Gray Sandstone Research Articles

Influence of Spoil Type on Chemistry and Hydrology of Interflow on a Surface Coal Mine in the Eastern US Coalfield

Surface mining for coal is responsible for widespread degradation of water resources and aquatic ecosystems in the Appalachian Region, USA. Because native topsoils are typically not retained on Appalachian mined sites, mine soils are usually composed of crushed overburden. This overburden tends to contribute high salinity loads to downstream aquatic systems. Also, loss of transpiration from forests and reduced infiltration associated with conventional reclamation procedures lead to altered water budgeting and stream morphology. To investigate the influence of the geologic composition of this overburden on water quality and tree growth, a series of experimental plots were constructed on a reclaimed surface mine site in eastern Kentucky, USA, in 2005. Treatments included unweathered GRAY sandstone, weathered BROWN sandstone, and MIXED sandstones and shale spoils. Plots were composed of end-dumped, uncompacted spoils and were designed to drain interflow through data acquisition stations for sampling purposes. Most water chemical parameters had stabilized across all treatments by 9 years after spoil placement. Discharge volume was not different among treatment types through the first 3 years after placement. However, 9 years after placement, seasonal variation in discharge on BROWN is more extreme than that on MIXED or GRAY. In addition, planted tree growth on BROWN has drastically outpaced growth on GRAY or MIXED, suggesting that evapotranspiration may be influencing seasonal variation in water discharged from BROWN. These results suggest that placement of brown weathered spoils when soil substitutes are required may lessen hydrologic impacts via improved tree growth and water utilization on surface-mined sites in Appalachia.

Analysis on the Metallogenic Conditions and Perspective of Nb-Ta Mineral in ZhaoJinggou, Inner Mongolia

ZhaoJinggou Nb-Ta deposit was discovered in 1967.After a series of exploration, a summary report of preliminary exploration of ZhaoJinggou Nb-Ta deposit was submitted. The detail exploration was carried out in this mineral aera in 2010.The deposit was sited in the middle part of the northern margin of north China platform, YinShan lifted block and north wing of Daqingshan anticlinorium. A series of metamorphose rocks of Proterozoic to Neoproterozoic were widely distributed in this area. Nb-Ta veins intruded into the structural fissure of dark grey pebbled metamorphic sandstone of Middle Carboniferous Shuanmazhuang Formation. Through verification of deep drilling, it exsited a larger decalcified feldspathized granodiorites and albite granites, which had a relationship with the formation of these veins. The intensity of albitization determined the grade of Nb-Ta minerals.And albitization caused the richment of other rare elements, which had a comprehensive utilization value. Based on the detailed exploration, the Zhaojinggou deposit should have a good mineralize perspective, which may exist the large alkaline albite lithium mica granite Nb-Ta deposits in deep or outer-ring of mining area.

Large-Scale Bleaching of Red Beds Related To Upward Migration of Hydrocarbons: Los Chihuidos High, Neuquen Basin, Argentina

Abstract The striking arrangement of colorful facies in the sandstones outcrops of the Los Chihuidos high, Argentina, has been attributed to the surface expression of hydrocarbon-induced alteration. The Huincul Formation (late Cenomanian–early Turonian) is part of the thick continental red-bed-dominated Neuquen Group, which consists of meandering fluvial deposits developed in a foreland basin. Visual distinctions reveal four diagenetic facies: red, white, gray, and minor brown sandstones. Differences in the diagenetic mineralogy among sandstones facies are interpreted to depend on the degree of interaction with hydrocarbon-bearing solutions and the relative position of the redox roll front developed during this process. The red facies represents the original oxidized sandstone, with hematite, kaolinite, quartz and albite overgrowths, and calcite cement precipitated under oxidizing conditions during the regional burial diagenesis. The white facies formed during the interaction of red beds with reduced fluids (in presence of hydrocarbons or organic acids), where clasts and cement were partially dissolved, and iron was reduced to Fe2+ due to redox reactions and removed, resulting in the sandstone decoloration and in a marked development of the secondary porosity. Minor montmorillonite replaced kaolinite and detrital feldspars, and a poikilotopic calcite precipitated, filling the pores. The gray and the brown sandstone bound the redox front, which is characterized by the presence of abundant clay minerals and oxide minerals enriched in vanadium and copper. Montmorillonite and secondary hematite are dominant in the more oxidized gray sandstones whereas interstratified chlorite–montmorillonite is more abundant in the more reduced brown sandstones. The coexistence of these minerals indicates metastable reducing–oxidizing conditions at the redox front. Based on diagenetic characteristics, tectonic framework, maturation timing of source rocks, and petroleum-emplacement history, hydrocarbons could have migrated into the Huincul Formation during the Tertiary uplift, but later erosion could have released the hydrocarbons and exhumed the reservoir. This multi-scale investigation of diagenetic features related to burial history and to structure-controlled upflow of hydrocarbons in a succession of siliciclastic rocks enhances modeling of a regional-scale redox system worldwide. Our study offers new insight into the application of authigenic minerals to trace hydrocarbon pathways along red beds and to evaluate the reservoir quality, in the understanding the importance of fluid compositions, mixing, and fluid–rock interaction along a major redox system.

