observations on the role of the bernice coal field sullivan county pennsylvania anthracites in the development of coalification theories in the appalachians abstract the bernice coal field sullivan county pennsylvania contains anthracite rank coal in relatively unfolded strata that setting along with a misinterpretation of the significance of apparent rank anomalies led to examples from the bernice coal field being used in the development of coalification theories in the late 1800 s and early 1900 s the evidence available was used to justify both theories of thrust pressure coalification and rank variation due to original differences in the peat or peat accumulation processes as opposed to thermal metamorphism

biaxial vitrinite reflectance in coals of the elk valley coalfield southeastern british columbia canada ninety nine grab coal samples collected from ten different diamond drill cores from the jurassic cretaceous mist mountain formation in the elk valley coalfield in southeastern british columbia were analyzed petrographically for mean maximum vitrinite reflectance rmax mean random vitrinite reflectance rm and the lengths of the maximum intermediate and minimum axes of the reflectance indicating surface or ris of vitrinite rmaxrint andrmin coal rank in the coalfield ranges from high volatile a to low volatile bituminous values of rmax in the core samples range from 0 95 to 1 50 rmax rm rmax rint and rmin are all strongly intercorrelated r 0 89 in all combinations the vitrinite in all samples is biaxial in most cases biaxial negative as a consequence rmax is always less than rmax the relationship being rmax 1 044 rmax there is no relationship between degree of vitrinite reflectance anisotropy as represented by the ris shape and rank the results indicate that a secondary stress field not perpendicular to bedding existed during coalification

multiscale organisation of organic matter associated with gold and uranium minerals in the witwatersrand basin south africa abstract organic matter from the northern part of the early proterozoic witwatersrand basin carbon leader reef was investigated using optical om and transmission electron tem microscopes completed by xrd analysis the multiscale organization texture microtexture structure of the organic matter was observed in order to gain information about the processes which affected organic material after its deposition in sediments in the micrometre scale optical microscope the shape and size of the reflectance indicating surface ris of the organic matter were determined the organic matter reveals a prevailing biaxial symmetry the size of ris is generally dependent on uranium and increases with increasing uranium concentration furthermore it appears that more than one ris is present within the scale of a single sample each with a different symmetry and size the presence of domains differing in organisation of the aromatic framework was confirmed by tem observation in the df mode the aromatic skeleton of organic matter is composed of short often crumpled mostly isolated non stacked polyaromatic layers whose fringe length corresponds to 3 16 aromatic rings the data indicate reorganization of the polyaromatic organic matter structure under stress in high pressure and relatively low temperature conditions the organic matter was in a solid state within the rocks before the pressure event

textural transformation of thermally treated anthracites abstract the organic matter of anthracites consists of turbostratic two dimensional crystalline order stacks of three to five aromatic layers called the basic structural units bsu the arrangement of bsu forms the texture of anthracites which corresponds to their chemical and physical properties including optical properties reflectance values thermal treatment leads to the changes in the arrangement of bsu the character of structural and textural transformation of anthracites during heating can be determined based on the changes of reflectance values of anthracites several anthracites of various ranks were thermally treated over the temperature range of 400 673 k 1000 c 1273 k in an inert atmosphere n2 at atmospheric pressure the reflectance indicating surfaces ris were reconstructed and reflectance indicatrix parameters were calculated according to the kilby method specially modified for the study of anthracites it was found that the relative increase of reflectance values rmax rmin was greater for the lower metamorphosed samples than for the higher ones however the higher rank of initial samples the greater their final reflectance values and the anisotropy of the texture attained at 1000 c it indicates that the texture of the higher metamorphosed anthracites meta anthracites is more flexible for rearrangement during heating than the texture of the lower metamorphosed anthracites moreover the difference in the changes of reflectance values versus temperature for the higher and for the lower rank anthracites suggests that meta anthracites have undergone stronger natural metamorphism equivalent to about 200 c in comparison with the other anthracites it could be said that the character of textural transformations of individual anthracites results from the degree of their metamorphism and in a consequence from the texture of parent sediments

