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The AAPG/Datapages Combined Publications Database

AAPG Bulletin


Volume: 63 (1979)

Issue: 9. (September)

First Page: 1580

Last Page: 1580

Title: Elemental Analyses of Devonian Shales in Southern West Virginia: ABSTRACT

Author(s): Michael E. Hohn, Donald W. Neal

Article Type: Meeting abstract


Elemental compositions were determined on 690 samples of well cuttings from 19 wells in the Devonian shales of southern West Virginia; each well was sampled at roughly 50-ft (15 m) intervals. Sampling included all major stratigraphic intervals with special emphasis on five stratigraphic units: Chagrin Shale, Huron Member of the Ohio Shale, White Slate (correlates with Java Formation and Angola Shale Member of the West Falls Formation), Rhinestreet Shale Member of the West Falls Formation, and the Marcellus Shale. After calculating mean percentages within each unit, hand contouring maps, making trend-surface analyses, and diagramming vertical variations, individual elements showed regional and stratigraphic trends. Silica increases upsection, whereas potassium and MgO decr ase. The Marcellus Shale exhibits very high values for calcium and phosphate. Sulfur, strontium, and zinc appear to reflect the quantities of organic matter, which are higher in the black shale of the Huron Member and the Rhinestreet Member relative to the gray shales of the White Slate and the Chagrin Shale. The amounts of titanium, iron, and phosphate are low in black shales.

Regionally, sulfur is higher in the westernmost parts of the study area and appears to be related to the presence of a platform where conditions were conducive to its concentration. Silica is low in the central part of the area. Manganese is highest in the gray shales and areas of black shales interpreted to have been deposited in deeper water; manganese correlates inversely with sulfur, suggesting the influence of redox conditions on manganese deposition.

The results confirm the recent work on stratigraphic correlation of the Devonian shales in West Virginia. They also conform to the picture of the Devonian sea in this area as a platform with a deeper area and sediment source in the east, and possibly a second source in the west.

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Copyright 1997 American Association of Petroleum Geologists