用户名: 密码: 验证码:
Jurassic subsidence history of the Hazelton Trough–Bowser Basin in
详细信息   在线全文   PDF全文下载
摘要

Backstripping calculations performed on a stratigraphic section near Todagin Mountain, north-central British Columbia, indicate that the northern edge of the Hazelton Trough–Bowser Basin was characterized by two phases of enhanced subsidence. An initial episode of rapid subsidence occurred in the Pliensbachian, during which bimodal volcanic flows and associated sedimentary rocks were deposited in a shallow-marine environment. This episode corresponds to the end of a rifting event in the Stikine arc when most of the accommodation space was generated by extensional faulting of the predominantly igneous basement. Slower subsidence took place in Toarcian to Bajocian time along with deposition of a condensed section in a deep-water basin. This part of the history is consistent with thermal subsidence following the end of volcanism. An increase of subsidence rates in the Bathonian–Callovian interval was accompanied by increased sediment supply, marking the start of deposition of the Bowser Lake Group. This second pulse of rapid subsidence can be explained by sediment loading alone but the subsidence history does not rule out tectonic loading of the basin floor. The Jurassic subsidence history observed at Todagin Mountain is consistent with a simple extensional model defined by a rifting episode followed by thermal contraction and sediment loading. Tectonic loading might also have played a role in the second episode but is not required by the subsidence model.

© 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