X-Radiograph Atlas of Lithotypes and Other Structures in the Devonian Shale Sequence of West Virginia and Virginia

摘要

X-radiographs of 525 samples from cored wells and outcrops serve as the basis for a study of fabric elements in the Upper Devonian shale sequence of West Virginia and Virginia. Four shale lithotypes have been identified from X-radiographs: (1) thinly-laminated shale, (2) lenticularly-laminated shale, (3) sharply-banded shale, and (4) non-banded shale. The order from 1 to 4 follows decreasing lateral fabric continuity. Two non-shale lithotypes, siltstones and concretions are also recognized. Gas production from this shale section is associated with lithotypes possessing high lateral fabric continuity. Thus, a classification based on fabric elements appears useful both for interpretation of depositional environments and for interpretation of reservoir properties. Forty-nine illustrations of lithotypes, other sedimentary structures, and tectonic features are given. (ERA citation 04:054160)