correlation between optical chemical and micro structural parameters of high rank coals and graphite abstract in order to identify the parameters that best characterize the chemical and structural evolution of organic matter during coalification the relationships between optical chemical and micro structural parameters in high rank coals and natural graphite were studied the samples include anthracites from penarroya belmez espiel basin spain douro basin portugal and alto chicama basin peru and natural graphite from canada mozambique and austria correlations between the following optical parameters were assessed vitrinite random reflectance rr reflectance indicating surfaces ris axis rmax rint and rmin and ris parameters ram rev and rst as well as bw and ai anisotropy parameters furthermore the chemical parameters used were chosen according to their significant variation in coals namely volatile matter carbon and hydrogen contents calculated in dry ash free basis vmdaf cdaf hdaf as well as the h c atomic ratio structural organization was characterized by micro raman spectroscopy and xrd raman parameters used were the full width at half maximum fwhm and position of g and d1 bands on the first order raman spectrum and the id1 ig intensity area ratio the selected xrd parameters were interlayer spacing d002 and crystallite sizes la and lc results show that i rmax ris axis seems to correlate best with chemical and micro structural parameters ii for the majority of studied samples hdaf and h c atomic ratio are the only chemical parameters with significant correlations with rmax iii the fwhm of the g band of raman spectrum shows good linear correlation with the xrd parameter d002 and iv structural organization of carbon materials as measured by trends in their optical and crystalline parameters is influenced by their hydrogen content daf basis and therefore by the h c atomic ratio

the occurrence of anthracites in an area characterized by lower rank coals in the upper silesian coal basin of poland abstract the results of petrographical geological and chemical examinations on anthracites semianthracites and medium low volatile bituminous coals from jastrzebie in the upper silesian coal basin of poland are presented the coking coals mined in this region exhibit volatile matter v daf 18 26 free swelling index fsi 3 8 and reflectance r m 1 10 1 35 and are inertiniterich coals i 25 63 coal seam 504 of the anticlinal beds namurian b has been affected by thermal metamorphism and contains both coking coals and coals of higher rank according to the criterion of polish standards this coal seam varies from anthracite v daf daf 10 14 in rank the carbon content is slightly lower and the hydrogen content a little higher than those of typical anthracites and semianthracites the reflectance values r m 1 56 2 62 are generally lower than the r m values proposed by the international committee for coal petrology as boundary values for anthracites and bituminous coal the magnitude of anisotropy and microhardness were also examined examinations of optical properties prove that the metamorphism exhibited by the coals is the result of elevated temperature and variable pressure the analyses of the maceral composition indicate that there is a decrease in the inertinite content in anthracites vitrinite exhibits the features of thermally altered coal the micrinite content shows a little variation in coking coals a strongly fluorescing bituminous substance with the optical features of exsudatinite was found the constructed geological section of coal seam 504 shows distinct regular changes in chemical and physical properties as well as the petrographic composition which may be caused by the heat flux of a magma intrusion not localized so far

raman spectra of carbonaceous material in metasediments a new geothermometer metasedimentary rocks generally contain carbonaceous material cm deriving from the evolution of organic matter originally present in the host sedimentary rock during metamorphic processes this organic matter is progressively transformed into graphite s s and the degree of organisation of cm is known as a reliable indicator of metamorphic grade in this study the degree of organisation of cm was systematically characterised by raman microspectroscopy across several mesozoic and cenozoic reference metamorphic belts this degree of organisation including within sample heterogeneity was quantified by the relative area of the defect band r2 ratio the results from the schistes lustres western alps and sanbagawa japan cross sections show that 1 even through simple visual inspection changes in the cm raman spectrum appear sensitive to variations of metamorphic grade 2 there is an excellent agreement between the r2 values calculated for the two sections when considering samples with an equivalent metamorphic grade and 3 the evolution of the r2 ratio with metamorphic grade is controlled by temperature t along the tinos cross section greece which is characterised by a strong gradient of greenschist facies overprint on eclogite facies rocks the r2 ratio is nearly constant consequently the degree of organisation of cm is not affected by the retrogression and records peak metamorphic conditions more generally analysis of 54 samples representative of high temperature low pressure to high pressure low temperature metamorphic gradients shows that there is a linear correlation between the r2 ratio and the peak temperature t c 445 r2 641 whatever the metamorphic gradient and probably the organic precursor the raman spectrum of cm can therefore be used as a geothermometer of the maximum temperature conditions reached during regional metamorphism temperature can be estimated to 50 c in the range 330 650 c a few technical indications are given for optimal application

