to seams deposited in interdistributary or lower delta plain settings in other basins and provide support for the interpreted sedimentological setting of this sequence the coal seams of the bras d or section show little variation in gross

high resolution linkage of channel coastal plain and shallow marine facies belts desert member to lower castlegate sandstone stratigraphic interval book cliffs utah colorado usa

sequence stratigraphic significance of sharp based lowstand shoreface deposits kenilworth member book cliffs utah the kenilworth member of the blackhawk formation upper cretaceous campanian is nearly continuously exposed from price to hatch mesa in the book cliffs utah five main depositional environments are recognized coastal plain foreshore and upper shoreface lower shoreface inner shelf and incised valley fill deposits the shelf to shoreface deposits combine to form nine coarsening upward wave to storm dominated parasequences that are 7 32 m thick and that split basinward into smaller coarsening upward successions or bedsets that are 2 18 m thick a maximum of four bedsets occurs within an individual parasequence bedset bounding surfaces are occasionally marked by thoroughly bioturbated iron rich carbonate cemented sandstones within the parasequences in the subsu face similar bedset bounding surfaces may act as permeability barriers or baffles leading to reservoir compartmentalization parasequences 1 6 form an aggradational to progradational parasequence set of the highstand systems tract parasequences 7 and 8 occur as sharp based lowstand shoreface deposits at price river and battleship butte forming the attached lowstand systems tract and parasequence 9 forms the transgressive systems tract the base of each lowstand shoreface is marked by an organic rich lag deposit that consists of granules coarse grained sandstone wood fragments coal intraclasts and shell debris the sharp base basal lag deposit and basinward shift in facies delineate a sequence boundary at the base of each lowstand shoreface deposit the presence of two sharp based lowstand shorefaces suggests that the kenilworth lowstand was punctuated by a stillstand the sharp based lowstand shoref ce sandstones form the bulk of the attached lowstand systems tract and represent one end member in a continuum of lowstand deposits the other end member is the detached lowstand systems tract revising existing sequence stratigraphic models to include both types of lowstand systems tracts is a first step toward improving the accuracy of these models which are often used as prospecting tools in lowstand deltaic environments

practical problems in the application of the sequence stratigraphic method and key surfaces integrating observations from ancient fluvial deltaic wedges with quaternary and modelling studies sequence stratigraphy solved the basic problem that genetically related but different lithofacies were routinely assigned to different lithostratigraphic units defined by arbitrary vertical and horizontal cutoffs stratigraphically important stratal relationships and especially stratal terminations for example lapout can be observed in seismic data and can be documented in continuous outcrops such as in the deserts of the western interior of north america and in closely spaced well log data sets in sparse data sets interpolation of lapout patterns introduces uncertainty in correlation and designation of sequences and systems tracts and their associated surfaces diachroneity of fluvial terrace deposits is documented using detailed facies architectural studies and calls into question the assumed chronostratigraphic significance of many so called sequence boundaries identified in the rocks of the cretaceous interior seaway of north america sequence boundaries formed during prolonged sea level falls may be less chronostratigraphically significant than transgressive surfaces formed during rapid rises as a consequence flooding surfaces are theoretically more significant and also have greater utility as allostratigraphic boundaries although they may also exhibit diachroneity tectonic unconformities produce differential lithospheric deformation which results in angular unconformities although the angle of discordance may be very small in the cretaceous interior seaway of north america such unconformities may be expressed by marine erosion in distal basin settings regional isochronous bentonites provide useful marker beds that clearly illustrate angular discordance in the fluvial realm such tectonic discontinuities may be indicated by changes in palaeocurrent orientations as well as by provenance changes although sequence stratigraphy provides a powerful methodology and theoretical framework for correlating and understanding the evolution of stratigraphic successions in the context of changing accommodation allostratigraphy remains the only accepted scheme for the formal naming of stratigraphic units based on bounding discontinuities whatever type of sequence stratigraphy or allostratigraphy is preferred in all cases it is key to recognize that sequence stratigraphy at its heart is the re ordering correlation and sometimes renaming of stratigraphic units on the basis of bounding discontinuities and their correlative surfaces as opposed to the arbitrary lithofacies oriented approach using broad facies zones for example shazam lines or arbitrary cutoffs such as is used in traditional lithostratigraphy

effect of relative lake level changes in mire lake system on the petrographic and floristic compositions of a coal seam in the most basin miocene czech republic abstract exposures in the bilina opencast mine provide a direct evidence that the 3 5 m thick upper bench of the main seam in the most basin passes over a distance of about a kilometre into a hundred metres thick equivalent of clastic deltaic sediments with gilbert type mouth bars and thus clearly corroborates the co existence of lacustrine delta mire system deposition of the delta and the upper bench of the main seam were affected by five short term lacustrine incursions possibly related to tectonic subsidence before final lacustrine transgression took place between the temporary lacustrine incursions delta mouth bars prograded into an extensive mire being separated only by a shallow compaction lake along mouth bars foreland however most clastics introduced from delta were caught by dense vegetation in a narrow proximal zone of mire and did not affect more distal parts of relatively dry woodland mire with water table fluctuating around the surface it is therefore characterised by low ash yield and increased resinite fusinite and inertodetrinite contents palynological data indicate that the peat forming vegetation of the upper bench of the main seam was dominated by taxodiaceae glyptostrobus athrotaxis and calamus palm accompanied by paludal species of the family pinaceae and rich undergrowth of ferns and vaccinium type ericaceae progradation of delta mouth bars to the proximity of the study section is documented by increasing proportion of allochthonous elements produced by plants colonizing the flood plain and delta plain areas nyssa taxodium parrotia ulmus pyramidalis and comptonia pinus oviformis associations in contrast during periods of temporary lacustrine transgressions the mire was replaced by open water environment which favoured deposition of clay rich coals or partings 30 of ash yield of the flooding horizons in spite of fact that delta body retreated to the basin margin and the clastics were introduced from a larger distance rare palynomorphs indicate only sparse vegetation cover of aquatic plants during this time clay content seems to be the best indicator of the water level fluctuations facies indices e g tpi and gi show only poor correlation to hydrological and floristic changes detected in the mire lake system

