recovery of small strain stiffness following blast induced liquefaction based on shear wave velocity measurements changes in soil fabric following liquefaction have been studied using various in situ methods and often return inconclusive or conflicting observations the time rate variation of stiffness when

the us geological survey s national coal resource assessment the results abstract the us geological survey and the state geological surveys of many coal bearing states recently completed a new assessment of the top producing coal beds and coal zones in five major producing coal regions the appalachian basin gulf coast illinois basin colorado plateau and northern rocky mountains and great plains the assessments which focused on both coal quality and quantity utilized geographic information system technology and large databases over 1 600 000 million short tons of coal remain in over 60 coal beds and coal zones that were assessed given current economic environmental and technological restrictions the majority of us coal production will occur in that portion of the assessed coal resource that is lowest in sulfur content these resources are concentrated in parts of the central appalachian basin colorado plateau and the northern rocky mountains

cone penetration test calibration for erksak beaufort sea sand discussion this is a discussion of a paper by the same title which appeared in volume 24 canadian geotechnical journal pp 601 610 the authors of the original paper are k been b e lingnau j h a crooks and b leach

particle sizes effect of the elements in the south china sea sediment off pahang coastal during the northeast monsoon pre and the southwest monsoon post periods the pahang water determined an effect of the sizes of sediment particles on 11 elements distribution during the monsoon season the elements were of very high concentration in a sediment particle size of 40 63 and 90 m the lower concentration of the elements was associated with a sediment size of 125 250 and 500 m it has been observed in this research study that a concentration of elements increases with a decrease in a size of the sediment particles the sediment from the northeast pre monsoon consisted of a finer particle size than the southwest post monsoon sediments overall the concentration of the elements in the northeast pre monsoon sediment was higher than the southwest post monsoon sediment the northeast monsoon is highly influenced due to an input of fresh sediment from the rivers into the south china sea as well as due to a redistribution in the surface sediment there were many differences in sediment element content between the two monsoon seasons but an anthropogenic impact was only found in lead pb

geochemistry of the alginite and amorphous organic matter from type ii s kerogens abstract maceral fractions of the type ii s kerogens from the monterey formation miocene california u s a and duwi formation campanian maastrichtian egypt were separated by density gradient centrifugation the monterey fm kerogen sample was comprised chiefly of light red fluorescing amorphous organic matter aom the flash pyrolyzate of which was characterized by a predominance of alkylbenzenes alkylthiophenes and alkylpyrroles in contrast the pyrolyzates of its alginite concentrate showed a highly aliphatic character typical of this maceral with the series of n alkenes and n alkanes c6 c26 predominating the pyrolyzate of the dominant light brown fluorescing aom of the duwi fm kerogen had a relatively high concentration of alkylbenzenes and alkylthiophenes while its alginite concentrate showed a more aliphatic character upon pyrolysis there was a marked enrichment of thiophenic sulfur in the light colored aom of both samples and also pyrrolic nitrogen in the case of the monterey relative to the alginite the results support a bacterially mediated degradative origin for type ii s amorphous organic matter with algal remains as the primary source of the kerogen

cone penetration test calibration for erksak beaufort sea sand interpretation of the cone penetration test in sands is generally based on empirical calibrations from tests in large diameter calibration chambers although interpretation of these calibration data for clean sands in terms of the state parameter is expected to be broadly applicable to other sands material specific correlations are desirable for many projects this paper describes a series of calibration chamber tests carried out on a sand dredged from the beaufort sea for construction of artificial islands this erksak sand is a uniformly graded subrounded medium grained sand with a fines content of 3 6 the testing chamber described is 1 4 m in diameter and allows independent control of vertical horizontal and back pressures on the sand sample samples of the sand were prepared by moist compaction to preserve the fines content and then back pressure saturated the chamber test data are presented and confirm that the erksak sand fits the general trends observed for other sands very well a method i

effects of silt content and void ratio on the saturated hydraulic conductivity and compressibility of sand silt mixtures the hydraulic conductivity the coefficient of consolidation and the coefficient of volume compressibility play major roles on the pore pressure generation during undrained and partially drained loading of granular soils with fines this paper aims to determine how much these soil parameters are affected by the percentage of fines and void ratio of the soil the results of a large number of flexible wall permeameter tests performed on 60 specimens of two poorly graded sands with 0 5 10 15 20 and 25 nonplastic silt are presented and discussed hydraulic conductivity measurements were done at effective confining stresses of 50 300 kpa the evaluation of the data shows that the hydraulic conductivity and the coefficient of consolidation of sands with 25 silt content are approximately two orders of magnitude smaller than those of clean sands the coefficient of volume compressibility of the sand silt mixtures is affected in a lesser degree by void ratio silt content and confining stress the influence of the degree of saturation on the laboratory measured k values is also discussed

direct simulation of random field samples from sparsely measured geotechnical data with consideration of uncertainty in interpretation random field theory has been increasingly used in probabilistic geotechnical analyses over the past few decades where a random field generator with random field parameters is needed to simulate random field samples rfss of interest estimation of random field parameters particularly correlation functions or correlation length generally requires extensive measurements however the data gathered from site characterizations are usually sparse particularly for small or medium sized projects therefore it is difficult to provide an accurate estimation on random field parameters and the random field parameters estimated and subsequently used in rfs generation might contain significant uncertainty this leads to a challenge of properly simulating rfss in consideration of such uncertainty this paper aims to address this challenge by developing a novel random field generator which is capable of directly generating rfss from sparse measurements obtained during site characterization and properly accountin

simplified geostatistical analysis of earthquake induced ground response at the wildlife site california u s a almost all natural soils are highly variable and rarely homogeneous in this study the seismic response of the wildlife site imperial valley california u s a has been analysed to assess the e

optical characteristics of amorphous kerogens and the hydrocarbon generating potential of source rocks abstract four recurring types of amorphous kerogen are optically identified in petroleum source rock samples and are related to hydrocarbon generating potential defined here as geochemically interpreted oil prone or gas prone at this time a genetic classification is not possible the different amorphous kerogen types are distinguished on the basis of microscopic textural differences type a chunky compact masses with mottled network or weak polygonal textures type b very small dense elongate oval or rounded individual grains type c clumpswith granular fragmented or globular textures type d thin platy or rectangular individual grains geochemistry defined oil prone samples generally contain types a and or d separately or combined geochemically defined gas prone samples rarely contain type a and vary in amounts of types b c and or d the samples in this study contain dominantly one of the four types of amorphous kerogen so the geochemical analyses of the whole rock or bulk concentrated kerogen samples are assumed to be analyses of the dominant amorphous type the samples were chemically analyzed by several techniques to determine the oil or gas generating potential the establishment of relations between specific optical and chemical properties of kerogen types can make visual kerogen analyses more meaningful in predicting the hydrocarbon generation potential of source rocks