assessment of ground based monitoring techniques applied to landslide investigations a landslide complex in the whitby mudstone formation at hollin hill north yorkshire uk is periodically re activated in response to rainfall induced pore water pressure fluctuations this paper compares long term measurements i e 2009 2014 obtained from a combination of monitoring techniques that have been employed together for the first time on an active landslide the results highlight the relative performance of the different techniques and can provide guidance for researchers and practitioners for selecting and installing appropriate monitoring techniques to assess unstable slopes particular attention is given to the spatial and temporal resolutions offered by the different approaches that include real time kinematic gps rtk gps monitoring of a ground surface marker array conventional inclinometers shape acceleration arrays saa tilt meters active waveguides with acoustic emission ae monitoring and piezometers high spatial resolution information has allowed locating areas of stability and instability across a large slope this has enabled identification of areas where further monitoring efforts should be focused high temporal resolution information allowed the capture of s shaped slope displacement time behaviour i e phases of slope acceleration deceleration and stability in response to elevations in pore water pressures this study shows that a well balanced suite of monitoring techniques that provides high temporal and spatial resolutions on both measurement and slope scale is necessary to fully understand failure and movement mechanisms of slopes in the case of the hollin hill landslide it enabled detailed interpretation of the geomorphological processes governing landslide activity it highlights the benefit of regularly surveying a network of gps markers to determine areas for installation of movement monitoring techniques that offer higher resolution both temporally and spatially the small sensitivity of tilt meter measurements to translational movements limited the ability to record characteristic s shaped landslide movements at hollin hill which were identified using saa and ae measurements this high sensitivity to landslide movements indicates the applicability of saa and ae monitoring to be used in early warning systems through detecting and quantifying accelerations of slope movement

vitrinite reflectance anisotropy as a tectonic fabric element the anisotropy of the coal maceral vitrinite was analyzed in relation to the tectonic setting of a coal from the southern anthracite field in pennsylvania for the coal studied the maximum intermediate reflectance plane essentially paralleled the axial plane of the synclinorium n66 e strike 64 se dip

lithological dependency and anisotropy of vitrinite reflectance in high rank sedimentary rocks of the ibbenburen area nw germany implications for the tectonic and thermal evolution of the lower saxony basin abstract covering a depth interval of 1200 m thirty one rock samples were collected from a well drilled in the beust field of the ibbenburen anthracite mine lower saxony basin nw germany these rock samples consist of high rank coals anthracites claystones siltstones and sandstones of pennsylvanian age analytical methods include the measurement of random vitrinite reflectance vr r rotational reflectance vr rot as well as maximum and minimum reflectances vr max and vr min enabling the evaluation of the lithological influence on vitrinite reflectance as well as the indication of tectonic stresses in the lower saxony basin by applying the ris reflectance indicating surface analysis method this study shows that not only due to the high rank of the studied samples and associated anisotropic character but also due to lithological dependency a partially significant scatter of measured vr r can be observed the scatter in coals is significantly less than in other sedimentary rocks e g standard deviation in coals can be up to 7 less than in siltstones the expected increase of standard deviation with increasing rank and accordant anisotropy was not observed for vr r but rather for vr max with the exception of coals displaying a relatively constant and low deviation throughout the depth maturity interval mean vr r values of coals differ from those of other sedimentary rocks at equal depths vr r measured in claystones is consistently higher compared to associated coal seams and can be elevated by up to 10 silt and sandstones always display lower vr r with differences of up to 16 at very high levels of thermal maturity vitrinite reflectance depends not only on maximum paleotemperature but also on lithology leading to differences in pressure propagation and thus deformation additionally radioactive trace elements in coals and organic matter rich claystones provide a local secondary heat source 40 k and 232 th are preferentially bound to clay particles which are enriched in the studied claystones and depleted in the silt and sandstones possibly leading to higher vitrinite reflectance observed in the claystones ris analysis shows a predominantly negative biaxial distribution indicating the absence of thermal overprinting by a possible intrusion bramsche massif during the late cretaceous which would have induced a uniaxial distribution instead this implies in addition to vertical stresses due to depositional loading the presence of a secondary stress field not perpendicular to bedding which is related to the inversion of the lower saxony basin this information presents in combination with previous basin modeling results additional evidence for deep subsidence with subsequent uplift being the cause for the present day maturity patterns observed in the lower saxony basin