Paleomagnetism of upper Ediacaran clastics from the South Urals: Implications to paleogeography of Baltica and the opening of the Iapetus Ocean

The progress in understanding the evolution of the Earth during the Ediacaran–Cambrian is greatly hindered by the scarcity and inconsistency of paleomagnetic data for this time interval. In order to acquire new data and clarify the confusing situation, Upper Ediacaran clastic rocks of the Basu Formation were sampled at several localities in the westernmost parts of the South Urals that is the deformed margin of Baltica at least since the beginning of the Neoproterozoic. With the aid of stepwise thermal demagnetization, a dual-polarity high-temperature component (HTC) was reliably isolated from gray and maroon sandstones and siltstones at 34/49 sites. The HTC mean direction D°=55, inclination I°=−35 (k=31, α95°=4.5) corresponds to a paleolatitude of 19°±3°. The reversal and fold tests are positive for the HTC. The slump test on two meter-sized slumps shows that the HTC predates slumping in one case and is coeval with it, in the other, thus convincingly indicating the primary origin of the HTC. Also, we demonstrate that inclination shallowing is either absent altogether, or, at worst, less than 10°, in these rocks; hence the position of Baltica can be reliably reconstructed for time 560–575Ma. We reviewed paleomagnetic data with ages from 615 to 530Ma for Baltica and Laurentia and come to the conclusion that there is still no uncontestable scenario for the opening of the Iapetus Ocean that is based on non-controversial geologic and paleomagnetic data.

Nutrient concentrations in tree leaves on brown and gray reclaimed mine soils in West Virginia

Surface mining in Appalachia disrupts large areas of forested land. Federal and state laws require disturbed lands be reclaimed by re-constructing the landscape and replacing soil materials to provide a rooting medium. If insufficient quantities of native topsoil are available, substitute materials derived from the overburden may be used as soil media. This study examined soil and foliar nutrient concentrations of three hardwood tree species on areas where brown and gray sandstone overburden were applied as substitute growth media at the Birch River mine in West Virginia. Soil and foliar nutrient concentrations found in four experimental plots were compared to soil and foliar nutrient concentrations found in a nearby native Appalachian forest. Many foliar nutrients such as phosphorus and potassium were lower in all three tree species on most mine soils compared to trees growing in nearby native forest soils and to tree nutrient concentrations from the literature. Foliar and soil nutrient concentrations in the Brown mine soil were similar to those found in native forest soil, while the Gray mine soil provided significantly lower levels of nutrients. Overall, low nutrient availability in mine soils translates into generally lower foliar nutrient concentrations in trees growing on mine soils. After six years, amended topsoil substitutes and Brown mine soil produced higher foliar nutrient concentrations than Gray mine soil.

