Geological and geophysical data recently gathered in the English Channel permit delineation of the main basement structures beneath the Mesozoic and Cenozoic cover. These are, from north to south, (1) a Paleozoic trough, (2) a mafic rock complex, probably ophiolitic, and (3) a Precambrian craton, with a thin Paleozoic cover restricted to some grabens. This disposition suggests the presence of a cryptic suture. Arguments based on stratigraphy (the terranes grow older to the north), structure (faults are parallel to the mafic rock complex, and horsts and grabens are found in the craton), geochronology (the pre-Hercynian intrusions show a distinct arrangement in time and space), petrography (calcalkalic intrusions and an arc of ignimbrites are found), and paleontology (two faunal realms existed during early Paleozoic time) suggest that subduction could have occurred between late Proterozoic and middle Paleozoic time under the Domnonean domain.
© 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 |