field monitoring of the corvara landslide dolomites italy and its relevance for hazard assessment the corvara landslide is an active slow moving rotational earth slide earth flow located uphill of the village of corvara in badia one of the main tourist centres in the alta badia valley in the dolomites province of bolzano italy present day movements of the corvara landslide cause national road 244 and other infrastructures to be damaged on a yearly basis the movements also give rise to more serious risk scenarios for some buildings located in front the toe of the landslide for these reasons the landslide has been under observation since 1997 with various field devices that enable slope movements to be monitored for hazard assessment purposes differential gps measurements on a network of 47 benchmarks has shown that horizontal movements at the surface of the landslide have ranged from a few centimetres to more than 1 m between september 2001 and september 2002 over the same period vertical movements ranged from a few centimetres to about 10 cm with the maximum displacement rate being recorded in the track zone and in the uppermost part of the accumulation lobe of the landslide borehole systems such as inclinometers and tdr cables have recorded similar rates of movement with the depths of the major active shear surfaces ranging from 48 m to about 10 m from these data it is estimated that the active component of the landslide has a volume of about 50 million m3 in this paper the monitoring data collected so far are presented and discussed in detail to prove that the hazard for the corvara landslide considered as the product of yearly probability of occurrence and magnitude of the phenomenon can be regarded has as medium or high if the velocity or alternatively the volume involved is considered finally it is also concluded that the monitoring results obtained provide a sound basis on which to develop and validate numerical models manage hazard and support the identification of viable passive and active mitigation measures

reflectance anisotropy of upper carboniferous coals in the appalachian foreland basin pennsylvania u s a abstract patterns of vitrinite reflectance anisotropy in coal are represented by a three dimensional graphical form resembling an ellipsoid termed the vitrinite reflectance indicating surface vri naturally occurring vris from the northern appalachian basin pennsylvania range in shape from biaxial negative to biaxial positive depending on their coalification history and tectonic setting vri shapes are measured by estimating the magnitudes of the three principal reflectances rmax rint and rmin either on oriented blocks or non oriented grain mounts spatial orientations of the principal axes are determined by reflectance measurements on oriented polished cores the various vri shapes are portrayed on axial ratio diagrams i e plots of r max r int on the vertical axis and r int r min on the horizontal axis axial ratio diagrams are also used to depict the progressive change in vri shape with coalification standard deviations of the principal reflectance axes as measured on oriented cores average around 0 09 in magnitude and 5 in orientation measurements are highly reproducible between pairs of oriented cores estimates of the principal reflectance magnitudes as measured on oriented vs non oriented samples agree on average to within 0 04 for rmax 0 08 for rint and 0 20 for rint coal bearing strata in the north central coal fields medium volatile bituminous coal to semianthracite in northern pennsylvania were diagenetically altered in a predominantly burial strain environment and exhibit structural evidence of only mild tectonic deformation vris from this suite of coals are biaxial negative with rmin axes roughly perpendicular to bedding with increasing rank toward the southeast these vris plot along a straight line pathway on the axial ratio diagram emanating from near the origin and extending through the biaxial negative deformation field vris of coals from the western middle anthracite field exhibit a wide range of shapes and orientations which is indicative of a more complex tectonic history in their present day orientation rmin axes are scattered about a great circle distribution the pole to which is precisely coincident with regional fold axes when beds are unfolded to a flat lying orientation they become significantly less scattered indicating that most coalification here preceded the final phase of alleghanian folding rmax axes of sporinite grains are alwayas aligned parallel to bedding which suggests that the strata were still flat lying and not subject to tectonic forces when the coals passed through the 1st and 2nd coalification jumps

graphitization of organic matter and fluid deposited graphite in palaeoproterozoic birimian black shales of the kaya goren greenstone belt burkina faso west africa palaeoproterozoic black shales form an essential part of the birimian volcanosedimentary belt in burkina faso west africa the mean rmax values and the atomic h c values of the bulk carbonaceous matter bcm together with rock structures and mineral assemblages indicate that these carbon rich rocks were metamorphosed to sub greenschist and low grade greenschist facies x ray diffraction reveals that the 002 graphite peak width in half maximum fwhm ranges from 0 43 to 0 71 2 in sub greenschist facies and from 0 27 to 0 41 2 in greenschist facies rocks but the d 002 values in both groups of rocks are approximately the same 3 35 a the bcm of individual samples is composed of particles with very variable shape reflectance and raman spectra type i particles that predominate in sub greenschist facies are fine grained irregular or elongate bodies 1 to 3 m in size their maximum reflectance rmax ranges between 2 5 and 8 2 and raman parameters r1 and r2 range from 0 5 to 1 4 and 0 5 to 0 8 respectively type ii particles are lath shaped up to 40 m large bodies commonly arranged parallel to white mica flakes the number of these particles increases from sub greenschist to greenschist facies maximum reflectance varies between 6 and 11 2 and r1 and r2 raman parameters range from 0 05 to 0 7 and from 0 1 to 0 5 respectively type iii particles occur in hydrothermally altered and sheared rocks these are nodular aggregates composed of grains up to 10 m in size this type of particles has very high reflectance rmax 11 15 and its raman spectra indicate a very high degree of structural ordering corresponding to well ordered graphite type i particles represent original organic matter in the metasediments type ii particles are believed to have been formed either in situ by solid state transformation of type i particles or by crystallization from metamorphic fluids gradual graphitization of the type i organic particles and the growth of lath shaped type ii particles from a fluid phase is assumed to have taken place under the peak metamorphic conditions associated with the burial of birimian sediments during thrust tectonism progressive tectonic accretion and crustal thickening during the d1 event of the eburnean orogeny the growth of equant high reflectance postkinematic nodular aggregates of type iii particles is ascribed to the reduction of co2 rich fluids during a hydrothermal event associated with late eburnean d2 exhumation and strike slip movements type i carbonaceous particles were only slightly affected by high temperature low pressure contact metamorphism during intrusion of late eburnean magmatic bodies whereas formation of type ii or iii particles was not recorded in contact metamorphosed rocks at all