miocene depositional environment and climate in western europe the lignite deposits of the lower rhine basin germany abstract miocene lignites representing a depositional history of about 7 million years 18 11 ma before present have been studied by organic petrological and organic geochemical methods including analysis of stable carbon and oxygen isotopes the three lignite seams investigated morken frimmersdorf garzweiler developed from peats which grew in a nutrient depleted paralic environment situated close to the sea all seams have low ash mineral matter contents but seam frimmersdorf is richer in sulfur as compared to seams morken and garzweiler sulfur richness and distribution in seam frimmersdorf might be due to the diagenetic effect of sulfate reduction and pyrite precipitation following flooding by the sea and deposition of the marine neurath sands on top of seam frimmersdorf geochemical palaeotemperature analysis gdgt revealed a warm climate during deposition of the peats representing lignite seams morken and frimmersdorf which shifted towards lower temperatures 2 3 c during deposition of the uppermost seam garzweiler i e at about 13 11 ma before present this trend is basically supported by cellulose oxygen isotope values which show a significant scatter however carbon isotope values are less variable indicating predominance of angiosperms in the peat vegetation and rather stable environmental conditions as well as floral assemblage organic petrological studies reveal predominance of small plants and a nutrient depleted environment a modified groundwater index gwiac was applied suggesting deposition above the general groundwater level

distribution of discontinuous mudstone beds within wave dominated shallow marine deposits star point sandstone and blackhawk formation eastern utah deposits of wave dominated shorelines are typically considered to act as relatively simple hydrocarbon reservoirs and are commonly modeled as tanks of sand however important heterogeneities that can act as barriers to fluid flow occur at the parasequence bedset and bed scales especially in viscous oil or low permeability oil fields heterogeneities at the parasequence and bedset scales have been well studied but discontinuous mudstone beds occurring within the shoreface have received little attention the book cliffs and wasatch plateau are among the best exposed and best studied deposits of wave dominated shallow marine systems in the world two parasequences within these outcrops have been studied in detail to investigate the distributions of intrashoreface shales and to propose models for the controls on their distribution a data set consisting of 30 km 18 6 mi of virtual outcrops derived from oblique helicopter mounted light detection and ranging lidar scanning with supporting stratigraphic sections makes it possible to collect a large quantity of accurate geometric data of depositional elements from inaccessible cliffs nine hundred and twenty one discontinuous mudstone beds were measured these occur as ellipses with long axes oriented normal to the paleoshoreline lengths and widths of these mudstone beds exhibit a lognormal distribution with means of 21 9 and 13 8 m 71 9 and 45 3 ft respectively within the shoreface succession the number of mudstone beds increases downward whereas size does not vary significantly with stratigraphic height an average of 100 m 328 ft cumulative length of shale exists per 100 m 328 ft of horizontal outcrop this increases threefold near both wave dominated deltas and bedset boundaries that reflect minor sea level fluctuations during progradation

biomarker and stable carbon isotope systematics of fossil wood from the second lusatian lignite seam of the lubstow deposit poland abstract decay of fossil wood gelification collected from the middle miocene 2nd lusatian lignite seam at the lubstow open cast mine poland is characterised by its maceral variety fluorescence intensity and cellulose content cellulose decomposition leads to lower molar h c ratio values of the organic matter as indicated by higher total organic carbon toc content of samples characterised by low cellulose content biochemical formation of hydrocarbons in the wood due to enhanced microbial activity is evidenced by higher hydrocarbon content in the extracts higher relative proportions of n alkanes and hopanoids are observed in the hydrocarbon fractions of wood remains characterised by low cellulose yield the results provide evidence for the formation of these compounds during biogeochemical transformation of organic matter hopanoid contents are considered to reflect the activity of aerobic bacteria and or fungi because of enhanced perylene content in the hydrocarbon fractions from gelified wood samples fungi are considered as the major precursor carriers of this polycyclic aromatic hydrocarbon the results provide evidence that biomarker composition of fossil wood can be used to trace biochemical transformation processes chemotaxonomical classification of fossil wood fragments as gymnosperms most probably species of the coniferales families taxodiaceae cupressaceae are based on the molecular composition of terpenoid hydrocarbons and a mean 13 c value of 24 5 depletion of gelified samples in 13 c as compared to ungelified wood is caused by the effect of progressive decomposition of cellulose the data indicate that cellulose 13 c data mean 13 c 20 8 are also affected by wood decomposition and so only samples with comparable cellulose content should be used for the reconstruction of environmental changes inter species as well as intra plant variation in carbon isotope differences and of decay resistance between cellulose and lignin have to be taken into account

pliocene lignites from apofysis mine amynteo basin northwestern greece petrographical characteristics and depositional environment coal petrological investigation along with proximate and elemental analyses were undertaken to determine the petrographic characteristics of the apofysis lignites amynteo basin northwestern greece and their depositional environment eight samples representing different lignite beds of the apofysis deposit were collected from a borehole the apofysis lignites have an eu ulminite b reflectance of rr 0 22 and in terms of lithotype belong to matrix soft brown coals huminite is the most abundant maceral group and consists mostly of humodetrinite inertinite has relatively low percentages whereas liptinite concentrations are low in the lower lignite beds and higher in the upper ones ternary plots and facies indices were employed in order to investigate the palaeoenvironment the depositional environment of the apofysis lignites is not definitely ascribed to a forest swamp or a reed marsh environment the high ash content of the analysed samples is a clear indication of a topogenous setting low tissue preservation index tpi and high gelification index gi values are observed high alkalinity and strongly reducing conditions may be inferred from the presence of syngenetic framboidal pyrite the low tpi values which indicate high bacterial activity and thus high ph conditions and the preservation of gastropod shells and chlorophyllinite high gi indicates a constant influx of calcium rich waters into the coal swamp the apofysis lignite deposit may be interpreted to be autochthonous to hypoautochthonous the peat accumulation was governed by a high groundwater level wet telmatic to limno telmatic facies and a moderate subsidence rate

carbonate cementation in a sequence stratigraphic framework upper cretaceous sandstones book cliffs utah colorado abstract three macroscopic diagenetic features can be recognized in the sandstones of the upper cretaceous desert member of the blackhawk formation and castlegate sandstone of the mesaverde group exposed in the book cliffs utah each of which have distinctive form geometry and stratigraphic distribution diagenetic alterations are 1 leached zones whitecaps up to 10 m thick beneath coal beds 2 large up to 8 m concretionary carbonate cemented bodies in amalgamated shoreface and thin fluvial sandstones and 3 thin up to 2 m laterally extensive carbonate cemented horizons beneath major marine flooding surfaces each feature has distinct petrographic and geochemical signatures and formed through discrete diagenetic processes large isolated carbonate cemented bodies are composed of ferroan dolomite most of which precipitated during early diagenesis field and petrographic data coupled with stable isotope data early cements 13c 2 5 to 3 4o oo vpdb 18o 7 8 to 12 0o oo vpdb 87sr 86sr 0 7078 later cements 13c 3 1 to 5 7o oo vpdb 18o 12 0 to 15 1o oo vpdb 87sr 86sr 0 7093 suggest precipitation from meteoric fluids input into sediments during times of relative sea level fall the source of carbonate for the dolomite cement was dissolution of detrital dolomite from beneath coals by organic acids and subsequent mobilization by meteoric fluids carbonate precipitation in laterally extensive cement horizons appears to have started as a result of hiatus in sediment accumulation during marine flooding events relative sea level rise cement precipitation in these horizons continued through sediment burial as a result of organic matter oxidation reactions in overlying organic rich mudstones the results of this study show a link between sedimentation related to changes in relative sea level and diagenesis leading to the potential for the development of process based predictive models of early diagenesis in depositional successions

