Crustal structure and exhumation of the Dabie Shan ultrahigh-pr
详细信息   在线全文   PDF全文下载
摘要

Crustal-penetrating seismic reflection data across the ultrahigh-pressure (UHP) Dabie Shan orogen show that the Yangtze craton was subducted beneath the Sino-Korean craton, forming a bivergent orogenic fabric strikingly similar to “normal” (non-UHP) collision belts. Hence preservation of UHP minerals (coesite and diamond) may be unrelated to differences between collisional histories, but may be due to opportunities for subsequent intracrustal uplift of material that is routinely returned from mantle depths into the lower crust in most collisional orogens. Only a narrow channel (≤5 km) now exists from the mantle into the crust through which UHP material was returned to lower-crustal depths as thin slabs. We image the Dabie Shan as a crustal-scale dome formed during postcollisional intracrustal uplift by core-complex–type exhumation of the lower crust, tectonically unrelated to the earlier exhumation from >100 km to <35–40 km.

© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号

地址:北京市海淀区学院路29号 邮编:100083

电话:办公室:(+86 10)66554848;文献借阅、咨询服务、科技查新:66554700