碳酸岩U系测年在滇西北北衙组地层抬升速率计算中的应用

Application of Carbonatite Uranium Series Dating Method in the Calculation of the Beiya Formation Stratigraphic Uplifting Rate in Northwest Yunnan

自第四纪以来,滇西北地区地壳活动强度明显增强,地震活动频繁,区域稳定性越来越低,人类生存环境严酷。选取滇西北地区鹤庆—洱源断裂带经过的北衙组地层作为研究对象,通过对干涸的溶洞内鹅管碳酸盐矿物进行U系不平衡法准确定年,厘定出构造隆升作用的起始时间,最终计算得出该套地层抬升速率为2.4mm/a。北衙组地层的迅速抬升,反映了滇西北地区作为青藏高原东南扩展前缘的地球动力学过程,可能与青藏高原下地壳物质向滇西流动汇聚有关。同时,该抬升速率为滇西地区国家重大工程建设的设防抗震提供了可靠的数据支撑。

Since the Quaternary,the intensity of crustal activity in the northwestern Yunnan region has been significantly enhanced,earthquake activity is frequent,regional stability is getting lower and lower,and human living environment is harsh.The paper selected the Beiya formation as the research object,which was been through with the Heqing-Eryuan fault zone.By using the U series unbalance method of the goose tube in the dried karst cave,the starting time of the tectonic uplift is determined.Finally,the uplift rate of Beiya formation is calculated to be 2.4mm/a,which provides reliable data support for the major construction of the country.