rethinking the incised valley fill paradigm for campanian book cliffs strata utah colorado u s a evidence for discrete parasequence scale shoreface incised channel fills

petro chemical characterisation and depositional paleoenvironment of lignite deposits of nagaur western rajasthan india the objective of this study was to know about the depositional environment and petrographic characteristics of lignite deposits of the nagaur district rajasthan india and to decipher source rock potential lignite samples have been collected from all the working and exposed lignite seams from matasukh lignite mines of nagaur following the pillar sampling method the petrographic study has been done following the international committee for coal and organic petrology and iso norms the study has shown that nagaur lignites are mostly dominated by the huminite group of macerals followed by liptinite group the huminite group is mainly represented by attrinite textinite and ulminite whereas liptinite is represented mainly by primary liptinites such as resinite sporinite suberinite and cutinite an inertinite group of macerals occurs in the least concentration as compared to the huminite and liptinite group macerals and mainly represented by the semifusinite funginite and inertodetrinite in these lignites carbonate mineral matters are dominating over the pyrite and argillaceous mineral matter the maceral constituents present in the studied samples indicate a high proportion of type iii kerogen and are capable of generating gases only based on the reflectance of eu ulminite b maceral nagaur lignites may be classified as low rank b lignite b the study reveals that lignites originated in the bog forest under ombrotrophic to mesotrophic hydrological conditions gelification index and the tissue preservation index suggest an accumulation of peat in the marshy environment

coal petrology and the origin of coal macerals a way ahead the development of coal petrology and the establishment of a nomenclatural system have proved of major use both for the industrial utilization of coal and for the development of a broad understanding of coal formation and diagenesis the development over the past 30 years however of nomenclature that includes aspects of plant origin and process is a retrograde step e g pyrofusinite degradofusinite and funginite equally problematic is the use of prescriptive formulae to indicate coal origins this paper reviews some of the problems involved with coal petrology as it is usually practiced in addition new advances in organic geochemical techniques have led to a fuller understanding of the relationship of plants and coal macerals recent research on the origin of coal macerals is presented and there is a discussion of the problems and challenges facing coal petrologists a holistic approach to studies of the origin of coal and coal macerals which includes not only petrographic but also chemical and biological studies is advocated d 2002 elsevier science b v all rights reserved

flow units connectivity and reservoir characterization in a wave dominated deltaic reservoir meren reservoir nigeria the meren e 01 agbada formation middle miocene reservoir offshore nigeria consists of a lower progradational shoreface succession terminated by a minor sequence boundary overlain by a progradational and retrogradational shoreface succession deposition occurred in a wave dominated delta front as indicated by the presence in core of hummocky cross beds slumped units and turbidites eight flooding surfaces were correlated and isopach maps sandstone quality trend maps and mudstone quality trend maps were constructed for each parasequence this work revealed a complex reservoir architecture characterized by shoreface clinoforms and a history of progradation and retrogradation cycles three different three dimensional geological characterizations of the e 01 reservoir were built a geostatistical model that used only well data a more geologically complex facies based model that used the sandstone quality trend maps in addition to well data and the most geologically complex sequence stratigraphic model that used mudstone quality trend maps in addition to the above data the three models were analyzed in terms of sandstone continuity and connectivity to hypothetical injector and producer wells only the sequence stratigraphic model predicted significant vertical compartmentalization through tortuosity generated by flooding surface mudstones waterflood fluid flow simulation of a downdip sector of the geologic models predicts similar recovery for the three models but a significantly different distribution of unswept oil only the sequence stratigraphic model identified parasequences with abundant unswept oil that are large enough to be economic infill prospects history matched full field fluid flow simulations verify both the reservoir compartments predicted by the sequence stratigraphic model and infill targets

high resolution sequence stratigraphic correlation between shallow marine and terrestrial strata examples from the sunnyside member of the cretaceous blackhawk formation book cliffs eastern utah the sunnyside member of the upper cretaceous blackhawk formation in the book cliffs of eastern utah provides an ideal opportunity to investigate high resolution sequence stratigraphic correlation between shallow marine and terrestrial strata in an area of outstanding outcrop exposure the thick laterally extensive coal seam that caps the sunnyside member is critical for correlating between its shallow marine and terrestrial components petrographic analysis of 281 samples obtained from 7 vertical sections spanning more than 30 km 18 mi of depositional dip enabled us to recognize a series of transgressive regressive coal facies trends in the seam on this basis we were able to identify a high resolution record of accommodation change throughout the deposition of the coal as well as a series of key sequence stratigraphic surfaces the stratigraphic relationships between the coal and the siliciclastic components of the sunnyside member enable us to correlate this record with that identified in the time equivalent shallow marine strata and to demonstrate that the coal spans the formation of two marine parasequences and two high frequency fourth order sequence boundaries this study has important implications for improving the understanding of sequence stratigraphic expression in terrestrial strata and for correlating between marine and terrestrial records of base level change it may also have implications for improving the predictability of vertical and lateral variations in coal composition for mining and coalbed methane projects