evaluation of the structure of bituminous coal from sośnica mine in the upper silesian coal basin poland using reflectance indicating surface ris parameters abstract the effect of a magmatic intrusion on the optical properties reflectance anisotropy and optical character of vitrinite in low rank bituminous coals was examined the study focused on coal samples collected at different distances from an intrusion emplaced into seam no 416 in so nica mine near gliwice in the upper silesian coal basin poland in the immediate contact zone coal transformed into natural coke may be seen for comparison laboratory carbonization of coals weakly changed or apparently unchanged by the intrusion was carried out the results obtained confirmed that during carbonization of the low rank coal heating alone with no external pressure makes possible the reorganization of carbon planes that is responsible for the increase of vitrinite reflectance the heating leads to the destruction of coal structure cross linkages aliphatic groups or heteroatoms and various further transformations of the structural net in addition to the removal of volatile carbonization products external pressures affect the transformation process especially by promoting the rearrangement of small structural units to form further elements of anisotropic structure thus in the case of coal from the immediate contact of the intrusion pressures resulted in values of anisotropy parameters higher than those characterizing coal heated in the laboratory up to 1200 c but in the absence of stress the source of pressure that strongly affected the coal in the mine was probably intrusion related weak tectonism in the region of the so nica mine could explain the fine biaxial optical character of the low rank parent coals more generally pressures associated with thermally evolving gasses conceivably led to the growth of structural anisotropy in the walls of degassing pores finally some structural changes seen in coal adjacent to the intrusion may reflect hydrothermal activity

review and update of the applications of organic petrology part 1 geological applications abstract organic petrology developed as coal petrology at the beginning of the 20th century dedicated mainly to the study of coals because of their utilization in industry coal petrology was then considered a branch of coal science later with the development of specialized nomenclature classification of coal components and the standardization and improvement of analytical microscopical methods this discipline expanded in interests and name becoming organic petrology organic petrology carries a broader context being as well a tool applied in the study of dispersed organic matter in sedimentary rocks due to its importance in exploration for fossil fuel resources at present organic petrology is a discipline widely recognized for its role in fundamental and applied research with respect to both coal utilization and in geosciences throughout the 20th century several important monographs have been published on the discipline of organic petrology including stach s textbook of coal petrology 1st edition 1935 2nd 1975 3rd 1982 updated as the more general organic petrology by taylor et al 1998 more recently the text applied coal petrology the role of petrology in coal utilization was published by suarez ruiz and crelling 2008 this review is the first in a two part review series that describes and updates the role of organic petrology in geosciences a second part complementing this one and focused on the applications of organic petrology to other scientific fields will follow

genesis and rank distribution of upper carboniferous coal basins in the cantabrian mountains northern spain abstract the cantabrian mountains located in the nw of the iberian peninsula constitute the most important coal mining district of spain anthracitic and bituminous coals high and medium rank coals have been mined in the area since the end of the nineteenth century and they currently account for about 70 of the total coal resources of the country the region forms part of the cantabrian and west asturian leonese zones of the iberian variscan fold belt and is strongly deformed by a set of imbricate thrusts coeval folds and high angle faults coal bearing successions are westphalian and stephanian pennsylvanian in age and are exposed in numerous coalfields of variable size arranged roughly parallel to the tectonic structures coal rank varies from medium rank bituminous d coals rr 0 5 to high rank anthracites a coals rr