Setting the stage for the genesis of the giant Bendigo ore system

Abstract The Ordovician sediments that host the giant Bendigo saddle reef gold deposits consist of a 3 km-thick sequence of turbiditic sandstones and interbedded siltstones and mudstones. Sedimentological studies suggest the succession formed within a major deep marine channel–levee complex similar to those described from contemporary continental margin to basin plain settings outboard of major river systems (e.g. the Amazon, Mississippi and Congo). Black shales, which are commonly the immediate host rocks to the epigenetic gold reefs, are interpreted to be over-bank deposits or abandoned channel fills, developed adjacent to active channels which were sandstone-dominated and had an incised axial thalweg marked by the coarsest-grained sediments present. Organic carbon content of the black shales at Bendigo varies from 0.2 to 2 wt%, compared with the grey shales, siltstones and sandstones, which vary from 0.05 to 0.2 wt%. Trace elements fall into two main groups: (a) elements that have a linear relationship with aluminium, and are controlled by the detrital clay content (Sn, Ba, Rb, Li, Cs, Mn, Cr and Tl); and (b) elements that show relationships with both aluminium and organic carbon (V, U, Ni, Zn, Cu, Bi, Pb, Se, Ag and Au) and are controlled by both the clay and organic matter content in the carbonaceous shales. The elements in the second group are enriched in the black shale facies. The background gold content of the black shales in the drill holes distal from mineralization averages 8.9 ppb, compared with the sandstones with 1.5 ppb. Most of the gold in the shales is present in diagenetic pyrite and marcasite, which laser ablation inductively coupled mass spectrometer (LA-ICPMS) analyses indicate varies from 5 to 3850 ppb and averages 370 ppb Au. The geochemical data suggest that this syngenetic gold was most likely sourced by erosion of the hinterland, and transported attached to detrital clay particles or as colloidal gold, by a high-volume feeder river system. High Rb/K ratios in the shales support a highly weathered source typical of a giant river system. By analogy with modern systems, following transport into deep marine channel–levee complexes via continental margin canyons, gold and other redox sensitive trace elements were ultimately trapped by reduction, adsorption and complexation with organic matter in the sub-oxic to anoxic over-bank deposits. Oxidation of much of the organic matter during diagenesis released the gold and certain trace elements (Ni, Co, Se, Ag, Cu, Bi, Pb), which became incorporated into diagenetic pyrite. Enrichment of gold in diagenetic pyrite of the black shale facies of the Ordovician turbidites at Bendigo was the first stage in a two-stage process that produced the world-class quartz–gold saddle reef deposits. Supplementary material: Whole rock analyses for sedimentary rocks in drill holes NBD005 and NBD186, Kangaroo Flat Mine, Bendigo, are available at http://www.geolsoc.org.uk/SUP18732

English

Steep topography and thin native soils characterize the coal mining regions of southern West Virginia. State and federal regulations require replacement of native topsoil during reclamation for re-establishment of a vegetative cover. Due to hazards and expense associated with collecting this thin layer of soil before mining, regulators have allowed mine operators to use substitute topsoil materials, including weathered (brown) and unweathered (gray) geologic materials for growth media. For pasture and hayland post-mining land uses, substitute materials provide suitable physical and chemical properties for establishment and growth of forages with fertilization and liming. When reforestation is the post-mining land use, regulations in West Virginia require a 1.2 m layer of native topsoil and brown weathered sandstone, but unweathered materials may be used if native topsoil quantities are insufficient. This study examined tree growth on areas where brown and gray sandstone materials were applied to the surface as growth media at the Samples Mine in West Virginia. In a study already published at this site, we found significant differences in tree growth on brown and gray sandstone plots. For this study, we selected two additional gray sandstone plots for comparison to the original brown and gray plots. The two original sites were brown sandstone compacted and gray sandstone compacted, and we added nearby plots of gray sandstone slightly compacted and gray sandstone compacted and then ripped. Average pH ranged from 7.3 to 7.9 on the gray plots compared to 5.4 on the brown plot. Tree growth on brown sandstone was more than triple that of tree growth on all of the gray sandstone plots. Mean tree volume index on the brown compacted plot was 3108 cm 3 while mean tree volume index was significantly lower on the gray compacted plot (909 cm³), the gray slightly compacted plot (407 cm 3 ), and the gray ripped plot (885 cm³). Eight years after reclamation, the gray sandstone plots, whether slightly compacted, compacted, or ripped, showed poor tree growth compared to brown sandstone. Gray sandstone has proven to be an inferior topsoil substitute for reforestation on this site.

Depositional Environment of the Devonian Quartz Sandstones in the Bāle Sand Pits

This paper summarises data about the depositional environment of Devonian quartz sandstones in Latvia and discusses new fieldwork data from Bāle 1 and Bāle 2 sand pits. The commercial bed in these sand pits is composed of fine to gravel size grained white and pale gray sandstones with mud clasts and quartz pebbles in places. Studies in Bāle sand pit sectors 1 and 2 suggest the deposition of sediments in details channel and sand bars, with the scarce influence of tidal processes on sedimentation.

