John J. Renton

Pennsylvanian deposystems and paleoclimates of the Appalachians

Abstract Central Appalachian basin rocks indicate major changes in source areas, base level, and climate for Late Mississipian through Late Pennsylvanian time. Through time, dominant source areas change from craton and northeastern orogen to southeastern orogenic mountains. The Mississipian—Pennsylvanian uncomformity correlates with a worldwide eustatic event. Early Pennsylvanian rocks contrast markedly with underlying Mississippian Mauch Chunk redbeds in composition and texture yet the source areas and alluvial plain setting were similar. Seas transgressed northeastward during Middle and earliest Late Pennsylvanian time along axes of the Pocahontas and Dunkard basins while fluvial-dominant deltas prograded northwestward. This progradation (1) progressively extended the coastal plain, (2) provided coastal swamp environments for peat accumulation, and (3) eventually cut off the narrow seaway of Dunkard basin from the Central Interior by Late Pennsylvanian and transformed it into a large shallow freshwater lake. Redbeds, calcium carbonate concretions and gilgai paleosol structures of Late Mississippian and Late Pennsylvanian rocks suggest seasonally dry tropical climate whereas the lithologies of the earlier Pennsylvanian rocks are indications of everwet tropical climates with their quartz-rich fluvial sandstones, high quality coals, and aluminum-rich clay deposits. Streams change from predominantly bedload to suspended load generally from Early to Late Pennsylvanian, in response to changes in paleoslope gradient, distance from source area, unvegetated highland, and change from everwet to intermittently dry tropical climate. Greater dryness is suggested for increased alkaline conditions observed in paleosols, carbonates, and coal beds of Late Pennsylvanian time, but sufficiently wet to prevent evaporite deposition.

FTIR microspectroscopy of particular liptinite- (lopinite-) rich, Late Permian coals from Southern China

Abstract The Late Permian coals from Southern China are unique in their high content of lopinite (liptinite) and elemental hydrogen and typically produce high yields of tar. Typical of the Late Permian coals of Southern China, the coals used in this study show special petrographic and chemical characteristics, as well as significant oil-producing potential. Studies of these coals and of their content of the lopinite maceral will help to explain the genesis of both the lopinite maceral and of the oil-producing potential of the coals. In this study, an FTIR spectrometer was used in the standard transmission mode to generate the IR spectra of the whole coal. An FTIR spectrometer, equipped with a microscope in the reflectance mode, was used to analyze the chemical structure of individual coal macerals, including lopinite, vitrinite, semifusinite and inertinite. The chemical structure of lopinite is characterized by its higher content of longer and less branched aliphatic side chains and distinct C=0 groups. The oil-producing potential of the coals is attributed to their higher content of lopinite.

Association of coal macerals, sulfur, sulfur species and the iron disulphide minerals in three columns of the Pittsburgh coal

