geochemistry and petrology of palaeocene coals from spitsbergen part 1 oil potential and depositional environment abundant oil prone coal type iii kerogen deposits are preserved within the high latitude middle palaeocene todalen member of the central tertiary basin spitsbergen island norwegian arctic the coals svea longyear svarteper and askeladden seams have been subjected to only minor previous geochemical characterisation focussing upon the longyear seam this paper characterises the present prospective and economic oil potential of the svalbard coals organic biomarker parameters fe s chemistry and coal maceral analysis are then applied to understand the provenance and environmental origins of this unusual source rock the upper todalen mbr coals longyear svarteper and askeladden seams have significantly more oil potential than the lower svea seams with estimated retortion yields of 170 190 kg tonne vs 24 kg tonne respectively the longyear seam exhibits relatively high hi values ca 300 400 mg g toc consistent with a hydrogen rich mixed type ii iii kerogen source greatest oil potential is shown to be favoured by formation within a fen environment with high bacterial degradation 100 g g toc hopanes marine influence 0 5 wt sulfur fe s 0 9 and the unique temperate high latitude palaeocene climate of svalbard leading to preservation of hydrogen rich organic matter via organo sulfur bond formation

the upper ordovician black shales of southern quebec canada and their significance for naturally occurring hydrocarbons in shallow groundwater abstract shale gas exploration in the st lawrence platform of southern quebec eastern canada focussed on the upper ordovician utica shale from 2006 to 2010 during which 28 wells were drilled 18 of which were fracked the st lawrence platform is thus considered as a pristine geological domain where potential environmental effects of fracking can be evaluated relative to the natural baseline conditions of the shallow aquifers in the saint edouard area southwest of quebec city it has been shown that groundwater carries variable and locally high levels of naturally occurring dissolved hydrocarbons in which thermogenic ethane and propane can be found fifteen shallow 30 147 m wells were drilled into bedrock and sampled cores and cuttings with the purpose of characterizing the shallow bedrock in a shale gas pre development context the shallow bedrock geology is made of three upper ordovician clastic formations the lotbiniere and les fonds formations are time and facies correlative with the utica shale present at a depth of 1 5 to 2 km in this area they are dominated by calcareous black shales with minor siltstone and micrite beds the nicolet formation is the youngest unit of the area and consists of gray to dark gray shales with locally abundant thick siltstone and fine grained sandstone beds the organic matter in the lotbiniere and les fonds formations is represented by solid bitumen with subordinate liptinite algae graptolites and chitinozoans representing normal marine type ii kerogen both formations are at the post peak hydrocarbon generation as indicated by the equivalent random vitrinite reflectance of 0 94 to 1 04 rock eval data support the type ii nature of the kerogen and the late oil window maturation level hydrocarbon extracts from the three formations have yielded high to low concentrations of c1 to c6 for all units an upward decrease in total volatiles c1 c2 c3 together with an increase in the gas dryness ratio c1 c2 c3 is recorded the transitions occurring at depths shallower than 50 m where the shales are more fractured the upward increase in the gas dryness ratio results from the more significant reduction of ethane and propane concentrations compared to that of methane consistent with the dryness ratio trend the 13 c vpdb values of methane change from thermogenic values 50 for deeper samples to more biogenic negative values 2 h vsmow trend of more negative values at shallower depths is noted the 13 c vpdb and 2 h vsmow values of rock hosted methane indicate that samples at shallow depth recorded a microbial influence it is proposed that diffusion and some microbial degradation of hydrocarbons are responsible for the decrease of rock volatiles and the in situ generation of biogenic methane in the shales at shallow depths to mix with the in situ thermogenic methane the utica shale is a very good source rock with high generation potential however thermogenic volatiles can also originate from shallower units with much shorter migration pathways the mixed thermogenic and biogenic methane in the groundwater results from fracture enhanced diffusion and biodegradation of volatiles at shallow depths

source location dependency site response in the taipei basin of taiwan by using hvsr analysis abstract techniques using horizontal to vertical spectral ratios hvsr have frequently been adopted in many studies particularly of seismic site amplification however the influence of source location on the hvsr is not previously well studied this paper studies the variation of the s wave hvsr in the taipei basin based on a variety of hypocenter locations the earthquake records are classified into three categories include depth azimuth and distance we report the s wave hvsr to have strong focal depth dependence for which the hvsr of the deep events are larger than shallow events besides the s wave hvsr in the northern and northeastern parts of the basin also displays source azimuthal dependence however there is no apparent difference in source distance dependence in contrast to the s wave hvsr the coda wave hvsr all showed no apparent difference for various earthquake hypocenter locations the synthetic modeling results support our idea that the cause of the variation of hvsr results for different earthquake focal depths is the different s wave angles of incidence into the basin based on the dependency of the site amplification on the focal depth a focal depth dependent empirical transfer function etf was established the focal depth dependent etf was verified to improve the accuracy of the ground motion prediction by using the stochastic method in this study we demonstrate that the source location effect especially the focal depth can significantly influence the s wave hvsr and therefore needs to be taken into account in site response investigation

petrographic and geochemical contrasts and environmentally significant trace elements in marine influenced coal seams yanzhou mining area china abstract the yanzhou mining area in west shandong province china contains coals of permian and carboniferous age the 31 and 32 seams of the permian shanxi formation and seams 6 15 17 of the carboniferous taiyuan formation were analyzed for coal petrology mineralogy and geochemical parameters the parameters indicate that the coal is high volatile bituminous in rank the coal is characterized by high vitrinite and low to medium inertinite and liptinite contents these properties may be related to evolution of the coal forming environment from more reducing conditions in a marine influenced lower delta plain environment for the early taiyuan coals to more oxidizing paleoenvironments in an upper delta plain for the upper shanxi coal seams the major mineral phases present in the coal are quartz kaolinite pyrite and calcite sulfur is one of the hazardous elements in coal the major forms of sulfur in coal are pyritic organic and sulfate sulfur pyritic and organic sulfur generally account for the bulk of the sulfur in coal elemental sulfur also occurs in coal but only in trace to minor amounts in this paper the distribution and concentration of sulfur in the yanzhou mining district are analyzed and the forms of sulfur are studied the sulfur content of the taiyuan coal seams is considerably higher than that of the shanxi coals organic sulfur content is positively correlated to total and pyritic sulfur the vertical variation of cu zn pb as th u and sulfur contents in coal seam 3 of the shanxi formation in the xinglongzhuang mine show that all these trace elements with the exception of th are enriched in the top and bottom plies of the seam and that their concentrations are also relatively high in the dirt bands within the seam the pyritic sulfur is positively correlated with total sulfur and both are enriched in the top bottom and parting plies of the seam the concentrations of the trace elements are closely related to sulfur and ash contents most of the trace elements are correlated with the ash content and may be associated with the mineral matter in the coal

the significance of graptolite reflectance in regional thermal maturity studies queen elizabeth islands arctic canada abstract variations in reflectance and bireflectance of graptolites taken from the cape phillips formation in the queen elizabeth islands arctic canada are documented graptolites taken from core samples from melville island possess a wide range of reflectance 1 75 3 90 r0max graptolites taken from outcrop samples from the other islands have a much narrower reflectance distribution 0 57 0 81 r0max the latter indicate that the organic matter is in the mature stage of hydrocarbon generation conodont colour alteration indices in strata from arctic canada and in the cape phillips formation in eldridge bay e 79 melville island are low 1 1 5 and agree with the low reflectance of the cape phillips graptolites the higher maximum reflectance values of the melville island graptolites indicate that the host sediments have experienced deeper burial and exposure to elevated temperatures compared to graptolites in the same formation of other islands this study demonstrates that graptolite reflectance can delineate relatively accurately the thermal conditions that sediments enclosing them have experienced and when combined with bitumen reflectance and stratigraphic and structural evidence graptolite reflectance can be useful in assessment of thermal maturity and thickness of eroded section in lower palaezoic successions

the silurian qusaiba hot shales of saudi arabia an integrated assessment of thermal maturity abstract the lower silurian qusaiba hot shales qhs are proven source rocks for oil within the paleozoic and possibly some of the mesozoic reservoirs in saudi arabia moreover these shales have oil shale potential where they are immature and shallow enough for mining as well as unconventional shale oil and shale gas potential in areas where they are within oil maturity and gas maturity levels respectively the qhs were deposited in relatively shallow marine environments under anoxic water conditions resulting in accumulation of amorphous kerogen organic walled graptolites and acritarchs across the arabian basin organic matter quality does not show much variation for the qhs but the maturity varies greatly as a result of varying burial history thermal maturity assessment of shale source rocks that lack vitrinite such as the qusaiba hot shales continues to be challenging especially where conflicting measurements are obtained from different sources this paper presents an integrated assessment of qhs thermal maturity parameters based on cores from 13 carefully selected boreholes that based on regional basin models are believed to cover a wide maturity range ca 0 5 to 2 0 ro we conducted some analyses on kerogen maceral petrography graptolite reflectance uv fluorescence whole rock pyrolysis raman spectroscopy of graptolite and other analyses on bitumen extracts gc and gc ms of saturate and aromatic fractions and ftir spectroscopy of the asphaltene fraction we show that using many thermal maturity parameters reduces uncertainty significantly and we therefore recommend that graptolite reflectance analyses should be conducted in support of other maturity indicators proper reflectivity measurements of the graptolites set the reference for comparison of other maturity parameters obtained from petrographic geochemical and spectroscopic techniques our work provides a template by which qusaiba thermal maturity can be more accurately estimated when only a limited set of maturity parameters is available

graptolites as indicators of the temperature histories of rocks a pilot study of the optical properties of graptolite skeletal materials shows progressive changes of reflectance bireflectance refractive index and absorptive index produced by temperature changes related to depth of burial samples of lower ordovician to upper silurian graptolites were selected from across canada from locations where the conodont alteration indices of adjacent conodont collections provide a control index of temperature the reaction to temperature of graptolite skeletal material appears to be similar to that of bitumen but somewhat different to that of the vitrinite and liptinite maceral components of coal maximum reflectance in oil and bireflectance appear to be the characteristics most diagnostic of maximum temperature and both show progressively higher rates of increase at higher temperatures these factors show potential for more sensitive discrimination of temperatures at high levels of conodont alteration indices the optical properties of graptolites may perhaps provide a useful tool for unravelling the post depositional histories of lower palaeozoic rocks in deformed belts