New paleomagnetic data on the Silurian and Devonian sedimentary rocks from Podolia, SW Ukraine, and kinematics of the East European platform in the Middle Paleozoic

Paleomagnetic data are the priority source of information for global paleotectonic reconstructions representing horizontal movements of the crustal blocks. Upon receipt of new paleomagnetic data, kinematic models of the East European platform in the Paleozoic are regularly revised and improved. The article presents results of the paleomagnetic study of sedimentary gray-colored and red beds of the Silurian and Lower Devonian sequences located in the Dniester river basin, Podolia region, SW Ukraine. The study covered 17 outcrops that are stratigraphically correlated with the Wenlock, Ludlow, Pridoli states of the Sillurian and the Lochkovian stage of the Devon. Over 400 samples of grey limestone, argillite, dolomite, red limestone and sandstone were analyzed, and two components of natural remnant magnetization (NRM) were revealed. The first component with SSW declination and negative inclination is revealed in the majority of the samples during AF- and T-magnetic cleaning. Its pole positions, that are calculated separately for each series, are trending to the Permian segment of the apparent polar wander path (APWP) published by Torsvik et al. [2012] for Baltica / Stable Europe. Considering its chemical origin, this NRM component is related to formation of authigenic minerals due to rock remagnetization. The second component is revealed only in some samples taken from the red beds (during thermal demagnetization in the range of unblocking temperatures from 590 to 690 °С) and in few samples of grey limestone (in AF fields from 30 to 70 mT or in the range of unblocking temperatures from 300 to 460 °С). This component has SW declination and positive inclination, goes to the origin of coordinates of the diagrams, and has all the indicators of primary magnetization of sediments. Calculated positions of the poles (0 oS and 329 oE for grey limestone of the Tiverskaya series, 2.3 °S and 338.4 °E for red beds of the Dniestrovskaya series, etc.) are well correlated with the Devonian segments of APWP for Baltica / Stable Europe. The same is true for the Silurian poles. The new results suggest that in the Ludlow, the East European platform was located at the near-equatorial latitudes of the Southern Hemisphere, and in the Pridoli, it moved to the north towards the equatorial latitudes of the Southern Hemisphere. Later on, the drifting mode was changed, and the platform moved to the south. In the Lochkovian, its position was stabilized at the equatorial latitudes of the Southern Hemisphere. Drifting of the platform can be described by counterclockwise rotation by 16° around the Euler pole (Φ=34 °S, Λ=247 °E).

Hardwood Tree Growth on Amended Mine Soils in West Virginia

Each year surface mining in Appalachia disrupts large areas of forested land. The Surface Mining Control and Reclamation Act requires coal mine operators to establish a permanent vegetative cover after mining, and current practice emphasizes soil compaction and planting of competitive forage grasses to stabilize the site and control erosion. These practices hinder recolonization of native hardwood trees on these reclaimed sites. Recently reclamation scientists and regulators have encouraged re-establishment of hardwood forests on surface mined land through careful selection and placement of rooting media and proper selection and planting of herbaceous and tree species. To evaluate the effect of rooting media and soil amendments, a 2.8-ha experimental plot was established, with half of the plot being constructed of weathered brown sandstone and half constructed of unweathered gray sandstone. Bark mulch was applied to an area covering both sandstone types, and the ends of the plot were hydroseeded with a tree-compatible herbaceous seed mix, resulting in eight soil treatments. Twelve hardwood tree species were planted, and soil chemical properties and tree growth were measured annually from 2007 to 2012. After six growing seasons, average tree volume index was higher for trees grown on brown sandstone (5333 cm) compared with gray sandstone (3031 cm). Trees planted in mulch outperformed trees on nonmulched treatments (volume index of 6187 cm vs. 4194 cm). Hydroseeding with a tree-compatible mix produced greater ground cover (35 vs. 15%) and resulted in greater tree volume index than nonhydroseed areas (5809 vs. 3403 cm). Soil chemical properties were improved by mulch and improved tree growth, especially on gray sandstone. The average pH of brown sandstone was 5.0 to 5.4, and gray sandstone averaged pH 6.9 to 7.7. The mulch treatment on gray sandstone resulted in tree growth similar to brown sandstone alone and with mulch. After 6 yr, tree growth on brown sandstone was about double the tree growth on gray sandstone, and mulch was a successful amendment to improve tree growth.

