Electron Microscopy and X-ray Analysis of Lacustrine Clays from the Charo Canyon, State of Michoacán, Mexico

G. Carbajal de la Torre1, I. Israde Alcántara1, J. Serrato Rodríguez1 and J. Reyes-Gasga2
1 Instituto de Investigaciones Metalúrgicas U.M.S.N.H., Apdo. Postal 52 B, C.P. 58000 Morelia, Michoacán, México
2 Instituto de Física, UNAM, Apdo. Postal 20-364, 01000 México, D.E, México

Abstract: In this paper we analyzed by electron microscopy and X-ray diffraction (XRD) the exposed lacustrine clay in a stratigraphic column at Charo Canyon, State of Michoacán, Mexico. Smectite, cristobalite, albite and quartz are the main mineral species in the sediments. Smectite is the most abundant and has a nanometric twinned small particle habit. The low crystallinity of the smectite detected in some of the samples seems to be associated with instability of the paleohydrological regime in which clayey material was deposited. Iron from underlying volcanic ash is apparently responsible for the iron concentration detected in the smectite structure.

Key Words: Clays • Electron Microscopy • Geology • X-Ray Analysis

Clays and Clay Minerals; June 1998 v. 46; no. 3; p. 330-339; DOI: 10.1346/CCMN.1998.0460312
© 1998, The Clay Minerals Society
Clay Minerals Society (www.clays.org)