The use of trace elements to determine provenance relations among different types of Georgia kaolins
This study evaluates the proposition that different types of commercial kaolin district were derived from different source rocks. This analysis was made by comparing the cobalt, lanthanum, scandium and thorium concentrations of commercial kaolins to in situ kaolins derived from igneous and metamorphic rocks of the southeastern Piedmont provence. These elements are effective provenance indicators of fine grained sedimentary rocks because acidic (i.e., felsic) source rocks contain high levels of thorium and lanthanum; whereas, basic (i.e., basic) source rocks contain high levels of scandium and cobalt. Also, these elements are relatively immobile under surface weathering conditions. The -2 micrometer fraction of in situ kaolins derived from granite and gneiss adjacent to the kaolin belt contains relatively high concentrations of thorium (25.5-86.6 ppm) and lanthanum (46.0-256 ppm) and low concentrations of cobalt (7.5-25.2 ppm) and scandium (13.8-28.3 ppm). In contrast, in situ kaolins derived from intermediate metavolcanic rocks contain relatively low abundances of thorium (5.6-20.7 ppm) and lanthanum (17.5-122 ppm) and high concentrations of cobalt (18.6-55.5 ppm) and scandium (13.8-48.9 ppm). After consideration of factors that cause chemical fractionation of trace elements in low temperature environments the following provenance relationships are indicated: (1) the Cretaceous (soft) kaolins of Middle Georgia and South Carolina are derived from granite and gneiss, (2) the east Georgia and South Carolina Tertiary (hard) kaolins are derived from a mixture of approximately 70% metavolcanic rocks and 30% granite/gneiss source rocks, and (3) the Middle Georgia tertiary (hard) kaolins are derived from predominantly metavolcanic source rocks with distinct zones dominated by detritus from granite/gneiss sources. The differences in source material are controlled by the availability of source material exposed to alteration and erosion during the different time periods.
- Research Organization:
- Indiana Univ., Bloomington, IN (United States)
- OSTI ID:
- 6870207
- Resource Relation:
- Other Information: Thesis (Ph.D.)
- Country of Publication:
- United States
- Language:
- English
Similar Records
Preliminary study of the uranium potential of the Wadesboro Triassic basin, North Carolina
Geochemical provenance of anomalous metal concentrations in stream sediments in the Ashton 1:250,000 quadrangle, Idaho/Montana/Wyoming