the lateral and vertical reflectance and petrological variation of a heat affected bituminous coal seam from southeastern british columbia canada abstract thermally altered pods of coal of very high rank have been observed in a high volatile bituminous coal seam in the eastern side of eagle mountain elk valley coalfield british columbia rank changes have been measured over a strike distance of 7 5 m from 1 24 to 7 1 r o max corresponding to a rank gradient of 0 78 r o m 1 petrologically unaltered to extremely altered vitrinite showing nongranular basic anisotropy mosaic textured liptinite and pyrolytic carbon are the most abundant components the limited presence of mosaic on vitrinite is an indication that the coal seam may have been weathered prior to being heat affected evidence points to localized temperatures as high as 1 000 c which could have been caused by a lightning strike the eastern side of eagle mountain has experienced higher temperatures than the western side and it appears that the heat front and zone of alteration have an irregular pattern pointing to saturation of parts of the coal seam by water four types of pyrolytic carbon having distinct morphology anisotrophy and optical path with increasing temperature were observed reflectance of pyrolytic carbon falls within the zone of heat affected coals whereas the optical path of heat affected seam 15 samples is different from that of fresh coal with increasing rank finally the reflectance of vitrinite in heat affected coal is higher than the reflectance of vitrinite in carbonaceous shale in the seam 15 section

optical characteristics of graptolite bearing sediments and its implication for thermal maturity assessment abstract graptolite reflectance was thought to be one of the most useful thermal maturity indicators for graptolite bearing sediments however the relationship between graptolite reflectance and vitrinite reflectance is not well established graptolites especially in the wufeng longmaxi formations from the ordovician to silurian of south china have been mistaken for vitrinite like particles or solid bitumen which results in inconsistent data on the thermal maturity in this paper we have employed optical microscope techniques to describe the detailed optical characteristics of graptolites and solid bitumen in the wufeng longmaxi formations laboratory simulation of maturation was used to determine the relationship between graptolite reflectance and vitrinite reflectance the organic constituents in the wufeng longmaxi formations are mainly composed of graptolites and solid bitumen granular and non granular graptolites were observed in the wufeng longmaxi formations with non granular as the most common texture solid bitumen can be distinguished from non granular graptolites by its coarse surface weaker anisotropy and lower random reflectance the combination of non polarized and polarized light is very helpful to distinguish solid bitumen from graptolite for comparison organic material from the early ordovician alum shale formation of sweden and estonia was also studied the macerals of the alum shales are mainly composed of lamalginites mineral bituminous groundmasses graptolites and solid bitumen the major textures of the graptolites in the sweden and estonia sediments are non granular and granular respectively both non granular graptolite and vitrinite reflectances display a systematic increase with the increase of heating temperature and time the granular graptolites in the estonian sample were gradually changed to non granular graptolites following laboratory simulated maturation indicating that granular graptolites can transform into non granular graptolites with maturation solid bitumen in the wufeng longmaxi formations was derived from the solid residue of kerogen and or post oil bitumen the graptolite random reflectance is a better thermal maturity indicator than graptolite maximum reflectance and is more precise due to the smaller standard deviation several equations are proposed to determine the thermal maturity of the graptolite bearing sediments based on graptolite random reflectance graptolite maximum reflectance and solid bitumen random reflectance

an evaluation on h v ratio vs spectral ratio for site response estimation using the 1994 northridge earthquake sequences the applicability of the single station h v method based on the spectral ratio between the horizontal and the vertical components of strong ground motions is examined for site response estimation using the high quality data from the 1994 northridge earthquake sequence instead of using rayleigh wave data from microtremors the large amplitude wave part of the s wave data is used and based on the 1994 northridge mainshock and aftershock recordings we have found that upon averaging over a number of recordings for a given station the station site responses derived both from the single station h v ratio and from the standard spectral ratio with respect to a reference rock site station are sufficiently close for practical purposes we therefore conclude that the h v ratio can reasonably predict the resonant frequency and the amplification level of a site response especially for sites in the neighborhood of the epicenters in the absence of a reference rock site station the h v ratio provides a practical alternative to the standard site response estimation

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

pore structure of the graptolite derived om in the longmaxi shale southeastern upper yangtze region china abstract the lower silurian longmaxi shale in the southeastern upper yangtze region which has been the main target for shale gas exploration and production in china is black marine organic rich shale and rich in graptolites graptolites usually only periderms preserved in shales are important organic component of the longmaxi shale however the pore structure of graptolite periderms and its contribution to gas storage has not yet been studied before a combination of optical microscopy for identification and mark of graptolite and scanning electron microscope sem for pore observations were conducted for the longamxi shale samples results show that pores are anisotropic developed in the longmaxi graptolite periderms and greatly associated with their fine structure micrometer sized fractures and spindle shaped pores between cortical fibrils in the cortical bandage are greatly developed at section parallel to the bedding while they are rare at section perpendicular to the bedding besides numerous sapropel detritus rich in nanometer sized pores are discretely distributed in the shale though graptolite periderms are low porosity from sem image analysis microfractures and elongated pores along the graptolite periderm wall may still make the graptolite an interconnected system together with the discrete porous sapropel detritus in shale these graptolite derived organic matter om may form an interconnected organic pore system in the shale the difference of pore development observed in graptolite periderms and sapropel detritus also give us new insight for the organic pore heterogeneity study the om composition their fine structure and orientation in the rock may be important factors controlling om pore development the combination of identifying om type under optical microscopy and pores observation under sem for may be an effective method to study the om pore development especially in shale that contain more om

analysis of spectral ratios for estimating ground motion in deep basins abstract use of nakamura9s spectral ratio horizontal versus vertical components is investigated theoretically for deep sedimentary basins by considering semi circular and semi spherical valleys the ratio is evaluated from the steady state surface response for different incident waves based on this ratio both the resonant frequencies and ground motion amplification are determined the results based on nakamura9s ratio are compared with those based on the sediment to bedrock spectral ratios kagami9s ratio the results show that for both two and three dimensional models nakamura9s technique predicts well the fundamental resonant frequency but it could not determine higher resonant frequencies of the basins the error in nakamura9s estimate of the fundamental resonant frequency increases for stations near the valley center for alluvial valleys considered in this article nakamura9s ratio failed to predict accurately surface ground motion amplification

on the horizontal to vertical spectral ratio in sedimentary basins the horizontal to vertical spectral ratio hvsr has been used by many researchers to characterize local conditions in terms of the dynamic response of the soil one of its variants is that proposed by nakamura 1989 in which records of microtremors are used usually the analysis is aimed to obtain the predominant period of the site under study in this work we explore what can be achieved by using this method we study the response of different configurations under incident waves coming from an explosive source using the indirect boundary element method ibem we investigate two cases low and high velocity contrast holding constant the physical properties inside the basin and changing only the properties of the bedrock then we compute the seismic response using the horizontal sediment to bedrock spectral ratio sbsr at various locations on the free surface of the basins and compare it with the one calculated by the hvsr at the same locations the comparison shows that in general the predominant period computed with the hvsr is not the same as that obtained by the sbsr in all the locations on the other hand the hvsr approximation can reasonably well predict the fundamental local frequencies when the impedance contrast between the basin and the bedrock is low however hvsr cannot be used in sedimentary basins having a high impedance contrast with respect to the bedrock below

organic petrology of selected oil shale samples from the lower carboniferous albert formation new brunswick canada incident light microscopy was used to describe maturation and composition of organic material in oil shale samples from the lower carboniferous albert formation of new brunswick the maturation level was determined in normal white light by measuring vitrinite reflectance and in fluorescent light by measuring fluorescence spectra of alginite b results indicate low to intermediate maturation for all of the samples composition was determined by maceral analysis alginite b is the major organic component in all samples having significant oil potential oil yields obtained from the fischer assay process and oil and gas potentials from rock eval analyses correlate to the amounts of alginite b and bituminite determined in the samples in some of the samples characterized by similar high concentrations of alginite b decrease in fischer assay yields and oil and gas potentials is related to an increase in maturation as expressed by increase in the fluorescence parameter lgrmax and red green quotient of alginite b incident light microscopy particularly with fluorescent light offers a valuable tool for the identification of the organic matter in oil shales and for the evaluation of their oil and gas potentials end of article last page 494

assessing thermal maturity of palaeozoic rocks from reflectance of chitinozoa as constrained by geochemical indicators an example from southern ontario canada the reflectance of chitinozoa chr0 was investigated as an alternative technique of determining the level of thermal maturity of organic rich palaeozoic rocks in southern ontario these sedimentary strata which include the ordovician collingwood member and the blue mountain formation as well as the devonian marcellus formation lack vitrinite precluding the application of a standard vitrinite reflectance vr0 technique chr0 shows a proportional increase at marginal to moderate maturities being on average 20 to 25 higher than expected vitrinite reflectance the reflectance data fall into a very narrow range showing a high degree of consistency for each lithostratigraphic unit the average chr0 are as follows collingwood mbr 0 63 georgian bay area and 0 88 toronto area blue mountain fm 0 92 marcellus fm 0 68 correlation with more conventional optical and geochemical maturity parameters obtained from the same set of samples fluorescence of tasmanites leiosphaeridia and gloeocapsomorpha alginite rock eval tmax extract data distribution of terpanes and steranes in extracts indicates that within the area of study the beginning of the catagenetic stage corresponds to chr0 0 65 equivalent vr 0 50 whereas the threshold of significant oil generation is reached at chr0 0 9 equivalent vr 0 70 therefore the blue mountain formation is thermally mature with respect to hydrocarbon generation throughout the whole area of study the collingwood shales are mature only in the toronto area while those occurring in the georgian bay area as well as the marcellus shales have yet to enter the main stage of hydrocarbon generation this integrated approach of assessing thermal maturity shows that chr0 when constrained with other maturity parameters is a very reliable indicator of thermal maturity in lower to middle palaeozoic sedimentary rocks

reflectance cross plot analysis of graptolites from the anchi metamorphic region of northern maine u s a abstract reflectance crossplot analysis a graphical technique plotting apparent reflectance maxima and minima against the apparent bireflectance and previously used primarily for interpretation of biaxial vitrinite data is applied to graptolite reflectance data from the subgreenschist and chlorite zones of northern maine u s a to determine the value of the intermediate reflectance axis rint the shape and change in the graptolite reflecting indicating surface gris with rank and calculate random reflectance from the crossplots gris shapes for this region were found to become rapidly oblate with increasing maturation in addition the random reflectance calculated as the arithmetic mean of the three reflectance axes compares favorably with the measured mean random reflectance

