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Lexington, KY, United States

Hower J.C.,University of Kentucky | Eble C.F.,Kentucky Geological Survey | Dai S.,China University of Mining and Technology | Belkin H.E.,U.S. Geological Survey
International Journal of Coal Geology | Year: 2016

Four eastern Kentucky Pennsylvanian coals (from oldest to youngest, the Manchester, Pond Creek, Fire Clay, and Hazard coals) were examined for their total rare earth element (REY) concentration and the possible mechanisms for enrichment of the rare earths. Based on previous studies, four possible modes are considered: terrigenous, tuffaceous, infiltrational, and hydrothermal, with the Dean coal, a correlative of the Fire Clay coal, considered to be a typical example of the tuffaceous mode. The Fire Clay owes much of its high REY content to the presence of a volcanic-ash-fall tonstein, with REY-bearing zircon and phosphates in the coal in numerous locations. Some of the original REY elements may have components of the detrital minerals deposited in the peat. Leaching of REY from the tonstein into the surrounding coal and the hydrothermal overprint of mineralizing fluids associated with the northwestwardly movement of the Pine Mountain thrust sheet contributed to the total REY signature in the Fire Clay coal. Not all coals are going to have the complex history of the Fire Clay coal, but it should be considered that the total history of REY enrichment by multiple mechanisms is what gives us both the total REY concentration and the relative distribution of the individual lanthanide elements. © 2016 Elsevier B.V. Source


Hansen A.E.,Kentucky Geological Survey | Hower J.C.,University of Kentucky
International Journal of Coal Geology | Year: 2014

Hardgrove grindability index (HGI) has been a standard test in the coal and coal-fired power generation industries since the 1930s. Previous studies have demonstrated the relationship between HGI and coal rank and the maceral and mineral composition. In particular, within the high volatile bituminous rank range, HGI increases with an increase in coal rank and, for any specific rank, decreases with an increase in the liptinite content. Fundamentally, the HGI test is approximately at the scale of coal microlithotypes, the microscopic assemblages of macerals. In this study, for two relatively narrow rank ranges, each spanning 0.05% Rmax, we examined the relationship between HGI and several maceral and microlithotype ratios for Pennsylvanian eastern Kentucky coals. While some relationships do show statistically significant trends, not all were as well defined as might have been expected. © 2014 Elsevier B.V. Source


Richardson A.R.,University of Kentucky | Richardson A.R.,Chesapeake Energy Co. | Eble C.F.,Kentucky Geological Survey | Hower J.C.,University of Kentucky | O'Keefe J.M.K.,Morehead State University
International Journal of Coal Geology | Year: 2012

The Pennsylvanian No. 5 Block coal bed in eastern Kentucky is one of several coals considered to be among the splint coals of the Central Appalachians. The coals are generally noted for their inertinite-rich dull lithotypes. Petrographic aspects of the lithologies reveal both fire-derived and degradation-derived inertinites in the assemblages. Fire is not an exclusive contributor to the origin to inertinite macerals; there are many other biological factors, such as the actions and interactions of fungi, bacteria, and insects, which must be considered in the alteration of plant materials to form inertinite macerals. Fungi physically and chemically alter plant tissues to form macerals with a distinct morphology and chemistry different than those formed from fire and other abiological processes. Insects, as secondary sources of wood degradation within a mire, are responsible for physical, such as boreholes from wood-consuming insects, and chemical alteration of plants. Degradation observed in macrinite may be boreholes from wood-consuming insects such as mites. Some inertinite macerals, in particular, macrinite, may be the result of inert fecal pellet conglomerates preserved in the mire. Overall, macerals of the same name can form from multiple and complex biological and abiological processes. © 2012 Elsevier B.V.. Source


Xie F.,China Earthquake Administration | Wang Z.,Kentucky Geological Survey | Liu J.,China Earthquake Administration
Pure and Applied Geophysics | Year: 2011

Seismic hazard and risk in the Beijing-Tianjin-Tangshan, China, area were estimated from 500-year intensity observations. First, we digitized the intensity observations (maps) using ArcGIS with a cell size of 0.1 × 0.1°. Second, we performed a statistical analysis on the digitized intensity data, determined an average b value (0.39), and derived the intensity-frequency relationship (hazard curve) for each cell. Finally, based on a Poisson model for earthquake occurrence, we calculated seismic risk in terms of a probability of I ≥ 7, 8, or 9 in 50 years. We also calculated the corresponding 10 percent probability of exceedance of these intensities in 50 years. The advantages of assessing seismic hazard and risk from intensity records are that (1) fewer assumptions (i. e., earthquake source and ground motion attenuation) are made, and (2) site-effect is included. Our study shows that the area has high seismic hazard and risk. Our study also suggests that current design peak ground acceleration or intensity for the area may not be adequate. © 2010 BirkhÄuser / Springer Basel AG. Source


Liu J.-W.,China Earthquake Administration | Wang Z.-M.,Kentucky Geological Survey | Xie F.-R.,China Earthquake Administration
Chinese Journal of Geophysics (Acta Geophysica Sinica) | Year: 2010

This paper attempts to analyze seismic hazard and risk in Beijing-Tianjin-Tangshan,. , area from 500-year intensity observations, and to provide the basic parameters or intensities for seismic design and other mitigation considerations. First, we digitized the intensity observations (maps) using ArcGIS with a cell size of 0.1 degree × 0.1 degree. Second, we performed a statistical analysis on the digitized intensity data and derived intensity-frequency relationship (hazard curve) for each cell. Finally, we estimated seismic risk in terms of a probability that intensity exceeds VII, VIII, or IX in a certain periods (i. e., 50years) based on the assumption of a Poisson distribution for earthquake occurrence. We also estimated the corresponding intensity with 10 percent probability of exceedance in 50 years. The results shows that the area has high seismic risk and the current design requirement for the area may be not adequate. Source

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