solid bitumen reflectance and rock eval tmax as maturation indices an example from the nordegg member western canada sedimentary basin abstract marine organic rich rock units commonly contain little for vitrinite reflectance v r 0 measurement the most commoly used method of assessing thermal maturity this is true of the lower jurassic nordegg member a type i ii sulphur rich source rock from the western canada sedimentary basin this study examines the advantages and pitfalls associated with the use of rock eval t max and solid bitumen reflectance b r 0 to determined maturity in the nordegg vitrinite reflectance data from cretaceous coals and known coalification gradients in the study area are used to extrapolate v r 0 values for the nordegg t max increases non linearly with respect to both b r 0 and extrapolated v r 0 values a sharp increase in the reflectaance of both solid bitumen and vitrinite occurs between t max 440 450 c and is coincident with a pronounced decrease in hydrogen index values and the loss of solid bitumen and telalginite fluorescence over the same narrow t max interval this t max range is interpreted as the main zone of hydrocarbon generation in the nordegg and corresponds to extrapolated v r 0 values of 0 55 0 85 the moderate to high sulphur contents in the kerogen played a significant role in determining the boundaries of the nordegg oil window a linear relationship between b r 0 and extrapolated v r 0 as proposed elsewhere is not true for the nordegg b r 0 increases with respect to extrapolated v r 0 according to jacob s 1985 formula v r 0 0 618 b r 0 0 40 up to v r 0 0 72 b r 0 0 52 beyond this point b r 0 increases sharply relative to extrapolated v r 0 according to the relatioship v r 0 0 277 b r 0 0 57 r 2 0 91 the break in the b r 0 v r 0 curve at 0 72 v r 0 is thought to signifiy the peak of hydrocarbon generation and represents a previously unrecognized coalification jump in the solid bitumen analogous to the first coalification jump of liptinites

influence of a tundra freeze thaw cycle on sulfide oxidation and metal leaching in a low sulfur granitic waste rock abstract drill cuttings were collected at 1 m depths from an instrumented low sulfur experimental waste rock pile containing a 4c pyrrhotite that had been exposed to the extreme freeze thaw cycle of a tundra climate boreholes were drilled from the top to base in the center of the pile and near the core batter transition waste rock samples were analyzed for carbon sulfur and metal concentrations sulfur oxidation states and variation in iron and nickel forms due to oxidative dissolution of pyrrhotite results from x ray absorption spectroscopy and aqueous extraction experiments were used to relatively compare samples from various depths in the boreholes which indicate sulfide weathering fronts that decrease in intensity from the top to core to base at the center of the pile and from the core batter transition to the center of the pile the tundra climate and waste pile configuration produce a permafrost base a seasonally frozen core and an atmospheric like zone near the surface the fluctuation of the freeze thaw cycle caused the greatest sulfide weathering near the surface and lesser weathering in the core and base of the pile metal and sulfur rich leachate from the higher weathering zone likely is collecting on a variable and seasonal frozen surface beneath the surface layer that causes metals and s to precipitate and or sorb during a portion of the year the accumulation of sulfur and metals with the flux of this frozen surface produces a nickel and possibly an iron and sulfur enrichment zone beneath the surface layer in the center of the pile the weathering front from the top to core to base of the pile and from core batter transition to the core corresponds to a previously formulated leachate model but the enrichment zone below the surface zone is unique to this conceptual waste rock weathering model for this tundra climate

origin distribution and hydrogeochemical controls on methane occurrences in shallow aquifers southwestern ontario canada abstract natural gas reservoirs in organic rich shales in the appalachian and michigan basins in the united states are currently being produced via hydraulic fracturing stratigraphically equivalent shales occur in the canadian portion of the basins in southwestern ontario with anecdotal evidence of gas shows yet there has been no commercial shale gas production to date to provide baseline data in the case of future environmental issues related to hydraulic fracturing and shale gas production such as leakage of natural gas saline water and or hydraulic fracturing fluids and to evaluate hydrogeochemical controls on natural gas accumulations in shallow groundwater in general this study investigates the origin and distribution of natural gas and brine in shallow aquifers across southwestern ontario an extensive geochemical database of major ion and trace metal chemistry and methane concentrations of 1010 groundwater samples from shallow domestic wells in bedrock and overburden aquifers throughout southwestern ontario was utilized in addition select wells n 36 were resampled for detailed dissolved gas composition 13 c of ch 4 c 2 c 3 and co 2 and d of ch 4 dissolved gases in groundwater from bedrock and overburden wells were composed primarily of ch 4 29 7 98 6 mol of total gas volume n 2 0 8 66 2 mol ar o 2 0 2 3 4 mol and co 2 0 1 2 mol ethane was detected but only in low concentrations 100 in situ saturation were found in bedrock wells completed in the upper devonian kettle point formation middle devonian hamilton group and dundee formation and in surficial aquifers overlying these organic rich shale bearing formations indicating that bedrock geology is the primary control on methane occurrences a few n 40 samples showed na cl br evidence of brine mixing with dilute groundwater however only one of these samples contained high 60 in situ saturation ch 4 the relatively low 13 c values of ch 4 89 9 to 57 3 covariance of d values of ch 4 and h 2 o positive correlation between 13 c values of ch 4 and co 2 and lack of higher chain hydrocarbons c 3 in all but one dissolved gas sample indicates that the methane in groundwater throughout the study area is primarily microbial in origin the presence or absence of alternative electron acceptors e g dissolved oxygen fe no 3 so 4 in addition to organic substrates controls the occurrence of microbial ch 4 in shallow aquifers microbial methane has likely been accumulating in the study area since at least the late pleistocene to the present as indicated by the co variance and range of d values of ch 4 314 to 263 and associated groundwater 19 to 6 d h 2 o

precise gps acoustic positioning of seafloor reference points for tectonic studies abstract global networks for crustal strain measurement provide important constraints for studies of tectonic plate motion and deformation to date crustal strain measurements have been possible only in terrestrial settings on continental plates and island sites within oceanic plates we report the development of technology for horizontal crustal motion determination at seafloor sites allowing oceanic plates to be monitored where islands are not available seafloor crustal monitoring is an important component of global strain measurement because about 70 of the earth s surface is covered by water and this region contains most of the tectonic plate boundaries and zones of crustal deformation using the global positioning system gps satellites and underwater acoustics we have established a geodetic reference site on the juan de fuca plate at 2 6 km depth approximately 150 km off the northwest coast of north america we measure the baselines between this site and two terrestrial gps stations on vancouver island british columbia the juan de fuca plate site is an appropriate setting to develop seafloor observation methods since it is a well studied area easily accessible from west coast canadian and united states ports determination of seafloor motion at this site addresses questions related to convergence between the juan de fuca and north american plates across the cascadia subduction zone at the juan de fuca seafloor geodetic reference site we installed precision acoustic transponders on the seafloor and measured ranges to them from a sound source at a surface platform ship or buoy the platform is equipped with a set of three gps antennas allowing determination of the sound source position at times of signal transmission and reception merging the satellite and acoustic data allows determination of the transponder network location in global reference frame coordinates data processing to date suggests repeatabilities of 0 8 cm north and 3 9 cm east in the seafloor transponder network position relative to reference points on vancouver island

evidence of viscoelastic deformation following the 2011 tohoku oki earthquake revealed from seafloor geodetic observation the gps acoustic seafloor positioning has detected significant postseismic movements after the 2011 tohoku oki earthquake m9 0 just above the source region off the pacific coast of eastern japan in contrast to the coastal global navigation satellite systems sites where trenchward upward movements were reported the offshore sites above the main rupture zone in the northern part of the source region exhibit landward displacements of tens of centimeters with significant subsidence from almost 3 years of repeated observations at the sites above around the edge of the main rupture zone smaller amount of trench normal movements was found although the terrestrial movements were reasonably interpreted by afterslip beneath the coastal area these offshore results are rather consistent with effects predicted from viscoelastic relaxation in the upper mantle providing definitive evidence of its occurrence on the other hand the results in the southern part of the source region imply superposition of effects from viscoelastic relaxation and afterslip