regional thermal maturity in the franklinian mobile belt melville island arctic canada abstract the thermal maturity and source rock potential of the palaeozoic sediments in the franklinian mobile belt melville island arctic canada have been studied using reflected light microscopy of approximately 400 polished whole rock samples organic matter in the palaeozoic strata of the franklinian mobile belt is represented mainly by bitumen in the ordovician and silurian and a combination of liptinite and vitrinite in the devonian different bitumen types have been identified depending on their morphology reflectance range and association to the enclosing mineral matrix thermal maturity of the palaeozoic strata based on vitrinite equivalent reflectance calculated from bitumen reflectance is high an indication that the strata are in the overmature stage of hydrocarbon generation and that only dry gas should be expected the presence of numerous types of bitumen indicates that hydrocarbons have been generated and migrated through the sediments regional variations in the thermal maturity of palaeozoic sediments in the franklinian mobile belt are mostly a function of depth of burial which is affected by subsidence folding and amount of erosion

organic petrology and geochemistry of tournaisian age albert formation oil shales new brunswick canada abstract lacustrine oil shale and shale samples of the tournaisian age albert formation in new brunswick canada taken from six locations were analyzed by organic petrology using reflected white and fluorescence light microscopy and by rock eval pyrolysis to determine their depositional environment and hydrocarbon generating potential calcium th and ca contents of the samples were also determined using icpms the results were compared to the big marsh lacustrine oil shale of carboniferous age in nova scotia organic matter consists mostly of filamentous alginite bacterial remains and matrix bituminite which fluoresce green to dark yellow organic matter was deposited in a lake basin the regular layering of algal remains and wrapping around mineral particles indicate deposition in a low energy setting below wave base which resulted in the stratification of the organic matter and the enclosing mineral matrix there are also fluorescing to non fluorescing bitumens present in parts of the albert oil shale the bitumens were incorporated as a result of hydrocarbon migration during deposition of the oil shales the two are considered to be syn sedimentary because the bitumens are part of the regular rock layering and the fact that the organic matter is wrapped around mineral grains the bitumens in the albert oil shales consist of fluorescing wurtzilite and non fluorescing albertite the albert oil shales have lower input of terrestrial sediments containing th and are carbonate rich the variation of th u ratio and toc wt indicates that the albert oil shales have different mineralogy than those from the big marsh ones there are two types of carbonates particles in the albert oil shale a syngenetic angular particles which are suspended in the organic matter but may also occur as micrite and b rounded to angular and possibly transported particles containing oil inclusions as a result variations in th u and calcium divided the oil shales into a low calcium lacustrine type which includes the big marsh oil shale the albert oil shale and shale deposited far from the albert mine and few samples from a deposit close to the albert mine that have high calcium content and some of them contained oil inclusions the higher toc of samples collected from the bitumen mining area in the albert mine is related to bitumen impregnation due to hydrocarbon migration variation of hi mg hc g toc and authigenic uranium in the albert oil shale indicates that depositional environment was more anoxic than most of the oil shales in the big marsh deposit rock eval pyrolysis data and accompanying organic petrology analysis indicate that the samples are mostly immature to marginally mature as indicated by ro ran of 0 60 0 68 and variation in the fluorescence red green and blue green and blue r g b g b quotients variations in maturity indicators such as hi and tmax are caused by other factors such as quantity of organic matter in the samples the hydrogen index hi vs tmax plot of the oil shales displays a wide range of hi within a narrow tmax range of 438 442 c indicating immature to marginally mature type i kerogen there is a slight trend of increasing tmax into the oil window with increasing hi likely due to the extreme mass of hydrocarbons in these samples which requires higher energy to breakdown rather than burial related thermal maturity maturity of the albert oil shale increases from east to west within the study area as indicated by the westward increase of all three fluorescent quotients of both filamentous algae and matrix bituminite and in the ro the reflectance of the albert oil shales measured on vitrinite is mostly suppressed compared to the nearby mapleton organic lean shale in new brunswick there is also a correlation between hi and ro ran in the oil shale samples studied the higher is the hi the lower is the ro the majority of the oil shale samples have a very high potential for hydrocarbon extraction using the ex situ methodology at 30 l t and the upper 20 of the samples have the potential for in situ extraction at 60 l t

ebb tide dynamics and spreading of a large river plume abstract momentum balances in the near field region of a large tidally pulsed river plume are examined the authors concentrate on a single ebb tide of the columbia river plume using the regional ocean modeling system roms configured to hindcast flow conditions on the washington and oregon shelves and in the columbia river estuary during ebb plume interior streamwise balances are largely between advection pressure gradient and frictional forces stream normal balances in this region reduce to centrifugal cross stream pressure gradient and coriolis terms i e the gradient wind balance commonly assumed in river plume bulge investigations temporal derivatives are most important at the plume front and as the ebb progresses winds were light and contributed little to the force balance midebb stress and vertical salt flux were largest at a midplume depth where stratification and vertical shear were also high consistent with shear induced mixing internal stress slows the spreading plume consi

comparison of the geochemistry of lacustrine oil shales of mississippian age from nova scotia and new brunswick canada abstract the bulk elemental concentration of selected albert formation oil shale deposits of mississippian age from new brunswick was analyzed using icp ms and prompt gamma results compared to that of the big marsh oil shale of similar age from nova scotia reflected white and fluorescence light was used to determine the characteristic organic matter and rockeval analyses were used to determine the hydrocarbon potential of oil shale both albert and big marsh oil shales were deposited in lacustrine environments based on geological and sedimentological evidence the big marsh oil shale has low and stable b content 28 54 ppm which stays almost constant and with the range for freshwater with depth by contrast the oil shales from the albert formation from new brunswick have high and were for albert oil shale the big marsh deposit in contrast had stable discharge and recharge with higher aluminosilicate input and limited or no carbonate content the rate of sedimentation as determined by na k and th k ratios indicates that the albert oil shales deposited at a slower rate as compared to the big marsh oil shales the lower th u ratio for albert oil shale as compared to the big marsh is likely due to lower input of weathered and recycled sedimentary terrestrial flux and allochthonous u content into the lacustrine setting during their deposition albert oil shales deposited in oxic dysoxic conditions based on their cr and v cr ratio suggesting a well oxygenated and uniform warm temperature upper water level variation of ca sr versus ca mn ratios for the albert oil shale indicates low mn ca and relatively high sr ca ratio for most of the samples due to low terrigenous influx and warmer water which is supported by the mineralogy of the oil shales which contain low quartz and clay minerals the presence of higher authigenic u and mn ca ratio for albert oil shale indicates low terrestrial flux and therefore th as compared to big marsh oil shales the rare earth element rees content is higher for the big marsh oil shales owning to a higher input of aluminosilicate than the albert oil shale as supported by variation of y and la and that of hydrogen index hi and heavy rare earth hrees the albert oil shale displays a positive eu anomaly typical of a high carbonate environment by contrast big marsh which shows a negative eu anomaly which is typical of upper continental crust

an early carboniferous visean lacustrine oil shale in canadian arctic archipelago the lower carboniferous visean emma fiord formation in the canadian arctic archipelago is an oil shale of lacustrine origin composed of black carbonaceous shale siltstone and marlstone with interbedded sandstone conglomerate and oolitic and algal limestones at kleybolte peninsula on ellesmere island the emma fiord formation was deposited on the tectonically active northwestern rim of the sverdrup basin it is now thermally overmature and well beyond the dry gas zone of organic maturation vitrinite reflectance approx 5 0 in contrast the emma fiord sequence on grinnell peninsula devon island near the southern edge of the sverdrup basin is immature to marginally mature vitrinite reflectance 0 26 0 44 and is composed predominantly of liptinite rich oil sha e these kerogen rich rocks contain a high volume of microcrystalline calcite and compositionally are marlstones the emma fiord lake system probably was a closed basin and may have been thermally and chemically stratified meromictic seasonal or continuous high organic productivity by phytoplankton and bacteria in the epilimnion resulted in accumulation of lipid rich calcareous sediment below an anoxic hypolimnion the emma fiord oil shales on grinnell peninsula contain both autochthonous and allochthonous organic material two types of oil shales are recognized in this sequence 1 alginite rich oil shales with a clay carbonate matrix in which liptinite content may be as high as 93 of the organic matter the hydrogen oxygen index indicates kerogen of intermediate composition between types i and ii these oil shales are hydrogen rich and oxygen poor 2 alginite poor oil shale with a carbonate matrix relatively hydrogen poor and oxygen rich the hydrogen oxygen index indicates kerogen of intermediate composition between types ii and iii the emma fiord oil shales were deposited in lakes formed immediately prior to or possibly synchronous with the initiation of rifting in the sverdrup basin syntectonic red bed conglomerates derived from uplifted horst blocks directly overlie the emma fiord rocks a few beds of conglomerate and sandstone in the upper part of the emma fiord formation possibly record the onset of faulting the formation closely resembles contemporaneous sequences in northern alaska yukon territory greenland and spitsbergen clearly similar tectonic and paleoclimatic factors influenced sedimentation over this area in the early carboniferous with the sverdrup basin locations lying within 10 15 of the paleoequator

petrology depositional environment and utilization potential of late paleocene coals from the obed marsh deposit west central alberta canada abstract the obed marsh coal deposit is of late paleocene age and contains over 200 million tons of subbituminous b to high volatile bituminous c coal petrographic analysis of three sections from seams 1 and 2 reveals high amounts of huminite and relatively low amounts of liptinite and inertinite with the exception of some intervals in both seems the persistent high ratio of huminite to liptinite and inertinite indicates a relatively reducing environment a feature also expressed by the relatively low inertinite content examination of the in seam profiles also indicates undisturbed peat accumulation over long periods of time the obed coals similar in rank and composition to the hat creek coals of british columbia formed in a freshwater environment and can be used as feedstock for combustion gasification furthermore the intervals rich in liptinite and petroleum like substances may be utilized for liquefaction hydrogenation

slar and in situ observations of ocean swell modification by currents and bathymetry at the columbia river entrance this report demonstrates the value of side looking airborne radar slar as an effective research tool which can provide important directional wave information needed in nearshore studies slar derived directional wave measurements and in situ wave height data are utilized in a one dimensional model of wave current bathymetry interaction on the columbia river bar good qualitative agreement is found with the observations and moderate discrepancies are interpreted in terms of two dimensional processes not accounted for by the theory