Hardwood Tree Growth after Eight Years on Brown and Gray Mine Soils in West Virginia

Surface coal mining in Appalachia disturbs hundreds of hectares of land every year with the removal of valuable and ecologically diverse eastern deciduous forests. After the passage of the Surface Mining Control and Reclamation Act in 1977, coal mine operators began planting a variety of grasses and legumes as a fast and economical way to reestablish a permanent vegetative cover to meet erosion and site stabilization requirements. However, soil compaction and competitive forage species have arrested the recolonization of native hardwood tree species on these reclaimed sites. Three 2.8-ha demonstration plots were established at Catenary Coal's Samples Mine in Kanawha County, West Virginia, of weathered brown sandstone and unweathered gray sandstone. Half of each plot was compacted. Each plot was hydroseeded with a low-competition herbaceous cover and planted with 11 hardwood tree species. After eight growing seasons, average tree volume index was nearly 10 times greater for trees grown in the brown sandstone treatments, 3853 cm, compared with 407 cm in gray sandstone. Trees growing on compacted treatments had a lower mean volume index, 2281 cm, than trees growing on uncompacted treatments, 3899 cm. Average pH of brown sandstone was 5.2 to 5.7, while gray sandstone was 7.9. The gray sandstone had much lower fine soil fraction (<2-mm) content (40%) than brown sandstone (70%), which influenced nutrient- and water-holding capacity. Brown sandstone showed significantly greater tree growth and survival and at this stage is a more suitable topsoil substitute than gray sandstone on this site.

A review of the stratigraphy and stratigraphic nomenclature of the Dunkard Group in West Virginia and Pennsylvania, USA

Dunkard Group strata, the youngest Paleozoic rocks in the Appalachian Basin, extend from the base or top of the Waynesburg coal (varying among neighboring state geological surveys) to the highest exposures. Geologic investigation and mapping of the Dunkard Group began with the First Pennsylvania Geological Survey in the 1830s, but poor exposure, exposure of only limited stratigraphic intervals, and lack of significant economic commodities have hampered stratigraphic studies. Maximum thicknesses in excess of 335m (1100ft) are found beneath the highest ridges along the synclinorium axis near Wileyville, West Virginia and Windy Gap, Pennsylvania and the stratigraphic correlation of these sites is shown with composite sections constructed from core records and measured sections. Distinct facies provinces are documented in the Dunkard Group, from south to north interpreted as (1) upper fluvial plain, (2) lower fluvial plain, and (3) fluvial–lacustrine deltaic plain. This spatial array of facies provinces is illustrated by a cross section through Dunkard Group and underlying Monongahela Group strata based on drillers' and geologists' core logs. Strata in the upper fluvial plain are cyclic sequences of red, green, and gray, nonfissile mudstone and claystone paleosols exhibiting vertic features, red, green and gray fissile shale, and gray and green sandstone. Coal and limestone are rare, although abundant calcareous material is present as nodules and cement. In contrast, the fluvial–lacustrine deltaic plain cycles are comprised of coal and nonmarine limestone, fewer fluvial shale and sandstone units, and only rare redbeds. The lower fluvial plain cycles exhibit a transition between the other two provinces, containing coal and nonmarine limestone, as well as significant fluvial units and redbeds. Coal beds in the Dunkard Group are best developed in the fluvial–lacustrine deltaic plain but are generally thin and low in quality. Stratigraphically extensive, laterally continuous road cuts and numerous subsurface exploration records, particularly long continuous cores targeting coal beds beneath the Dunkard Group, now aid in better understanding the stratigraphy of the Dunkard Group and will aid in future investigations of these rocks.