man s influence on the erosion and transport of sediment by asian rivers the yellow river huanghe example during the holocene sediment input from the yellow river to the yellow sea and adjacent areas has amounted to about 3000 km 3 detailed records from river gauging stations over the past 70 yrs together with estimates based on earlier historic records suggest that the river has contributed 2300 km 3 of sediment during the last 2300 yrs an average discharge of 1 km 3 yr 1 x 10 9 t yr prior to extensive agricultural use of the loess plateau in northern china beginning about 200 bc therefore the river s load must have been about 0 1 km 3 yr an order of magnitude lower than that at present a broad delta 20 m below sea level suggests that early holocene rates were higher than the pre agricultural average and therefore that middle holocene loads were low

assessment of heavy metal contamination in the surface sediments in the mangrove ecosystem of gulf of kachchh west coast of india this study was an attempt to understand the role of biogeochemical processes in controlling the heavy metal distribution in the mangroves and to assess heavy metal pollution load viz cr fe mn co ni cu zn cd and pb in the gulf of kachchh india various biogeochemical processes and anthropogenic factors were playing an important role in altering the concentration of heavy metals in the sediments a significant correlation of mn fe and pb with zn implies the role of diffused anthropogenic activities the organic carbon content 1 47 3 25 and clay content 0 1 2 5 seem to play a significant role in the metal concentration factor analysis suggested two different processes factor i strongly indicating anthropogenic activities and factor ii indicating the combination of natural marine in situ reduction processes biogeochemical with partial anthropogenic influence the enrichment factor ef and geochemical index igeo of cu were higher at old bedi port s5 whereas both these values were higher for cu as well as cd at jam salaya s8 igeo values indicate that sediments around the estuarine mouths were polluted with heavy metals as compared to other locations except chodeshwar s9 pli value 1 was reported in almost all the locations with a slightly higher value reported at narara s7 1 57 and new bedi port s4 1 56 the findings of this study would help in formulating guidelines for controlling the pollution and suggest the ways by which the mangroves of the gulf of kachchh could be revitalized

some chemical structural features of coals of differing maceral distributions and stratigraphy six north american bituminous coals four carboniferous and two cretaceous and eight maceral concentrates from carboniferous british seams have been heated with tetralin and hydrogen to 400 c the hexane soluble parts of the products were separated by column chromatography and the fractions were then analyzed by gas chromatography mass spectrometry in all cases the aromatic hydrocarbon fraction was a very complex mixture containing a number of alkylated biphenyls diphenylmethanes and ethanes and polycyclic compounds however single ioncchromatography m z 142 showed that in addition to these the products from five of the six american coals contained homologous series of long chain n alkylnapththalenes with alkyl groups extending to c16 in other fractions from the american coals homologous series of n alkylfurans and alkylphenols were found to be major components as also were many alkylcyclohexenones related to isophorone extensive homologous series of n alkyl aromatics were not detected in products from any of six vitrinites from british seams though series of n and iso alkylphenols were found in the products from two sporinite concentrates a number of polycyclic ketones apparently related to sterols were found in the products from the british vitrinites but not from any american coals reasons for what appear to be systematic structural differences between the american and british coals are discussed differences in stratigraphy are noted and it seems not impossible that differences in source vegetation are significant

finite element analysis of the nerlerk underwater berm failures finite element analyses have been carried out to investigate the possible causes of failure during construction of the nerlerk underwater berm a hydraulically placed sand slope designed to form

world wide delivery of river sediment to the oceans new data and new estimates from old data show that rivers with large sediment loads annual discharges greater than about 15 times 10 6 tons contribute about 7 times 10 9 tons of suspended sediment to the ocean yearly extrapolating available data for all drainage basins the total suspended sediment delivered by all rivers to the oceans is about 13 5 times 10 9 tons annually bedload and flood discharges may account for an additional 1 2 times 10 9 tons about 70 of this total is derived from southern asia and the larger islands in the pacific and indian oceans where sediment yields are much greater than for other drainage basins

spatial variability drained and undrained deviatoric load response geotechnical properties vary in space geostatistical parameters such as the mean the standard deviation and the correlation length are characteristic for each sediment and formation history the effects of spatial variability on the drained and undrained shear response of soils are investigated using numerical parametric studies where multiple realisations are tested for selected geostatistical parameters results show that the mean undrained shear strength decreases as spatial variability and correlation length increase spatial variability prompts strain localisation along neighbouring weak zones under both drained and undrained loading heterogeneous contractive media show internal homogenisation during drained deviatoric loading and the drained shear resistance evolves towards the critical state media with higher variability and longer correlation length require higher strain to attain internal homogenisation anisotropy in spatial correlation causes anisotropy in shear strength an intermediate d

stochastic evaluation of static liquefaction in a predominantly dilative sand fill the paper investigates the potential for liquefaction in a predominantly dilative hydraulic sand fill and in particular whether pockets of loose material could have been instrumental in the failure of the nerlerk underwater berm this has been achieved stochastically by linking random field theory for modelling spatial variability with finite elements for computing geostructural response specifically a double hardening soil model has been calibrated against data from 74 triaxial tests on erksak sand for a wide range of sand states while state parameter statistics have been derived from 71 cone penetration tests from two beaufort sea sand islands multiple realisations of structural performance have then been carried out by generating univariate random fields of state parameter from which the soil model parameters have been inferred the results demonstrate that it may be possible for a predominantly dilative fill to liquefy due to the presence of semi continuous loose zones arising from deposit

on the fundamental difference between coal rank and coal type abstract this article addresses the fundamental difference between coal rank and coal type while theoretically settled long ago as being different aspects of coal systems science the two concepts are still often confounded in recent years this has resulted in the publication of several works stating that coal type changes with coal rank coal type refers solely to coals depositional origin and the maceral mineral admixture resulting from that origin coal types typically fall in to two categories humic coals developed from peat and sapropelic coals developed from organic mud either type may be allocthonous or autochthonous and within types further refinement of depositional environment can be made coal rank refers to the changes in geochemistry and resultant changes in reflectance caused by increasing thermal maturity of the coal thus it provides an overprint of maturity on existing coal types with proper techniques such as use of crossed polars and etching maceral forms can be differentiated even at high ranks and the original coal type determined

