Coarse-grained, protolithionite-muscovite granite with a finer grained muscovite granite margin (Yashan batholith), intruded by small bodies of muscovite granite which form the locus of a tungsten vein system at the Xinfang tungsten mine. Two sheetlike bodies, a lower lithium mica granite and an upper topaz-lepidolite granite intrude the upper contact between the protolithionite-muscovite granite and the host metasediments. The granites are crosscut by unmineralized porphyry dikes that are exploited as a source of kaolin. The topaz-lepidolite granite is a major, low-grade Ta-Nb-Li deposit which is exploited via open-pit mining.
Ref.:
- Lin Yin, Pollard, P.J., Hu Shouxi, and Taylor, R.G. (1995): Geologic and geochemical characteristics of the Yichun Ta-Nb-Li deposit, Jiangxi Province, South China. Economic Geology 90(3), 577-585.