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White clays of Pennsylvania

Bulletin 1558-D

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Abstract

The white clays of Pennsylvania are composed chiefly of kaolinite and various amounts of illite. Most of the white clays are silty and a few are sandy. Quartz or chert is the only nonclay mineral in the whitest material; goethite is also present in the colored samples high in iron. The average alumina content is slightly more than 20 percent in samples from three clay pits and less than 15 percent in samples from five clay pits. The white clay deposits are found in eastern, south-central, and central Pennsylvania. They occur in rocks of the Appalachian basin that range in age from Cambrian to Devonian; however, their age of formation is Cretaceous or later. Some of the deposits are the result of katamorphic alteration, and some are the result of weathered material being transported and deposited in sinkaoles or caverns. The presence of alunite in one deposit suggests the possibility that the clay may be the result of both katamorphic and hydrothermal alteration.

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Additional publication details

Publication type:
Report
Publication Subtype:
USGS Numbered Series
Title:
White clays of Pennsylvania
Series title:
Bulletin
Series number:
1558
Chapter:
D
Year Published:
1984
Language:
English
Publisher:
U.S. Government Printing Office
Description:
iv, 38 p.
Larger Work Title:
Contributions to the geology of mineral deposits
First page:
D1
Last page:
D38
Country:
United States
State:
Pennsylvania
County:
Blair County, Centre County, Cumberland County, Huntingdon County, Lancaster County, Monroe County, York County