Correlation Of Coal Beds Research Articles

Systematics of nonmarine bivalve mollusks from the Indian Gondwana Coal Measures (Damuda Group, Permian, India)

Nonmarine bivalves from the Permian of the Indian Gondwana Coal Measures are described for the first time. Six new bivalve genera, Gondwanaiadites, Bakulia, Gangamya, Raniganjelia, Gondwanadontella, and Indonellina, and 13 new species of four families from the Raniganj Formation of the Raniganj, Jharia, and North Karanpura basins of the Damodar valley are established. Morphological characters used in the descriptions of the Indian fauna only represented by external molds and imprints of shells are reviewed. The position of the Indian fauna of nonmarine bivalves in the modern system of Bivalves is considered. The stratigraphic distribution of nonmarine bivalves and use for correlation of coal beds are analyzed. All of new genera closely resemble the genera from the Kuznetsk Coalfield, where the stratigraphic scale for Angaraland is established. Three stratigraphic intervals of the Raniganj Formation are recognized based on the species composition of bivalves. They are found useful for interbasin correlation, despite a low morphological and taxonomic diversity. The lower interval is characterized by Gondwanaiadites olgae sp. nov. and Bakulia damodarensis sp. nov. The middle interval has an interesting assemblage of Raniganjelia, Gondwanadontella, and Indonellina.. The upper interval is characterized by Gangamya jhariaensis and Gangamya elongata. The assemblage under study is dated Kazanian–Urzhumian. The bivalve fauna from the “water body facies” of Indian Gondwana was presumably more saltwater than that of the Kuznetsk Basin.

Palynology of late Middle Pennsylvanian coal beds in the Appalachian Basin

Fossil spores and pollen have long been recognized as valuable tools for identifying and correlating coal beds. This paper describes the palynology of late Middle Pennsylvanian coal beds in the Appalachian Basin with emphasis on forms that assist both intra- and interbasinal coal bed correlation. Stratigraphically important palynomorphs that originate in late Middle Pennsylvanian strata include Torispora securis, Murospora kosankei, Triquitrites minutus, Cadiospora magna, Mooreisporites inusitatus, and Schopfites dimorphus. Taxa that terminate in the late Middle Pennsylvanian include Radiizonates difformis, Densosporites annulatus, Dictyotriletes bireticulatus, Vestispora magna, and Savitrisporites nux. Species of Lycospora, Cirratriradites, Vestispora, and Thymospora, as well as Granasporites medius, Triquitrites sculptilis, and T. securis end their respective ranges slightly higher, in earliest Late Pennsylvanian age strata. Late Middle Pennsylvanian and earliest Late Pennsylvanian strata in the Appalachian Basin correlate with the Radiizonates difformis (RD), Mooreisporites inusitatus (MI), Schopfites colchesterensis– S. dimorphus (CP), and Lycospora granulata– Granasporites medius (GM) spore assemblage zones of the Eastern Interior, or Illinois Basin. In the Western Interior Basin, these strata correlate with the middle-upper portion of the Torispora securis– Laevigatosporites globosus (SG) and lower half of the Thymospora pseudothiessenii– Schopfites dimorphus (PD) assemblage zones. In western Europe, late Middle Pennsylvanian and earliest Late Pennsylvanian strata correlate with the middle-upper portion of the Torispora securis– T. laevigata (SL) and the middle part of the Thymospora obscura– T. thiessenii (OT) spore assemblage zones. Allegheny Formation coal beds also correlate with the Torispora securis (X) and Thymospora obscura (XI) spore assemblages, which were developed for coal beds in Great Britain.

Characterizing coal beds in western Kentucky with the AlLaSc coherent triad

Cyclic sedimentation and lateral facies changes make coal bed correlations inconclusive and difficult. This uncertainty can be further complicated if a coal basin has been structurally deformed. Coal macerals can be studied to indicate the nature and degree of coalification. Their use in coal bed correlation, however, is limited. Most of the trace elements and their ratios that have been studied show significant within-bed lateral and stratigraphic variations, and thus are not effective in correlating coal beds regionally. Geochemically coherent groups of elements, such as rare earth elements (REE) and platinum group elements (PGE), appear to be highly differentiated in coal-forming environments. Geochemical coherent elemental triads appear to be useful for coal bed identification or fingerprinting. The best triad which was demonstrated to be effective in coal bed characterization in western Kentucky, is that of Al, La and Sc. These three elements are highly correlated with one another and they can be determined accurately and simultaneously with instrumental neutron activation analysis (INAA). The elemental triad AlLaSc is used to identify and fingerprint three key coal beds in western Kentucky: the Springfield (western Kentucky No. 9), the Davis (western Kentucky No. 6), and the Mining City and Dawson Springs are both considered to be the No. 4 coal bed in western Kentucky). Four distinct groupings can be recognized by use of the AlLaSc triad. The Dawson Springs coals have the highest Al/(La + Sc) ratios, followed by the Springfield, the Davis and the Mining City. The Mining City coal bed generally has the highest La/Sc ratio. However, the Dawson Springs is not correlated with the Mining City using the triad analysis, even though they have reportedly similar stratigraphic positions in the western Kentucky coal basin. The AlLaSe triad appears to be effective in discriminating between the Springfield and the Davis coal beds throughout the entire Illinois Basin. Furthermore, the range of concentration variation of the ALLaSc triad suggests individual groupings of the No. 4 coal in western Kentucky. In addition to characterizing these coal beds, the AlLaSc triad may be used to confirm stratigraphic correlations.

