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Chemistry of illite/smectite and end-member illite

January 1, 1986

Chemical data from three different series of diagenetic illite/smectites (I/S), analyzed statistically by two regresion techniques, indicate that the content of fixed-K per illite layer is not constant, but ranges from ∼0.55 per O10(OH)2 for illite layers in randomly interstratified I/S (R=0; > 50% smectite layers) to ∼1.0 per O10(OH)2 for illite layers formed in ordered I/S (R>0; <50% smectite layers). By extrapolation of the experimental data, the following chemical characteristics were obtained for end-member illite derived from the alteration of smectite in bentonite: average fixed-K per illite layer = 0.75 per O10(OH)2; total charge = about −0.8; cation-exchange capacity = 15 meq/100 g; surface area (EGME) = 150 m2/g.

Publication Year 1986
Title Chemistry of illite/smectite and end-member illite
DOI 10.1346/CCMN.1986.0340403
Authors J. Srodon, D.J. Morgan, E.V. Eslinger, D. D. Eberl, M.R. Karlinger
Publication Type Article
Publication Subtype Journal Article
Series Title Clays and Clay Minerals
Index ID 70186161
Record Source USGS Publications Warehouse
USGS Organization Toxic Substances Hydrology Program