organic petrology and rockeval analysis of the lower carboniferous emma fiord formation in sverdrup basin canadian arctic archipelago abstract samples of the lower carboniferous emma fiord formation from two localities in the sverdrup basin of arctic canada were examined using reflected white and fluorescent light the samples from kleybolte peninsula on ellesmere island show a relatively high level of thermal maturity in contrast those from grinnell peninsula on devon island are immature to marginally mature and include subbituminous coals and oil shales two types of oil shales are distinguished on the basis of liptinite content mineral matrix rockeval pyrolysis analysis and concentration of boron one is characterized by a liptinite rich clay carbonate matrix with a relatively high hydrogen index and boron content and the other by a liptinite poor carbonate matrix with a relatively low hydrogen index and boron content hydrogen rich components of these shales consist of alginite matrix bituminite and minor amounts of exsudatinite and sporinite kerogen types iii and iv comprise only minor components of the organic matter thermal maturity of the grinnell peninsula oil shales increases with depth matrix bituminite in these oil shales has seeped into cavities and microfractures in the kerogen types iii and iv forming exsudatinite the distribution and character of the organic constituents and also the concentration of boron in these samples indicate a fresh to brackish water environment

arthropod cuticles in coal an abundance of scorpion cuticles from westphalian upper carboniferous coals of yorkshire is described and other records of arthropod cuticles in coals are reviewed the absence of cuticles assignable to arthropod groups other than scorpions is thought to be due to preferential preservation of the unique exocuticle of scorpions it alone is preserved and appears to retain an organic nature the cuticle is recovered from all the lithotypes of humic bituminous coals although it is most common in coals rich in inertinite macerals from the present study it is uncertain whether the scorpions were aquatic or terrestrial the recognition of arthropod cuticle as a coal maceral could aid environmental interpretations the abundance of arthropod cuticle in the coals studied indicates its potential use in correlation and in determining the thermal maturity of sediments

comparison of source rock geochemistry of selected rocks from the schei point group and ringnes formation sverdrup basin arctic canada abstract organic rich from the schei point group middle to late triassic in age and the ringnes formation late jurassic from the sverdrup basin of the canadian arctic archipelago have been geochemically evaluated for source rock characterization most samples from the schei point group are organic rich 2 toc and are considered as immature to mature oil prone source rocks kerogen types i i ii iia and ii iia these kerogen types contain abundant aom1 aom2 and alginite tasmanales nostocopsis leiosphaeridia acritarch and dinoflagellate with variable amounts of vitrinite inertinite and exinite samples from the ringnes formation contain dominant vitrinite and inertinite with partially oxidized aom2 alginite and exinite forming mostly immature to mature condensate and gas prone source rocks kerogen type ii iii iib iii and a few ii iia schei point samples contain higher bitumen extract saturate hydrocarbons and saturate aromatic ratio than the ringnes samples triterpane and sterane dominant c 30 distribution patterns and stable carbon isotope of bitumen and kerogen suggest that the analyzed samples from the schei point group are at the onset of oil generation and contain a mixture of sapropelic algal and minor terrestrial humic organic matter sterane carbon number distributions in the ringnes formation also suggest a mixed algal and terrestrial organic matter type there are some variations in hopane carbon number distributions but these are apparently a function of thermal maturity rather than significant genetic differences among samples pyrolysis gas chromatography mass spectrometry of the two samples with similar maturity shows that the schei point sample generates three times more pyrolyzate than the ringnes sample both samples have a dominant aliphatic character although the ringnes sample contains phenol and an aromaticity that is higher than that of the schei point sample

hard rock spectral models for intermediate depth vrancea romania earthquakes the frequency dependent amplification for rock sites as well as apparent source spectra were studied using an earthquake ground motion database collected in romania almost all events occurred in the vrancea focal zone southeast carpathians which is characterized by a high rate of occurrence of large earthquakes in a narrow focal volume the seismic activity ranges within an almost vertical stripe in depths between 60 and 170 km the database used includes several hundred records from more than 100 small magnitude m w 3 5 5 3 earthquakes that occurred in 1996 2004 and six acceleration records obtained during four large m w 7 2 6 9 6 3 and 6 0 earthquakes the characteristics of amplification were evaluated using the well known technique of horizontal to vertical h v fourier spectral ratio of the s wave phase lermo and chavez garcia 1993 the apparent source spectra were obtained from horizontal components using site h v propagation path geometric spreading and anelastic attenuation and near surface attenuation kappa factor corrections seismic radiation within the frequency range from 0 2 0 3 to 15 20 hz during the earthquakes of various magnitudes in the vrancea zone may be described by an omega square single corner frequency spectral model 2 brune spectrum the stress parameter which controls high frequency spectral amplitudes increases with magnitude from 20 30 bars for m w 3 5 up to 200 250 bars for m w 4 8 5 3 and up to 1000 bars for the case of large m w 6 0 6 5 events empirical amplification h v for rock sites showing stability for particular locations reveal high variability from station to station which together with variations of values of kappa reflects influence of local geologic and geomorphologic factors

regional maturity as determined by organic petrography and geochemistry of the schei point group triassic in the western sverdrup basin canadian arctic archipelago abstract maturity and source rock potential of organic rich beds in the triassic schei point group in the sverdrup basin arctic canada have been investigated using reflected light microscopy and the results are compared with other maturity parameters determined geochemically i e rock eval and biomarker maturation parameters the samples evaluated belong to the eden bay member of the hoyle bay formation and contain a predominance of marine algal material in the form of tasmanales and dinoflagellates along with mixed terrestrial organics the rock matrix is dominantly carbonate with some shaly input indicating that the rocks were deposited in an iron poor highly euxinic environment with few exceptions there is good agreement between parameters determined using microscopy namely r o max and r gq and geochemical parameters t max hi dia c 27 dia c 27 reg c 27 steranes s s r c 29 steranes the ternary diagram showing the abundance of normalized c 27 c 28 and c 29 regular steranes indicates a mostly marine depositional environment for the schei point source rock this is confirmed by the abundance of marine fauna and flora in these samples analytical results from several different techniques indicate that the source rocks become more mature from the margin towards the axis of the sverdrup basin this is due in part to the increase in overburden of sediments in the axis of the basin also the high thermal conductivity of salt has strongly influenced the maturity of schei point source rocks over the crest of the salt cored structures i e well hazen f 54 and the proximity of salt has enhanced maturation levels at well rock point j 43 the sections investigated were also considered to have an excellent gas potential due to their higher than average toc content

an overview of pre devonian petroleum systems unique characteristics and elevated risks abstract the radiation of land plants at the onset of the devonian resulted in a change in the character of available biomass which in turn introduced changes to the nature of petroleum systems this study examines the nature of pre devonian petroleum systems prior to this significant evolutionary event conventional hydrocarbon resources have been associated with pre devonian petroleum systems across the globe including the neoproterozoic infracambrian huqf supergroup of the oman basin the riphean vendian sequences of east siberia the cambrian of the murzuq basin the ordovician of the tarim basin and the silurian qusaiba of saudi arabia although individual accumulations can be quite significant e g hassi messaoud has ultimate recoverable reserves of 10 billion barrels the relative importance of pre devonian derived oils is thought to be limited compared to the global conventional resource base with growing interest in unconventional resources the relative importance of these systems is expected to increase as resource plays such as the ordovician utica shale of the appalachian basin the cambrian of china and possibly the silurian of central and eastern europe develop the advanced ages of these systems result in some unique properties and amplify risks that exist in younger petroleum systems differences in the nature of the biomass contributing to pre devonian source rocks may give rise to oils that display unique geochemical characteristics for example there are some precambrian oils where c 29 steranes dominate even though land plants were absent there are also ordovician source rocks dominated by gloeocapsamorpha prisca a primitive prokaryote which yield oils containing limited amounts of c 20 components and nearly lack pristane and phytane the potential for unconventional reservoirs in pre devonian systems may also be highly dependent upon the age of the system as biological evolution influences the availability and nature of biogenic silica an important factor controlling brittleness and fracability literature has shown that biogenic silica from different sources displays varying degrees of resistance to diagenesis which allows the formation of a silica network and influences brittleness for example radiolaria present during the cambrian are more resistant to diagenesis than diatoms which did not evolve until the jurassic risks associated with preservation of hydrocarbons are also amplified in pre devonian petroleum systems many such systems have been exposed to significant thermal stresses resulting in the cracking of oil and wet gas others have had complex tectonic histories potentially resulting in the breaching of seals or changes in pvt conditions that can result in gas loss gas loss may also occur through diffusion from these older reservoirs as a result of long residence times

site response evaluation using the h v ratio at the yan liau station in hualien taiwan four days after the december 13 1990 hualien taiwan earthquake m l 6 9 a temporary array of fifteen triaxial digital accelerographs was deployed in the epicenter area to monitor aftershocks approximately 600 earthquakes triggered this array during the three month deployment period the yan liau station s63 alone recorded 162 events most of the accelerograms at s63 exhibit resonance we have estimated site responses at the yan liau station using both the single station spectral ratio or h v ratio method and the traditional spectral ratio method that compares ratios at a soil site with those at a reference hard rock site based on site response analyses of s waves and coda waves of ground motion recordings both types of waves show that the h v ratio provide a good estimate at the resonant frequency although the site amplification factor is overestimated in addition the study of microtremor is also a good alternate for estimating the site predominant frequency while the ground acceleration or pga gradually increases the resonant frequency shifts to lower frequencies

convergence and downwelling at a river plume front abstract the small scale structure of the circulation and hydrography at the frontal boundary of the connecticut river plume in long island sound has been resolved using a novel combination of instruments a towed acoustic doppler current profiler adcp and a rigid array of current meters and conductivity temperature sensors observations were made during the latter half of the eastward ebb tide when the river plume was well established and the front was moving to the west at approximately 0 3 m s 1 two across front transects revealed a horizontal convergence rate in the across front velocity components at 0 6 m of 0 05 0 1 s 1 this was associated with a salt induced horizontal density gradient of 10 2 kg m4 observations obtained during a period in which the towed adcp was caught in the zone of maximum surface convergence showed significant downwelling with a near surface maximum of 0 2 m s 1 vertical velocities of this magnitude are consistent with observed magnitudes of the convergence rate at 0 6