petrography geochemistry and depositional setting of the san pedro and santo tomas coal zones anomalous algae rich coals in the middle part of the claiborne group eocene of webb county texas two coal zones the san pedro and the overlying santo tomas are present for nearly 35 km in outcrop surface and underground mines and shallow drill holes along the strike of the middle part of the claiborne group eocene in webb county texas a sandstone dominated interval of 25 to 35 m separates the two coal zones which range up to 3 m in thickness each coal zone contains carbonaceous shales thin 0 75 m impure coal beds and thin 0 85 m but commercially significant nonbanded coal beds the nonbanded coals are different from other tertiary coals of the gulf of mexico coastal plain unlike lignites that are typical of the older wilcox group paleocene eocene and younger jackson group eocene nonbanded coals of the claiborne group have high vitrinite reflectance values 0 53 rmax and high calorific yields average 6670 kcal kg or 12 000 btu dry basis the coals are weakly agglomerating free swelling index is 1 5 2 0 and have an apparent rank of high volatile bituminous the coal bearing portion of the middle claiborne group in the rio grande area represents a fining upward transition from sandstone dominated marine influenced lower delta plain depositional environments to more inland mudstone rich predominantly freshwater deltaic settings discontinuities within the san pedro coal zone are attributed mainly to the influence of contemporaneous deposition of distributary mouth bar sand bodies the less variable nature of the santo tomas coal zone reflects its origin in the upper part of an interlobe basin that received only minor clastic influx petrographic attributes of the nonbanded coals indicate that they formed subaqueously in fresh to possibly brackish waters a highly degraded groundmass composed of eugelinite is the main petrographic component approximately 71 mineral matter free basis an enriched liptinite fraction approximately 23 probably accounts for unusually high calorific values there is negligible inertinite petrographic study of polished blocks indicates that approximately 10 percent of the nonbanded coal from both coal zones is composed of green algae fructifications which also occur in clastic rocks of the coal bearing interval such algal material cannot be identified or quantified by conventional coal petrographic techniques that utilize particle pellets or by palynological analyses that include acid preparation

effects of spatial variability on liquefaction induced settlement and lateral spreading abstractnonlinear dynamic numerical simulations of infinite slopes are used to examine the effects of spatial variability in penetration resistances on liquefaction induced settlement and lateral spreading for gently sloping ground and to develop guidance on selecting representative properties for uniform models simulation results for models having uniform properties uniform models are compared to results for models having spatially correlated gaussian random field property distributions stochastic models results are presented for sets of stochastic model realizations and a set of ground motions scaled to a range of peak ground accelerations computed responses and ground deformations settlements and lateral displacements for these uniform and stochastic models are used to identify representative properties as a percentile of the stochastic distributions for which the uniform models produce reasonable agreement with the median of the stochastic model responses the effects of the scales of fluct

application of confocal laser scanning microscopy clsm to autofluorescent organic and mineral matter in peat coals and siliciclastic sedimentary rocks a qualitative approach abstract organic matter occurring in the form of macerals and natural solid bitumens in peats coals and siliciclastic sediments of various stratigraphic ages and locations was studied by means of conventional incident light microscopy and clsm classical optical microscopic investigations are restricted by conventional 2 d imaging and are often hindered by the associated out of focus blur effects the qualitative application of clsm overcomes these limitations permitting to reveal precisely 3 d morphology and detailed microstructure of autofluorescent organic matter the in depth examinations along z axis in xy xz or yz scanning modes at increments of 250 nm are capable to reconstruct 3 d internal configuration and arrangement occurring in autofluorescent macerals the non invasive and non destructive laser raster technique is applied to characterize in situ autofluorescent organic particles at micron to sub micron scale resolution in polished whole rock pellets in this study we demonstrate that clsm is suitable to i detect fine scale microstructure of autofluorescent organic matter iii reconstruct 3 d morphology at cellular and tissue level iii analyze maceral composition in terms of its relicts and fragments beyond the classical optical assignment limits iv detect and examine inorganic components enclosed in the embedding mineral bituminous groundmass and v differentiate mineral constituents from the remaining organic matter clsm as an optical microscopic technique was applied to generate high resolution 2 d and 3 d images projections as well as 3 d reconstructions of autofluorescent objects excited with aid of laser induced light operating at variable visible wavelengths clsm is applicable to support microscopic studies of thermally immature and mature organic matter within the oil and early gas windows enclosed either within siliciclastic and carbonate sediments or in peat and low to medium rank coals the application of this technique will be of great interest to a wide range of geology related disciplines such as petroleum geology biostratigraphy marine geology peat petrography and archeology

spatial variation in liquefaction risk basic concepts and methods of random field theory useful for characterizing distributed disordered systems are applied to a soil deposit to evaluate the spatial extent of liquefaction under typical conditions the soil deposit modelled after a site located at the wildlife management area in california is represented by a three dimensional random properties field and is subjected to multiple realizations of a space time random field of earthquake ground motion patterned after the superstition hills event of 1987 based on monte carlo analysis using a deterministic one dimensional nonlinear finite element program spatial variability of liquefaction risk is assessed and techniques for improving estimates of liquefaction risk accounting for local spatial variation are investigated les concepts et m6thodes de base de la theorie de champ aleatoire servant caracteogonriser les systemes desordonnes repartis sont appliqueogons un d pot de sol pour evaluer 1 etendue spatiale de la liquefaction dans

sediment transport of the godavari river basin and its controlling factors abstract the mean annual water flow and sediment transport of the godavari river are estimated to be 92 km 3 and 170 10 6 ton t respectively in terms of sediment transport and the rate of physical erosion 555 t km 2 yr 1 the position of the godavari would be ninth and fifth respectively among the world rivers geology of the basin is the main controlling factor of the sediment transport the sedimentary rocks located in the lower part of the basin and constituting 7 of the total basin area are responsible for 33 of the sediment load more than 67 of sediment load is silt and clay annual monthly and daily variations in sediment transport indicate that a few selected days in the hydrological year control the annual sediment budget our latest estimates are nearly twice that of our earlier values the presently available global estimates on sediment transport need to be re evaluated

