[1] Stanford Univ, Dept Geol & Environm Sci, Stanford, CA 94305 USA
[2] Univ Cambridge, Dept Earth Sci, Cambridge CB2 3EQ, England
[3] Univ Calif Santa Cruz, Inst Marine Sci, Santa Cruz, CA 95064 USA
[4] Univ Calif Berkeley, Berkeley, CA 94720 USA
[5] Univ Wisconsin, Dept Geol, Oshkosh, WI 54901 USA
[6] Guizhou Geol Survey, Guizhou Reg Mapping Team, Guiyang 550005, Peoples R China
[7] Guizhou Univ, Resources & Environm Engn Coll, Guiyang 550003, Guizhou Prov, Peoples R China