petrological and chemical characteristics of liptinite rich coals from alberta canada a suite of liptinite rich coals from the lower cretaceous mannville group in the subsurface of alberta canada has been studied with respect to its organic petrology and organic geochemistry the samples are rich in fluorescing vitrinite perhydrous sporinite cutinite exsudatinite and bituminite rock eval analysis shows that the coals are enriched in hydrogen hydrogen index up to 320 mg hc g toc and depleted in oxygen oxygen index up to 11 mg co2 g toc the value of tmax ranges from 445 to 460 c indicating a late catagenic level of thermal maturity equivalent to ro 1 0 1 1 but the vitrinite reflectance is between 0 68 and 0 81 indicating that it is lowered by as much as 0 4 the pyrolysis chromatograms of the coal samples are dominated by substituted benzenes toluene and xylenes naphthalenes phenanthrenes substituted phenols cresols and small amounts of n alkanes in the range c20 gas chromatography mass spectrometry of the steranes and terpanes indicates little or no contribution of allochthonous bitumen to the coals in addition the mz 217 sterane traces are dominated by c29 compounds with little c27 and c28 this along with the high terpane to sterane ratio mz 191 to mz 217 8 8 indicates that the bitumen was generated from terrestrially derived organic matter the bitumen in the coals has most likely been autogenerated by the coals themselves in response to thermal stress the originally sapropelic coals were probably deposited in an anaerobic environment and were much enriched in hydrogen this study shows that terrigenous organic matter when associated with an anomalous liptinite content may have the potential to generate bitumen

critical considerations when assessing hydrocarbon plays using rock eval pyrolysis and organic petrology data data quality revisited abstract the dramatic increase in exploration for unconventional hydrocarbon resources has inherently fuelled the need for new source rock geochemical data the need for new data comes along with an increasing number of new users many of whom do not possess the background to interpret accurately and evaluate the quality of data sets generated by different geochemical screening techniques e g rock eval pyrolysis vitrinite reflectance here datasets from rock eval pyrolysis vitrinite reflectance and leco toc analyses are scrutinized and compared to show how failing to recognize good vs bad datasets can dramatically change interpretations during prospect or play appraisals detector saturation contamination of the sample with drilling fluid and suppression of both tmax and vitrinite reflectance are examples of complications that could compromise the validity of the results and the play or prospect reviews derived from them in addition misconceptions such as leco toc is better than rock eval 6 toc expressed by many users are a consequence of the lack of understanding of how different screening techniques and instrumentation work a solid understanding of these pitfalls and limitations can provide inexperienced geoscientists and engineers with the required support to improve risk maps for hydrocarbon charge analysis and source rock evaluations when using classic guidelines for interpreting results

field observation of low to mid frequency acoustic propagation characteristics of an estuarine salt wedge the estuarine environment often hosts a salt wedge the stratification of which is a function of the tide s range and speed of advance river discharge volumetric flow rate and river mouth morphology competing effects of temperature and salinity on sound speed in this stratified environment control the degree of acoustic refraction occurring along an acoustic path a field experiment was carried out in the columbia river estuary to test the hypothesis the estuarine salt wedge is acoustically observable in terms of low to mid frequency acoustic propagation linear frequency modulated acoustic signals in the 500 2000 hz band were transmitted during the advance and retreat of the salt wedge during may 27 29 2013 results demonstrate that the salt wedge front is the dominant physical mechanism controlling acoustic propagation in this environment received signal energy is relatively stable before and after the passage of the salt wedge front when the acoustic path consists of a single medium either entirely fresh water or entirely salt water and suffers a 10 15 db loss and increased variability during salt wedge front passage physical parameters and acoustic propagation modeling corroborate and inform the acoustic observations

influence of refractory organic matter on source rock hydrocarbon potential a case study from the second white specks and belle fourche formations alberta canada abstract dilution by inert refractory organic carbon can have a significant impact on the hydrocarbon potential of source rocks in this study a correction of total organic carbon based on petrographic observations is proposed to give a better indication of hydrocarbon generation potential this correction shows that although the second white specks formation is an excellent hydrocarbon source rock hydrogen index and total organic carbon are influenced by dilution from refractory organic carbon of various sources the results show that a higher degree of dilution occurs within the belle fourche formation than the second white specks formation this dilution can have a significant impact on the hydrocarbon potential of the rock volumetric calculation of the inert carbon fraction using organic petrographic methods provides a semi quantitative method to correct total organic carbon values for the refractory organic carbon dilution effect incorporation of the dilution corrected organic carbon value in hydrogen index calculations allows a greater understanding of source rock hydrocarbon potential this method provides better differentiation of the small scale variation between micro facies and formation as observed in the second white specks and belle fourche formations than traditional bulk geochemical methodologies and previously proposed correction methodologies degree of dilution either through transport of recycled allochthonous or autochthonous reworking of organic matter in situ is highly variable and represents a significant challenge in the characterization of heterogeneous source rocks this study investigates the organic petrology and geochemistry of a sediment core from the thermally immature area of the upper cretaceous second white specks formation and belle fourche formation reflectance and relative abundance of three maceral groups bituminite alginite and refractory organic carbon macerals showed significant organic matter compositional differences between micro facies in the second white specks formation a change is also observed in organic matter composition from the upper part of the belle fourche formation to the second white specks formation these compositional changes represent shifts in sediment source sea floor oxygen levels and depositional energy levels these changes can be episodic as observed between micro facies or longer time scale trends as observed between the studied formations

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

observations and modeling of a tidal inlet dye tracer plume a 9 km long tracer plume was created by continuously releasing rhodamine wt dye for 2 2 h during ebb tide within the southern edge of the main tidal channel at new river inlet nc on 7 may 2012 with highly obliquely incident waves and alongshore winds over 6 h from release coawst coupled roms and swan including wave wind and tidal forcing modeled dye compares well with aerial hyperspectral and in situ observed dye concentration dye first was transported rapidly seaward along the main channel and partially advected across the ebb tidal shoal until reaching the offshore edge of the shoal dye did not eject offshore in an ebb tidal jet because the obliquely incident breaking waves retarded the inlet mouth ebb tidal flow and forced currents along the ebb shoal the dye plume largely was confined to 4 m depth dye was then transported downcoast in the narrow few 100 m wide surfzone of the beach bordering the inlet at 0 3 m s 1 driven by wave breaking over 6 h the dye plume is not significantly affected by buoyancy observed dye mass balances close indicating all released dye is accounted for modeled and observed dye behaviors are qualitatively similar the model simulates well the evolution of the dye center of mass lateral spreading surface area and maximum concentration as well as regional inlet and ocean dye mass balances this indicates that the model represents well the dynamics of the ebb tidal dye plume details of the dye transport pathways across the ebb shoal are modeled poorly perhaps owing to low resolution and smoothed model bathymetry wave forcing effects have a large impact on the dye transport

thermal maturity of lower paleozoic sedimentary successions in arctic canada mean maximum graptolite reflectance values from numerous sections in arctic canada range from 0 6 in cornwallis island and northwestern devon island to 4 7 in ellesmere island we attribute this great lateral reflectance variation to differing burial depths of the graptolite bearing strata beneath thick synorogenic siliciclastic covers we attribute the low maturity of rocks in northern cornwallis and eastern bathurst islands to a maximum burial of about 2 km elsewhere we used the paleogeographic location and proximity to the ellesmerian overthrust wedge to interpret the measured reflectance values in northern ellesmere island where the highest graptolite reflectance values 4 7 occur as much as 9 6 km of synorogenic siliciclastics accumulated on a tectonically loaded carbonate shelf initial synorogenic siliciclastics encountered substantial submarine to basin relief and thus about 2 km of sediment were deposited prior to the initiation of deposition on the adjacent drowned shelf also the deep water sequence probably was underlain by attenuated continental crust adjacent to the southeastward advancing ellesmerian overthrust wedge together these factors caused deposition of as much as 7 6 km of sediment in western melville island and as much as 9 6 km in northeastern ellesmere island on the drowned shelf synorogenic stratal thicknesses were less a feature we attribu e to a thicker more rigid crustal sequence and greater distance from the ellesmerian tectonic loading we expect liquid hydrocarbons to be generated from the organic matter in the shales in areas with a graptolite r0 maximum gr0 max of less than 1 7 the presence of two types of solid bitumens having different reflectances morphologies and optical textures suggests that hydrocarbons were generated and migrated through the graptolite bearing strata we expect only gaseous hydrocarbons in areas where gr0 max exceeds 2 0 r0

anisotropic fragments in strongly folded and faulted coals from the rocky mountain area of southeast british columbia the mammoth coal seam in southeastern british columbia canada was structurally thickened to 100 m as a result of laramide folding and faulting samples from the coal seam examined using reflected light microscopy include thermally altered coal macerals their by products e g pyrolytic carbon and in addition heat affected preoxidized coke the heat affected residues are composed of material formed by friction produced from faulting of the coal bearing strata the pyrolytic carbon was formed from the distillation of coal and from coal tar pitch the occurrence of preoxidized heat affected vitrinite suggests that the mammoth coal seam was oxidized before faulting

petroleum source rock potential of the silurian dadas shales in the hazro and korudag regions of southeast anatolia turkey abstract shales of the silurian dadas formation exposed in the southeast anatolia were investigated by organic geochemical methods the toc contents range from 0 24 to 1 48 wt for the hazro samples and 0 19 to 3 58 wt for the korudag samples tmax values between 438 and 440 c in the hazro samples indicate thermal maturity tmax values ranging from 456 to 541 c in the korudag samples indicate late to over maturity based on the calculated vitrinite reflectance and measured vitrinite equivalent reflectance values the korudag samples have a maximum of 1 91 r g v in the gas generation window while a maximum value of 0 79 r amor v of one sample from the hazro section is in the oil generation window illite crystallinity ic values of all samples are consistent with maturity results pr ph ratios ranging from 1 32 to 2 28 and c29 c30 hopane ratios 1 0 indicate an anoxic to sub oxic marine carbonate depositional environment the hazro shales do not have any shale oil or shale gas potential because of their low oil saturation index values and early to moderate thermal maturation at first glance the korudag shales can be considered a shale gas formation because of their organic richness thickness and thermal over maturity however the low silica content and brittle index values of these shales are preventing their suitability as shale gas resource systems

surface wave breaking over sheared currents observations from the mouth of the columbia river measurements of waves and currents from freely drifting buoys are used to evaluate wave breaking parameterizations at the mouth of the columbia river where breaking occurs in intermediate depths and in the presence of vertically sheared currents breaking waves are identified using images collected with cameras onboard the buoys and the breaking activity is well correlated with wave steepness vertical shear in the currents produces a frequency dependent effective current that modifies the linear dispersion relation accounting for these sheared currents in the wavenumber spectrum is essential in calculating the correct wave steepness without this wave steepness can be over under estimated on opposing following currents by up to 20 the observed bulk steepness values suggest a limiting value of 0 4 the observed fraction of breaking waves is in good agreement with several existing models each based on wave steepness further a semi spectral model designed for all depth regimes also compares favorably with measured breaking fractions in this model the majority of wave breaking is predicted to occur in the higher frequency bands i e short waves there is a residual dependance on directional spreading in which wave breaking decreases with increasing directional spread this article is protected by copyright all rights reserved