interplate locking condition derived from seafloor geodetic data at the northernmost part of the suruga trough japan we observed seafloor crustal deformation at two observation sites on opposite sides of the suruga trough off japan from 2005 to 2011 to investigate the interplate locking condition at the source region of the anticipated great subduction earthquake named tokai earthquake we estimated the displacement velocity vectors relative to the amurian plate on the basis of repeated observations our results at the two points suruga northeast and suruga northwest snw were 42 8 mm yr toward n94 3 w and 39 11 mm yr toward n84 9 w respectively these directions are the same as those measured at on land gps stations the magnitudes of the velocity vectors indicate a significant shortening of approximately 4 mm yr between snw and on land gps stations located to the west of the suruga trough the results show that the plate interface is strongly locked no slip shallower than the source region of the anticipated tokai earthquake

relationship between petroleum composition and depositional environment of petroleum source rocks crude oils of nonmarine source can be distinguished from those of marine shale source and from oils originating in marine carbonate sequences by using a battery of geochemical parameters as demonstrated with a sample suite of nearly 40 oils a novel parameter based on the presence of c30 steranes in the oil was found to be a definitive indication of a contribution to the source from marine derived organic matter a second novel parameter based on monoaromatized steroid distributions was effective in helping to distinguish nonmarine from marine crudes and can be used to gauge relative amounts of higher plant input to oils within a given basin sterane distributions were similarly useful for detecting higher plant input but were less effective than monoaromatize steroid distributions for making marine versus nonmarine distinctions concentrations of high molecular weight paraffin can also be effective nonmarine indicators but are influenced by maturation and biodegradation processes certain algal derived nonmarine oils may show little high molecular weight paraffin response oils from carbonate sources with a few exceptions can be distinguished by having low pristane phytane ratios low carbon preference indexes and high sulfur contents gammacerane indexes and carbon isotope ratios of the whole crude are not effective in distinguishing these types of environmental differences on a global basis

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

the diavik waste rock project measurement of the thermal regime of a waste rock test pile in a permafrost environment abstract the interior thermal regime of a field scale experimental waste rock pile in the northwest territories canada was studied test pile construction was completed in the summer 2006 and temperature data was collected continuously since that time to february 2009 the temperature data indicates the test pile cooled over the study period with an average heat energy release of 2 5 104 and 2 6 104 mj in 2007 and 2008 respectively the mean annual air temperature maat at the site was 8 9 c during the period between 2006 and 2009 with a permafrost table at a depth of 4 m in bedrock away from the pile because of this cold environment the upward movement rate of the 0 c isotherm into the test pile at its base was approximately 1 5 m a 1 during 2007 and 2008 thermistor strings installed immediately below the base of the test pile showed the test pile basal temperatures remained near and below 0 c during the study period furthermore due to low rates of sulfide mineral oxidation elevated temperatures in the interior of the test pile were not observed the average air velocity in the pore space in july 2007 and 2008 was about one third of that during january of each year based on temperature distributions therefore due to higher air velocity during the winter it is expected that heat transfer is greater during winter

thermal maturity source rock potential and kinetics of hydrocarbon generation in permian shales from the damodar valley basin eastern india abstract this study investigates the source rock characteristics of permian shales from the jharia sub basin of damodar valley in eastern india borehole shales from the raniganj barren measure and barakar formations were subjected to bulk and quantitative pyrolysis carbon isotope measurements mineral identification and organic petrography the results obtained were used to predict the abundance source and maturity of kerogen along with kinetic parameters for its thermal breakdown into simpler hydrocarbons the shales are characterized by a high toc 3 4 mature to post mature heterogeneous type ii iii kerogen raniganj and barren measure shales are in mature late oil generation stage rr raniganj 0 99 1 22 rr barren measure 1 1 1 41 vitrinite is the dominant maceral in these shales barakar shows a post mature kerogen in gas generation stage rr barakar 1 11 2 0 and consist mainly of inertinite and vitrinite the 13corg value of kerogen concentrate from barren measure shale indicates a lacustrine marine origin 24 6 30 84 vs vpdb and that of raniganj and barakar 22 72 25 03 vs vpdb show the organic provenance to be continental the 13c ratio of thermo labile hydrocarbons c1 c3 in barren measure suggests a thermogenic source discrete bulk kinetic parameters indicate that raniganj has lower activation energies e 42 62 kcal mol compared to barren measure and barakar e 44 68 kcal mol temperature for onset 10 middle 50 and end 90 of kerogen transformation is least for raniganj followed by barren measure and barakar mineral content is dominated by quartz 42 63 siderite 9 15 and clay 14 29 permian shales in particular the barren measure as inferred from the results of our study demonstrate excellent properties of a potential shale gas system

first measurement of the displacement rate of the pacific plate near the japan trench after the 2011 tohoku oki earthquake using gps acoustic technique the subduction rate of an oceanic plate may accelerate after large earthquakes rupture the interplate coupling between the oceanic and overriding continental plates to better understand postseismic deformation processes in an incoming oceanic plate we directly measured the displacement rate of the pacific plate near the japan trench after the 2011 tohoku oki earthquake using a gps acoustic technique over a period of 2 years september 2012 to september 2014 the displacement rate was measured to be 18 0 4 5 cm yr 1 n302 0 e relative to the north american plate which is almost twice as fast as the predicted interseismic plate motion because the sum of steady plate motion and viscoelastic response to the tohoku oki earthquake roughly accounts for the observed displacement rate we conclude that viscoelastic relaxation is the primary mechanism responsible for postseismic deformation of the pacific plate and that significant subduction acceleration did not occur at least not during the observation period

comparison of michigan basin crude oils abstract michigan basin oils from the ordovician trenton silurian niagaran and devonian dundee formations have been geochemically compared by gc gc ms and carbon isotope mass spectrometry one oil from each formation was selected for detailed analysis which included measurement of individual n alkane 13 c values the ordovician and devonian oils are strikingly similar to one another yet clearly different from the silurian oil this pattern is unexpected because ordovician and devonian reservoirs are physically separated by the silurian strata from time temperature considerations the devonian oil probably was formed in older strata and has migrated to its present location our analyses suggest a common source for the devonian and ordovician oils

petrographic and geochemical characterization of organic rich mississippian black shales in the north of spain vegamian formation cantabrian zone abstract black shales 1 60 m thick with minor cherts radiolarites and phosphate nodules of mississippian age middle upper tournaisian vegamian formation occur in the fold and thrust belt of the cantabrian zone n spain at the base of the carboniferous succession which is infilling the variscan foreland basin the vegamian formation was accumulated in a similar sedimentary and paleogeographic context to the upper devonian carboniferous black shales of the appalachian arkoma fort worth western canada and antler foreland basins north america and to the variscan foreland basin in belgium and germany five stratigraphic sections were investigated in the southern branch of the cantabrian zone corresponding to the shallower sectors of the passive margin of the variscan foreland basin in n spain where this stratigraphic unit reaches a thickness of generally the organic matter is dominated by bitumen found either as diffuse masses or concentrated in spaces and cavities often parallel to the bedding planes or filling voids within calcite veins and fractures generally the bitumen masses are homogeneous without secondary porosity but occasionally they show mosaic optical texture indicating thermal transformation anastomosing structures likely related to bituminite are also common and exhibit a large range of reflectances autochthonous organic matter algae bacteria is seen as scarce tasmanites and liptodetrinite whereas allochthonous components vitrinite inertinite are also scarce except in the olleros section the range of reflectances of vitrinite like particles is similar to that of bitumen but the identification is uncertain and therefore the reflectance of bitumen brr has been used for thermal maturity assessment a gaussian like distribution of bitumen reflectances was found for la brana section brr 0 70 whereas a bimodal distribution was observed in olleros brr 0 70 and vegamian sections brr 0 95 and large scatter of readings in millaro brr 1 55 the vitrinite reflectance equivalent estimated from aromatic compounds indicates that most of the existing correlations between vitrinite and bitumen reflectances underestimate the maturity of the lowest reflecting sections and overestimate it in the highest reflecting one ts toc ratios the geochemistry of organic matter and spectral gamma ray measurements suggest a normal marine to dysoxic environment of deposition with only local anoxia at the base of the vegamian formation