paleoenvironmental conditions of puertollano coals spain petrological and geochemical study abstract in the present work petrographic geochemical and mineralogical data have been combined with results from prior paleobotanical studies in order to determine the sedimentary and postsedimentary diagenetic factors responsible for the physicochemical properties of coal seams and associated sediments from the puertollano stephanian coal basin although the coal seams 4 originated under similar lacustrine conditions the highest coal seams 1 and 1 bis show higher production preservation of structured tissues telinite and collotelinite than the lowest coal seams 2 and 3 where destruction of the cell tissues collodetrinite is predominant differences in degree of preservation as a result of changes in the environmental sedimentary conditions in the water table ph redox may explain the different maceral distribution this feature may also be due to the increase in degree of humification from the highest seams 1 and 1 bis to the lowest seams 2 and 3 however the gentle thermal maturation undergone by these stephanian coals only produced a slight modification in the physicochemical properties of the organic matter in general alkaline synsedimentary conditions could be deduced from the dominance of organic sulphur with respect to pyritic sulphur reducing conditions for seam 1 1 bis and 2 and more oxidant conditions for seam 3 can be deduced from maceral sulphur and carbonate distribution other diagenetic processes involved organic and inorganic sediments for example a kaolinitisation process with a different intensity for the early diagenetic stages suggests the occurrence of leaching processes which affected both organic and inorganic sediments

geomorphological and sequence stratigraphic variability in wave dominated shoreface shelf parasequences physical stratigraphy within shoreface shelf parasequences contains a detailed but virtually unstudied record of shallow marine processes over a range of historical and geological timescales using high quality outcrop data sets it is possible to reconstruct ancient shoreface shelf morphology from clinoform surfaces and to track the evolving morphology of the ancient shoreface shelf our results suggest that shoreface shelf morphology varied considerably in response to processes that operate over a range of timescales 1 individual clinoform surfaces form as a result of enhanced wave scour and or sediment starvation which may be driven by minor fluctuations in relative sea level sediment supply and or wave climate over short timescales 10 1 10 3 years these external controls cannot be distinguished in vertical facies successions but may potentially be differentiated by the resulting clinoform geometries 2 clinoform geometry and distribution changes systematically within a single parasequence reflecting the cycle in sea level and or sediment supply that produced the parasequence 10 2 10 5 years these changes record steepening of the shoreface shelf profile during early progradation and maintenance of a relatively uniform profile during late progradation modern shorefaces are not representative of this stratigraphic variability 3 clinoform geometries vary greatly between different parasequences as a result of variations in parasequence stacking pattern and relict shelf morphology during shore face progradation 10 5 10 8 years these controls determine the external dimensions of the parasequence

parameterizing parasequences importance of shelf gradient shoreline trajectory sediment supply and autoretreat the basic reservoir flow unit in shallow marine depositional systems is the parasequence since it is bounded top and base by regionally extensive shales that can form barriers to fluid flow as a result it is the key stratigraphic unit requiring parameterization for both exploration and development purposes a database comprising 3385 measurement points from 385 parasequences from 28 locations and 16 different passive margin and foreland basins was compiled from outcrop and subsurface data analysis of the data suggests that a mean value for parasequence thickness is 17 m 56 ft mean parasequence sandstone fraction is 0 60 and mean shoreface sand body thickness is 8 m 26 ft the mean maximum parasequence progradation distance is 23 km 14 mi the results indicate that there are two critical controls that can significantly vary the parameter values stated above 1 stacked shoreline trajectory or systems tract and 2 shelf gradient the analyses indicate that shelf gradient is the most important parameter that has a first order control on parasequence properties shelf gradient in the ancient can be approximated to high gradient or low to moderate gradient categories via analysis of parasequence thickness change versus progradation distance from wells mean parasequence thickness or mean progradation distance from seismic attribute data parasequence progradation distance is to some degree predictable if stacked shoreline trajectory shelf gradient category and mean parasequence thickness are known the data suggest that there are two types of parasequences accommodation dominated and supply dominated parasequences the progradation distance of these parasequences are controlled by delta autoretreat mechanisms modulated by the combination of fifth and fourth order milankovitch scale orbitally forced climate change driven sediment supply cycles interacting with eustatically and tectonically driven accommodation cycles

mechanisms for forming discontinuity surfaces within shoreface shelf parasequences sea level sediment supply or wave regime abstract a 2d process response model was used to evaluate potential mechanisms involved in the formation of small scale stratigraphic variability that is observed within progradational wave dominated shoreface shelf parasequences model experiments which are based on scenarios that consist of a 25 ky progradational phase suggest that discontinuity surfaces form when either sediment supply or sea level fall rapidly or when wave height regime increases over relatively short time periods 102 104 y during coastal progradation in these cases mean deposition rate near the lower shoreface drops which combined with coastal progradation results in a discontinuity surface both observed and simulated discontinuity surfaces form predominantly in lower shoreface deposits and bound meter scale stratigraphic cycles simulations show that wave regime variability affects the shoreface shelf to a much greater depth than minor sea level change therefore facies shifts along wave climate induced bounding surfaces occur over wider reaches of the shoreface shelf system than sea level induced facies shifts high frequency variability in sediment supply rate results in the formation of discontinuity surfaces across which there are no distinct facies shifts

botanical control on banding character in two new zealand coal beds abstract two new zealand coal beds were examined using a palaeobotanical approach to determine controls on banding characteristics the morley cretaceous coal is thickly 5 to 1 or 32 to 2 mm and well 25 banded whereas the brunner eocene coal is essentially non banded palynological analyses indicate that the morley was formed from a gymnosperm dominated vegetation with a secondary component of angiosperms in contrast the brunner was dominated by angiosperm vegetation with only a minor component of gymnosperms however it was found that any xylite vitrain bands 1 mm in either coal bed were comprised exclusively of secondary xylem of probable gymnosperm origin the presence of gymnosperm wood i e secondary xylem forming the larger bands in both coals can be related to the relative resistance of this material to chemical and physical decay as compared to all other plant tissues an absence of angiosperm wood in either the morley or brunner coal beds may be the result of the relative chemical degradability of angiosperm wood as compared to gymnosperm wood alternatively angiosperms in either of the two palaeo mires may have been shrubby and thus did not produce abundant woody tissue in either case the banded nature of the morley coal bed is the result of the presence of gymnosperm wood and the non banded nature of the brunner is the result of being dominated by a flora angiosperm which is easily degraded

cyclic floral succession and fire in a cenozoic wetland peatland system abstract the cyclic succession of brown coals in the latrobe valley gippsland basin australia records an exceptional floral and charcoal record from the late oligocene to middle miocene new palynological geological and charcoal data are consistent with existing colourimetry carbon isotope and organic geochemical and palaeobotanical data indicating that the repeated lithotype cycles represent relative drying terrestrialization based on this detailed palynological study the vegetation succession within the latrobe valley peatlands is interpreted to have begun with a fire prone emergent marsh of bulrushes typhaceae which grades landward into a fire prone meadow marsh of rushes restionaceae heaths ericaceae and coral ferns gleicheniaceae this marsh environment then developed into a forested bog with gymnosperms e g the podocarpaceae dacrycarpus and dacrydium as the dominant trees until an ombrogenous forest bog developed predominantly consisting of angiosperms e g nothofagus quintinia the similarity between vegetation successions in new zealand and the lightening upwards cycles from the latrobe valley coals suggests that new zealand s modern vegetation communities represent a floral analogue for the successions preserved in the latrobe valley coals high abundances of micro and macro charcoal recorded in the darker lithotypes within the lithotype cycles of the m1b and m2a seams suggest that the latrobe valley peatlands were subject to repeated fires during the late oligocene to early miocene