thermal maturity and hydrocarbon potential of the sedimentary succession from the hecla field in sverdrup basin arctic canada abstract the thermal maturity and source rock potential of the upper palaeozoic and mesozoic sediments in the hecla field melville island arctic canada have been studied using reflected light microscopy and rock eval pyrolysis approximately 250 polished whole rock samples were examined and their reflectance r 0 random measured in addition approximately 100 samples were subjected to rock eval toc analyses hydrogen rich organic matter in the schei point group sediments is dominated by alginite tasmanales dinoflagellate cysts with minor amounts of sporinite cutinite resinite and liptodetrinite in an amorphous fluorescing matrix vitrinite reflectance in cretaceous sediments ranges from 0 41 to 0 54 in jurassic sediments it ranges from 0 43 to 0 64 and in triassic sediments from 0 50 to 0 65 the triassic schei point group calcareous shales and marlstones contain organic matter mainly of marine origin whereas the predominantly terrestially derived organic matter present in the jameson bay lower jurassic and in the upper jurassic to lower cretaceous deer bay formations have ower toc only the ringnes formation has a toc content of equivalent to or greater than schei point source rocks within the schei point group the cape richards and eden bay members of the hoyle bay formation are slightly richer in toc than the murray harbour formation cape caledonia member higher average toc contents 3 0 have been reported in the cape richards and eden bay members in almost all hecla drillholes variations in the level of thermal maturity of mesozoic sediments in the hecla field are a function of burial depth the stratigraphic succession thickens towards the main sverdrup basin depocentre located in a n ne direction the pattern of the isoreflectance contours at the top of the triassic barrow formation is similar to that of formation boundary lines of the same formations an indication that present day maturation levels are largely controlled by basin subsidence

microtremor survey in talchir india to ascertain its basin characteristics in terms of predominant frequency by nakamura s ratio technique abstract the talchir basin one of india s oldest basins has been a subject of interest because of its rich coal deposits the maximum thickness of the basin is about 1500 m beyond the basin is the hard metamorphic rocks of precambrian age the ambient noise survey data have been analyzed for the talchir basin using nakamura s technique of horizontal vertical spectral ratio hvsr to ascertain the basin structure in terms of the predominant frequency the predominant frequency varies from 0 25 hz to 7 8 hz but a major portion of the basin comes under the range of 0 3 hz 2 4 hz while on the metamorphic rocks it is as high as 7 8 hz the variation in predominant frequency shows a good correlation with the sediment thickness of the basin the results have been compared with the previous studies by other researchers and it shows consistency with the northerly dip of the basin the present study has also been compared with the results of the synthetic seismogram that was performed for the talchir basin the predominant frequency obtained from hvsr technique complements well with the frequency at which the peak response spectra ratio is observed the present study of the predominant frequency identifies quite well the characteristics of talchir basin and is in good agreement with the synthetic ground motion modeling of the region

oil prone alginite macerals from organic rich mesozoic and palaeozoic strata saskatchewan canada abstract hydrogen rich oil prone remnants of algae or alginite macerals are examined from organic rich carbonate and siliciclastic phanerozoic intervals at saskatchewan canada using incident light fluorescence microscopy upper cambrian alginites from siliciclastic rocks contribute to types ii iii kerogen as defined by rock eval pyrolysis and consist mainly of unicellular prasinophyte leiosphaeridia unique agglomerations of synsphaeridium sphaeromorphs and two types of coccoidal gloeocapsomorpha alginite middle ordovician platform to basin shales host mainly disseminated gloeocapsomorpha prisca alginite macerals types i ii kerogen upper ordovician platformal carbonates contain disseminated and stromatolitic varieties of g prisca alginite type i kerogen with the latter occasionally forming wholly organic well preserved microtextures concentrations of nostocaceae like filamentous alginite type ii kerogen occur locally in upper ordovician carbonates and form unique brecciated and crinkled stromatolites middle devonian type ii kerogen rich intervals from a platform setting are dominated by stromatolitic nodularia like filamentous alginite whereas abundant leiosphaeridia and tasmanites alginite characterize inter reef basinal palaeoenvironments middle and upper devonian organic rich intervals associated with evaporites contain mainly stromatolitic filamentous alginite with only minor amounts of prasinophyte alginite black shales of devonian mississippian age contain abundant leiosphaeridia and tasmanites alginites within a type ii amorphous kerogen network the smallest leiosphaeridia occur in inner shelf rocks whereas the largest forms characterize outer shelf to basin devonian mississippian shales mesozoic marine marls and shales contain prasinophyte alginite dominated by small unnamed sphaeromorphs leiosphaeridia tasmanites and minor pterosphaeridia types ii iii kerogen fresh to brackish water colonial botryococcus alginite as part of a type ii kerogen occurs initially in mesozoic strata deposited in nearshore palaeoenvironments

algal bloom episodes and the formation of bituminite and micrinite in hydrocarbon source rocks evidence from the devonian and mississippian northern williston basin canada organic petrology incident light microscopy of middle devonian inter reef laminates and devonian mississippian epicontinental black shales williston basin canada indicates that algal bloom episodes and consequential bacterial activity played a significant role in the accumulation of amorphous bituminite iii rich organic microfacies corpohuminite like algal akinete cells produced by filamentous algae during algal bloom periods are persistent maceral inclusions within the potential hydrocarbon source rock intervals these cells ro mean range 0 24 0 90 are regarded as positive indicators of stressful palaeoenvironmental conditions unicellular tasmanites and leiosphaeridia marine alginite and variably degraded alginite remnants ghosts within the amorphous kerogen may be products of cell lysis photo oxidation and microbial alteration these processes are characteristic of algal bloom periods minute ca 1 m spheroidal and coccoidal bacteria like macerals are dispersed throughout the bituminite iii network attesting to the importance of microbial activity within the water column and sediment during and after organic matter accumulation dispersed granules laminations and replacement textures of micrinite like macerals within bituminite iii are interpreted as remnants of microbial alteration rather than a residual product of thermal maturation and hydrocarbon generation

graptolite reflectance in the prehnite pumpellyite zone of northern maine u s a abstract reflectance data has been collected on ordovician lower devonian graptolites from the prehnite pumpellyite metamorphic region in northeast aroostook county maine u s a at the northern end of the appalachian mountain belt the data is reported as the mean maximum reflectance which crossplots maximum and minimum reflectance vs bireflectance demonstrate is similar for samples mounted either perpendicular or parallel to bedding given a moderately sized data set 20 points like the prehnite pumpellyite subfacies graptolite reflectance increases from west 1 5 to east 5 5 and supports a post early devonian acadian age for the regional metamorphism reflectance contours show however that the area of highest metamorphism is to the east rather than the southeast where limited data suggest the level of metamorphism may actually decrease slightly illustrating the advantage of continuously increasing organic maturation indicators for outlining thermal patterns in broad areas of low grade regional metamorphism

site effect evaluation using spectral ratios with only one station the spectral ratio technique is a common useful way to estimate empirical transfer function to evaluate site effects in regions of moderate to high seismicity the purpose of this paper is to show that it is possible to estimate empirical transfer function using spectral ratios between horizontal and vertical components of motion without a reference station the technique originally proposed by nakamura to analyze rayleigh waves in the microtremor records is presented briefly and it is discussed why it may be applicable to study the intense s wave part in earthquake records results are presented for three different cities in mexico oaxaca oax acapulco gro and mexico city these cities are very different by their geological and tectonic contexts and also by the very different epicentral distances to the main seismogenic zones affecting each city each time we compare the results of nakamura s technique with standard spectral ratios in all three cases the results are very encouraging we conclude that if site effects are caused by simple geology a first estimate of dominant period and local amplification level can be obtained using records of only one station

dolomite fluorescence red green quotient a potential new thermal maturity indicator abstract geochemical and petrographic effects of burial temperature on sedimentary organic matter have long been recognized and used as various thermal maturity indicators i e pyrolysis tmax conodont and spore coloration vitrinite bitumen zooclast reflectance and fluorescent spectrometry i e max and red green quotient this study investigates variations in the fluorescence color spectra in the visible light spectrum of authigenic dolomite over a wide range of thermal maturities two sample sets of calcareous shales siltstones from eastern and western canada with sparse dolomite crystals in the rock matrix were selected to examine the relationship between thermal maturity and fluorescent properties of dolomite results from a range of thermal maturities from the oil window to the dry gas window reveal a strong positive correlation between the red green quotient q of dolomite crystals and equivalent vitrinite reflectance vroeqv values this can be optically described as the color shift in fluorescent properties of dolomite with increasing maturity this strong positive correlation between q and thermal maturity can potentially be used as an alternative thermal maturity indicator in calcareous shales with low organic content compilation of worldwide data is required to understand the relationship trend and conversion equations among dolomite q and other established thermal maturity indicators

an integrated platform for thermal maturity assessment of polyphase long lasting sedimentary basins from classical to brand new thermal parameters and models an example from the on shore baltic basin poland abstract paleo thermometers in sedimentary basins often drive to misleading thermal modelling when applied alone or only on potentially productive paleozoic source rocks different paleo thermal and thermo chronological data have been used as constraints to model the silurian to cenozoic succession of a recently drilled well in the onshore portion of the baltic basin in northern poland this dataset provides an integrated platform for thermal maturity assessment contributing to the highly debated reconstruction of the thermal history of the baltic basin in the last decade the well stratigraphy consists of a lower paleozoic marine clayey and arenaceous calcareous succession about 1000 m thick that is unconformably overlain by a 2000 m thick permian to cenozoic sequence developed in a continental to shallow marine environment optical microscopy ft ir and raman spectroscopy analysis of organic matter have been coupled with u th he data to produce a robust vitrinite reflectance profile and constrain the 1d thermal modelling of the well in addition such a thermal maturity profile was validated by an independent thermal modelling calibrated by the smectite illitization kinetics both models identify high heat flow conditions up to 1 7 hfu at the end of mesozoic the lower paleozoic succession entered the late oil window of hc generation during this last heating event

