论文部分内容阅读
延长数百至数千公里的线状构造带,其中地壳以扩张占优势,并有地幔物质上升的称为裂谷。裂谷形成作用表现为地壳的变薄,直到完全断裂和产生洋壳。裂谷带为被正断层所限定的延长的深地堑,其中充填有巨厚的碎屑和火山沉积。对于裂谷带来说,碱性岩浆活动是典型的;表现为在地堑中是碱性或拉斑玄武岩的溢出,在其两侧则是超基性、超碱性和酸碱性成分的中心式岩俸的侵入。某些研究者认为裂谷形成作用主要在显生宙,甚至只在新生代发生。而在更老的时期——里菲、早元古和太古——只产生似裂谷构造,
Extending hundreds to thousands of kilometers of linear tectonic belts, in which the crust is dominated by expansion and the rise of mantle material is called rifting. Rift formation is manifested by the thinning of the crust until it is completely fractured and the oceanic crust is created. The rift zone is an extended deep graben delimited by normal faults, filled with massive debris and volcanic deposits. Alkaline magmatic activity is typical for rifting zones; it is characterized by basal or tholeiitic basalts overflowing in the graben, and ultrabasic, overbased and acid-base components on either side of it Center-type rock pension invasion. Some researchers believe that rifting is mainly found in the Phanerozoic, even only in the Cenozoic. In the more advanced periods, that is, Reeve, Early Proterozoic, and Archaean - produced rift-like structures,