organic geochemistry and petrology of subsurface paleocene eocene wilcox and claiborne group coal beds zavala county maverick basin texas usa abstract coal samples from a coalbed methane exploration well in northern zavala county maverick basin texas were characterized through an integrated analytical program the well was drilled in february 2006 and shut in after coal core desorption indicated negligible gas content cuttings samples from two levels in the eocene claiborne group were evaluated by way of petrographic techniques and rock eval pyrolysis core samples from the paleocene eocene indio formation wilcox group were characterized via proximate ultimate analysis in addition to petrography and pyrolysis two indio formation coal samples were selected for detailed evaluation via gas chromatography and fourier transform infrared ftir and 13c cpmas nmr spectroscopy samples are subbituminous rank as determined from multiple thermal maturity parameters elevated rank relative to similar age coal beds elsewhere in the gulf coast basin in the study area is interpreted to be a result of stratigraphic and or structural thickening related to laramide compression and construction of the sierra madre oriental to the southwest vitrinite reflectance data along with extant data suggest the presence of an erosional unconformity or change in regional heat flow between the cretaceous and tertiary sections and erosion of up to 5 km over the cretaceous the presence of liptinite rich coals in the claiborne at the well site may indicate moderately persistent or recurring coal forming paleoenvironments interpreted as perennially submerged peat in shallow ephemeral lakes with herbaceous and or flotant vegetation however significant continuity of individual eocene coal beds in the subsurface is not suggested indio formation coal samples contain abundant telovitrinite interpreted to be preserved from arborescent above ground woody vegetation that developed during the middle portion of mire development in forested swamps other petrographic criteria suggest enhanced biological chemical and physical degradation at the beginning and end of indio mire development fluorescence spectra of sporinite and resinite are consistent and distinctly different from each other attributed to the presence of a greater proportion of complex asphaltene and polar molecules in resinite gas chromatography of resinite rich coal shows sesquiterpenoid and diterpenoid peaks in the c14 17 range which are not present in resinite poor coal quantities of extracts suggest bitumen concentration below the threshold for effective source rocks 30 50 mg hydrocarbon g total organic carbon hc g toc saturate aromatic and pristane phytane pr ph ratios are different from values for nearby tertiary reservoired crude oil suggesting that the indio coals are too immature to source liquid hydrocarbons in the area however moderately high hi values 200 400 mg hc g rock may suggest some potential for naphthenic paraffinic oil generation where buried more deeply down stratigraphic structural dip extractable phenols and c20 alkanes are suggested as possible intermediates for acetate fermentation in microbial methanogenesis which may however be limited by poor nutrient supply related to low rainfall and meteoric recharge rate or high local sulfate concentration

spatial variability of the undrained strength of clays the objective of this study is to provide a simple yet accurate procedure for the description of the spatial variability of the undrained shear strength s u of soft clays this is achieved on the basis of experimental findings and field observations of the depth dependent nature of s u the main features of the method are a linear with depth variation of the mean value and standard deviation of s u and a smooth exponential function that describes the correlation between values received by s u at different vertical locations the developed procedure is illustrated in a case study involving actual strength data two sites are selected from the general area investigated in connection with the west side highway in new york city each site is characterized by the values of s u obtained along two boreholes using field vane shear tests the results of the applied analysis verify previous findings on the vertical variability of s u and demonstrates the applicability of the present procedure in the commonly encountered situations with limited data

back analysis of the nerlerk berm liquefaction slides reply pressuremeter 39th canadian geotechnical conference ottawa hird c c and hassona f 1986 discussion on a state parameter for sands giotechnique 36 1 pp 123132 huntsman s r 1985 dctcrmination of ir sitlc lateral pressure of cohesionless soils by static cone penetrometer ph d thcsis university of california at berkeley berkeley ca huntsman s r m tcmell j k klejbuk l and sihinde s 1986 lateral stress measurement during cone penetration asce specialty conference on use of in situ testing in gcotcchnical engineering blacksburg va jefferies m g stewart h thomson r a a and roberts b j 1985 molikpaq deployment at tarsiut p 45 plenary session paper proceedings asce specialty confercncc on civil engineering in the arctic offshore arctic 85 san francisco mitchell d e 1984 liquefaction slides in hydraulically placed sands proceedings of 4th international symposium on landslides toronto m j o connor a n d associates 1982 an evaluation of the regional surficial geology of the southern bcaufort seas geological survey of canada report parry r h g 1971 stability analysis for low embankments on soft clays stress strain behaviour of soils roscoc memorial symposium cambridge g t foulis co henlcy on thames england sladen j a d hollander r d and k r a i n j 1985 the liquefaction of sands a collapse surface approach canadian geotechnical journal 22 4 pp 564 578

spatio temporal dynamics of heavy metals in sediments of the river estuarine system mahanadi basin india dynamics of heavy metals in the surface sediments of mahanadi river estuarine system were studied for three different seasons this study demonstrates that the relative abundance of these metals follows in the order of fe mn zn pb cr ni co cu cd the spatial pattern of heavy metals supported by enrichment ratio data suggests their anthropogenic sources possibly from various industrial wastes and municipal wastes as well as agricultural runoff the metal concentrations in estuarine sediments are relatively higher than in the river due to adsorption accumulation of metals on sediments during saline mixing while there is a decreasing trend of heavy metal concentrations towards the marine side the temporal variations for metals such as fe mn zn ni and pb exhibit higher values during monsoon season which are related to agricultural runoff higher elemental concentrations are observed during pre monsoon season for these above metals except ni at the polluted stations and for metals such as cr co and cd at all sites which demonstrate the intensity of anthropogenic contribution r mode factor analysis reveals that fe mn oxy hydroxide organic matter caco3 and textural variables factors are the major controlling geochemical factors for the enrichment of heavy metals in river estuarine sediment and their seasonal variations though their intensities were different for different seasons the relationships among the stations are highlighted by cluster analysis represented in dendrograms to categorize different contributing sites for the enrichment of heavy metals in the river estuarine system

isometamorphic variations in the reflectance and fluorescence of vitrinite a key to depositional environment abstract petrographic investigations of serial ply samples from five high to medium volatile bituminous coal seams from australia 4 and canada 1 reveal substantial in seam variations in the reflectance and monochromatic microfluorescence intensities of the maceral subgroup telovitrinite the variations consist of one case of reflectance enhancement and fluorescence suppression and four cases of reflectance suppression and fluorescence enhancement the single case of reflectance enhancement and fluorescence suppression is due to the oxidation of the vitrinite nuclei at the sequence boundary between the bayswater and upper wynn seams in new south wales the four cases of reflectance suppression and fluorescence enhancement result from the syn and epigenetic absorption by the vitrinite nuclei of hydrogen donated by presumably anaerobic bacteria generated lipids two of the coals are marine influenced the liskeard seam from the bowen basin by combined syngenetic and epigenetic effects and the greta seam from the sydney basin mainly by epigenetic contact with sea water for both coals the results are strong vitrinite reflectance suppression and fluorescence enhancement the remaining two coals the bulli seam from the sydney basin and a coal seam from the gates formation in british columbia show moderate epigenetic effects on the optical properties of telovitrinite by fresh water in the bulli seam which was studied in two adjacent localities the reflectance suppression and fluorescence enhancement of telovitrinite are stronger under sandstone roof than under shale roof in some cases the epigenetic effects are superimposed on syngenetic telovitrinite reflectance and fluorescence variations resulting from the cogeneration and mixing of different telovitrinite precursors for example autochthonous roots and hypautochthonous or allochthonous shoots a measure of the degree of dispersal and mixing is the coefficient of variation of telovitrinite reflectance and or fluorescence this coefficient correlates well with detrital minerals and dispersed macerals e g inertodetrinite and to a lesser extent sporinite some comments are made on slitted so called pseudovitrinite which is regarded as a telovitrinite that was subjected to very weak post coalification desiccation and possibly oxidation without losing much of its thermoplastic properties

