Clay mineralogy of weathering profiles from the Carolina Piedmont.
Saprolite profiles (12) that formed over various crystalline rocks from the Charlotte 1o X 2o quadrangle showed overall similarity in their clay mineralogy to depths of 6 to 45 m indicating control by weathering processes rather than by rock type. Most saprolite contained 10-25% clay, and ranged 3 to 70%. Kaolinite and halloysite composed = or >75% of the clay fraction of most samples. The ratio kaolinite:halloysite ranged widely, from 95% kaolinite to 90% halloysite, independent of depth. Clay-size mica was present in all profiles, and ranged 5-75% over a sericite schist. Mixed-layer mica-smectite and mica-vermiculite were subordinate; discrete smectite and vermiculite were rare. The abundance of halloysite indicates a continuously humid environment since the time of profile formation, because of the rapidity with which halloysite dehydrates irreversibly. -R.S.M.
Citation Information
Publication Year | 1981 |
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Title | Clay mineralogy of weathering profiles from the Carolina Piedmont. |
Authors | P. J. Loferski |
Publication Type | Article |
Publication Subtype | Journal Article |
Series Title | Southeastern Geology |
Index ID | 70012165 |
Record Source | USGS Publications Warehouse |