the diavik waste rock project design construction and instrumentation of field scale experimental waste rock piles the physicochemical processes that affect acid mine drainage amd in unsaturated waste rock piles and the capabilities of small scale laboratory experiments to predict amd from waste rock are not well understood an integrated laboratory and field study to measure and compare low sulfide waste rock and drainage characteristics at various scales has been initiated this paper describes the design construction and instrumentation of three field scale experimental waste rock piles test piles and six active zone lysimeters at the diavik diamond mine in the northwest territories canada the test piles are comprised of granitic and sulfide bearing metasedimentary waste rock excavated during open pit mining operations one test pile contains waste rock with a target s content of 0 08 wt s and the third test pile contains the higher sulfide waste rock 0 08 wt s and was re sloped and capped with a low permeability till layer and a low sulfide waste rock cover the first two test piles are approximately 15 m high with bases of 50 m by 60 m and the re sloped test pile has a larger base of 80 m by 125 m instrumentation was selected to measure matrix flow geochemistry of pore water and drainage gas phase o2 concentration temperature evolution microbiological populations waste rock permeability to air and thermal conductivity as well as to resolve mass and flow balances instrument locations were selected to characterize coupled physicochemical processes at multiple scales and the evolution of those processes over time instruments were installed at a density such that the number of instruments that survived construction 40 to 80 by instrument type was sufficient to allow adequate characterization of the physicochemical processes occurring at various scales in the test piles

petrographic maturity parameters of a devonian shale maturation series appalachian basin usa iccp thermal indices working group interlaboratory exercise abstract this paper presents results of an interlaboratory exercise on organic matter optical maturity parameters using a natural maturation series comprised by three devonian shale samples huron member ohio shale from the appalachian basin usa this work was conducted by the thermal indices working group of the international committee for coal and organic petrology iccp commission ii geological applications of organic petrology this study aimed to compare 1 maturation predicted by different types of petrographic parameters vitrinite reflectance and spectral fluorescence of telalginite 2 reproducibility of the results for these maturation parameters obtained by different laboratories and 3 improvements in the spectral fluorescence measurement obtained using modern detection systems in comparison with the results from historical round robin exercises mean random vitrinite reflectance measurements presented the highest level of reproducibility group standard deviation 0 05 for low maturity and reproducibility diminished with increasing maturation group standard deviation 0 12 corrected fluorescence spectra provided by 14 participants showed a fair to good correspondence standard deviation of the mean values for spectral parameters was lowest for the low maturity sample but was also fairly low for higher maturity samples a significant improvement in the reproducibility of corrected spectral fluorescence curves was obtained in the current exercise compared to a previous investigation of toarcian organic matter spectra in a maturation series from the paris basin this improvement is demonstrated by lower values of standard deviation and is interpreted to reflect better performance of newer photo optical measuring systems fluorescence parameters measured here are in good agreement with vitrinite reflectance values for the least mature shale but indicate higher maturity than shown by vitrinite reflectance for the two more mature shales this red shift in max beyond 0 65 vitrinite reflectance was also observed in studies of devonian shale in other basins suggesting that the accepted correlation for these two petrographic thermal maturity parameters needs to be re evaluated a good linear correlation between max and tmax for this maturation series was observed and max 600 nm corresponds to tmax of 440 c nevertheless if a larger set of devonian samples is included the correlation is polynomial with a jump in max ranging from 540 to 570 nm up to 440 c of tmax the max mostly reaches up to 500 nm beyond a tmax of 440 c max is in the range of 580 600 nm this relationship places the red shift when the onset of the oil window is reached at tmax of 440 c moreover the correlation between hi and max r2 0 70 shows a striking inflection and decrease in hi above a max of 600 nm coincident with the approximate onset of hydrocarbon generation in these rocks

the diavik waste rock project persistence of contaminants from blasting agents in waste rock effluent abstract during mining operations explosives are used to fragment rock into workable size fractions mine water chemistry can be affected by blasting agent residuals including nh3 no 2 no 3 cl and clo 4 at the diavik diamond mine northwest territories canada waste rock generated from open pit and underground mining is stockpiled on site three large scale test piles measuring 60 by 50 m at the base and 15 m in height along with four 2 2 m lysimeters each 2 m in height were constructed at diavik as part of a comprehensive research program to evaluate the quality of water emanating from waste rock stockpiles ongoing monitoring of the water chemistry since 2007 shows that blasting residuals comprise a large proportion of the dissolved constituents in the initial pore water and effluent leach tests conducted on freshly blasted rock from diavik indicate the mass of n released corresponds to a 5 4 n loss from the blasting explosives this mass is in the range for n loss reported for blasting operations at diavik during the period when the test piles were constructed the total mass of n released from the lysimeters was also within this range the three large scale test piles have only released a small fraction of the n estimated to be contained within them blasting of waste rock contributes so 4 2 to effluent through the oxidation of sulfide minerals in the rock during the blast during the initial flush of water the test pile that contained waste rock with the higher s content was observed to release higher concentrations of so 4 2 than the test pile with lower s content waste rock mass balance calculations based on the ratios of so 4 2 to total n can be used to estimate the relative contributions of sulfide oxidation within the test piles and so 4 2 released when s in the host rock is oxidized during blasting these calculations provide an estimate of s mass released during the first flush of the test piles

environmental influences on the stable carbon isotopic composition of devonian and early carboniferous land plants abstract systematic analysis of the stable carbon isotopic composition of fossil land plants 13cp has the potential to offer new insights regarding paleoclimate variation and plant environment interactions in early terrestrial ecosystems 13cp was measured for 190 fossil plant specimens belonging to 10 genera of early to late devonian age archaeopteris drepanophycus haskinsia leclercqia pertica psilophyton rhacophyton sawdonia tetraxylopteris and wattieza and 2 genera of early carboniferous age genselia and rhodeopteridium collected from sites located mainly in the appalachian basin 22 30 s paleolatitude for the full carbon isotopic dataset n 309 13cp ranges from 20 3 to 30 5 with a mean of 25 5 similar to values for modern c3 land plants in addition to a secular trend 13cp exhibits both intra and intergeneric variation intrageneric variation is expressed as a small mean 0 45 13c enrichment of leaves and spines relative to stems that may reflect differential compound specific compositions intergeneric variation is expressed as a much larger to 5 spread in the mean 13cp values of coeval plant genera that was probably controlled by taxon specific habitat preferences and local environmental humidity among early devonian taxa sawdonia yielded the most 13c depleted values 27 1 1 7 reflecting lower water use efficiency that was probably related to growth in wetter habitats and leclercqia haskinsia and psilophyton yielded the most 13c enriched values 23 0 1 6 22 3 1 3 and 24 8 1 6 respectively reflecting higher water use efficiency probably related to growth in drier habitats

the diavik waste rock project implications of wind induced gas transport abstract wind induced gas transport in a test scale unsaturated waste rock pile was investigated at the diavik diamond mine northwest territories canada differential gas pressures were measured in 2008 at 49 locations within a field scale experimental waste rock pile test pile and at 14 locations on the surface of the test pile at 1 min intervals wind speed and direction were measured at 10 min intervals and decomposed into north south east and west vectors correlations between wind vectors and pressure measurements indicate that the wind influences pressure fluctuations in the test pile the strength of the correlation is roughly inversely proportional to the distance between the measurement ports and the atmospheric boundary the relationship between the magnitude of the wind vector and pressure fluctuations on the surface of the test pile is non linear however the relationship between internal and surface pressure measurements is linear suggesting that gas flow within the test pile follows darcy s law spectral analysis demonstrates that the dominant periods of the wind range from 1 to 14 d a 1 d analytical solution to the flow equation is used to demonstrate that long periods have the most pronounced effect on transient gas flow within the test pile and that the penetration depth of the wind induced gas pressure wave is a function of wind period and permeability of the test pile