probabilistic stability analysis of a tailings dyke on presheared clay shale probabilistic slope stability analysis offers an efficient framework for logical systematic incorporation of un certainty into slope design the slow integration of probabilistic slope analyses into practice is attributed among other factors to the lack of published studies illustrating the implementation and benefits of such techniques a spreadsheet based probabilistic slope analysis methodology is applied to evaluate the stability of a section of the syncrude tailings dyke in fort mcmurray canada the dyke is approximately 44 m high and is founded on presheared clay shale the performance of the dyke is governed by uncertainties about material properties and pore water pressures starting with field and laboratory data this study demonstrates the techniques used in quantifying the various components of param eter uncertainty conducting a probabilistic assessment and estimating the probability of unsatisfactory performance the probability of unsatisfactory performance of the dyke is estimated to be 1 6 10 3 field monitoring data indicate that the dyke performance is adequate the study thus provides a first link between probability figures and perfor mance the analysis also quantifies the relative contributions of the various sources of uncertainty to the overall uncer tainty in the factor of safety

spatial variability of cpt parameters and silty fines in liquefiable beach sands abstractincreasing awareness of the role of spatial variability in the assessment of liquefaction susceptibility has driven the need to characterize the vertical and horizontal spatial variability

the liquefaction of sands a collapse surface approach recent large scale slides occurring during the hydraulic placement of an artificial island berm in the beaufort sea resulted from the liquefaction of the berm sand subsequent laboratory tests and

petrology of liquefaction residues from the breckinridge cannel western kentucky abstract solid residues from the liquefaction at four temperatures of the breckinridge coal bed an alginite rich coal from western kentucky provide examples of the changes to be expected in the relatively rare alginite rich zones of humic coals vitrinite reacts at low temperatures and in the 385 c 15 min residue its product appears to be vitroplast which is a matrix between relatively unreacted bituminite alginite particles both alginite and bituminite show signs of softening by 427 c 15 min both macerals still fluoresce at 427 c 15 min by 435 c 15 min the residues are dominated by a granular residue most likely derived from bituminite with some alginite contribution possible an anisotropic semi coke possibly derived from the repolymerization of tars and oils was observed at all temperatures framboidal anisotropic sulfides pyrrhotite distinctly different from any sulfide observed in the raw coal are well developed in the higher temperature residues

do river deltas in east india retreat a case of the krishna delta abstract the construction of multiple dams and barrages in many indian river basins over the last few decades significantly reduced river flow to the sea and affected the sediment regime more reservoir construction is planned through the proposed national river linking project nrlp which will transfer massive amounts of water from the north to the south of india the impacts of these developments on fertile and ecologically sensitive deltaic environments are poorly understood and quantified at present in this paper an attempt is made to identify locate and quantify coastal erosion and deposition processes in one of the major river basins in india the krishna using a time series of landsat images for 1977 1990 and 2001 with a spatial resolution ranging from 57 0 m to 28 5 m the dynamics of these processes are analyzed together with the time series of river flow sediment discharge and sediment storage in the basin comparisons are made with similar processes identified and quantified earlier in the delta of a neighboring similarly large river basin the godavari the results suggest that coastal erosion in the krishna delta progressed over the last 25 years at the average rate of 77 6 ha yr 1 dominating the entire delta coastline and exceeding the deposition rate threefold the retreat of the krishna delta may be explained primarily by the reduced river inflow to the delta which is three times less at present than 50 years ago and the associated reduction of sediment load both are invariably related to upstream reservoir storage development

an analysis and comparison of observed pleistocene south carolina usa shoreline elevations with predicted elevations derived from marine oxygen isotope stages geological maps of south carolina covering 6800 km2 confirm the existence of eight preserved pleistocene shorelines above current sea level marietta 42 6 m wicomico 27 4 m penholoway 21 3 m ladson 17 4 m ten mile hill 10 7 m pamlico 6 7 m princess anne 5 2 m and silver bluff 3 m current geochronologic data suggest that these eight shorelines correlate with marine oxygen isotope stages mis as follows marietta older than mis 77 wicomico mis 55 45 penholoway mis 19 or 17 ladson mis 11 ten mile hill mis 7 pamlico mis 5 princess anne mis 5 and silver bluff mis 5 or 3 except for the mis 5e pamlico and possibly the mis 11 ladson the south carolina elevations are higher than predicted by isotope proxy based reconstructions the 4 m of total relief from the pamlico to the silver bluff shoreline in south carolina for which other reconstructions suggest an expected relief of 80 m illustrates the lack of match our results suggest that processes affecting either post depositional changes in shoreline elevations or the creation of proxy sea level estimates must be considered before using paleo sea level position on continental margins

reliability assessment of slopes with three dimensional rotated transverse anisotropy in soil properties the influence of soil variability on three dimensional 3d probabilistic slope stability analysis has been previously investigated for soils that display isotropic spatial variability features or

a multi facetted study of a cretaceous coal with algal affinities i provenance of the coal samples and basic compositional data abstract this coal of cretaceous age and from southwest utah attracted attention because a lithobody from it showed a high hydrogen content and excellent behavior in liquefaction the seam is 230 cm thick and consists of an upper and lower lithobody of a clarodurainic type extensively weathered surrounding two lithobodies of canneloid boghead character the petrography of the canneloid boghead lithobodies is complex the vitrinite content is only about 25 and the bulk of the material appears to consist of a matrix of what may be bituminite appreciable amounts of resinite and liptodetrinite are also present if the suggested affinity to canneloid boghead coal types is correct the lithobodies would be regarded as saprohumolithic in character and were probably formed in an open body of water ultimate analysis shows hydrogen contents of 7 dmmf or greater fourier transform infrared spectroscopy shows that the samples have a high degree of aliphatic character methylene chains being abundant carboxylic acid groups are present presumably as a result of weathering subtraction of spectra shows that one canneloid boghead lithobody is appreciably more weathered than others

geology of gulf coast lignites edited by r b finkelman and d j casagrande environmental and coal associates houston 1986 224 pp 39 00