Petromineralogic and Rock Magnetic Aspects of Clastic Sedimentation in the Surma Basin, Mizoram

Abstract: We present here comprehensive petromineralogic, mineral magnetic and lithologic observations from five stratigraphic sections representing the Barail Group, Middle and Upper units of Bhuban Formation, Bokabil Formation and Tipam Group in the Mizoram area. These stratigraphic units mainly display interplay of the grey and buff colored sandstones of the clast compositions varying from sub-lithic to lithic arenites (Q79F4L17 to Q55F3L42) including sedimentary, meta-sedimentary and subordinate igneous rock fragments. The buff sandstones with higher lithic fragments [Q69F4L27 (Ls61Lm38Lv1)] are dominated by recycled components with higher clast angularity (VA1A15SA51SR24R8WR0.4) relative to the grey sandstones. Mineral magnetic studies decipher bimodal (ferri- and antiferromagnetic) mineralogy with higher concentration in buff sandstones relative to the unimodal ferrimagnetic nature of the grey sandstones. The study infers that the buff sandstones mark the regressive phases driven by hinterland uplifts; whereas the growth of the grey sandstone facies is marked by transgressive basinal processes. Gradual increase in the frequency and appearance of the buff sandstones in the Surma stratigraphy, therefore, can be related to the evolution of the Indo-Burmese ranges.

Early Oligocene paleosols of the Dagshai Formation, India: A record of the oldest tropical weathering in the Himalayan foreland

This study reports paleopedological features of the fossil soils that formed during the earliest phase of continental sedimentation in the Himalayan foreland. The fluvial sequence of the Dagshai Formation (31.6±3.9Ma to 30.3±3.9Ma) exposed along the Koshaliya River, NW Himalaya, contains four pedofacies (named Pedofacies A–D) of ferruginous paleosol sequences contained within overbank sediments. The Dagshai Formation unconformably overlies the marine Subathu Formation. Pedofacies A consists of 3–4 well-developed ferruginous paleosols overlain by gray sandstone beds. Pedofacies B–D are marked by a progressive decrease in pedogenesis. These paleosols occur as 0.5m to 1.5m thick Bw/Bt/Btk/Bk/Bss horizons that are marked by extensive development of rhizoliths, pedogenic carbonate, and iron-rich clay pedofeatures that correspond to modern Entisols, Inceptisols, Alfisols and Vertisols. Based on early Oligocene paleogeographic position of the northward-drifting Indian Plate, it is inferred that these paleosols were formed at ~18°N paleolatitude in the Dagshai sub-basin in the Himalayan foreland. Micromorphology, geochemical analyses, weathering indices, and stable isotope composition of paleosols indicate tropical climate (paleoprecipitation of 947–1256mm and paleotemperature of ~25°C) with an initial phase of monsoonal conditions during pedogenesis. These paleoclimatic conditions favored C3 paleovegetation immediately after the transition from greenhouse to icehouse conditions.

Provenance and tectonic setting of the Triassic Yidun Group, the Yidun Terrane, Tibet

The Yidun Group extends from the Shangri-La region to the south and the Changtai region to the north, and is an important component of the Triassic Yidun arc in the eastern Tibetan plateau. It is composed of the Lieyi, Qugasi, Tumugou and Lanashan Formations from the base upward. Both the Lieyi and Lanashan Formations consist dominantly of black or gray slate and sandstone, whereas the Qugasi and Tumugou Formations have variable amounts of mafic to felsic volcanic rocks and tuffs accompanied with gray slate and sandstone.Sandstone from the Yidun Group has variable CIA values from 55 to 76, indicative of mild to moderate weathering condition for the source rocks. All the sandstones define a general weathering trend nearly parallel to the A-CN boundary in the A-CN-K triangular diagram, implying limited effect of diagenetic and post-depositional K-metasomatism. Dominant detrital quartz and feldspar grains of the sandstones suggest predominantly felsic sources. Relatively high Y/Ni and low Cr/V ratios of sandstones from the Yidun Group indicate more contribution from felsic than mafic sources. Similarly, the Yidun sandstones have Co/Th and La/Sc ratios generally similar to upper continental crust (UCC) and cluster between UCC and felsic sources, indicating felsic rocks as primary sources. Granodiorite represents the average chemical composition of sources as evaluated by extending the predicted weathering trend back to the feldspar join in A-CN-K diagram.Prominently high Zr/Sc ratio or Hf concentration and Paleoproterozoic Nd modal ages (1.94–2.21 Ga) point to input of recycling components derived from old sedimentary source in a relatively stable tectonic setting.