evolution of porosity and geochemistry in marcellus formation black shale during weathering abstract soils developed on the oatka creek member of the marcellus formation in huntingdon pennsylvania were analyzed to understand the evolution of black shale matrix porosity and the associated changes in elemental and mineralogical composition during infiltration of water into organic rich shale making the reasonable assumption that soil erosion rates are the same as those measured in a nearby location on a less organic rich shale we suggest that soil production rates have on average been faster for this black shale compared to the gray shale in similar climate settings this difference is attributed to differences in composition both shales are dominantly quartz illite and chlorite but the oatka creek member at this location has more organic matter 1 25 wt organic carbon in rock fragments recovered from the bottom of the auger cores and nearby outcrops and accessory pyrite during weathering the extremely low porosity bedrock slowly disaggregates into shale chips with intergranular pores and fractures some of these pores are either filled with organic matter or air filled but remain unconnected and thus inaccessible to water based on weathering bedrock soil profiles disintegration is initiated with oxidation of pyrite and organic matter which increases the overall porosity and most importantly allows water penetration water infiltration exposes fresh surface area and thus promotes dissolution of plagioclase and clays as these dissolution reactions proceed the porosity in the deepest shale chips recovered from the soil decrease from 9 to 7 while kaolinite and fe oxyhydroxides precipitate eventually near the land surface mineral precipitation is outcompeted by dissolution or particle loss of illite and chlorite and porosity in shale chips increases to 20 as imaged by computed tomographic analysis weathering causes i greater porosity ii greater average length of connected pores and iii a more branched pore network compared to the unweathered sample this work highlights the impact of shale water o 2 interactions in near surface environments 1 black shale weathering is important for global carbon cycles as previously buried organic matter is quickly oxidized and 2 black shales weather more quickly than less organic and sulfide rich shales leading to high porosity and mineral surface areas exposed for clay weathering the fast rates of shale gas exploitation that are ongoing in pennsylvania texas and other regions in the united states may furthermore lead to release of metals to the environment if reactions between water and black shale are accelerated by gas development activities in the subsurface just as they are by low temperature processes in our field study

release transport and attenuation of metals from an old tailings impoundment abstract the oxidation of sulfide minerals from mine wastes results in the release of oxidation products to groundwater and surface water the abandoned high sulfide camp tailings impoundment at sherridon manitoba wherein the tailings have undergone oxidation for more than 70 a was investigated by hydrogeological geochemical and mineralogical techniques mineralogical analysis indicates that the unoxidized tailings contain nearly equal proportions of pyrite and pyrrhotite which make up to 60 wt of the total tailings and which are accompanied by minor amounts of chalcopyrite and sphalerite and minute amounts of galena and arsenopyrite extensive oxidation in the upper 50 cm of the tailings has resulted in extremely high concentrations of dissolved so4 and metals and as in the tailings pore water ph 1 m thick geochemical modeling and mineralogical analysis indicate that the hardpan layer consists of secondary melanterite rozenite gypsum jarosite and goethite the minerals indicated mainly control the dissolved concentrations of so4 fe ca and k the highest concentrations of dissolved metals are observed directly above and within the massive hardpan layer near the water table at a depth of 4 m most metals and so4 sharply decline in concentration although dissolved concentrations of metals and so4 decrease below the water table these concentrations remain elevated throughout the tailings with up to 60 600 mg l 1 fe and 91 600 mg l 1 so4 observed in the deeper groundwater during precipitation events surface seeps develop along the flanks of the impoundment and discharge pore water with a geochemical composition that is similar to the composition of water directly above the hardpan these results suggest that shallow lateral flow of water from a transient perched water table is resulting in higher contaminant loadings than would be predicted if it were assumed that discharge is derived solely from the deeper primary water table the abundance of residual sulfide minerals the depletion of aluminosilicate minerals in the upper meter of the tailings and the presence of a significant mass of residual sulfide minerals in this zone after 70 a of oxidation suggest that sulfide oxidation will continue to release acid metals and so4 to the environment for decades to centuries

chitinozoan reflectance a lower palaeozoic thermal maturity indicator abstract chitinozoan reflectance r ch is an innovative technique of thermal maturation determination suitable for lower palaeozoic sediments where the established reflectance scale vitrinite reflectance r v is not applicable due to the lack of vitrinite reflectance measurements are taken from polished sections of chitinozoa a group of lower palaeozoic organic walled marine microfossils these vase shaped palynomorphs are optically isotropic have thick homogeneous test walls and are easy to identify making then ideal for organic petrology from over 1000 samples collected 54 possessed both chitinozoa and vitrinite enabling direct calibration of the two scales a clear linear relationship exists between the two parameters the equation resulting from this study is r ch 1 152 r v 0 08 with a correlation coefficient of 0 989 there is a suggestion of a maturity discontinuity between 1 and 2 r ch but due to the high sample redundancy rate only 5 of samples possessed both vitrinite and chitinozoa it was not possible to supply more data at this maturity level chitinozoan reflectance is a powerful thermal maturity indicator for lower palaeozoic sediments the technique has significant advantages over its maln rivals particularly the ease of particle identification and the fact that it is independent of facies thus quantitative maturity data with a high spatial and temporal resolution can be gained from pre devonian marine sedimentary sequences

the mineral and aqueous phase evolution of sulfur and nickel with weathering of pyrrhotite in a low sulfide granitic waste rock abstract the release of s and metals from the weathering of waste rock pyrrhotite fe 1 x s is affected by oxidation pathways the presence and concentration of fe substitution metals e g ni and fe oxyhydr oxide products a 4c monoclinic pyrrhotite fe7s8 ni fe substitution of about 1 200 in a low sulfide waste rock was weathered in the laboratory and at a field site to identify the evolution of s oxidation distribution and coordination of ni and possible adsorption of ni on secondary fe minerals mineral phase s was present in the 2 1 0 4 and 6 oxidation states prior to its release as so42 into solution the thiosulfate s2o32 pathway of sulfide oxidation was indicated by the presence of polythionates and s2o32 sulfur as s2o32 was more persistent than sulfite so32 prior to oxidation to so42 the release of ni during the oxidative dissolution of pyrrhotite was influenced by its distribution in the grain diffuse throughout the grain solid solution mineral or concentrated in exsolved pentlandite fe ni 9s8 lamellae within the pyrrhotite with the oxidation of s ni coordination changed from bonding with reduced s species to bonding with oxygen prior to its release with so42 sulfur as so42 typically stayed in solution with release from the pyrrhotite but the solubility of released ni was dependent on leachate ph a near neutral ph induced the adsorption of ni onto fe oxyhydr oxides which formed during oxidation of the pyrrhotite in some grains ni was found concentrated in fe distal precipitates as opposed to the closer alteration layers zones of the sulfide grain subsequent dissolution of the fe oxyhydr oxides or desorption of ni with a change in ph provides a delayed release of ni into solution this improved understanding of the oxidation pathway of s coordination and release of ni and influence of fe oxyhydr oxides in the weathering of pyrrhotite will assist in determining appropriate reaction rate factors and element release rates for prediction of acid rock drainage

influence of freeze thaw dynamics on internal geochemical evolution of low sulfide waste rock abstract continuous monitoring of a 15 m high heavily instrumented experimental waste rock pile 0 053 wt s since 2006 at the diavik diamond mine in northern canada provided a unique opportunity to study the evolution of fresh run of mine waste rock as it evolved over annual freeze thaw cycles samples were collected from soil water solution samplers to measure pore water properties from twelve 4 to 16 m 2 basal collection lysimeters to measure basal leachate properties in the region underlying the crest of the pile the core and from basal drains to measure aggregate total pile leachate properties by 2012 monitoring of pore water geochemistry within the core structure of the test pile revealed an apparent steady state with respect to weathering geochemistry represented by i a flush of pre existing blasting residuals and applied tracers ii declining ph iii a stepwise progression and subsequent equilibrium with acid neutralizing phases depletion of available carbonates equilibrium with respect to aluminum hydroxide phases and subsequent iron iii hydroxide phases and iv concordant release of so 4 major cations ca mg k na si and trace metals al fe ni co cu zn distinct high concentration spring flushes characteristic of drainage in northern environments and primarily explained by a combination of fluid residence time and the build up of oxidation products over the winter were released from core drainage each season following the initial flush the concentration of all dissolved constituents steadily declined with distinct minimums prior to freeze up the opposite trend was observed in the cumulative pile drainage in which early season leachate dominated by snowmelt and batter flow had low concentrations and late season leachate dominated by contributions from the core of the pile indicated by season end merging of core and cumulative drainage geochemistry had higher concentrations northern waste rock pile drainage geochemistry is strongly influenced by freeze thaw cycling and varying core and batter subsystem contributions to total drainage a comprehensive understanding of thermal cycling in waste rock piles is an important component of temporal predictions of drainage water composition based on up scaling or reactive transport modeling