3d effects in seismic liquefaction of stochastically variable soil deposits the natural variability of soil properties within geologically distinct and uniform layers has been proven to greatly affect soil behaviour and to induce significant variability in the predicted response previous studies concluded that small scale heterogeneity greatly affects the liquefaction potential of saturated soil deposits and provided geotechnical design guidelines to account for the effects of various characteristics of spatial variability those studies were based on two dimensional analyses of soil liquefaction in a vertical plane assuming plane strain behaviour therefore the correlation distance of soil variability in a direction normal to the plane of analysis was implicitly taken as infinite i e no variability in the third direction in this study a monte carlo simulation approach involving generation of sample functions of non gaussian multivariate multidimensional random fields and non linear finite element analyses is used to investigate the effects of soil heterogeneity on the

the cone penetration test in sands part ii general inference of state the state parameter concept provides a new method of characterizing sand behaviour but the utility of the concept relies on the ability to measure the state parameter in situ part i of this paper demonstrated a relationship between normalized cone resistance and state parameter for monterey sand in this paper the state parameter approach is applied to data from calibration chamber tests on several sands it is shown that this approach leads to a common relationship for all the data that includes the effects of material type quantified by the slope of the steady state line the state parameter for a sand can therefore be determined in situ with a reasonable precision using a general framework of interpretation which applies to all uncemented sands la notion de parametre d etat fournit une nouvelle methode pour caracteriser le comportement des sables mais son utilite depend de la possibilite de mesurer le parametre d etat in situ la premiere partie de cet article demontre une relation entre la resist

sedimentary and botanical factors influencing peat accumulation in the mississippi delta the holocene mississippi delta system consists of six cyclic deltaic packages associated peat deposits are planar and eutrophic and accumulate in areas abandoned by deltaic sedimentation peats that formed in large scale interlobe basins are the subject of this paper true peats 75 organic matter average 81 7 organic matter on a dry weight basis controls on quality and lateral distribution of peat deposits are botanical parent material the balance between subsidence and accretion rates detrital clastic influx and marine inundation botanical parent material inferred from 13 c signatures and microtome sections is always freshwater originating either in forested swamps or under herbaceous floating mats sphagnum spp is essentially absent in order for peat to accumulate rates of accretion and subsidence must balance long term subsidence rates in the study area increase from about 0 10 to 0 30 cm a 1 over a distance of 40 km from upper to lower delta plain subsurface accretion rates for true peats at a depth of 2 3 m however average about 0 05 cm a 1 renewed coarse detrital clastic influx terminates peat accumulation the largest quantities of true peat are found together with relatively large amounts of organic poor clastic sediments mostly clays delta lobe abandonment and consequent coastal erosion causes salt water intrusion into freshwater environments resulting saline marsh sediments have maximum organic matter contents of 35 in a transgressive setting these may overlie older high quality low ash freshwater peats leaching experiments reveal the presence of water soluble salts in both transgressed and fresh peats leaching reduces ash values by 1 5 to 1 3 suggesting that such losses may occur during early diagenesis it is possible that some commercial coal seams originated in analogous interlobe environments where leaching and possibly silica mobilization reduced the originally high ash contents to acceptable levels

class a prediction of arctic caisson performance from august 1985 to march 1986 numerical predictions were made of the performance of a mobile arctic caisson subjected to ice forces a constitutive model for soil was calibrated using available laboratory data and the model incorporated within a finite element computer program features of performance predicted included maximum caisson displacement the modes of internal displacement for drained and undrained conditions whether the performance would indeed be drained or undrained and if undrained where high excess pore pressures would be found in april 1986 the caisson was subjected to large ice forces approaching the design limit and the predictions were verified on site to a remarkable degree for this problem physical models predicted an erroneous response dans la periode aout 1985 mars 1986 des predictions numeriques furent effectuees pour le comportement d un caisson arctique mobile soumis aux forces des glaces un modele constitutif pour le sol fut calibre par l emploi des donnees de la

trace element geochemistry of river sediment orissa state india abstract geochemical analyses of bottom sediment from rivers flowing through orissa state india indicated that trace element concentrations were extremely variable and commonly higher than crustal abundance the highest elemental concentrations were associated with the brahmani river followed by the baitarani and mahanadi rivers although all three rivers drain similar geology the brahmani river catchment is heavily industrialized and sediment collected downstream from industry confirms that anthropogenic activity influenced its chemical composition a similar pattern was observed in sediments collected downstream from towns in the mahanadi and baitarani catchments in both examples the clay size fraction was shown to be the most highly reactive component of the sediments comparisons between metal concentrations from the upper to lower stretches of the three river systems indicated no net accumulation downstream apparently trace elements discharged into the river system tend to be short lived in the water column rapidly settling out or becoming adsorbed into the bottom sediment although for much of the year the trace metals may remain locally incorporated as bottom sediment during monsoonal episodes where bedload transport can be significant the effects of pollution may expand over regional distances 1997 elsevier science b v

heavy metal distribution in sediments of krishna river basin india suspended and bed sediments collected from the entire region of the krishna river and its major tributaries were analyzed for heavy metals v cr mn fe co ni cu zn and pb by the thin film energy dispersive x ray fluorescence technique there is considerable variation in the concentration of elements towards downstream which may be due to the variation in the subbasin geology and various degrees of human impact suspended particles are enriched in heavy metals throughout the basin relative to bed sediments the heavy metals are enriched in coarse size fractions 10 90 m throughout the krishna river except its tributary bhima where finer fractions 2 m dominate transition elements correlate very well with each other there is a striking similarity between the bed sediments of krishna river and the indian average when the annual heavy metal flux carried by the krishna river was estimated and viewed in relation to the other major riverine transport the krishna is seen to be a minor contributor of heavy metals to the bay of bengal