recognition of vitrinite with non uniaxial negative reflectance characteristics non uniaxial negative reflectance characteristics are being reported for coals from around the world with increasing frequency these data have traditionally been collected from oriented sections cut from a block of coal to determine the magnitudes of the principal reflectance axes to make data collection less time consuming a method of determining the principal reflectance axes from a standard crushed coal sample has been developed the method requires measurement of the maximum and minimum apparent reflectances from a series of randomly oriented vitrinite particles the reflectance crossplot displays these two reflectance values against their difference or bireflectance the paper describes the method of interpreting the resultant pattern to determine the values of the three principal reflectance axes analysis of coals from the british columbia rocky mountains and foothills revealed biaxial and uniaxial positive as well as uniaxial negative reflectance characteristics a new measure of maturation rev is proposed which is based purely on the lengths of the three principal reflectance axes rm approximates this value but is influence by any eccentricity of the reflectance indicating surface ris vitrinite with a non uniaxial reflectance characteristics cannot be adequately described by a single measure such as rmaxorrm but requires reference to both the size and shape of the ris a reflectance determination such as rev or rm provides rank astm information whereas the new measures rst and ram describe a reflectance indicating surface shape which is the result of maturation and tectonic histories vitrinites with non uniaxial negative reflectance characteristics are abundant in the coalfields of the rocky mountains and foothills of british columbia rmax does not fully describe the reflectance character of these coals and does not describe the potentially useful ris shape

precursor and metamorphic condition effects on raman spectra of poorly ordered carbonaceous matter in chondrites and coals abstract geothermometers based on raman spectrometry of carbonaceous matter and covering a wide range of temperatures 100 650 c have been developed over recent years while raman data have been largely interpreted in terms of temperature they are also the fingerprint of certain metamorphic conditions especially in the low temperature range relevant to poorly ordered carbonaceous matter this study investigates the raman spectra of two series of chondritic carbonaceous matter and coal samples formed from different precursors and under different metamorphic conditions the raman spectra of polyaromatic carbonaceous matter pcm from 42 chondrites and 27 coal samples measured with visible 514 nm and ultra violet 244 nm excitation wavelengths are analyzed the raman spectra of low rank coals and chondrites of petrologic types 1 and 2 which contain the more disordered pcm reflect the distinct carbon structures of their precursors the 514 nm raman spectra of high rank coals and chondrites of petrologic type 3 exhibit continuous and systematic spectral differences reflecting different carbon structures present during the metamorphism event they result from differences in the chemical structures of the precursors concerning for instance the reticulation of polyaromatic units or an abundance of ether functional groups or possibly from a lack of carbonization processes to efficiently expel oxygen heteroatoms due to weak lithostatic pressure and confinement these results suggest that the use of low temperature carbon thermometers should be restricted to a given geological context at the same time the sensitivity of raman spectra to precursors and certain metamorphic conditions could be used to obtain information other than temperature the analysis also provides evidence of the accretion of relatively homogeneous pcm precursors among ordinary co and cv carbonaceous chondrite parent bodies given that the 514 nm raman spectra of pcm efficiently trace the metamorphism grades looking closer however the 514 nm raman data are more scattered in chondrites than in coals and the maturity tracers are less sensitive and miscorrelate with the atomic h c ratio suggesting slight compositional and structural differences among the pcm precursors accreted

oxidatively and thermally altered high volatile bituminous coals in high temperature coal fire zone no 8 of the wuda coalfield north china abstract coal fires have received increasing attention due to their environmental economic and social impacts their significant influence on coal properties is widely documented by geophysical and geochemical methods the present paper demonstrates by means of coal petrological methods significant changes of microstructure optical appearance and optical properties of medium rank bituminous coals affected by an underground coal fire the studied changes are suggested to result from distinct oxidative and thermal alterations induced by a high temperature regime temperatures over 800 c encountered in the coal fire zone no 8 wuda coalfield the investigated coal seam no 9 represents a high volatile a bituminous coal and is dominated by vitrinite followed by inertinite with minor amounts of liptinite the microstructure of the coal fire affected coals facilitate a broad spectrum of characteristic features the microscopic analyses revealed development of 1 non tectonic fissures and non tectonic fractures 2 distinct micropores 3 dark oxidations rims and 4 bright spots interpreted as incipient mesophases optical properties were characterised for megasporinite and vitrinite in the examined megasporinite a noticeable anisotropy and distinct granular appearance was observed in the investigated coals both a dominant increase as well as a minor decrease in both random and maximum vitrinite reflectances were documented for 1 coal grains and 2 dark rimmed vitrinite at non tectonic fissures and non tectonic fractures in addition also a characteristic bimodal vitrinite population was measured the increase in bireflectance was clearly documented for two sub zones within the coal fire zone no 8 the applied kilby s cross plots suggested a large overlapping of the data sets of r max and r min indicating marked changes in vitrinite structure the applied coal petrological approach revealed distinct changes to the coal s microstructure appearance as well as to optical properties induced by the underground coal fire the presented coal petrographic approach may help determine the extent of coal fires in coal mines and the direction of propagation of coal fire front

