Neoproterozoic regolith

Region East, Southeast
Mineral systems
Deposit types
Other minerals

Information leading to the delineation of this focus area

Basis for focus area Focus area outlines a belt of Neoproterozoic granitic rocks.
Identified resources None.
Production None.
Status Unknown.
Estimated resources Unknown.
Geologic maps Prouty (1923), scale 1:63,360; Osborne and others (1989), scale 1:250,000.
Geophysical data Inadequate aeromagnetic and aeroradiometric data: Rank 3-5 aeromagnetic and Rank 5 aeroradiometric surveys.
Favorable rocks and structures Lithology, in situ regolith thickness, highly evolved granitic system, anorogenic and highly fractionated igneous-type granites, tin, fluorine; igneous-related kaolin deposits.
Deposits None.
Evidence from mineral occurrences Potential from mineral system/deposit type.
Geochemical evidence High proportion of chemically extractable REE (absorbed REE and soluble REE minerals). Tetrad behavior in granite and/or regolith.
Geophysical evidence Unknown.
Evidence from other sources Igneous rocks, climate history, in situ regolith development.
Comments Studies demonstrate significant potential in the southeastern United States for regolith-hosted clay deposits of a type containing light-middle REE and Y, and an as-yet-unknown potential for high-value heavy REE deposits of the type mined in South China.
Cover thickness and description Variable, soils, partially weathered igneous rock.
Authors Nora K. Foley, Robert A. Ayuso, Bernard E. Hubbard.
New data needs Geologic mapping, and geochemical analyses.
Geologic mapping and modeling needs 1:24,000 scale geologic mapping to determine the extent and distribution of granite-derived regolith and prospective source plutons and geochemical analyses to assess the resource quality/grade.
Geophysical survey and modeling needs High resolution aeromagnetic and radiometric coverage, and electromagnetic data (EM) resistivity.
Digital elevation data needs Lidar complete.