terrestrial laser scanning in geology data acquisition processing and accuracy considerations terrestrial laser scanning or lidar is a recent innovation in spatial information data acquisition which allows geological outcrops to be digitally captured with unprecedented resolution and accuracy with point precisions and spacing of the order of a few centimetres an enhanced quantitative element can now be added to geological fieldwork and analysis opening up new lines of investigation at a variety of scales in all areas of field based geology integration with metric imagery allows 3d photorealistic models to be created for interpretation visualization and education however gaining meaningful results from lidar scans requires more than simply acquiring raw point data surveys require planning and typically a large amount of post processing time the contribution of this paper is to provide a more detailed insight into the technology data collection and utilization techniques than is currently available the paper focuses on the workflow for using lidar data from the choice of field area and survey planning to acquiring and processing data and finally extracting geologically useful data because manufacturer specifications for point precision are often optimistic when applied to real world outcrops the error sources associated with lidar data and the implications of them propagating through the processing chain are also discussed

intra parasequence architecture of an interpreted asymmetrical wave dominated delta although modern wave dominated shorelines exhibit complex geomorphologies their ancient counterparts are typically described in terms of shoreface shelf parasequences with a simple internal architecture this discrepancy can lead to poor discrimination between and incorrect identification of different types of wave dominated shoreline in the stratigraphic record documented in this paper are the variability in facies characteristics high resolution stratigraphic architecture and interpreted palaeo geomorphology within a single parasequence that is interpreted to record the advance of an ancient asymmetrical wave dominated delta the standardville ab1 parasequence of the aberdeen member blackhawk formation is exposed in the book cliffs of central utah usa this parasequence and four others in the aberdeen member record the eastward progradation of north south trending wave dominated shorelines within the standardville ab1 parasequence distal wave dominated shoreface shelf deposits in the eastern part of the study area are overlain across a downlap surface by southward prograding fluvial dominated delta front deposits which have previously been assigned to a separate stranded lowstand parasequence formed by a significant allogenic change in relative sea level high resolution stratigraphic analysis of these deposits reveals that they are instead more likely to record a single episode of shoreline progradation characterized by alternating periods of normal regressive and forced regressive shoreline trajectory because of minor cyclical fluctuations in relative sea level interpreted normal regressive shoreline trajectories within the wave dominated shoreface shelf deposits are marked by aggradational stacking of bedsets bounded by non depositional discontinuity surfaces interpreted forced regressive shoreline trajectories in the same deposits are characterized by shallow incision of fluvial distributary channels and strongly progradational stacking of bedsets bounded by erosional discontinuity surfaces that record enhanced wave base scour fluvial dominated delta front deposits most probably record the regression of a lobate delta parallel to the regional shoreline into an embayment that was sheltered from wave influence wave dominated shoreface shelf and fluvial dominated delta front deposits occur within the same parasequence and their interpretation as the respective updrift and downdrift flanks of a single asymmetrical wave dominated delta that periodically shifted its position provides the most straightforward explanation of the distribution and relative orientation of these two deposit types

the origin of lithotype cycles in oligo miocene brown coals from australia and germany abstract brown coal colour lithotype cycles range from 10 to 30 m thick in oligo miocene coals of the latrobe valley gippsland basin australia similar colour lithotype cycles occur in the lusatia german miocene brown coals in both the latrobe valley and germany the cycles often display well developed colour lightening upward trends as defined by new colourimetry measurement the typical lithotype cycle boundary is abrupt between light below and dark lithotype above geological geochemical palynological and macrofossil evidence is consistent with a relative drying terrestrialisation upward depositional model for each cycle and the overlying dark lithotype represents renewed peat accretion the dark lithotype may include charcoal near the cycle base explained by the fire prone and highly flammable nature of the herbaceous reed wetlands in both the german and australian coals wetter darker lithotypes are characterized by a gymnosperm paleoflora while drier lighter lithotypes are characterized by angiosperms in the german rhenish miocene brown coal exposed in large open cut mines at garzweiler and hambach a 1 0 m spaced sampling and colourimetry measurement program shows lightening upwards cycles for the morken seam frimmersdorf a seam frimmersdorf b seam and for the garzweiler ii seam at hambach where the 60 m thick main seam includes amalgamations of frimmersdorf a frimmersdorf b and garzweiler i ii iii seams the lightening upwards trends provides a means of stratigraphic subdivision the palaeogeographic setting for latrobe valley and german brown coals is similar in latrobe valley the seams split and thin to the east into marine facies in the rhenish and lusatia brown coals they also split and thin to the north into marine facies the two rhenish mines at hambach and garzweiler respectively typify end members of this palaeogeography the hambach mine is located in a distal location where sulphur content is negligible the garzweiler mine is located in a proximal location to the marine boundary where sulphur content is higher the colourimetry and facies succession suggest german brown coal deposition followed a similar cyclic depositional succession to the latrobe valley and that this succession may be fundamental in all thick coal seams

digital outcrop models applications of terrestrial scanning lidar technology in stratigraphic modeling abstract laser ranging is extremely accurate and efficient terrestrial scanning lidar light detection and ranging applied to outcrop stratigraphic mapping enables researchers to capture laser range data at a rate of thousands of individual x y z and laser intensity points per second these data in conjunction with complementary remotely and directly sampled data are used to conduct high precision facies characterization and to construct 3d geological computer models outcrop data are presented here to explain our workflow and to discuss the construction of rock based 3d digital outcrop models doms reproducibility and quantification are the drivers of this methodology high resolution terrestrial lidar acquisition processing interpretation and visualization are discussed and applied to mapping of geological surfaces in three dimensions laser generated models offer scientists an unprecedented visualization medium in a quantitative 3d arena applications of this technology include constructing and visualizing complex 3d earth models from outcrops for improved reservoir modeling flow simulation in hydrocarbon and aquifer systems and property modeling to constrain forward seismic modeling