conversion of carbonaceous material to graphite within the greywacke zone of the eastern alps morphology and reflectance of carbonaceous material cm in late carboniferous metasediments of the eastern greywacke zone eastern alps indicate a mixture of vitrinite grainy textured and lamellar shaped particles as imaged by high resolution atomic force microscopy vitrinite and the grainy textured particles show mesophase structures which can be described as facetted nanocrystals within the carbon matrix high resolution transmission electron microscopy has revealed two types of microtextures representing different degrees of graphitization the first type is characterized by elongated ring shaped microtextures whereas the second type is characterized by graphite lamellae and polygonal flakes with long range ordered aromatic layers in spite of the heterogeneity of the cms the geographical distribution of quantitative metamorphic parameter raman spectra parameter x ray diffraction pattern microscopic reflectance suggests a graphitization process which is promoted by advective heat transport during post collisional processes in a tentative pressure time path late cretaceous thrusting results in a turbostratic ordering of the aromatic layer ordering to long range ordered aromatic layers was achieved during the late cretaceous paleogene exhumation of mid crustal rocks beneath the eastern greywacke zone

reflectance anisotropy and syn deformational coalification of the jewel seam in the cadomin area alberta canada abstract the jewel seam of the cadomin area is complexly folded and cut by several thrust faults vitrinite reflectance anisotropy was determined from twenty oriented coal blocks collected from various structural positions five of the blocks have uniaxial anisotropies five have biaxial positive anisotropies the remaining ten are biaxial negative the biaxial coals display maximum reflectance axes parallel to nearby fold axes which suggests a relationship between vitrinite anisotropy and deformation the biaxial vitrinite reflectance ellipsoids result from superposition of tectonic strains on a primary sedimentary burial related uniaxial anisotropy a tectonic stress field was probably present during the later stages of sedimentary burial and subsequent deformation coalification resulted largely from pre deformational sedimentary burial but the final coalification stage was syn deformational as illustrated by the intersection of isorank surfaces and the jewel seam and the biaxial vitrinite reflectance anisotropy

on the optically biaxial character and heterogeneity of anthracites abstract the results of the study of optical properties of 13 anthracites from different parts of the world are presented in this paper measurements of reflectance values were made on non oriented vitrinite grains for a minimum of 300 points per sample the reconstruction of reflectance indicating surfaces ris were made by kilby s method kilby w e 1988 recognition of vitrinite with non uniaxial negative reflectance characteristics int j coal geol 9 267 285 kilby w e 1991 vitrinite reflectance measurement some technique enhancements and relationships int j coal geol 19 201 218 it was found that the use of kilby s method for strongly anisotropic materials like anthracites did not give unambiguous results some improvement in kilby s method consisting of the division of the cumulative cross plot into several elemental components is suggested each elemental cross plot corresponds to a textural class of anthracite which is characterized by the values of ris main axes rmax k rint k and rmin k k 1 2 n n number of classes the global texture of anthracite is characterized as a ris with main axes calculated as the weighted means of r max r int and r min for each class of this anthracite the division of cumulative kilby s cross plot on elemental components makes possible the calculation of new coefficients ht and h10 characterizing the heterogeneity of the structure and texture of anthracites the results of our study show that all anthracites have biaxial negative textures but their heterogeneity varies in a wide range of ht and h10 coefficients depending upon the individual coal basin

