【摘要】 基性岩墙群代表了陆壳伸展裂解事件,可为大陆再造及造山作用过程的动力学研究提供时间约束。本文利用LA_ICPMS方法对秦祁造山带接合部位陇山岩群中首次报道的基性岩墙群进行了锆石U_Pb同位素测年,获得440Ma左右的年龄。结合区域资料,认为在中央造山带中段可能普遍存在440Ma左右的一期伸展裂解事件。这一信息对中央造山带的构造演化及成矿地质背景研究具有重要地质意义。更多还原

【Abstract】 Mafic dykes represent a possible event of crustal break_off and can constrain the time of land_rebuilding and dynamics in this area. The authors found some unreported mafic dykes in the Qinling and Longshan Groups between the Qinling and the Qilian orogenic belts. A 440 Ma U_Pb age was measured for these dykes using zircon LA_ICPMS, which indicates that a regional extension might have occurred in the Qinling and the Qi_ lian orogenic belts. The data is very important in the study of the evolution and mineralization of the Qinling and the Qilian orogenic belts.更多还原