sedimentological aspects of the humber group upper jurassic of the south central graben uk north sea complex structure poorly understood sedimentology and poor biostratigraphic control make the upper jurassic humber group of the south central graben one of the least understood and most complex hydrocarbon reservoirs of the north sea detailed logging of available core from 19 exploration wells has been combined with an improved understanding of the relevance of trace fossils and a recognition of important base level variations to provide a greatly enhanced understanding of the depositional system active within the area at that time a new sedimentological model based upon the distribution of facies and facies associations illustrates that upper jurassic structure and consequent basin geometry were the principal controls upon the distribution of depositional environments rifting and second order transgression controlled the back stepping onlap patterns observed and higher frequency base level fluctuations controlled the internal architecture of individual sandbodies the model presented accounts for features of these deposits that were previously considered anomalous such as the thickness of bioturbated sandstones paucity of foreshore deposits and complex age relationships of sands

was the oligocene miocene a time of fire and rain insights from brown coals of the southeastern australia gippsland basin abstract lithotype cycles ranging from 10 to 30 m thick in the brown coals of the latrobe valley gippsland basin australia display well developed lightening upward trends cycle tops are characterized by abrupt and unconformable boundaries with the overlying cycle geological geochemical palynological and macrofossil evidence is consistent with a relative drying terrestrialization upward depositional model for the cycles the abundance of charcoal in dark lithotypes near the cycle bases is explained by the fire prone and highly flammable nature of the herbaceous reed wetlands in common with similar modern wetlands in modern australasia in which the dark lithotypes are suggested to have formed this together with the greater preservation potential of charcoal in subaqueous environments results in the wettest facies of the latrobe valley coals having the highest charcoal contents despite prevailing warm wet climate conditions and the predominance of rainforests that are suggested to have characterized the cenozoic of southern australia some swamp taxa were clearly already pre adapted to tolerate fire and are likely to have been the ancestors of the fire adapted floral communities of modern arid australia

cyclic sedimentation in tertiary lower rhine basin germany the liegendrucken of the brown coal open cast fortuna mine abstract in the lower rhine basin at the northwestern headlands of the schiefergebirge in western germany the oligocene miocene koln formation once was splendidly exposed in the former fortuna mine one of the open cast mines of the regional brown coal mining industry there a complex 60 m thick clastic marine shoreline succession was studied coastal marine sediments were formed along a high energy coast in the basal sediment fill of the basin due to repeated ingressions of the tertiary north sea a number of subtidal to supratidal coastal onlap cycles developed this study provides first knowledge about cyclic sedimentation in the tertiary of the lower rhine basin

progradational and backstepping shoreface deposits in the ladinian to early norian snadd formation of the barents sea shoreface sandstone deposits within the early carnian part of the snadd formation of the norwegian barents sea can be traced for hundreds of kilometres in the depositional strike direction and for tens of kilometres in the depositional dip direction this study uses three dimensional seismic attribute mapping and two dimensional regional seismic profiles to visualize the seismic facies of these shoreface deposits and to map their internal stratigraphic architecture at a regional scale the shoreface deposits are generally elongate but show variable width from north east to south west which corresponds to a sediment source in the northern part of the basin and a southward decrease in longshore sediment transport the snadd formation presents an example of how large scale progradational shoreface deposits develop the linear nature of its shoreface deposits contrasts with more irregular cuspate wave dominated deltaic shorelines that contain river outlets and instead implies longshore drift as the main sediment source in map view discrete sets of linear features bounded by truncation surfaces scale directly to beach ridge sets in modern counterparts the shoreface deposits studied here are characteristic in terms of scale and basin wide continuity and offer insight into the contrast between shallow marine deposition under stable triassic greenhouse and fluctuating holocene icehouse climates findings presented herein are also important for hydrocarbon exploration in the barents sea because they describe a hitherto poorly understood reservoir play in the triassic interval wherein the most prominent reservoir plays have so far been considered to be found in channelized deposits in net progradational delta plain strata that form the topsets to shelf edge clinoforms the documented presence of widespread wave dominated shoreface deposits also has implications for how the relative importance of different sedimentary processes is considered within the basin during this period

the coal bearing cenozoic as pontes basin northwestern spain geological influence on coal characteristics lignite deposits in the cenozoic as pontes strike slip basin northwestern spain were formed as a function of specific paleoclimatic conditions and tectonic evolution of the basin during the early evolutionary stages the presence of active normal faults and thrusts inside the basin resulted in two subbasins with distinct differences in sedimentary records with respect to lignite seam occurrence thickness area1 extent and lithotype development in contrast during the late evolutionary stages the basin was not split and a more homogeneous sedimentary record in terms of coal seam occurrence and lithotype characteristics developed a total of 26 lignite samples distributed along the basin infill were analyzed by organic petrography and geochemistry all are lignite b astm the lignites deposited during lower basin infill sedimentation units 1 and 2 are dark matrix rich mainly huminitic brown coals with minor bright liptinitic rich coal lithotypes the dark huminitic coals in these units show sedimentological and paleontological evidence of lacustrine influence persistent relatively moderate to low tissue preservation index tpi values and high average gelification index gi values are characteristic of these limno telmatic coals lignites in the upper basin infill unit 4 are almost exclusively matrix rich huminitic brown coals persistent widespread low tpi values and variable but low average gi values are also characteristic of these telmatic coals the overall coal petrological data trend tpi gi and widespread development or absence of liptiniteenriched lignite layers recorded from the lower to the upper basin infill units agrees with the stratigraphic and sedimentological data which show a trend of increasingly drier conditions development of bright liptinite enriched lignite layers was widespread during the early basin evolutionary stages and was influenced by punctuated water table oscillations sedimentological petrological and organic geochemical data point to the conclusion that although the paleoenvironments where peat deposition took place did not undergo dramatic changes they were affected by distinguishable

the geology and coal petrology of a pleistocene lignite profile at horemi mine megalopolis basin peloponnese southern greece abstract the present study describes the geology coal petrology and geochemistry of a pleistocene coal bearing succession at horemi mine megalopolis basin southern greece within a 45 m interval 9 coal seams are exposed ranging in thickness from 20 cm to 10 m reflectances measured on the maceral type eu ulminite b range between 0 24 and 0 31 mean r random this indicates a coalification stage in the transition zone between peat and lignite rank of the a s t m classification for the horemi coals petrographic studies demonstrated the immature nature of these coals and the low degree of compaction during diagenesis compositionally the horemi coals are characterized by low amounts 5 3 vol of the inertinite group macerals moderate amounts 11 9 vol of liptinite group macerals and very high amounts 82 8 vol of the huminite group macerals on average and mineral matter free basis within the latter group densinite attrinite and ulminite make up the bulk of the samples results from proximate and ultimate analysis gave on average 53 7 bed moisture and 37 3 ash 45 8 volatiles and 18 1 fixed carbon d b calorific value determinations vary between 1805 and 5470 kcal kg mineral matter is high varying within the range 20 8 51 9 vol identifiable mineral constituents include quartz anhydrite illite feldspars calcite gypsum and chlorite and minor amounts of barite and pyrite reflectances obtained from ulminite were found to be negatively correlated with volatile matter whereas there is a trend for a positive correlation of them with calorific values

