Regularly Interstratified Chlorite—Dioctahedral Smectite in Dike-Intruded Shales, Montana

C L. Blatter, H. E. Roberson and G. R. Thompson
Department of Geology, State University of New York at Binghamton, New York 13901, U.S.A.
Department of Geology, University of Montana, Missoula, Montana, U.S.A.

Abstract: Corrensite or ‘corrensite-like’ minerals occur in dike-intruded shales and siltstones of the Montana Group and Colorado Group (Early Cretaceous) in Western Montana. The < 1 µm size fraction of one specimen of this “corrensite-like” material has been studied in detail. X-ray diffraction data and chemical analysis indicate that this specimen is a regular or nearly regular interstratification of chlorite and dioctahedral smectite. Also described are other samples, which contain corrensite and additional phases. These samples were taken at several localities where basic dikes have intruded these shales and siltstones.

Clays and Clay Minerals; August 1973 v. 21; no. 4; p. 207-212; DOI: 10.1346/CCMN.1973.0210402
© 1973, The Clay Minerals Society
Clay Minerals Society (www.clays.org)