The age of metamorphic rocks of the Wudang Group

Abstract: There have long been disputes about the age of the Wudang Group exposed in northwestern Hubei. This paper Reports the results of Sm? Juan Nd and Rb? Juan Sr dating of samples of metavolcanic Rocks of the the Wudang Group from North of Shiyan City, Taizipo of Wudang Mountain and Tucheng of in Fangxian County. The former Wudang Group consists of rocks of two parts of metavolcanic different ages. The protolith of one part of metavolcanic rocks originated at ~ 1972Ma and the materials of the volcanic rocks were derived from an area similar to the MORB mantle source area, During rock formatim no significant contamination with crustal material occarred; so they are the real Wudang Group . The age of the protolith of the other part is 1175-871Ma, similar to that of the protoliths of metavolcanic rocks of the Yaolinghe and Yunxi Groups, and their istopic compositions also show that this part of rock has an affinity to the latter. In the study of the stratigraphic age in an area with complex geological processes, good results may be obtained if we start with microscopic Nd isotope study.