English

Specific conductance and selenium (Se) are two water quality parameters of emerging concern in the Appalachian coalfields. Isolation of high specific conductance and Se producing spoils from environmental water flows using a low permeability barrier is one method of minimizing the leaching of these constituents from coal mine spoils. Ideally, the material used to form the barrier should be readily accessible, have low levels of specific conductance and Se, and be capable of achieving a low permeability with the proper moisture adjustment. Brown and gray weathered sandstones are often readily available at mine sites in the Appalachian coalfields. Spoil samples and water quality samples from the University of Kentucky Bent Mountain Research Complex near Pikeville, Kentucky indicated that these spoil types hold promise in meeting the criteria of being a low specific conductance producing material. However, these sandstones tend to have higher sand contents than those typically used in compacted barriers or liners in landfills. The objective of this study was to assess the potential of using brown and/or gray weathered sandstones to create a low permeability barrier. To meet the objective of the study, a total of four spoil samples (identified as M1-M4) were collected in 2012. Each spoil sample was obtained from a different mine in eastern Kentucky. Samples M1 and M2 consisted of brown sandstone; sample M3 was gray sandstone; and sample M4 was a mixture of brown and gray sandstones. Each spoil sample was screened and analyzed for soil texture. Spoil moisture content-density relationships and spoil saturated hydraulic conductivity-moisture content relationships were developed for each sample using double ring permeameters. Maximum saturated hydraulic conductivity values ranged between a low of 5.9 x 10 -8 cm s -1 to a high of 3.1 x 10 -7 cm s -1 in the laboratory for the <2mm fraction. These saturated hydraulic conductivity values were comparable to soils used to construct liners in landfills, particularly in instances where the percentage of fines in the spoils were about 50% or greater. When in the field, however, it is expected that these saturated hydraulic conductivity values will typically be 1-3 orders of magnitude higher due to rock fragments. These results demonstrate that brown sandstone, with its higher fines content, is likely a more suitable media than gray sandstone for constructing a low permeability barrier to isolate high specific conductance producing and/or Se generating spoils. Based on these laboratory results, field assessments of brown weathered sandstones for this application are recommended.

Neogene Stratigraphy Of The Eskişehir Graben And The Investigation Of Coal Deposition By Seismic Reflection Method

The study area is located within the Eskisehir Graben, north of Agapinar village in the Sevinc district and east of Eskisehir City. Miocene deposits unconformably overlie the basement of Paleozoic metamorphites and Mesozoic ophiolites. The m1 series constituted by gravel, sandstone and claystone is observed at the base of Miocene deposits. The overlying m2 series, from bottom to top, represents a sequence of partly conglomerate, green claystone, coal, gray sandstone, dark gray to green siltstone, bituminous marl, claystone, coal, green claystone, sandstone and fine grained conglomerate. The m3 series of limestone and conglomerate is patchy and Pliocene deposits consisting of loose gravel, claystone overly them. The stratigraphical succession in the region covered by Neogene deposits has been investigated during surveys and reservoir drilling in licence areas belonging to MTA. High resolution shallow seismic reflection data were collected on two lines crossing each other considering field conditions (vegetated areas, irrigation channels, Porsuk River, railway line, etc.) and locations of boreholes made in the basin. These collected data were assessed in the Data Processing Center of the Seismic Research Division of the Geophysical Research Department (MTA),to produce the final sections of the seismic reflection. The data were then correlated with borehole data on or adjacent to the lines. The surface of reflection (yellow colored level) which could be continuously traced through all sections was deduced as the Paleozoic basement corresponded to ophiolites in borehole data. Reflection surfaces which are observed in areas, where the seismic basement deepened by multi-staged discontinuity surfaces of the seismic basement and rely especially on slopes of seismic basement, were determined as coal-claycontactzone. It was also revealed that, data obtained from drilling works continuing in the region correlate with geophysical interpretations made on seismic profiles.

