Distribution of Clay Minerals and Ion-Exchange Capacity in Some Sedimentary Materials1

John C. Hathaway and Dorothy Carroll
U.S. Geological Survey, Washington
1 Publication authorized by the Director, U. S. Geological Survey.

Abstract: The cation-exchange capacity of the clay fraction was determined in 67 samples of various types of sedimentary materials, and the clay minerals were identified from x-ray diffractometer patterns of oriented aggregates. The probable quantitative clay mineral composition was established for each sample assuming a comparable degree of crystallinity for the clay minerals in the sample. Agreement was poor between the ion-exchange capacities determined and those predicted from the clay mineral composition. The results suggest that the figure obtained for the ion-exchange capacity of a sample of sedimentary material may be misleading as a guide to the types of clay minerals present.

The residual soils among the sedimentary materials examined had clay fractions with greater variation in ion-exchange capacity than did unconsolidated sediments generally of alluvial origin.

Clays and Clay Minerals; 1953 v. 2; no. 1; p. 264-276; DOI: 10.1346/CCMN.1953.0020122
© 1953, The Clay Minerals Society
Clay Minerals Society (www.clays.org)