a reactive transport model for marcellus shale weathering abstract shale formations account for 25 of the land surface globally and contribute a large proportion of the natural gas used in the united states one of the most productive shale gas formations is the marcellus a black shale that is rich in organic matter and pyrite as a first step toward understanding how marcellus shale interacts with water in the surface or deep subsurface we developed a reactive transport model to simulate shale weathering under ambient temperature and pressure conditions constrained by soil and water chemistry data the simulation was carried out for 10 000 years since deglaciation assuming bedrock weathering and soil genesis began after the last glacial maximum results indicate weathering was initiated by pyrite dissolution for the first 1000 years leading to low ph and enhanced dissolution of chlorite and precipitation of iron hydroxides after pyrite depletion chlorite dissolved slowly primarily facilitated by the presence of co2 and organic acids forming vermiculite as a secondary mineral a sensitivity analysis indicated that the most important controls on weathering include the presence of reactive gases co2 and o2 specific surface area and flow velocity of infiltrating meteoric water the soil chemistry and mineralogy data could not be reproduced without including the reactive gases for example pyrite remained in the soil even after 10 000 years if o2 was not continuously present in the soil column likewise chlorite remained abundant and porosity remained small if co2 was not present in the soil gas the field observations were only simulated successfully when the modeled specific surface areas of the reactive minerals were 1 3 orders of magnitude smaller than surface area values measured for powdered minerals small surface areas could be consistent with the lack of accessibility of some fluids to mineral surfaces due to surface coatings in addition some mineral surface is likely interacting only with equilibrated pore fluids an increase in the water infiltration rate enhanced weathering by removing dissolution products and maintaining far from equilibrium conditions we conclude from these observations that availability of reactive surface area and transport of h2o and gases are the most important factors affecting rates of marcellus shale weathering of the in the shallow subsurface this weathering study documents the utility of reactive transport modeling for complex subsurface processes such modelling could be extended to understand interactions between injected fluids and marcellus shale gas reservoirs at higher temperature pressure and salinity conditions

inverse correlation between the molybdenum and uranium isotope compositions of upper devonian black shales caused by changes in local depositional conditions rather than global ocean redox variations abstract coupled mo u isotope data from the upper devonian kettle point formation ontario canada provide a cautionary tale regarding interpretation of global ocean redox conditions using data from euxinic black shales in the gore of chatham core the kettle point black shales have high mo concentrations 48 473 g g and consistently high mo u ratios 3 times the mo u ratio of modern seawater suggesting a euxinic depositional environment these shales yield an inverse correlation r 0 89 p

the diavik waste rock project initial geochemical response from a low sulfide waste rock pile abstract three large scale experimental waste rock piles test piles were constructed and instrumented at the diavik diamond mine in the northwest territories canada as part of an integrated field and laboratory study to measure and compare physical and geochemical characteristics of experimental low sulfide waste rock piles at various scales this paper describes the geochemical response during the first season from a test pile containing 0 053 wt s bulk drainage chemistry was measured at two sampling points for ph eh alkalinity dissolved cations and anions and nutrients the geochemical equilibrium model minteqa2 was used to interpret potential mineral solubility controls on water chemistry the geochemical response characterizes the initial flushing response of blasting residues and oxidation products derived from sulfides in waste rock exposed to the atmosphere for less than 1 year sulfate concentrations reached 2000 mg l 1 when ambient temperatures were 10 c and decreased as ambient temperatures declined to 1 as total caco 3 suggesting all available alkalinity is consumed by acid neutralizing reactions concentrations of al and fe were 1 respectively trends of ph and alkalinity and the calculated saturation indices for al and fe oxy hydroxides suggest that dissolution of al and fe oxy hydroxide phases buffers the ph the effluent water showed increased concentrations of dissolved mn 1 ni 1 co 1 zn 1 cd 1 and cu 1 as ambient temperatures increased manganese is released by aluminosilicate weathering ni and co by pyrrhotite fe 1 x s oxidation zn and cd by sphalerite oxidation and cu by chalcopyrite cufes 2 oxidation no dissolved metals appear to have discrete secondary mineral controls changes in so 4 ph and metal concentrations indicate sulfide oxidation is occurring and effluent concentrations are influenced by ambient temperatures and possibly increasing flow path lengths that transport reaction products from previously unflushed waste rock

hydrocarbon biomarkers thermal maturity and depositional setting of tasmanite oil shales from tasmania australia this study represents the first geological and organic geochemical investigation of samples of tasmanite oil shale representing different thermal maturities from three separate locations in tasmania australia the most abundant aliphatic hydrocarbon in the immature oil shale from latrobe is a c19 tricyclic alkane whereas in the more mature samples from oonah and douglas river low molecular weight n alkanes dominate the extractable hydrocarbon distribution the aromatic hydrocarbons are predominantly derivatives of tricyclic compounds with 1 2 8 trimethylphenanthrene increasing in relative abundance with increasing maturity geological and geochemical evidence suggests that the sediments were deposited in a marine environment of high latitude with associated cold waters and seasonal seaice it is proposed that the organism contributing the bulk of the kerogen tasmanites occupied an environmental niche similar to that of modern sea ice diatoms and that bloom conditions coupled with physical isolation from atmospheric co2 led to the distinctive isotopically heavy 13c values 13 5 to 11 7 for the kerogen 13c data from modern sea ice diatoms 7 supports this hypothesis isotopic analysis of n alkanes in the bitumen 13 5 to 31 suggest a multiple source from bacteria and algae on the other hand the n alkanes generated from closed system pyrolysis of the kerogen 15 are mainly derived from the preserved tasmanites biopolymer algaenan the tricyclic compounds mean 8 both in the bitumen and pyrolysate have a common precursor they are consistently enriched in 13c compared with the kerogen and probably have a different source from the n alkanes the identification of a location where the maturity of the tasmanite oil shale approaches the oil window raises the possibility that it may be a viable petroleum source rock

observation of coseismic seafloor crustal deformation due to m7 class offshore earthquakes 1 we have developed an observation system for seafloor crustal deformation measurement combining the two following techniques the precise acoustic ranging and kinematic gps global positioning system positioning on july 14 2003 we installed the units for this observation system at the seafloor of the kumano basin japan 33 58 n 136 60 e we performed repeated observation six times on 1 july 15 16 and 21 2004 2 november 9 10 2004 3 may 18 and 20 2005 4 july 19 20 2005 5 august 18 19 2005 and 6 august 29 30 2005 the present observation system can stably determine the seafloor position with an rms repeatability of 3 cm in both horizontal components two m7 class offshore intraplate earthquakes occurred only 60 km from the kumano basin site on september 5 2004 we observed the coseismic horizontal displacement of 18 cm at the kumano basin site using the presently developed seafloor observation system our observation system can provide seafloor crustal deformation associated with crustal activities in offshore areas

