摘要
查藏错-申扎南北向裂陷带是横贯冈底斯山脉谢通门-申扎南北向断裂带的北段,格仁错北西向断裂为查藏错-申扎裂陷盆地的转换边界。裂陷盆地内没有发现前更新世沉积物,该裂陷带断开了上新世地层和5.45 Ma的白云母花岗岩体。从查藏错到申扎,裂陷带两侧的岩体、地层和构造线完全可以恢复和拼接。查藏错-申扎裂陷盆地获得130 ka沉积物年龄,为裂陷盆地已知最早的沉积物年龄。推测裂陷带的初始发育时间为晚更新世晚期。根据地质和定年研究,130 ka以来查藏错-申扎裂陷带东西向裂开的宽度为6750-12500m,以此计算裂陷盆地东西向扩张数率大于51.9mm/a。南北向挤压和东西向伸展是冈底斯地区地壳力学系统的两种表现形式。
The Chazang Co-Xainza fault belt is the northern segment of the Xaitongmoin-Xainza fault belt that traverses Gangdise. The northwest-striking Gyaring Co fault is a transform boundary of the Chazang Co-Xainza basin. There are no pre-Neogene sediments in the basin, which cuts Pliocene strata and a twomica granite of 5.45 Ma. Intrusions, strata and structural lines can be correlated on the two sides of the basin from Chazang to Xainza. Sediments of 130 ka are the oldest in the basin. The basin started 30000 a ago and reached a width of 6750-15250 m. So, the extensional speed is more than 5.19 cm/a, which is consistent with the result of GPS. Longitudinal compression and latitudinal extension are two modes of crustal dynamic system in the Gangdise area.
出处
《地质论评》
CAS
CSCD
北大核心
2005年第4期353-359,共7页
Geological Review
基金
本文为中国地质调查局青藏高原地质调查项目(编号2000130000914
200313000054)的成果。
