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The Allegheny Plateau in western Pennsylvania, western Maryland, and northern West Virginia has relatively flat-lying strata with southwest-northeast-trending anticlines cored by splay faults originating from the thrust faults and southeast-northwest-trending lineaments. The lineaments define both the structural relief of the anticlines and the coal rank. Coal rank in the Pennsylvanian Allegheny Group coals is medium volatile bituminous in the region of less-prominent structural relief and low volatile bituminous in the region with more pronounced anticlines. Zinc and Cl exhibit high values in coals in the vicinity of the lineaments. Although coal rank was not a parameter in the Principal components analysis, the highest rank coals clustered together in a quadrant defined, in part, by the Zn concentration. Zinc was selected as a parameter due to its possible link with hydrothermal mineralization and Zr and TiO 2 /Al 2 O 3 were selected based on their presumed association with detrital mineral influences. The highest rare earths + Y values in benches of the Lower Kittanning coal were found at sites close to the lineaments. Negative or negligible Ce anomalies (δCe) and strongly positive Gd anomalies (δGd) suggest marine or hydrothermal influences and negative Eu anomalies (δEu) along with high TiO 2 /Al 2 O 3 values suggest a terrestrial input. The plots of δCe vs. δGd and δCe vs. δEu show that the low volatile bituminous coals are segregated from the other coals, suggesting that the factors that influenced coal rank also influenced the distribution of the rare earth elements. • The Allegheny Front is the eastern region of the Northern Appalachian coalfields. • For this work, the focus was on the region to the east of the Chestnut Ridge anticline. • Pottsville, Allegheny, and Conemaugh formation coals were examined. • High concentrations of Zn and Cl in coals were associated with cross-strike lineaments. • Coal rank and rare earth emplacement may have been mutually controlled. [ABSTRACT FROM AUTHOR]

The Gzhelian (Stephanian C)-age Pittsburgh coal in southwestern Pennsylvania, eastern Ohio, northern West Virginia, and western Maryland has been mined since the 1700's. The coal contributed up to 80% of the US coking coal in the 1880's and continued to be an important source of coking coal through the 20th century. This high-vitrinite coal decreases in rank from medium and low volatile bituminous in Somerset County, Pennsylvania, and in adjacent parts of Maryland to high volatile C bituminous in Ohio, a distance of about 170 km. Detailed studies of the petrology and coking characteristics of the coal were conducted by Thiessen, Strunk, and others at the U.S. Bureau of Mines in the 1930's, and Aureal Cross conducted detailed petrographic and paleobotanical investigation in the 1950's. Later studies have examined the petrology and palynology of the coal in northern West Virginia. In this investigation, the coals collected by the Penn State Coal Research Section are re-examined in the light of modern coal petrographic nomenclature. Telovitrinite macerals generally dominate the vitrinite group and fusinite and semifusinite, along with minor macrinite, micrinite, and secretinite, comprise the inertinite group. • The Pittsburgh coal contributed large percentages of US coking coal from the 19th century through much of the 20th century. • Coal rank increases hvC bituminous in OH to medium and low volatile bituminous near the Allegheny Front in PA and MD. • Samples were re-examined with modern nomenclature in the light of several classic investigations. • Telovitrinite macerals generally dominate the vitrinite group. • Fusinite and semifusinite dominate the inertinite group. [ABSTRACT FROM AUTHOR]