Abstract This study of the Pittsburgh coal supports the premise that the amount of sulfur contained in coal, expecially that represented by the iron disulphide minerals, is largely the product of the same swamp chemistry that determines the relative abundances of the various coal macerals. Through its control of the microbial degradation of plant debris and peat, the swamp water pH determines the relative abundances of the vitrinite and exinite macerals. At swamp water pH values above 4.5, increased microbial degradation of the plant and peat materials would decrease the abundance of pre-vitrinitic materials, increase the pre-exinitic materials, produce disulphide ion via the microbial reduction of sulfate ion which would subsequently precipitate as iron disulphide minerals and result in an increase in mineral matter in the pre-coal peat. The subsequently produced coal would be more exinite rich, high in mineral matter and sulfur, especially pyritic sulfur. Within the Pittsburgh coal, the layers at the top and bottom of the coal bed and above and below the middle parting reflect non-ideal conditions of organic preservation. Because of the common chemical control for the production of exinites and iron disulphide minerals, the abundance of exinite and sulfur exhibit a strong statistical association within the Pittsburgh coal. Below pH 4.5, reduced microbial activity results in the preferential accumulation of the pre-vitrinitic woody tissues and the subsequent suppression of the relative abundance of pre-exinitic spores, pollen and cuticles. The same low-pH conditions solubalize the metals, especially iron, suppress the bacterial reduction of the sulfate ion to the disulphide ion and as a result inhibit the formation of the iron disulphide minerals. A coal produced under conditions of low pH would be bright, the sulfur content would be low and dominantly organic and because of the high degree of preservation of the plant debris, the mineral matter in the coal would be relatively low. Within the Pittsburgh coal, the general decrease in mineral matter and sulfur and increase in vitrinite content downward from the tops of both benches reflects the more ideal conditions for organic preservation prevalent within the original swamp. The degradation of plant debris and peat via dissolved oxygen in percolating groundwater or rainwater will result in an enrichment in the pre-exinitic materials but will inhibit the formation of the iron disulphide minerals. Some exinite-rich coal layers are therefore low in sulfur and dominated by organic sulfur. The amount of sulfur contained within partings will depend upon their mode of origin. If the partings formed by the extreme microbial degradation of the peat, they will usually be enriched in sulfur as illustrated by the high sulfur content of the middle parting. On the other hand, if they formed by the slow oxidation of the peat or are of detrital origin, the sulfur content may be low.

Application of Limestone to Restore Fish Communities in Acidified Streams

Abstract Five, second-order, acidic streams in West Virginia were treated with instream applications of fine-grained limestone. Three variations in treatment were tested to optimize limestone dissolution: the particle size of the limestone, the amount used, and the number of application points. The goal of the study was to develop a cost-effective method to restore water quality that would sustain fisheries for native brook trout Salvelinus fontinalis. In all of the treatments, water quality improved and the fish communities were either restored or enhanced. Before limestone treatment, only one of the study streams contained a reproducing brook trout population. Following treatment, the fish communities expanded rapidly from 0.01 kg/ha to a high of 38 kg/ha, and the number of species increased to a high of eight. The untreated control stream remained unchanged. Due to a lack of duplicate streams, a statistical comparison could not be made between the different sizes of limestone tested or the amounts adde...

Sand-sized limestone treatment of streams impacted by acid mine drainage

Direct single point, instreamapplications of limestone sand were made in twostreams severely acidified by acid mine drainage. After high flows distributed the sand downstream,dissolution of the limestone significantly reduced theacid loads in both streams. Data from the treatedstream sections and laboratory experiments showed thatthe efficiency of treatment was more dependent onlimestone particle size than CaCO3 content. Results from the stream treated with a narrow range oflimestone sand-sized particles showed a highutilization efficiency with nearly completedissolution of the limestone. The data indicated thatmonthly addition of limestone sand may be sufficientfor complete treatment of the streams studied. Ananalysis of such a treatment scheme indicated it to behighly cost efficient when compared to other activeand passive treatment systems.

Effects of Liming on Water Quality of Two Streams in West Virginia

In an effort to improve the fisheries potential of many West Virginia mountain streams by increasing the alkalinity and pH, the West Virginia Department of Natural Resources (DNR) is conducting research into the feasibility of a point source limestone application technique. This research was to provide data that would assist in the design of future projects and the selection of appropriate methodology. Thirteen metric t and 33.3 t of 0.64 cm crusher run ground limestone aggregate were applied as a single deposition to Crouch and Yokum Runs, respectively. Limestone was applied to Crouch Run a year prior to treatment of Yokum Run. The point source treatment produced discharge dependent changes in the downstream water chemistry. The pH increased from an average of 4.73 above the application point to 5.70 below. At high stream discharges, the pH dropped, but never to the pretreatment background level. Increases in Ca concentrations and ANC were also observed downstream of the limestone application site. Sediment analysis was performed to determine the calcite concentration within the stream bed by both an instrumental technique (x-ray fluorescence (XRF)) and an HC1 leach technique to indicate the extent of downstream movement and distribution of limestone. The analysis showed both a limited downstream transport and a variable spread of limestone across the stream channel. The XRF and wet laboratory methods of quantifying the calcite content of the sediments were compared. Although statistical analysis indicated a difference in precision between the x-ray fluorescence and HC1 leach methods, the acid leach method can be considered an economical alternative to x-ray fluorescence. Recommendations are made on methods to increase the effectiveness of the point source treatment and the design of future research.

