NW Univ Xian, Dept Geol, Xian 710069, Peoples R China
; Chinese Acad Sci, Inst High Energy Phys, Beijing 100080, Peoples R China
The basic dyke swarms, which have been deformed and metamorphosed, are widespread in the Wudang block. They are geochemically characterized by the continental tholeiites, and their Sm-Nd isochron age is (782 +/- 164) Ma. All of these indicate that there was an ancient continental block in the Proterozoic and a rifting occurring on this continental block during +/-800 Ma.