摘要
白垩纪事件是全球非常明显和重要的一次地质突发事件,包括洋壳的超巨量形成,地磁正超时达41 Ma之久(124～83 Ma),海水温度大幅度升高,黑色页岩沉积和石油形成的大量增长,海平面的快速上升,大气CO2水平的急剧升高,以及伴生的生物灭绝事件等.中-新生代的大火成岩省与冈瓦纳超大陆的裂解伴生,是超级地幔热柱产生的结果,而与欧亚超大陆的形成伴生分散火成岩省,是超级冷地幔下降流的结果,两者的联合构成全地幔对流的格局.全地幔对流模型为白垩纪地质演化、生物演化和环境演化的突变提供地球深部过程的约束.
In the Cretaceous there were a series of global catastrophic geological events, including an increase in the rate of oceanic crust formation, the long Cretaceous interval of normal magnetic polarity (super chron), with duration of 41 Ma from 124 Ma to 83 Ma, a significant increase of sea-water temperature and the deposition of black shales. These events were accompanied by oil generation, changes of eustatic sea level, increased CO_2 levels in the atmosphere, and biota extinction. In the Mesozoic and Cenozoic Large Igneous Provinces (LIPs) appear to be related to rifting and dispersal of the Gondwana supercontinent. These LIPs were the result of the activity of mantle plumes. The Dispersed Igneous Provinces (DIPs) are related to the convergence of the Euro-Asian plate, and were possibly the products of cold plumes. These two systems (hot plume and cold plume) make up the whole-mantle convection system. We suggest that whole-mantle convection system was the main constraint on processes of the deep interior during the Cretaceous and this system is responsible for the global catastrophic events in the geological, paleontological and paleoenvironmental records.
出处
《地学前缘》
EI
CAS
CSCD
北大核心
2005年第2期217-221,共5页
Earth Science Frontiers
基金
国家自然科学基金重点项目(40234048
40332020)
科学技术部国际合作项目(2001cb711002)
IGCP 430项目
教育部 211工程项目
关键词
大火成岩省
分散火成岩省
全地幔对流
白垩纪
Large Igneous Provinces (LIPs)
Dispersed Igneous Provinces (DIPs)
whole-mantle convection
Cretaceous