Optimal hardwood tree planting and forest reclamation policy on reclaimed surface mine lands in the Appalachian coal region

We study the optimal hardwood tree planting decision on reclaimed surface coal mines in the Appalachian region using a mine operator-focused, expected cost model that recognizes costs of preparing the site for tree planting, unit costs of planting seedlings, and opportunity costs of reforestation treatments and the performance bond. We also consider the possibility of failed initial attempts by incorporating the probability of reforestation success, based on empirical seedling ,survival rates and regulated tree survival standards, as well as fixed and unit costs of returning for additional planting. Optimal planting levels from 319 to 780 trees per acre and expected costs from $1049 to $2338 were found using simulations over a range of unit planting costs, fixed costs of replanting, tree survival standards, and interest rates. Further simulations compared optimal planting across un-weathered gray sandstone and weathered brown sandstone substrate materials, finding gray sandstone to be associated with lower expected costs. We conclude that optimal planting density and expected reforestation cost are sensitive to economic parameters, regulations, and planting substrate materials; and those policies influencing these factors may have substantial impact on reforestation outcomes and the choice of post-mining land use by mine operators. Our study provides a framework for understanding forest reclamation decisions that incorporates incentives faced by the mine operators who develop and implement the plans for mine reclamation, including forestry.

Evaluating Soil Genesis and Reforestation Success on a Surface Coal Mine in Appalachia

Surface mining poses a significant threat to the Appalachian region via forest loss and fragmentation. Reclamation methods that utilize heavy grading to prevent landslides and erosion create a compacted landscape that is not suitable for forest establishment or growth. Overburden materials derived from differing geologic strata can exhibit large variation in physical, chemical, and mineralogical properties. Determining which strata should be used for creating a rooting medium for successful reforestation is not well established. Twelve 0.2‐ha plots composed of either segregated brown sandstone, gray sandstone, shale, or a sandstone–shale mixture (four treatments; n = 3) were created on a surface mine in eastern Kentucky using a low‐compaction reclamation method. Each plot was planted with native hardwood tree seedlings following the Forestry Reclamation Approach. After two growing seasons, brown sandstone treatments had four times greater extractable P (Mehlich III) and five times greater total N than the other treatments. This helped contribute to greater tree growth on brown sandstone treatments. Spoil settling was faster in the shale treatments due to the loss of carbonate cements. Clay contents and 2:1 minerals were also greater in the whole soil of the shale treatments, leading to greater plant‐available water and a greater cation exchange capacity. Gray sandstone treatments exhibited alkaline conditions (pH = 8.8) that suppressed tree growth. The mixing of brown sandstone and shale overburdens may produce a suitable combination of higher fertility, water holding capacity, and faster settling in reclaimed mine environments.

Contrasting weathering and climate regimes in forested and cleared sandstone temples of the Angkor region

ABSTRACTComparative assessment of stone weathering intensities and bioclimatic conditions was conducted at four temples located in cleared and forested sites of the Angkor Park, based on similar protocols. Four thousand sculpted lotus petals carved in the same grey sandstone were categorized by using two customized scales of weathering intensity, and climate monitoring was conducted from December 2008 to November 2009. Whereas 70% of the sandstone lotus petals are almost completely destroyed by mechanical weathering in cleared areas, 74% of petals located in forested environments appear to be totally free of mechanical weathering and are only affected by superficial biochemical weathering. Ambient conditions are also contrasting, with the magnitude of the diurnal surface temperature and relative humidity ranges being three times higher at cleared sites than in wooded areas. As wetting–drying cycles are the driving force of sandstone decay at Angkor, causal links are suggested between weathering and climate regimes. In wooded areas, the microclimate is buffered by the forest and the associated lithobionts, which maintain constant humidity levels, reduce thermal stresses at the stone surface and induce a slow biochemical weathering regime. In cleared areas, direct exposure to sunshine and monsoon rains induces pronounced wetting–drying cycles conducive to swelling–shrinking movements and other potential processes, provoking the rapid mechanical decay of the sandstone. Even if local damage can be caused by tree roots, the forest cover and the associated lithobionts obviously play an overall protective role. Additionally, microtopographical factors related to architectural designs and post‐building events probably explain intra‐site and between site minor differences in the amount of sandstone decay, by influencing key factors such as the water residence time at the stone surface. Last, the contrasting weathering regimes in forested and cleared sites are but a trend, for besides overwhelming mechanical weathering, chemical weathering is also operative at cleared sites, as indicated by salt efflorescences and ferric oxidation. Copyright © 2012 John Wiley &amp; Sons, Ltd.