free hydrocarbons in uinta basin utah data indicate that wurtzilite is mainly alicyclic whereas gilsonite and albertite contain more aromatic structures however the presence of a substantial amount of condensed aromatic systems in general structure of the bitumens is not confirmed generation of the gilsonite from source oil shales has resulted in significant reduction of oxygen the changes in the character of the gilsonite and wurtzilite appear to be facies dependent but the difference between gilsonite and albertite is not only due to organic facies variation but also to significant diagenetic changes all evidence suggests that expulsion of the uinta basin bitumens except ozocerite has not been associated with any catagenetic changes the strong graphitizing potential of the uinta basin gilsonite w rtzilite and albertite suggests the absence or lack of thermally stable oxygen in the molecular structure of the bitumens and their source oil shales

correction criteria for the suppression of vitrinite reflectance in hydrogen rich kerogens preliminary guidelines abstract thermal maturity is an important factor when assessing the petroleum potential of a basin or particular source rocks although the vitrinite reflectance vr technique provides excellent results from coal samples it has limitations when source rocks are used one problem is the anomalously low vrs the suppression of vr vr suppression in hydrogen rich kerogens the anomalously low suppressed vrs discussed in this article are mainly caused by the problems that organic petrographers encounter in finding and measuring appropriate vitrinite particles in hydrogen rich kerogens vr suppression is recognized when lower than normal vrs are measured on exinite rich or amorphous rich intervals in a vr well profile vr vs depth it can also be recognized when anomalously low vrs relative to the regional coalification maturation pattern or to regional oil gas occurrences are encountered in an interval although vr suppression in organic rich rocks coals and oil shales is well documented guidelines for its correction are lacking a preliminary model fig 1 is presented to help correct the vr suppression in hydrogen rich kerogens measured suppressed vr in r o along with original when immature hydrogen index hio estimated via rock eval pyrolysis and or organic petrography data of a sample can be used to estimate the maximum true unsuppressed vr although the vr and hio data for an individual sample is sufficient to estimate the maximum true vr we recommend the use of data from several closely spaced samples the model was tested with examples from published data and found to reasonably correct vr suppression in hydrogen rich kerogens we plan to refine the model using data from rock samples suppressed unsuppressed pairs and pyrolysis data

the ordovician silurian boundary northern canadian cordillera graptolite and conodont correlation the upper ordovician graptolite facies of the northern canadian cordillera is divided into two biostratigraphic units the dicellograptus ornatus zone and the pacificograptus pacificus zone interb

variation of maturity indicators optical and rock eval with respect to organic matter type and matrix lithology an example from melville island canadian arctic archipelago abstract the variation of maturity indicators with respect to mineral matrix and organic matter types was examined from the mesozoic succession of melville island arctic canada the t max values of non marine deltaic samples show a much greater degree of scattering with respect to vitrinite reflectance whereas the marine samples show a narrow distribution this behaviour is most likely to be a consequence of the differences in the chemical properties of terrestrial versus marine organic matter which is a function of the organic matter type and of the depositional environment the non marine deltaic samples also show higher t max values than their marine counterparts an indication either of the higher degree of oxidation of the non marine deltaic samples or of the fact that type iii organic matter has intrinsically higher t max values than types i and ii organic matter at the same maturity level based on the relationship between hydrogen index hi and vitrinite reflectance ro it appears that marine organic matter is more sensitive high negative correlation to thermal maturity changes than non marine deltaic organic matter no clear correlation between s 2 hydrocarbon yield and ro maturity could be seen in the suite of samples both fluorescence parameters max and r g quotient increase with maturity but the trends have different slopes for the various macerals a function of their marine or non marine origin

effect of maceral subtypes and mineral matrix on measured reflectance of subbituminous coals and dispersed organic matter abstract the variability in reflectance of huminite texto ulminite eu ulminite a and b different types of corpohuminite and liptinite groups of macerals in subbituminous coals was examined using reflected light microscopy all macerals were selected from coal and interbedded carbonaceous shale and carbonate sediment samples from the 515 m thick coal deposit no 2 located in the hat creek valley of south central british columbia the measurements obtained reveal that in addition to burial depth reflectance distribution depends on maceral subtypes and associated mineral matrix huminite in the coals and sediments kerogen consists mainly of humotelinite with eu ulminite b being the dominant maceral sub type reflectance values determined on huminite in coals and type iiib kerogen increase from eu ulminite a and phlobaphinite type 1 through eu ulminite b and phlobaphinite type 2 to gelinite the reflectance of all five huminite maceral subtypes studied increases with depth however the increase of phlobaphinite type 1 and gelinite reflectance with depth is irregular a comparison of the reflectance values obtained for the same maceral subtype eu ulminite b from the interbedded coal shale and carbonate samples records consistent differences implying some dependence of the reflectance and perhaps rate of organic maturation on the mineral matrix generally the highest eu ulminite b reflectance was recorded from carbonate rocks and the lowest from shale whereas coal matrix produced intermediate values at present it is not known whether differences in reflectance of eu ulminite found in the above lithologies are due to differential retention efficiency of reaction products removal thermal conductivity of the lithologies or existence of a calcium carbonate catalyst

observations at the tidal plume front of a high volume river outflow 1 we present shipboard observations of very strong convergence vertical velocities and mixing and near bed impacts associated with the leading edge front of the tidally pulsed columbia river plume with upwelling favorable winds and riverflow of 4900 m3s 1 the plume propagates as a buoyant gravity current with a rotary bore like vertical frontal circulation and downwelling as strong as 0 35 m s 1 in waters as deep as 65 m near bed currents intensify to as much as 1 0 m s 1 after frontal passage and are often associated with elevated acoustic backscatter mixing is locally strong with an eddy diffusivity of o 0 2 m2s 1 50 m behind the front and t s diagrams imply plume mixing with 10 m deep ocean water these observations indicate that the leading edge front of a surface advected plume can cause exchanges of a nutrients between cold subsurface shelf waters and the river plume and b nutrients and sediments across the sediment water interface

scaling surf zone turbulence 1 turbulence in the surf zone the shallow region adjacent to the shoreline has a key role in beach erosion fertilization dispersal and larval settlement of marine invertebrates and microbial contamination dilution in beach waters breaking wave generated the dominant source surf zone turbulence is understood poorly a new surf zone turbulent dissipation rate scaling is derived that collapses new field surf zone observations with relatively high skill compared to other scalings the vertically uniform length scale is 1 6 the water depth and 15 of the wave energy flux gradient is dissipated below the mean surface field and laboratory surf zone turbulence observations are shown to be consistent using the scaling the non dimensional surf zone diffusivity and suspended sediment profile can be applied to sediment transport and a range of biological processes including microbial pathogen contamination of beach waters

airborne lidar measurements and model simulations of tides waves and surface slope at the mouth of the columbia river airborne light detection and ranging lidar measurements and model simulations are used to investigate the temporal and spatial variability of the water surface elevation at the mouth of the columbia river a series of 15 km transects repeated in 2 3 h flights over a two week period resolve processes at a range of scales that are important to the dynamics of the river mouth region including tides surface slope surface gravity waves and wave setup water surface elevations agree well with a nearby tide gauge with an average difference of 0 01 m and an root mean square error of 0 39 m significant wave heights derived from the lidar measurements agree well with in situ wave drifter measurements and are observed to react to both bathymetry and spatial temporal variations in currents increasing up to 228 on large ebb tides surface slopes varied from 2 7 times 10 5 to 2 6 times 10 5 over the course of a typical tide to as large as 6 3 times 10 5 to 4 8 times 10 5 during a larger tide the magnitude of the setup and set down due to wave height amplification during ebb tide was estimated to be 4 times 10 6 these observations demonstrate that many of the key dynamical variables at river mouths can be determined from airborne remote sensing measurements of water surface elevation and suggest that forthcoming altimetry products such as those from the surface water ocean topography altimeter may be able to provide new insight on monitoring in these complex regions

wave breaking turbulence at the offshore front of the columbia river plume observations at the columbia river plume show that wave breaking is an important source of turbulence at the offshore front which may contribute to plume mixing the lateral gradient of current associated with the plume front is sufficient to block and break shorter waves the intense whitecapping that then occurs at the front is a significant source of turbulence which diffuses downward from the surface according to a scaling determined by the wave height and the gradient of wave energy flux this process is distinct from the shear driven mixing that occurs at the interface of river water and ocean water observations with and without short waves are examined especially in two cases in which the background conditions i e tidal flows and river discharge are otherwise identical

nature and depositional environment of devonian coals from western melville island arctic canada abstract the petrology and depositional environment of a suite of middle to upper devonian coals and carbonaceous shales from melville island has been studied the majority of the coals and carbonaceous shales are cannel coal and canneloids the sporinite content of cannel coal ranges as high as 80 the reflectance of vitrinite in cannel coals is suppressed compared with the normal coal from the same area these coals were deposited in fresh to slightly brackish water in interdelta lobe bays and lacutrine complexes associated with lower delta plain settings as indicated by the boron content 4 71 ppm petrology cannel and canneloid and sedimentology

turbulence from breaking surface waves at a river mouth abstractobservations of surface waves currents and turbulence at the columbia river mouth are used to investigate the source and vertical structure of turbulence in the surface boundary layer tu

geological controls on the quality of coals from the west shandong mining district eastern china abstract the basic coal quality parameters coal petrology mineralogy and geochemistry were investigated for coal seams 2 3 and 4 permian shanxi formation and 11 12 13 and 15 carboniferous taiyuan formation of the xinwen and feicheng coal fields in the west shandong mining district east china rank parameters indicate a high volatile c to b bituminous rank for the shandong coal coal from the zhaizhen and cha zhuang mines is characterised by high vitrinite and low middle inertinite and liptinite contents inertinite contents show an increase towards the top of the stratigraphic sequence from coal seams 15 13 and 11 to coal seams 4 and 2 this trend may be related to a stratigraphic trend characterised by the evolution of relatively more reducing conditions of the synsedimentary coal forming environment in the early taiyuan coals marine influenced lower delta plain to more oxidising paleoenvironments of the upper shanxi coal seams upper delta plain major mineral phases present in the shandong coal are quartz kaolinite pyrite and calcite traces of other primary minerals dolomite ankerite illite opal feldspars and marcasite and weathering products gypsum melanterite and hematite can be found in several coal seams the lower permian coal seams two to four have a lower mineral content 8 14 ash db than the upper carboniferous coal seams 15 37 ash db owing to the lower proportions of quartz and sulphide mineral the occurrence and distribution of the different minerals in the shandong coal indicates a paragenetic sequence characterised by an early syngenetic stage detrital minerals framboidal euhedral and massive cell filling pyrite ankerite neomorphic quartz and kaolinite middle and late syngenetic stages radial and fibrous marcasite aggregates massive pyrite and an epigenetic stage carbonates and sulphides as cleat filling a clear differentiation exists between the shanxi and the taiyuan coal seams based on the higher sulphide contents of the taiyuan coal 3 3 to 6 2 s db compared with the shanxi coal 0 4 to 0 8 s db this differentiation is related to marine influence on the depositional environment of coal seams 11 to 15 which has been reported by earlier studies vertical variations of the abundance of major and trace elements are discussed on the basis of this differentiation an epigenetic external enrichment of ge mo and u at the top of most of the coal seams is observed and major and trace element affinities are deduced for the west shandong coal