Characteristics of zircons from volcanic ash-derived tonsteins in Late Permian coal fields of eastern Yunnan, China

Kaolinitic tonsteins of altered synsedimentary volcanic ash-fall origin are well developed in the Late Permian coal-bearing formations of eastern Yunnan Province. Because of their unique origin, wide lateral extent, relatively constant thickness and sharp contacts with enclosing strata, great importance has been attached to these isochronous petrographic markers. In order to compare tonsteins with co-existing, non-cineritic claystones and characterize the individuality of tonsteins from different horizons for coal bed correlation, a semi-quantitative method was developed that is based on statistical analyses of the concentration and morphology of zircons and their spatial distribution patterns. This zircon-based analytical method also serves as a means for reconstructing volcanic ash-fall dispersal patterns. The results demonstrate that zircons from claystones of two different origins (i.e., tonstein and non-cineritic claystone) differ greatly in their relative abundances, crystal morphologies and spatial distribution patterns. Tonsteins from the same area but from different horizons are characterized by their own unique statistical patterns in terms of zircon concentration values and morphologic parameters (crystal length, width and the ratio of these values), thus facilitating stratigraphic correlation. Zircons from the same tonstein horizon also show continuous variation in these statistical patterns as a function of areal distribution, making it possible to identify the main path and direction in which the volcanic source materials were transported by prevailing winds.

Southeastern Extension of the Lake Basin Fault Zone in South-Central Montana: Implications for Coal and Hydrocarbon Exploration

The Lake Basin fault zone, which is the eastern extension of the Lewis and Clark line, is a structural lineament extending west-northwest across central Montana and consists mainly of en echelon northeast-striking normal faults that have been interpreted to be surface expressions of left-lateral movement along a basement wrench fault. Information gathered from recent field mapping of coal beds and from shallow, closely-spaced drill holes resulted in detailed coal bed correlations, which revealed another linear zone of en echelon faulting directly on the extended trend of the Lake Basin fault zone. This faulted area, referred to as the Sarpy Creek area, is located 30 mi (48 km) east of Hardin, Montana. It is about 10 mi (16 km) long, 8 mi (13 km) wide, and contains 21 en echelon normal faults that have an average strike of N 63° E. We therefore extend the Lake Basin fault zone 20 mi (32 km) farther southeast than previously mapped to include the Sarpy Creek area. The Ash Creek oil field, Wyoming, 60 mi (97 km) due south of the Sarpy Creek area, produces from faulted anticlinal structures that have been interpreted to be genetically related to the primary wrench-fault system known as the Nye-Bowler fault zone. The structural similarities between the Sarpy Creek area and the Ash Creek area indicate that the Sarpy Creek area is a possible site for hydrocarbon accumulation.

Evidence for Extension of Lake Basin Fault Zone from Coal Bed Correlations in South-Central Montana and Implications for Hydrocarbon Exploration: ABSTRACT

The Lake Basin fault zone is a structural lineament that extends west-northwest across central Montana. The lineament consists mainly of en echelon northeast-striking normal faults that are surface expressions of left-lateral movement along a basement wrench fault. Information gathered from the recent field mapping of coal beds and from shallow, closely spaced drill holes in the northwest part of the Powder River basin, Montana, permit detailed coal bed correlations, which revealed another linear zone of en echelon faulting directly on the extended trend of the Lake Basin fault zone. The faulted area, herein named the Sarpy Creek area, is located 48 km (30 mi) east of Hardin, Montana. It is about 13 km (8 mi) long and 10 km (6 mi) wide and contains 20 en echelon normal fa lts that have an average strike of N65°E. The Lake Basin fault zone is therefore extended 32 km (20 mi) farther southeast than previously mapped to include the Sarpy Creek area. The Lake Basin oil field, Montana, and the Ash Creek oil field, Montana and Wyoming, produce from faulted anticlinal structures that have been interpreted to be genetically related to primary wrench-fault systems--the Lake Basin fault zone and Nye-Bowler fault zone, respectively. Therefore, the faulted area of Sarpy Creek (as yet unexplored), and areas southeastward from there along the trend of the Lake Basin fault zone are possible sites for hydrocarbon accumulation. End_of_Article - Last_Page 863------------

Plant Microfossils in Correlation of Coal Beds

An intensive study of fossil microspores, isospores, and prepollens isolated from Illinois coal beds has proved that numerous genera and species are present. The correlation of coal beds is possible because the geological range of many genera and species is proved, by this investigation, to be quite restricted. Preliminary experiments with specific interregional correlations have demonstrated a wide lateral distribution of plant microfossils necessary for the correlations of this type.