the zinc stable isotope signature of waste rock drainage in the canadian permafrost region leachate from a well instrumented experimental scale waste rock pile test pile at the diavik diamond mine northwest territories was monitored the well characterized waste rock consists of granite pegmatitic granite and biotite schist with an average total sulfur and carbonate carbon concentration of 0 053 and 0 027 wt respectively the leachate emerging from the southern basal drain of the waste rock pile has been monitored since 2007 the zinc stable isotope footprint was characterized alongside standard monitoring parameters during two field seasons may to november 2011 and 2012 the ph ranged between 4 3 and 6 8 and carbonate alkalinity was low or undetectable 35 mg l 1 caco3 the ph was governed by the oxidation of sulfide minerals and the dissolution of primary carbonate minerals and secondary al and fe oxyhydroxysulfates and hydroxides dissolved al and fe concentrations averaged 6 78 mg l 1 and 175 g l 1 respectively the main processes controlling zn concentrations in the range of 0 4 and 4 7 mg l 1 average 2 2 mg l 1 were the oxidative dissolution of sphalerite zns and the attenuation by secondary fe and al hydroxides zinc isotopes were fractionated mass dependently zinc isotope ratios ranging between 0 16 and 0 18 average 0 05 n 43 were consistent with values reported for sphalerite from other deposits the deviations in isotope ratios 0 36 were significant in comparison to analytical uncertainties 0 06 zinc isotope ratios and concentrations were largely uncorrelated suggesting that the processes affecting zn mobility had little or no impact on the zn isotope signature these data suggest that the zn isotope ratios of the waste rock leachate may be used as a fingerprint to track anthropogenic mine derived zn sources in an environment under fluctuating ph temperature and ionic strength

bakken madison petroleum systems in the canadian williston basin part 1 c21 c26 20 n alkylpregnanes and their triaromatic analogs as indicators for upper devonian mississippian epicontinental black shale derived oils abstract a series of 20 n alkylpregnanes and their triaromatic analogs have been tentatively identified in crude oils and source rock extracts from the western canada sedimentary basin when found in oils in this basin these compounds may serve as molecular indicators for source input from the uppermost devonian mississippian epicontinental black shales crown copyright

application of organic petrography in north american shale petroleum systems a review abstract organic petrography via incident light microscopy has broad application to shale petroleum systems including delineation of thermal maturity windows and determination of organo facies incident light microscopy allows practitioners the ability to identify various types of organic components and demonstrates that solid bitumen is the dominant organic matter occurring in shale plays of peak oil and gas window thermal maturity whereas oil prone type i ii kerogens have converted to hydrocarbons and are not present high magnification sem observation of an interconnected organic porosity occurring in the solid bitumen of thermally mature shale reservoirs has enabled major advances in our understanding of hydrocarbon migration and storage in shale but suffers from inability to confirm the type of organic matter present herein we review organic petrography applications in the north american shale plays through discussion of incident light photographic examples in the first part of the manuscript we provide basic practical information on the measurement of organic reflectance and outline fluorescence microscopy and other petrographic approaches to the determination of thermal maturity in the second half of the paper we discuss applications of organic petrography and sem in all of the major shale petroleum systems in north america including tight oil plays such as the bakken eagle ford and niobrara and shale gas and condensate plays including the barnett duvernay haynesville bossier marcellus utica and woodford among others our review suggests systematic research employing correlative high resolution imaging techniques and in situ geochemical probing is needed to better document hydrocarbon storage migration and wettability properties of solid bitumen at the pressure and temperature conditions of shale reservoirs

organic geochemistry and oil source correlations paleozoic of ohio routine analytical methods and new kerogen kerogen pyrolyzate techniques used for detailed petroleum geochemical studies permit the correlation of oils to their respective source rocks in ohio in the paleozoic section four good to excellent source units were identified the mississippian sunbury shale the devonian ohio shale and olentangy shale and the shales of the ordovician point pleasant formation these marine shales are dominantly oil prone with maturation levels that span the immature to peak oil generation range no source rocks examined exceeded an ro of 1 0 1 1 or equivalent the reservoired oils in ohio are mostly supermature based on normal alkanes pristane n c17 to phytane n c18 ratios low asphaltene and sulfur contents and high paraffin indices three basic oil groups were identified using oil characterization procedures group 1 consists of cambrian ordovician and some silurian oils group 2 consists of some silurian devonian one mississippian and some pennsylvanian oils and group 3 consists of oil from the mississippian berea sandstone oil source rock correlation techniques permitted the assignment of probable source rocks to each oil group group 1 oil was probably derived from the point pleasant shales group 2 oil was derived from the ohio shale and olentangy shale and group 3 oil came from the sunbury shale because the supermature oils in ohio occur in reservoirs with maturities generally under 0 8 ro the oils would have had to migrate from deep within the appalachian basin migration could have followed fracture zones unconformities or extensive and permeable units such as the silurian clinton sands

correlation of the subsurface lower and middle devonian of the lake erie region the completion of 6 detailed cross sections using the gamma ray logs of 94 closely spaced wells has provided new correlations and confirmed some earlier correlations of the lower and middle devonian strata of the lake erie region these sections connect western new york northwestern pennsylvania northern central and northwestern ohio southwestern ontario and southeastern michigan the lower devonian bois blanc limestone of western new york is continuous with the type bois blanc of northern michigan via southwestern ontario it has been traced southwestward across northern ohio and southward into the lower part of the type columbus limestone in central ohio the edgecliff clarence nedrow and moorehouse members of the overlying middle devonian onondaga limestone of western new york correlate with the upper columbus limestone of ohio the seneca member of the onondaga is equivalent to the overlying delaware limestone the amherstburg and lucas formations of the detroit river group of michigan and ontario can be traced southward across lake erie into the lower and middle parts of the upper columbus of ohio the amherstburg correlates with the edgecliff clarence nedrow and lower moorehouse members of the new york onondaga the lucas correlates with the middle part of the moorehouse member the dundee limestone of northwestern ohio michigan and ontario is an equivalent of the upper moorehouse and seneca members of the new york onondaga limestone it is not coterminous with the delaware of ohio as the base of the dundee is significantly older than the base of the delaware these correlations have been strengthened by tracing the stratigraphic positions of four different ash beds through the upper part of the carbonate sequence three of these ash beds are parts of the type tioga ash bed in the subsurface of northern pennsylvania a major regional unconformity separates the lower and middle devonian carbonate sequence from the overlying middle devonian terrigenous one the delaware and dundee limestones cannot be correlated with any part of the marcellus formation of the new york hamilton group in western new york the cherry valley limestone member of the marcellus formation rests directly and unconformably upon the onondaga in northwestern pennsylvania and northeastern ohio the union springs shale reappears between the cherry valley and the onondaga beneath central lake erie the union springs cherry valley and oatka creek members of the marcellus merge into the bell shale rockport quarry limestone and arkona shale of ontario the arkona can be traced across lake erie into the plum brook and lower olentangy shales of ohio the lower part of the terrigenous sequence of the lake erie region consequently is marcellus in age not skaneateles the prout ohio and hungry hollow ontario limestones are homotaxial and correlate with the centerfield limestone of new york the rockport quarry arkona and hungry hollow can be traced into the silica shale of southeastern michigan and northwestern ohio the widder shale and ipperwash limestone of ontario merge into the tenmile creek dolomite of michigan and ohio

the diavik waste rock project water flow through mine waste rock in a permafrost terrain abstract a field experiment is being carried out at the diavik diamond mine in northern canada to investigate the influence of unsaturated flow behavior on the quality of drainage from mine waste rock piles in a region of continuous permafrost this paper is part of a series describing processes affecting the weathering of waste rock and transport of reaction products at this site here the focus is on unsaturated water flow and its role in mass loading two 15 m high instrumented test piles have been built on 60 m by 50 m collection systems each consisting of lysimeters and a large impermeable high density polyethylene hdpe liner collection lysimeters are installed nearby to investigate infiltration in the upper 2 m of the waste rock porosity water retention curves and hydraulic conductivity functions are estimated from field measurements and for samples ranging in size from 200 cm3 to 16 m3 net infiltration in 2007 is estimated to have been 37 of the rainfall for mean annual rainfall conditions early season infiltration freezes and is remobilized as the waste rock thaws wetting fronts migrate at rates of 0 2 0 4 m d 1 in response to common rainfall events and up to 5 m d 1 in response to intense rainfall pore water and non reactive solutes travel at rates of