organic petrography of graptolite fragments from turkey abstract the reflectance and bireflectance of graptolite fragments silurian ordovician from southeast turkey were examined and the morphology was described using reflected light microscopy the dispersion of maximum and minimum reflectance of graptolites sectioned parallel and perpendicular to the bedding was also determined the graptolites were anisotropic and the anisotropy was stronger for sections perpendicular to the bedding the graptolite fragments show two types of surface morphology granular and non granular the granular type had a rough surface and granular anisotropy the non granular fragments showed a smooth surface and basic anisotropy the fine internal structure of graptolite was evident under crossed polars the reflectance of graptolite increased with depth and was higher than other organic material e g bitumen found in the same sediment the present study indicates that the reflectance of graptolite in sediment can be used to determine the maturity of the dediment

optical properties of scolecodonts and their use as indicators of thermal maturity abstract dispersion of reflectances in air and oil between 400 and 700 nm of a suiteof scolecodont concentrates with known conodont alteration index was determined using a reflected light microscope refractive and absorptive indices of these scolecodonts were calculated using their determined reflectances morphologically scolecodonts in carbonate show similar granular morphology to that of graptolites fine structural details of scolecodonts can be observed under reflected light reflectances refractive and absorptive indices of scolecodonts at 546 nm increase with increase of the conodont alteration index indicating that these properties of scolecodonts can be used to determine the maturity of sediments dispersion of the optical properties of scolecodonts follows similar trends to those for vitrinite natural bitumen and graptolites indicating similar molecular structural changes with increasing maturity

revelation of organic matter sources and sedimentary environment characteristics for shale gas formation by petrographic analysis of middle jurassic dameigou formation northern qaidam basin china abstract the 7th member of middle jurassic dameigou formation j2d7 in northern qaidam basin china was proposed to have good hydrocarbon generating potential in previous studies here we apply an integrated petrographic and geochemical analysis to investigate the depositional environment real thermal maturity and shale gas potential of organic matter om rich assemblage the relatively high content of c29 regular sterane 56 8 62 8 and vitrinite predominance in maceral composition suggesting plenty of higher plant input combined with the high pristane phytane ratio pr ph 2 8 8 2 and low gammacerane index 0 2 0 4 reveals oxic water column with in situ depositional condition of carbonaceous mudstone when the lower j2d7 was deposited the maceral composition of oil shale at the upper part of j2d7 is mainly amorphous om with small proportion of reworked vitrinite and inertinite consistent with a mainly algea and small amount of exogenous om input when associated with low pr ph 0 8 and high gammacerane index 4 3 the oil shale was deposited in an anoxic saline water column with mainly zooplankton om source the geochemical and petrographic result implies a transitional environment ranging from suboxic semi saline to oxic fresh water environment with varying proportion of higher plant and algae input by in situ deposition and distant transportation for the mudstone at the middle part of j2d7 by use of random reflectance ro distribution two sedimentary environment microcycles which are confirmed by maceral composition from the depth of 1983 m to 1962 m and 1954 m to 1931 9 m are differentiated within the homogenous mudstone section the variation of om input condition and alternation of depositional environment led to accumulation and deposition of various kinds of abundant om when j2d7 was deposited although the om has actually low maturity at oil window with vitrinite reflectance around 0 6 according to the petrographic results the liptinite inherited from higher plants especially suberinite is the main maceral to generate gaseous hydrocarbons at the low maturity which implies that the dameigou formation j2d7 of qaidam basin is of gas potential

normalograptus kufraensis a new species of graptolite from the western margin of the kufra basin libya normalograptus kufraensis sp nov occurs as monospecific assemblages in the tanezzuft formation at the western margin of the kufra basin jabal eghei southern libya these graptolites have parallel sided rhabdosomes with long straight virgellae climacograptid thecae and a full straight median septum n kufraensis is intermediate between ordovician graptolites from the n angustus perner lineage and the younger sister species n ajjeri legrand and n arrikini legrand n kufraensis differs from these taxa as follows it is broader than n angustus it has greater thecal spacing than n ajjeri or n arrikini a table comparing measurements of n kufraensis with 44 other normalograptus taxa differentiates it from other members of this morphologically conservative group even though n angustus and n ajjeri are very long ranging graptolites a stratophenetic approach suggests that the specimens from jabal eghei may be of late hirnantian or younger age the faunal composition and preservation suggests these graptolites occupied the cratonic invader biotope the stratigraphic succession records deglacial flooding and fluctuating of redox in the tanezzuft formation with the graptolites indicating a short lived interval of anoxia

breaking surface wave effects on river plume dynamics during upwelling favorable winds this study examines the dynamics of a buoyant river plume in upwelling favorable winds concentrating on the time after separation from the coast a set of idealized numerical simulations is used to examine the effects of breaking surface gravity waves on plume structure and cross shore dynamics inclusion of a wavebreaking parameterization in the two equation turbulence submodel causes the plume to be thicker and narrower and to propagate offshore more slowly than a plume in a simulation with no wave breaking in simulations that include wave breaking the plume has much smaller vertical gradients of salinity and velocity than in the simulation without breaking this leads to decreased importance of shear dispersion in the plumes with wave breaking much of the wideningrate of the plume is explainedby divergentekmanvelocities at the off and onshore edges some aspects of plume evolution in all cases are predicted well by a simple theory based on a critical richardson number and an infinitely deep ocean however because the initial plume in thesesimulationsisincontactwiththeseafloorintheinnershelf somedetailsarepoorlypredicted especially around the time that the plume separates from the coast

microstructure of graptolite periderm in silurian gas shales of northern poland abstract core samples of silurian graptolite shales from an exploration borehole within the baltic basin were examined by optical microscopy raman spectroscopy and high resolution transmission electron microscopy graptolite periderm is composed of poorly ordered carbonaceous material of mainly aromatic structures the dimension of the coherent domains is 1 2 nm they are composed of two to three stacked layers raman spectral parameters of graptolite periderm are correlated with the mean random rr and mean maximum rmax reflectance of graptolites the spectral id1 ig ratio predicts thermal maturity in a mean reflectance of graptolites rr range between 1 30 and 1 80 rmax 1 40 2 00 vitrinite reflectance equivalent vre 1 10 1 50 it is possible to calculate vreraman from the id1 ig ratio

fluorescence properties of palaeozoic oil prone alginite in relation to hydrocarbon generation williston basin saskatchewan canada abstract alginite macerals the oil prone microscopic components of hydrocarbon source rocks fluoresce in the visible region when irradiated with ultraviolet light the fluorescence properties max and red green quotient of coccoidal unicellular and filamentous alginite macerals were investigated in palaeozoic potential hydrocarbon source rocks northern williston basin saskatchewan canada this study documents the variation in fluorescence properties of alginite during thermal maturation and the onset of petroleum generation values of max nm of disseminated coccoidal gloeocapsomorpha alginite from upper cambrian siliciclastics and upper ordovician carbonates show different magnitudes of red shift with increasing thermal maturity gloeocapsomorpha prisca disseminated alginite and g prisca stromatolitic alginite from upper ordovician kukersites exhibit unique fluorescence properties with increasing thermal maturity the former undergoes a greater red shift in fluorescence than the latter over an 1800 m change in depth of burial devonian and mississippian unicellular prasinophyte leiosphaeridia and tasmanites alginite show a minimal change in fluorescence properties max 450 500 nm between vitrinite reflectance values of 0 35 and 0 65 ro beyond 0 65 ro vitrinite reflectance prasinophyte alginites show a marked red shift to a max of 560 600 nm this phenomenon is coincident with peak hydrocarbon generation from a type ii filamentous alginite bituminite kerogen within middle devonian carbonate source rocks a comparison of the fluorescence properties of palaeozoic prasinophytes with the fluorescence properties of mesozoic prasinophytes reveals that the latter undergo a substantially greater red shift in max with increasing thermal maturity relative to the former this conspicuous difference is interpreted as a reflection of the well documented distinct difference in species and abundance of leiosphaeridia and tasmanites alginite between the geological eras

structure and dynamics of the columbia river tidal plume front 1 time dependent buoyant plumes form at the outflow of tidally dominated estuaries when estuary discharge velocity exceeds plume internal wave speed c a sharp front forms at the plume s leading edge that expands from the time dependent source using observations of the columbia river tidal plume from multiple tidal cycles we characterize time evolving plume structure and quantify front speed uf plume internal wave speed c front curvature and ultimate extent we identify three distinct stages of propagation 1 initially the plume is strongly influenced by shallow bathymetry near the river mouth 2 as the front advances offshore the plume detaches from the bottom and expands as a freely propagating gravity current with relatively constant uf c and frontal froude number f uf c ambient currents explain intracycle variability in uf and winds alter front shape variability in ambient stratification associated with previous cycles plume remnants leads to complex fronts and internal waves 3 finally the plume decelerates adjusts toward geostrophy and may radiate additional internal waves using a simple kinematic model we suggest that constant frontal propagation speed uf 0 9 0 1 m s during stage 2 is primarily controlled by linearly increasing volume flux from the columbia river mouth as this discharge rate subsides the plume expands as a fixed volume with decreasing front speed stage 3 the plume s final extent is controlled by the rossby radius which scales with a length based on the total volume discharged this provides an integral description of plume front evolution based on the time dependent estuary discharge

earthquake site response study in giumri formerly leninakan armenia using ambient noise observations we have tested whether ambient noise observations reveal useful information regarding site response at sediment sites in giumri formerly leninakan armenia this was done by comparing the noise observations with spectral ratio site response estimates based on aftershock data of the 7 december 1988 earthquake we show that neither the horizontal component noise spectra alone nor spectral ratios taken with respect to a nearby bedrock site reveal useful information regarding site response however spectral ratios of horizontal components taken with respect to vertical components nakamura s method exhibit a prominent peak that corresponds to the fundamental resonant frequency observed in the aftershock data based on this and other recent investigations we conclude that nakamura s method may be a reliable procedure for determining the fundamental resonant frequency of sedimentary deposits from ambient noise observations