【摘要】 一般认为武当地块耀岭河群火山岩成岩年龄是700-1000Ma,与全球Rodinia超大陆裂解作用有关。本文从武当地块不同地点的耀岭河群火山岩中获得13颗锆石进行U-Pb法年龄测定,结果显示其年龄值具有高度的一致性,时代为632±1Ma,属震旦纪底界年龄,滞后于全球Rodinia超大陆裂解作用。作者认为本文测定的这组年龄值代表了耀岭河群火山岩的成岩年龄。耀岭河群火山岩的成岩年龄精确厘定对研究耀岭河群火山岩的地质含义有一定参考价值,同时也可能对秦岭Rodinia超大陆裂解等大地构造观点产生影响。更多还原

【Abstract】 The forming age of volcanic rocks of the Yaolinghe Group from Wudang block,Southern Qinling Mountain was previously thought to be between 700 and 1000 Ma and its origin is closely related with the evolution of the supercontinent Rodinia in common.We collected 13 zircon grains from the volcanic rocks of the Yaolinghe Group.U-Pb dating of these grain zircons shows that the age of the volcanic rocks is 632±1 Ma,indicating a difference from the age previously suggested.The authors argue that the zircon U-Pb dating result is credible and the 632±1Ma should represent the forming age of the volcanic rocks of the Yaolinghe Group.Hence,the grain-zircon U-Pb dating constrains the volcanic rocks of the Yaolinghe Group to be formed during the late Sinian Period.This study may have certain reference value to study the geological meanings of the volcanic rocks of the Yaolinghe Group,and may influence some standpoints about Rodinia super continent split in Qinlin belt.更多还原