three dimensional modeling of a shoreface shelf parasequence reservoir analog part 2 geologic controls on fluid flow and hydrocarbon recovery wave dominated shoreface shelf parasequences are commonly modeled as simple layer cake reservoirs yet analysis of modern and ancient analogs demonstrates that these intervals contain a more complex physical stratigraphy we investigate the impact of depositional and diagenetic heterogeneity associated with gently dipping clinoform surfaces on fluid flow and recovery during water flooding using a three dimensional model reconstructed from a well exposed outcrop analog we demonstrate that the volume of oil in place is affected by variations in facies thickness associated with interfingering along clinoforms whereas waterflood sweep efficiency is affected by barriers to flow along clinoform surfaces such as calcite cemented layers mudstones and siltstones sweep efficiency is low when water flooding is down depositional dip because oil is bypassed at the toe of each clinothem as water flows preferentially through high quality sandstone facies in the upper part of the parasequence sweep efficiency is higher when water flooding is up depositional dip because the gravity driven downward flow of water sweeps poorer quality sandstone facies in the lower part of the parasequence in both cases injectors may offer limited pressure support to producers water flooding along depositional strike yields good pressure support but poor sweep because the gravity driven flow of water into the lower part of the parasequence is significantly reduced this yields highly variable fluid saturations but a uniform pressure gradient which is consistent with pressure and fluid saturation data from the mature rannoch formation reservoir brent field united kingdom north sea simple layer cake models fail to capture the range of flow behaviors described above and overpredict recovery by up to 20 as a result

vertical and lateral variation in the petrography of the upper cretaceous sunnyside coal of eastern utah usa implications for the recognition of high resolution accommodation changes in paralic coal seams the sunnyside member of the upper cretaceous blackhawk formation in the book cliffs of eastern utah is composed of coal bearing coastal plain strata and wave dominated shoreface deposits the member includes a thick up to 6 m laterally extensive coal seam which formed in a large ombrotrophic raised mire parallel to the shoreline of the western interior seaway the petrographic composition of the sunnyside coal was investigated by means of maceral analysis and telovitrinite reflectance determinations of closely spaced samples taken from seven vertical sections through the seam sampling was carried out in a combination of outcrop and underground mine sites using lithotype logging to determine sample spacing the excellent exposure in the study area enables accurate stratigraphic correlation between sampling localities which are spread over more than 30 km of depositional dip and 50 km of depositional strike the correlation of petrographic trends between the seven sampled sections demonstrates the reproducibility of the results and suggests that they represent regional scale accommodation changes as opposed to localised variation in the mire on this basis we are able to identify a high resolution record of accommodation change throughout the deposition of the sunnyside coal spanning two cycles of increasing and decreasing accommodation we are also able to identify a marine flooding surface within the coal which can be traced down depositional dip into the time equivalent shallow marine strata where it represents a parasequence boundary the proportion of detrital minerals is used as the main discriminator of accommodation trends within the coal other useful indicators of conditions in the mire include semifusinite pyrite and isometamorphic variations in telovitrinite reflectance

sequence stratigraphic responses to shoreline perpendicular growth faulting in shallow marine reservoirs of the champion field offshore brunei darussalam south china sea the champion field offshore brunei darussalam comprises a thick middle upper miocene succession of shallow marine sediments associated with major growth fault systems and deposited as part of the paleo baram delta the structural evolution of the champion field has resulted in an unusual situation where growth faults strike perpendicular to the paleoshoreline orientation shoreface parasequences and tidal estuarine complexes are mapped directly from three dimensional 3 d seismic data calibrated from wells the seismic interpretations provide chronostratigraphic correlations that are more robust than some well based markers because the seismic interpretations have better spatial coverage depositional responses to growth faulting are defined by two end member models 1 layer thickening and 2 addition of layers in the hanging wall layer addition makes correlation across faults problematical growth may be accommodated by either or a combination of these processes and areas of layer addition are related to transgressive events in the hanging wall topographic changes thought to be associated with fault movements may fundamentally change shoreline type sand body orientations and petrophysical properties for discrete periods of time these stratigraphic complexities are linked spatiotemporally to accommodation history but cannot be adequately predicted from well data alone

three dimensional reconstruction of an in situ miocene peat forest from the lower rhine embayment northwestern germany new methods in palaeovegetation analysis palaeovegetation reconstructions particularly of fossil forests are generally restricted to scant information on the taxonomic composition relative abundance of individual taxa or on tree density we have developed new techniques for the analysis of stump horizons that result in a relatively detailed three dimensional reconstruction of ancient forests in addition a rough estimate of their above ground standing biomass can be calculated these techniques are applied to an in situ miocene peat forest preserved in the lower rhine embayment northwestern germany in a study area of 2500 m2 476 stumps were mapped and used in the forest reconstruction additionally pollen samples and leaf remains have been analysed the peat forest consists primarily of conifers in particular taxodiaceae and pinaceae with sciadopitys being the most common genus the only angiosperms in the wood flora were palms but in the pollen flora evidence for the myricaceae mastixiaceae ericaceae and a few other angiosperms is also present the forest was relatively dense with 1904 trees ha and a basal area of 164 m2 mean trunk diameter was 28 cm while mean tree height is calculated to have been 9 9 m height diameter and density distribution are illustrated using contour and three dimensional surface plots estimated above ground biomass is 750 t ha but this value also includes dead or partly dead trees this peat forest does not closely compare with previous reconstructions of miocene peat forests its three dimensional structure and biomass differ from those of modern bald cypress swamps