exploring debris flow history and process dynamics using an integrative approach on a dolomitic cone in western austria the evolution of a debris flow cone depends on a multitude of factors in the hydrogeomorphic system investigations of debris flow history and cone dynamics in highly active catchments therefore require an integrative approach with a temporal and spatial resolution appropriate for the goals of the study we present the use of an orthophoto time series to augment standard dendrogeomorphic techniques to describe the spatio temporal dynamics of debris flows on a highly active cone in the western austrian alps analysis of seven orthophotos since 1951 revealed a migration of active deposition areas with a resulting severe loss of forest cover 80 and a mean tree loss per year of 10 4 range 1 3 16 6 trees per year analysis of 193 pinus mugo ssp uncinata trees allowed the identification of 161 growth disturbances corresponding to 16 debris flows since 1839 and an average decadal frequency of 0 9 events as a result of the severe loss of forest cover we speculate that 20 of the more recent events were actually captured in the tree ring record giving a decadal return interval of 7 5 events for a period of 60 years based on three annual field observations it is evident that this catchment the barenrufe produces very frequent 1 yr small in the order of a few 10 to 100 m3 debris flows with minor material relocation the specific challenges of tree ring analysis in this tree species and in highly active environments are explicitly addressed in the discussion and underline the necessity of employing complementary methods of analysis in an integrative manner copyright 2012 john wiley sons ltd

raman spectroscopy of selected carbonaceous samples abstract this paper presents the results of raman spectra measured on carbonaceous materials ranging from greenschist facies to granulite facies graphite anchimetamorphism and epimetamorphism zones raman spectroscopy has come to be regarded as a more appropriate tool than x ray diffraction for study of highly ordered carbon materials including chondritic matter soot polycyclic aromatic hydrocarbons and evolved coal samples this work demonstrates the usefulness of the raman spectroscopy analysis in determining internal crystallographic structure disordered lattice heterogeneity moreover this methodology permits the detection of differences within the meta anthracite rank semi graphite and graphite stages for the samples included in this study in the first order raman spectra the bands located near to c a 1350 cm 1 defects and disorder mode a 1g and 1580 cm 1 in plane e 2g zone centre mode contribute to the characterization and determination of the degree of structural evolution and graphitization of the carbonaceous samples the data from raman spectroscopy were compared with parameters obtained by means of structural chemical and optical microscopic analysis carried out on the same carbonaceous samples the results revealed some positive and significant relationships although the use of reflectance as a parameter for following the increase in structural order in natural graphitized samples was subject to limitations

relationship between structure morphology and carbon isotopic composition of graphite in marbles implications for calcite graphite carbon isotope thermometry carbon isotope exchange between calcite and graphite is a useful and reliable geothermometer for medium to high grade marbles however in rare instances such as at naxos greece apparent disequilibrium carbon isotope fractionation between calcite and graphite has been previously reported in this study new results are presented on the morphological features x ray diffraction studies raman spectroscopic studies and carbon isotope studies of graphite three morphologically distinct graphite types are identified the first type is fine grained with distinct polygonal crystal aggregates having smooth pinacoid faces the second type consists of large botryoidal aggregates with typical crystal overgrowth features and the third type is normal large platy crystals associated with phlogopite graphite morphological features using an fe sem suggests that the botryoidal aggregates are composed of complexly intergrown and stacked graphite layers comprised of cone helix structures different types of graphite display distinct lc 002 and dg values as well as a sharp first order raman peak at 1580 cm 1 with disordered bands the presence of raman disordered bands in fine grained well crystallized graphite is attributed to edge effects carbon isotope analysis of graphite reveals that marble with fine grained well crystallized graphite show a consistent isotope fractionation with the calcite which perfectly match temperature estimates based on the mineral isograds in contrast coarse botryoidal graphite gives heterogeneous carbon isotope values about a few per mill and show anomalous carbon isotope fractionation between the calcite and graphite the graphite associated with phlogopite also shows variations in the carbon isotope values combining morphologic crystallographic and carbon isotopic data we conclude that the variations in carbon isotopic composition were caused by the overgrowth of graphite on the preexisting grain and that morphological observations and structural characterizations of graphite crystals is a key for predicting isotopic equilibration during metamorphism

vitrinite anisotropy resulting from simple shear experiments at high temperature and high confining pressure abstract orientations of r 0 max and r 0 min of vitrinite have been determined in coal samples that have been deformed in simple shear experiments at t 650 900 c confining pressures of 0 8 and 1 0 gpa and constant displacement rates of 10 5 10 6 s 1 samples chosen are a high volatile bituminous coal and two anthracites shear strains up to 3 0 were attained in experiments that lasted up to 100 h high temperature and large strains have facilitated an increase in r 0 max an increase in anisotropy bireflectance and reorientation of r 0 max and r 0 min results of these experiments indicate that tectonic strain at and above semi anthracite rank enhances the degree of molecular ordering leading to preferential growth of graphite and that vitrinite anisotropy may track with tectonic strain