petrographic characteristics of the wyodak anderson coal bed paleocene powder river basin wyoming u s a abstract six lithofacies of the thick 30 m wyodak anderson subbituminous coal bed of the fort union formation paleocene powder river basin wyoming can be delimited using megascopic and petrographic data previous lithofacies analysis of the rock types associated with the wyodak anderson bed suggested that raised peat accumulated in restricted parts of an inland flood plain the peat bodies were separated by deposits of contemporaneous possibly anastomosed channels in this study megascopic descriptions from four mine highwalls of the wyodak anderson coal bed were found to be similar to facies defined by microscopic data from core and highwall samples the data indicate that the upper and lower parts of the coal bed are rich in preserved wood remains for instance humotelinite whereas the middle part of the bed contains comparatively larger amounts of material that resulted from degradation and comminution of the peat e g eugelinite the facies are interpreted to be the result of different chemical and biological environments at the time of peat formation

a tidal origin for coarsening upward sequences above two wilcox lignites in east texas conventional palaeogeographic reconstructions show a large river system occupying the east texas embayment during the deposition of the wilcox group coarsening upward sequences above wilcox lignites in east texas have been interpreted as floodplain splays however the bedding types sedimentary structures and shallow scour surfaces in a coarsening upward sequence above the main seam at the martin lake mine in panola county indicate deposition in water stirred by tidal and wave activity the bedding types include sand streaks in mud and lenticular wavy and flaser bedding the sedimentary structures include abundant wave ripple lamination and large scale crossbeds with thin closely spaced mud drapes these crossbeds suggest traction currents of short duration alternating with periods of slack water pollen from broadleaf hardwood trees is the most common element of the palynoflora from the coarsening upward sequence at the mine the upper reaches of riverine estuaries along the se coast of the united states provide a modern analogue for the environment of deposition of the wilcox sediments at the martin lake mine here tidal currents extend inland to places where freshwater aquatic plants and forests border the estuaries the same bedding types and sedimentary structures that occur in the sediments at the martin lake mine occur in a coarsening upward sequence above a lignite at the big brown mine in freestone county recognition of the tidal origin of the coarsening upward sequences suggests an embayed coast or a shoreline within the east texas embayment during the deposition of the strata above the lignites

evaluation of soil state from sbp and cpt a case history the cone pressuremeter test cpt is widely used to determine the in situ state of cohesionless soils however although the cpt is simple inexpensive and accurate the subsequent interpretation

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

problems with interpretation of sand state from cone penetration test considerable attention has been given to the inference of sand density from indirect tests particularly the cone penetration test cpt data from tests performed in large scale chambers have demonstrated that for a given sand there is an approximately unique relationship between cpt tip resistance density or void ratio and effective stress level data have been presented to support the supposition that cpt tip resistance if normalized by division by the mean effective stress is uniquely related to the difference between the current void ratio and the void ratio at the steady state at the same mean stress level the paper presents a study of chamber test data for the ticino sand and demonstrates that there is no such unique relationship for this sand use of published correlations that fail to recognize this and other potentially important factors could result in interpretations of sand state that if carried through to design could in some circumstances be catastrophic a series of flow slides tha

classification of oil shales coals and other organic rich rocks abstract oil shales are a complex group of rocks which were deposited in a wide range of sedimentary environments and have a wide range of largely alginite dominated maceral assemblages a system of classifying oil shales and sapropelic coals is based on relative abundances of macerals classification of oil shales has applications to the commercial development of oil shale deposits and to the classification of petroleum source rocks

coals associated with tidal sediments in the wilcox group paleogene south texas abstract the several coal seams in 50 m of wilcox strata on the chacon creek east lignite property in south texas are closely associated with tidal sediments the coal bearing sequence is underlain by greenish bioturbated sandstone deposited in open marine water the sediments between the coals and cutting the coals consist of coarsening and fining upward sequences of interbedded sandstone and mudstone with lenticular wavy and flaser bedding and ripple laminated and cross bedded sandstone the sediments contain marine dinoflagellates and palynomorphs of an inland flora most of the sediment accumulated in tidal channels each coal is underlain by rooted strata usually an underclay palynomorphs in the lignite suggest the peat accumulated in low lying swamps dominated by tupelo trees these swamps lay along the landward margin of a tidal channel complex the channel complex probably extended 10 to 30 km inland from the main coastline repeated regressive and transgressive episodes with corresponding expansion and contraction of the peat swamps within the estuarine complex would explain the coal bearing sequence at chacon creek east

impacts of sediment retention by dams on delta shoreline recession evidences from the krishna and godavari deltas india river deltas are the major repositories of terrestrial sediment flux into the world s oceans reduction in riverine inputs into the deltas due to upstream damming might lead to a relative dominance of waves tides and currents that are especially exacerbated by coastal subsidence and sea level rise ultimately affecting the delta environment analysis of multi date satellite imagery and maps covering the krishna and godavari deltas along the east coast of india revealed a net erosion of 76 km2 area along the entire 336 km long twin delta coast during the past 43 years 1965 2008 with a progressively increasing rate from 1 39 km2 yr 1 between 1965 and 1990 to 2 32 km2 yr 1 during 1990 2000 and more or less sustained at 2 25 km2 yr 1 during 2000 2008 at present the krishna has almost become a closed basin with decreased water discharges into the delta from 61 88 km3 during 1951 1959 to 11 82 km3 by 2000 2008 and the suspended sediment loads from 9 million tons during 1966 1969 to as low as 0 4 million tons by 2000 2005 in the case of the godavari delta although the water discharge data do not show any major change there was almost a three fold reduction in its suspended sediment loads from 150 2 million tons during 1970 1979 to 57 2 million tons by 2000 2006 a comparison of data on annual sediment loads recorded along the krishna and godavari rivers showed consistently lower sediment quantities at the locations downstream of dams than at their upstream counterparts reports based on bathymetric surveys revealed considerable reduction in the storage capacities of reservoirs behind such dams apparently sediment retention at the dams is the main reason for the pronounced coastal erosion along the krishna and godavari deltas during the past four decades which is coeval to the hectic dam construction activity in these river basins copyright 2010 john wiley and sons ltd

erosion and sediment transport in the ganges river basin india abstract based on sampling of the entire region of the ganges basin chemical and sediment load supplied at various parts of the basin have been computed annual flux of materials from sub basin into the main basin and input to the hoogly estuary have been calculated and compared to major river systems of the world the total annual load at calcutta mouth of the river was calculated as 411 10 6 t 328 10 6 t sediment load 83 10 6 t chemical load erosion rate 549 t km 2 yr 1 is among the highest in this river system and controlling factors on a global scale such as basin area are discussed in detail annual decrease in basin elevation indicates a rapid process of denudation and such rates have a bearing on rates of shelf sediment accumulation