evidence of across shelf transport of fine grained sediments turbidite filled shelf channels in the campanian aberdeen member book cliffs utah usa the shore normal transport of fine grained sediments by shelf turbidity currents has been the focus of intense debate over the last 20 years many have argued that turbidity currents are unlikely to be a major depositional agent on the shelf however sedimentological architectural stratigraphic and palaeogeographic data from the campanian aberdeen member book cliffs eastern utah suggests otherwise and clearly demonstrates that storm generated and river flood generated underflows can transport a significant volume of fine grained sediments across the shelf these across shelf flowing turbidity currents cut large subaqueous channel complexes up to 7 m deep tens of kilometres basinward of their time equivalent shoreface the shelf channels were filled with organic rich siltstones mudstones and very fine to fine grained bouma like sandstone beds including wave modified turbidites hyperpycnites and classical turbidites deposition was above storm wave base palaeocurrent data reveal an overwhelmingly dominant across shelf east south east offshore directed transport trend tectonic activity and or concomitant palaeogeographic reorganization of the basin may favour the generation of these turbidite rich shelf deposits by altering the relative balance of wave versus fluvial energy increased erosion and sediment supply rates because of tectonic uplift of the hinterland may have increased the probability of fluvial dominance along the coastline and hence the possibility of submarine channelization in front of the river mouths additionally the coastline may have become more sheltered from direct wave energy thus allowing the fluvial processes to dominate seasonal increases in rainfall and storm activity may also favour the generation of across shelf underflows on wave dominated shorelines isolated shelf channels and lobes are most likely to be found down dip of fluvial feeder systems in relatively high sediment supply settings these features are also most likely to occur in systems tracts that straddle a sequence boundary especially those which are tectonically generated as these would enhance the potential for altering basin morphology and hence the balance of fluvial and wave energy isolated shelf channels are recognized in older and younger strata in the book cliffs region implying that wave supported gravity flows were a recurrent phenomena in the campanian of utah it is probable that isolated shelf bodies are preserved in other stratigraphic intervals in the cretaceous western interior of north america and other basins worldwide and are currently being overlooked or misidentified shoreface to shelf facies models should be revised to incorporate turbidite rich shelf deposits in some shelf settings

environmental history of the german lower rhine embayment during the middle miocene as reflected by carbon isotopes in brown coal stable carbon isotope investigations have been carried out on miocene brown coal from the garzweiler seam of the german lower rhine embayment material studied included fossil wood from seven different taxa and brown coal matrix isotope results from macrofossil analysis show variations of more than 6 within individual samples and reveal a general isotopic difference between angiosperm and gymnosperm wood specimens according to mean carbon isotope values found for gymnosperms angiosperms and brown coal matrix 23 3 26 0 and 25 8 the peat forming vegetation of the garzweiler seam was dominated by angiosperm taxa results from brown coal matrix establish a continuous high resolution depth profile of carbon isotope variations during the late middle miocene they show a significant and characteristic isotope pattern with distinct medium and short term cycles high frequency variations in the two main units of garzweiler seam locally split into three units the medium term 13c variations are most likely caused by varying proportions of gymnosperms within the peat forming vegetation while high frequency oscillations seem to be a direct signal of environmental changes a long term decline of carbon isotope values observed within the complete garzweiler seam from base to top is presumably due to a cooling trend in the miocene

marlies teichmuller 1914 2000 pioneering genetic coal petrologist some paleobotanical palynological and botanical influences on her research marlies teichmuller focused her career on genetic coal petrology in her investigations of the botanical components of coal and reconstructions of carboniferous and tertiary mires she was greatly influenced by eric stach walther gothan reinhardt thiessen rolf teichmuller paul thomson gilbert cady and william spackman jr some of these influences deal with paleobotany palynology and botany and these are set forth in this tribute

petrographic composition and depositional environments of the pliocene velenje lignite seam slovenia abstract a pliocene lignite seam up to 160 m thick occurs in the velenje depression in northern slovenia it forms part of a non marine transgressive sequence petrographic data together with ash and sulphur content of samples from two boreholes one located in the central and the other in the marginal part of the seam have been used to study vertical and lateral coal facies variations in the central part the lignite seam overlies fluvial sediments facies critical macerals and petrographic indices suggest that the lower ash rich part of the seam unit i accumulated in a wet forest swamp in an alluvial plain setting later this environment was replaced by a dry telmatic forest swamp unit iia according to our interpretation a decrease in tree density in units iib and iic reflects a change to a bush moor the transition from unit ii to unit iii is characterized by a rapid water table rise which resulted in the establishment of a wet limnotelmatic forest swamp within unit iii the tree density decreases and the degree of gelification increases towards the top of the seam suggesting a transition to a fen type environment another rapid water table rise ended peat formation in the eutrophic topogenous mire and established open lacustrine conditions a calcium rich environment resulted in high ph values and is responsible for high sulphur lignites up to 4 on a dry basis in the upper part of the seam the ph values were controlled by the amount of the inflowing lacustrine water only thin ash rich topotelmites accumulated along the northern margin of the mire there the seam originated in a wet forest swamp and was separated by limnic and fluvial sediments from other organic rich horizons due to its closer vicinity to the pre tertiary carbonates the depositional environment was probably even more alkaline therefore the lignite shows a higher degree of gelification and is even more sulphur rich up to 5 5 on a dry basis

quantifying clinothem geometry in a forced regressive river dominated delta panther tongue member utah usa this study presents a methodology for the quantitative description of small scale delta clinothems the quantitative bed data analysis is based on three dimensional virtual outcrop models generated by ground based laser scanning light detection and ranging a large number of clinothem bed measurements have been collected from the ancient forced regressive delta system of the panther tongue that crops out in utah usa in river dominated marginal marine environments clinothems separated by clinoform surfaces represent the former position of the delta front as it prograded systematic collection of data from virtual outcrop models has allowed for accurate spatially constrained measurement of individual bed thicknesses and the compilation of a detailed database on clinothems and associated clinoform geometries measurement locations were selected so that each measurement was 10 m down depositional dip from the previous one the study area covers 5 km2 within which 2376 measurements were made from 50 separate clinothems in 320 different positions within the virtual outcrop a bed taper parameter permitted the thinning of the clinothems to be described as a single number and thus allowed relative comparison between beds combined measurements were also used to calculate the average dip angle of the clinothems analysis of the vertical and lateral stacking of the clinothems has revealed a series of stratigraphic cycles which are termed bedsets stream mouth bars the surfaces that bound the bedsets are unremarkable and it is unlikely that their significance would be recognized without this style of detailed analysis a cyclic depositional pattern interpreted as related to autocyclic processes and compensational stacking of mouth bars is proposed as the origin of these packages mapped length thickness trends constrain the spread of these variables and can be used to constrain subsurface models of analogous hydrocarbon reservoirs