渤海湾盆地中—新生代岩石圈热结构与热-流变学演化

发布时间：2018-04-10 08:51

本文选题：渤海湾盆地　切入点：热历史　出处：《地学前缘》2017年03期

【摘要】：文章主要利用中—新生代热史、地壳分层结构以及流变学参数,模拟计算渤海湾盆地中—新生代岩石圈热结构和热-流变结构演化特征。结果表明,盆地由三叠纪—侏罗纪时期的"冷幔热壳"型岩石圈热结构转变为白垩纪至今的"热幔冷壳"型岩石圈热结构。从济阳坳陷岩石圈热-流变结构演化特征来看,中生代早期上地壳上部、中地壳上部及上地幔顶部表现为厚的脆性层;早白垩世初期中地壳上部及上地幔顶部的脆性层完全转变为韧性层;晚白垩世开始,中地壳上部出现薄层的脆性层;古近纪早期中地壳上部脆性层变薄变浅;现今则除了发育上地壳上部、中地壳上部脆性层外,上地幔顶部开始在浅部发育薄的脆性层。中—新生代岩石圈总强度演化表明在早白垩世晚期和古近纪早期经历了两期减弱,中生代早期岩石圈总强度远大于中侏罗世之后的岩石圈总强度。岩石圈热-流变结构和强度演化与华北克拉通破坏过程中岩石圈厚度的变化具有良好的对应关系,从侧面反映太平洋板块俯冲和回撤导致华北克拉通东部破坏的地球动力学过程。因此,岩石圈热-流变结构可以为盆地形成、大陆边缘和造山带等的动力学演化过程研究提供科学依据。
[Abstract]:Based on Meso-Cenozoic thermal history, crustal stratified structure and rheological parameters, the evolution characteristics of Meso-Cenozoic lithosphere thermal structure and thermo-rheological structure in Bohai Bay Basin are simulated and calculated in this paper.The results show that the thermal structure of the basin changed from the "cold mantle hot crust" lithosphere in the Triassic to the Jurassic period to the "hot mantle cold crust" type in the Cretaceous period.According to the evolution characteristics of lithospheric thermo-rheological structure in Jiyang depression, the upper upper crust, the upper middle crust and the top of the upper mantle in the early Mesozoic appear to be thick brittle layers.In addition to the upper crust and the upper middle crust, the upper mantle began to develop thin brittle layer in the shallow part.The evolution of total lithospheric strength in Mesozoic and Cenozoic shows that the total strength of the early Mesozoic lithosphere weakened during the late early Cretaceous and the early Paleogene, and the total strength of the lithosphere in the early Mesozoic is much greater than that after the Middle Jurassic.The thermal rheological structure and strength evolution of the lithosphere have a good correspondence with the thickness of the lithosphere during the failure of the North China Craton.Therefore, the lithospheric thermo-rheological structure can provide scientific basis for the study of the dynamic evolution process of basin formation, continental margin and orogenic belt.
【作者单位】：中国石油大学(北京)油气资源与探测国家重点实验室;中国石油大学(北京)地球科学学院;成都理工大学能源学院;中国石油华北油田公司;
【基金】：国家自然科学基金项目(41125010,91114202)
【分类号】：P313;P314

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