waste rock hydrogeology and geochemistry abstract the oxidation of sulfide minerals in waste rock has the potential to generate low quality drainage that can present a significant challenge to mine owners regulators and other stakeholders challenges involved in managing waste rock include the large volume of waste rock produced and the difficulty in predicting the quality and quantity of leach water due to the chemical and physical heterogeneities in the waste rock and the highly non linear coupling of geochemical and physical processes many important studies have been conducted over the past decade particularly at the field scale that have investigated the geochemical hydrological microbiological and gas and heat transport aspects of waste rock these studies show that although the parameters and processes that influence amd generation and solute release are fundamentally similar between different waste rock piles major differences in the dominant mechanisms of water gas and heat transport result from differences in the physical and mineralogical properties of the rock piles and the climatic conditions including the amount of precipitation and prevailing temperatures accurate prediction of the leach water quality from waste rock requires a detailed characterization of the properties of the rock piles and the coupling of processes specific to the particular conditions this paper provides a review of the physical and mineralogical characteristics of waste rock piles followed by a discussion of the principal processes related to sulfide oxidation and solute loading and concluding with a discussion on acid mine drainage prediction and prevention techniques

chitinozoan reflectance in the lower palaeozoic of the welsh basin vitrinite woody matter and spores are generally uncommon or absent in pre devonian sediments to determine organic maturity in the lower palaeozoic alternative methods such as chitinozoan reflectance must be employed chitinozoa are marine vase shaped organic walled microfossils of unknown affinity the reflectance of incident light from polished chitinozoa walls can provide reliable and accurate maturity data and due to their relative facies independency a high degree of resolution to regional maturity studies calibration of the chitinozoan reflectance scale with vitrinite reflectance enables palaeotemperature estimates to be made from pre devonian sediments the range of chitinozoan reflectance for the welsh basin is from under 1 to 8 this corresponds to estimated palaeotemperatures of under 100 c to over 300 c the regional spatial distribution of organic maturation recorded by chitinozoan reflectance in the welsh basin is attributed to palaeobasin form the increase in reflectance with age in the rocks of the myddfai steep belt and associated areas allows an estimation of a palaeogeothermal gradient in the silurian sequences around llandovery the gradient is calculated to be in the region of 50 c km 1 similar gradients are derived from other studies clay minerals metabasite mineral assemblages conodont colours the results from myddfai steep belt suggest the thermal peak occurred during the acadian event chitinozoan reflectivity demonstrates that with respect to hydrocarbon generation mature conditions occur on the palaeoplatform where the sedimentary sequences are relatively thin overmature conditions are prevalent in the palaeobasin where there is a thick sedimentary pile which has been subsequently deformed

sensitivity of biomarker properties to depositional environment and or source input in the lower toarcian of sw germany abstract a sequence of lower toarcian sediments which are highly contrasting in their depositional environment over a 5 m depth interval has been investigated in detail for the variability of geochemical properties which are used for source characterization and oil to source correlation lower liassic marls are representative of a well aerated shallow water environment in contrast to the immediately overlying bituminous shales which are deposited under extremely reducing conditions various properties have been found to vary considerably within these two units amongst the most important are carbon isotopic composition of the kerogen the pristane phytane ratios nickel as opposed to vanadyl porphyrins and the c27 dia regular steranes although maturation within the profile does not change some of the maturation dependent biomarker properties such as the monoaromatic steroid side chain cracking and the tm ts ratio exhibit large changes which can be assigned to diagenetic processes another maturation dependent property the 20s 20r epimerization of c29 steranes exhibits smaller changes which could also be due to early diagenetic processes the study suggests that reducing and oxidizing conditions i e eh and ph in the sediment exert an influence on several biomarker precursor product pathways in maturation studies initial variations due to depositional conditions have therefore to be taken into account

evidence for mixing of re os isotopes at 2 7 ga and support of a remobilized placer model in witwatersrand sulfides and native au abstract this study analyzes re and os contents of au rich sulfides from the carbon leader tau lekoa and mponeng the vcr mponeng and tau lekoa and the black reef modder east as well as native au in the carbon leader to further investigate the detrital placer modified detrital placer and hydrothermal models for the source of au in mines from the witwatersrand an isochron plot of the results from the four locations yields an imprecise isochron age of 2381 140 ma mswd 17 and initial 187 os 188 os 0 24 0 21 isochron plots for the individual reefs also yielded ages that are younger than the deposition of the basin witwatersrand sediments samples that possess higher concentrations of os 100 ppb and low 187 re 188 os ratios to unify all of the data providing a large variation of chronologic information os mixing diagrams for both gold and sulfide minerals produce realistic mixing trends when solving os initial ratios for 2050 ma the two most probable end members for the mixing relationships are a high os concentration non radiogenic source and a low os concentration highly radiogenic source the high concentration non radiogenic os source has been measured in multiple studies and has been clearly derived from the subcontinental lithospheric mantle sclm the low concentration highly radiogenic source is debatable the measured concentrations of os in the witwatersrand ores are much greater than published os concentrations in other hydrothermal ores the data could indicate a redistribution of the detrital os signatures at 2050 ma thus a modified detrital model best explains the previously published data and this data

offshore postseismic deformation of the 2011 tohoku earthquake revisited application of an improved gps acoustic positioning method considering horizontal gradient of sound speed structure

oil generation in the michigan basin a biological marker and carbon isotope approach abstract palaeozoic strata in the michigan basin produced crude oils which despite their rather small volume and economic value are interesting because of the considerable age of the basin and because of the opportunity to study generation and migration of oils within a relatively simple but ancient geological setting based on n alkane profiles biological marker distributions and carbon isotope ratios the oils belong to three main families of different genetic origin and a few less important mixed types silurian oils from salina and niagara limestones have broad n alkane distributions and abundant isoprenoid hydrocarbons a strong phytane over pristane predominance and the lack of diasteranes indicate a carbonate source for these oils chemical maturity parameters show that they are more mature than the oils from the other main families from which they are also clearly distinguished by carbon isotope ratios of hydrocarbon fractions and single n alkanes oils found in the calcareous ordovician trenton formation contain n alkane cyclohexylalkane and alkyl phenanthrene distributions typical of immature oils many oils from the devonian dundee reservoirs are very similar in overall composition to the trenton oils devonian traverse oils are considered to be mainly from a devonian source with some contribution of ordovician type oil and are of intermediate maturity based on calculations using kinetic parameters of biological marker reactions considerably deeper subsidence of the devonian source rock in the past is implied

organic petrology and organic geochemistry of devonian black shales in southwestern ontario canada abstract the hydrocarbon source rock potential of the devonian marcellus and kettle point black shales in southern ontario has been assessed using rock eval pyrolysis gas chromatography gas chromatography mass spectrometry and incident light microscopy both formations contain sufficient hydrogen rich organic matter type ii to be considered possible source rocks the kerogen is predominantly marine in origin this organic matter was deposited in a clastic algal dominated environment and mainly consists of unstructured bituminite and unicellular alginite the organic microfacies indicate shelf paleodepositional settings with a transition to an open basinal region the optical reflectance fluorescence and geochemical rock eval tmax extract yields distributions of steranes and terpanes maturity data indicate that the organic matter in the kettle point formation is immature whereas in the marcellus formation it has reached the early stages of hydrocarbon generation and expulsion some devonian oils occurring in this area have characteristics similar to the marcellus extracts suggesting that more mature equivalent units from the appalchian basin could be their source

trench normal variation in observed seafloor displacements associated with the 2011 tohoku oki earthquake 1 seafloor geodetic measurements using the gps acoustic technique just above the rupture area of the 2011 tohoku oki earthquake revealed strong trench normal variation in the horizontal crustal displacement associated with the earthquake one set of observations at a site only 50 km away from the trench yielded the most trench ward data ever reported with an accuracy better than 1 m it showed a coseismic displacement of up to 31 m whereas another set of observations 100 km away from the trench showed a 15 m displacement these horizontal data as well as vertical data from pressure gauges and tsunami observations strongly indicate that the seismic slip reached the trench they are also likely to contribute quantitatively to further investigations that reveal the coseismic behavior of the frontal wedge of the overriding plate in the source region along the japan trench