An experimental evaluation of the use of rock phosphate (apatite) for the amelioration of acid-producing coal mine waste

Abstract The weathering of coal and coal-associated rocks (AMD) containing iron disulphide minerals produces acid mine drainage. (AMD). This is the most important environmental problem in high-sulphur coal basins. It is generally agreed that the major oxidizing agent of FeS2 is the ferric ion. Experiments have shown that the average equilibrium voltage for the Fe3+/FeS2 system is 0.42 which corresponds to a Fe3+: Fe2+ ratio of 10−6: 1. In an ideal solution, if the Fe3+: Fe2+ ratio could be reduced to less than 10−6: 1, the Fe3+-oxidation of FeS2 could not take place. It has been shown that both Fe2+ and Fe3+ ions can be precipitated by the phosphate ion under ideal conditions at near-neutral pH-conditions, producing a Fe3+:Fe2+ ratio of 10−11: 1. Experiments utilizing rock phosphate (apatite) as a source of phosphate ion showed that the treatment of coal-associated rock containing iron disulphide minerals not only prevented the production of acid, but also terminated the production of acid from materials already undergoing oxidation. The results of these experiments indicate that rock phosphate (apatite) is an effective AMD ameliorant based upon its ability to reduce the Fe3+: Fe2+ ion ratio to below 10−6: 1 and its ability to reduce the subsequent solution potential to the less than 0.42 V, required to allow the oxidation of FeS2 by Fe3+.

A laboratory procedure to evaluate the acid producing potential of coal associated rocks

Abstract Pre-mine planning to minimize or eliminate the production of acid mine drainage (AMD) necessitates that the acid producing potential of each of the lithic units encountered in mining be evaluated. Presently used techniques to predict acid production are generally inadequate primarily because they are based upon unsubstantiated assumptions and because they do not provide the capability of determining the rate at which acid will be produced. This paper describes an experimental bench top procedure which will determine the rate and amount of acid that a rock will produce upon being exposed to the atmosphere. This procedure has been verified by predicting the acid production response of a 350 ton simulated backfill of coal associated rocks exposed to natural weathering conditions with better than 90% confidence.

The quantitative determination of FeS2 phases in coal by means of57Fe Mössbauer spectroscopy

A knowledge of the concentration of pyrite and marcasite in coals can provide important insight into the genesis of coal deposits. Determinations of the relative amounts of pyrite and marcasite by traditional methods of coal analysis are, however, beset with many difficulties. Using57Fe Mössbauer spectroscopy and a mild chemical treatment with hydrofluoric acid, a technique has been devised for the quantitative determination of the relative concentrations of pyrite and marcasite in samples of whole coals or their low-temperature ashes. The sample preparation procedure is comparable to less accurate methods. Good qualitative agreement has been obtained between ore microscopic and Mössbauer spectroscopic techniques for a series of extensively investigated whole coal samples.

Systematic Variability in the Mineralogy of the Low Temperature Ash of Some North American Coals

Abstract The mineralogy of coal ash is systematically distributed in recognizable patterns which are in turn a response to the basic depositional and early diagenetic geologic processes of the area. In general, the main control over the basic mineralogy of the ash appears to be the relative influence of the marine environment of the coal-forming swamp. Systematic changes in ash composition can be observed as one proceeds eastward from the Mid-Continent Coal Basin through the Illinois and Dunkard Basins to the Pocahontas Basin of southern West Virginia as the coal-forming environment becomes less influenced by marine conditions. The fresh-water coals of the western fields have ash compositions which compare closely with the lower Pottsville coals of the Pocahontas Basin. Systematic variability also exists on a within-a-mine basis where non-random patterns of sulfur and ash appear to reflect both de-positional and post-depositional processes.