摘要
秦巴地区的地壳构造线,浅部呈东西向展布,深部呈南北向展布,作者把这种深浅异向的构造暂称为“立交桥”构造。在深,浅不和谐构造之间,必然产生大滑脱,并使滑脱面的岩石产生熔融,形成地震 P 波低速层。此低速层是花岗岩类的主要岩浆源。低速层的深浅控制了花岗岩类岩浆的成分,陆壳的构造控制了岩体的定位。
The crust tectonic lines in the Qinling-Dabashan area are spreading in EW direction at the upper part and in SN direction at the lower part. The writers temporarily called this kind of tectonics with differential orient- ations batween the shallow and deep part a“Grade Separation Bridge”.A large-scale decollement may occur inevitably between the disharmonic shal- low and deep structures,thus melting the rocks at the decollement faces and forming a low velocity layer of the seismic P wave.The low velocity layer is a main magma reservoir of granitoid.The magma compositions of granit- oid are controlled by depth of the velocity layer,and orientions of rock bodies are controlled by the crustal structures.
出处
《陕西地质》
1989年第2期5-10,共6页
Geology of Shaanxi