afterslip and viscoelastic relaxation following the 2011 tohoku oki earthquake mw9 0 inferred from inland gps and seafloor gps acoustic data we simultaneously estimate 2 5 years of afterslip and viscoelastic relaxation as well as coseismic slip for the 2011 tohoku oki earthquake displacements at inland gps and seafloor gps acoustic stations are inverted using viscoelastic green s functions for a model with an upper elastic layer and lower viscoelastic substrate the result shows that afterslip is isolated from the rupture area and possibly asperities of historical earthquakes and has almost decayed by 10 september 2013 2 5 years after the main shock the inversion result also suggests that observed landward postseismic displacements at the seafloor gps acoustic stations are caused by the viscoelastic relaxation whereas trenchward displacements at inland stations are mainly an elastic response to afterslip

biomarkers as environmental indicators in a carbonate complex example from the middle to upper devonian holy cross mountains poland abstract autochthonous biomarker distributions were studied in an array of different subfacies of a devonian carbonate complex represented in platform reef and off platform shelf basinal systems it revealed that biomarkers are sensitive indicators of depositional environments and may serve to refine palaeoenvironmental interpretations of carbonate complexes based on classical sedimentological facies analyses the contrasting biomarker composition of the carbonate platform and reef complex versus shelf basin deposits is here interpreted as the effect of both more diverse biotic sources of a primary organic matter in the former environments highly scattered results of sterane distribution and contrasting styles of decay and bacterial reworking of the primary biomass peritidal dolostones deposited under anoxic to suboxic conditions and with scarce sedimentological evidence of elevated salinity reveal the highest potential of organic matter preservation among other platform reefal facies their biomarker composition includes several compounds indicating hypersaline conditions and anoxia whereas others in particular gammacerane indicate that the water column was stratified during sedimentation this observation constrains environmental interpretation of these deposits pointing to shallow subtidal lagoons with elevated salinity and low oxygen near bottom waters most probably originating from a salinity controlled stratification of the water column biomarkers diagnostic of green sulphur bacteria were found in both peritidal lagoonal dolostones and shelf basinal facies this indicates the existence of photic zone anoxia in the latter environment thus suggesting a shallow position of the redoxcline the frasnian famennian mass extinction event s apparently had no impact on the biomarker distribution in the shelf basinal system continuous across the stage boundary

cu isotopes and concentrations during weathering of black shale of the marcellus formation huntingdon county pennsylvania usa abstract the complex weathering processes which govern the production of soil from bedrock have proven difficult to understand for many lithologies weathering of black shale is of particular interest because it releases organic carbon and heavy metals as solutes and therefore impacts the health of terrestrial and aquatic ecosystems to understand black shale weathering a geochemical survey was initiated for soils developed on shales of the marcellus formation at a zero order catchment at a satellite site of the susquehanna shale hills critical zone observatory located in jackson corner pennsylvania this formation is an organic and metal rich carbonaceous shale that underlies much of new york pennsylvania ohio and west virginia in this paper we focus on the effects of weathering on variations of cu isotopes in the shale cu concentration data for soil were normalized using ti concentrations to document the mobility of cu relative to bedrock at both the ridgetop and valley floor depletion profiles for cu are documented in the soils the cu in the soils is depleted in 65 cu average 65 cu 0 5 0 2 compared to the parent material average 65 cu 0 03 0 15 consistent with loss of cu from soils the pore waters contain 10 ppb cu on average and are enriched in the heavy isotope average value 65 cu 1 14 0 44 rayleigh fractionation models using the concentration and isotope data of the soils are consistent with pyrite weathering and loss of cu from the ridgetop but downslope transport and cu re precipitation at the valley floor

the diavik waste rock project geochemical and microbiological characterization of low sulfide content large scale waste rock test piles abstract two experimental waste rock piles test piles each 15 m in height 60 m 50 m were constructed at the diavik diamond mine in northern canada to study the behavior of low sulfide content waste rock with a similarly low acid neutralization potential in a continuous permafrost region one test pile with an average of 0 035 wt s 4 2 and dissolved metals with a decrease in ph to 1 ni 2 3 mg l 1 cu 3 7 mg l 1 zn 35 g l 1 cd and 3 8 mg l 1 co corresponded to decreases in flow rate which were observed at the end of each field season when the contribution of the total outflow from the central portion of the test pile was greatest bacteria were present each year in spite of annual freeze thaw cycles the microbial community within the type i test pile included a population of neutrophilic s oxidizing bacteria each year changes in the water quality of the type iii test pile effluent were accompanied by changes in the microbial populations populations of acidophilic s oxidizing bacteria and fe oxidizing bacteria became more abundant as the ph decreased and internal test pile temperatures increased irrespective of the cold climate conditions and low s content of the waste rock the geochemical and microbiological results of this study are consistent with other acid mine drainage studies indicating that a series of mineral dissolution precipitation reactions controls ph and metal mobility and transport is controlled by matrix dominated flow and internal temperatures

paleozoic paleogeography of north america gondwana and intervening displaced terranes comparisons of paleomagnetism with paleoclimatology and biogeographical patterns new paleomagnetic data have become available in the past 5 yr that require modifications in previously published paleogeographic reconstructions for the silurian and devonian in this paper the new paleopoles are compared to published paleogeographic models based on paleoclimatologic and biogeographic data the data from the three fields of paleomagnetism paleoclimatology and biogeography are generally in excellent agreement and an internally consistent paleogeographic evolutionary picture of the interactions between north america gondwana and intervening displaced terranes is emerging during the interval of the ordovician silurian and devonian north america stayed in equatorial paleoposition while rotating counter clockwise the northwest african part of gondwana was in high southerly latitudes during the late ordovician and was fringed by peri gondwanide terranes such as southern europe armorica and avalonian basement blocks now found in eastern newfoundland nova scotia the boston basin the appalachian piedmont and northern florida subsequently gondwana and the peri gondwanide terranes displayed rapid drift with respect to the pole this drift translates into the following pattern of movement for northwest africa during the latest ordovician early silurian this area moved rapidly northward from polar to subtropical latitudes followed by equally rapid southward motion from subtropical to intermediate about 50 s paleolatitudes during the late silurian middle devonian it is likely that significant east to west motion accompanied the latter shift in paleolatitudes with the caledonian acadian orogeny the result of silurian to early devonian convergence and collision between gondwana and north america this collision sandwiched several of the intervening displaced terranes between gondwana and north america subsequent to this collision gondwana was separated in the late devonian by a medium width ocean from north america and the avalonian and southern european blocks which were left behind adjacent to north america this new ocean closed during the carboniferous and the resulting convergence and collision were the cause of the hercynian alleghanian orogenic belt problems remaining for future research besides the further gathering of reliable paleopoles involve the uncertain pre devonian position of the southern british isles in this scenario and the very rapid velocity with respect to the pole that results from the rapid late ordovician silurian apparent polar wander for gondwana

anomalous low velocity zone and linear alignment of seismicity along it in the subducted pacific slab beneath kanto japan reactivation of subducted fracture zone 1 a detailed investigation of the hypocenter distribution beneath kanto japan reveals a nw se trending linear alignment of seismicity within the subducted pacific slab we estimate the 3d seismic velocity structure in the pacific slab to understand the factors controlling the genesis of such intraslab earthquakes a narrow low velocity zone is imaged within the subducted slab over a length of 150 km which partly penetrates into the mantle portion of the slab the low velocity zone correlates in space with the nw se trending earthquake cluster a reactivation of hydrated fracture zone formed prior to subduction is probably related to the low velocity anomaly dehydration reactions of the hydrated oceanic mantle as well as the oceanic crust might lower the seismic velocity along the fossil fracture zone accompanied by intraslab earthquakes these observations support the hypothesis of dehydration embrittlement as the most viable mechanism for generating intraslab earthquakes