organic clastic facies relationships and chronostratigraphy of the barataria interlobe basin mississippi delta plain abstract the lithofacies of barataria basin an interlobe basin of the mississippi delta plain were established from analyses of 115 boreholes five organic lithofacies are distinguished by organic matter content botanical origin and degree of decomposition organic rich facies accumulated in three stages a b and c during two depositional events stage a developed locally but stages b and c developed as blankets over abandoned delta lobes protected from marine influx by a shoreline stage b lasted from 2 300 1 000 yr bp and ended when clastic sediments from renewed deltaic sedimentation blanketed the peats expanding the basin about 50 km seaward peat accumulation of stage c lasted from 900 yr bp to the present and is currently being terminated by subsidence induced transgression high quality stage b peats accumulated beneath herbaceous freshwater floating and emergent marshes mainly above the footwall of a strike oriented reactivated growth fault above the footwall the basin was shallower than on the hanging wall where the deeper basin invited more overbank sedimentation which increased ash content and diluted peats thus both tectonic and sedimentary factors influenced organic facies the quality and quantity of barataria basin peats differ from those of many deltaic coals however these peats accumulated in only 2 300 yr immediately after a rapid sea level rise frequent delta lobe switching increased organic matter preservation potential but did not provide sufficient time for the accumulation of thick low ash peats the geometries of organic and clastic facies are similar to those of some coal bearing strata

the influence of extractable organic matter on vitrinite reflectance suppression a survey of kerogen and coal types abstract the vitrinite reflectance suppression literature shows that while bitumen impregnation of the vitrinite group is often invoked as a significant contributor to suppression its existence is not often supported by petrological evidence this study examines bitumen impregnation as a factor in vitrinite suppression by comparing the vitrinite reflectance of source rock and coal samples before and after solvent extraction bitumen often defined as organic matter soluble or extractable in certain organic solvents should be removed by soxhlet method solvent extraction using chloroform removing the extractable bitumen should restore the suppressed reflectance to its true higher value however the solvent extracted samples averaged 0 014 r v less than that of the unextracted samples we conclude from these results and from other published data that reflectance suppression by bitumen impregnation in the vitrinite maceral group above the huminite stage of gelification is seemingly a rare phenomenon and whose effect on suppressing vitrinite reflectance is typically negligible

classification of torbanite and cannel coal i insights from petrographic analysis of density fractions torbanite and cannel coal are considered to be coals because of their low mineral content and overall physical morphology however the texture and composition of the organic matter in torbanite and cannel coal are similar to the kerogen occurring in oil shales and lacustrine source rocks therefore understanding the nature and origin of organic components in torbanite and cannel coal is of significance in the study of kerogen and petroleum formation in this research a set of torbanites and cannel coals from different locations throughout the world were petrographically characterized and processed using a density gradient centrifugation dgc technique microscopically the torbanite and cannel coal are composed of coarser maceral particles set in a fine grained to amorphous groundmass the groundmass is a mixture of more than one type of substance and accounts for 10 to 80 by volume of the torbanites and cannel coals botryococcus related alginite is the most characteristic component of the torbanite while sporinite typically is the main phytoclast in the cannel coals in most cases the groundmass is volumetrically the dominant component determining the overall character of the sample this observation calls into question the traditional practice of classifying such coals using the alginite to sporinite ratio variations in composition texture and fluorescence permits the recognition of three different types of groundmass lamalginitic bituminitic and vitrinitic high purity alginite sporinite vitrinite and varieties of groundmass were separated using the dgc technique the distribution of density fractions closely reflects the petrographic composition of the various torbanites and cannel coals distinct peaks on the density profiles represent the major organic components and peak magnitudes are functions of the percentage of the components demonstrating that the density gradient profiles can be used to distinguish the different types of torbanite and cannel coal the separation data also indicate a gradual shift towards higher density from lamalginitic to bituminitic to vitrinitic groundmass

cannel coals implications for classification and terminology abstract cannel coals are tough massive coals with a dull luster that break with an even compact grain and conchoidal cross fractures historically cannel coals were of significant economic and social importance during the early industrialization of the usa they were the source for a sophisticated petrochemical industry and a fuel source for heating gas making coke making and oil generation petrographic data proximate analysis and ultimate analysis data were obtained for 68 cannel coals from kentucky to decide how well the cannel coals fit the generally accepted definitions of a cannel coal four maceral assemblages were found sporinite with abundant medium grained vitrinite and inertinite sporinite with abundant fine grained vitrinite and inertinite of which micrinite is abundant bituminite may be present alginite with abundant fine grained vitrinite and inertinite and alginite and bituminite with minor vitrinite and inertinite volatile matter and h c ratios are highest for those samples with abundant liptinite with a sample from breckenridge having the highest value of each five samples were analyzed by the rock eval method the s2 and hi indices show that the coals would make excellent source rocks discrepancies between the values for the five samples are related to maceral composition and there may be a good correlation between source rock potential and importance as a feedstock for synthetic crude oil production in the 1800s the maceral composition of the microlithotypes is related to the environment of deposition coal composed of assemblage i formed in humic peat swamps in which unusually large numbers of spores were introduced possibly because of unusual climatically controlled reproductive cycles coals composed of assemblages ii to iv formed as sapropelic coals in lakes at some stage of peat swamp development

influence of spatial variability of soil young s modulus on tunnel convergence in soft soils abstract field data have shown the fact that soil spatial variability could aggravate the uncertainty of tunnel convergence d a key indicator for serviceability and safety of tunnels this paper presents a detailed numerical analysis to investigate the probabilistic response of tunnel convergence in spatially varied soft soils the soil young s modulus es is highlighted and modeled with isotropic and horizontally stratified anisotropic random fields respectively the influence of scale of fluctuation sof of the es on convergence d is discussed in detail with respect to different directions i e the vertical and horizontal directions both for and d it is observed that ignoring the spatial variability of es i e disregarding the possibility of unfavorable soft soil low stiffness soil locally around tunnel can underestimate the mean value of d the horizontally stratified anisotropic random field is more appropriate than isotropic random field in the sense of an accurate prediction especially when extreme tunnel convergence occurs in horizontally stratified anisotropic random fields the influence of horizontal and vertical sof is different on tunnel convergence the surrounding soils near tunnel crown and invert or across tunnel horizontal diameter are very critical to the tunnel convergence in addition the effect of horizontal sof x on failure probability of the calculated d exceeding the specified allowable dlim is limited when the x is larger than 4 84 times of tunnel outer diameter

assessment of soil spatial variability for linear infrastructure using cone penetration tests soil spatial variability has a significant impact on the reliability of geotechnical structures in particular the horizontal variability is important for linear infrastructure which has only lim