Hydrated Halloysite in Blue Hill Shale

Ada Swineford, John D. McNeal and Carl F. Crumpton
State Geological Survey, University of Kansas, Lawrence
State Highway Commission of Kansas, Manhattan

Abstract: Nodules of alunite and hydrated halloysite occur in the upper part of the Cretaceous Blue Hill shale at three localities in west-central Kansas. They have formed at the contact of septarian concretions with the shale and are associated with gypsum. The nodules are judged to have been formed by the action of sulfuric acid from pyrite on the potassium-bearing minerals of the Blue Hill shale, perhaps under special conditions of pH and Eh produced locally by the presence of septaria.

The minerals were studied and identified by x-ray diffraction, thermal data, chemical analysis, and electron and light microscopy.

Clays and Clay Minerals; 1953 v. 2; no. 1; p. 158-170; DOI: 10.1346/CCMN.1953.0020114
© 1953, The Clay Minerals Society
Clay Minerals Society (www.clays.org)