河北阳原–蔚县盆地形成–消亡的深部构造机理

Abstract

阳原–蔚县盆地位于大同盆地东段，由于该盆地东段泥河湾及其附近地区发现并发掘了大量哺乳动物群化石和古人类活动遗迹，使其成为我国乃至中亚地区地质生态变化以及人类起源与演化研究的重要基地。本文的科学问题是为什么如此适宜哺乳动物群生物繁衍栖息之地，却在很短的时期就演变成为山峦起伏、沟壑纵横、环境恶劣的丘陵地带？本研究认为：这与燕山运动以来张宣地区的隆起以及喜山运动以来汾渭裂谷系的断陷密切相关。它们均受深部上涌地幔热柱的控制和影响，导致了该区的地壳变形、岩浆活动，从而引起灾害频发、气候改变、环境变化、生态变异等。本文以地幔热柱(幔枝构造)理论为指导，探讨深部地幔上涌柱活动导致阳原–蔚县盆地的形成–消亡的机理及其演化过程。 Yangyuan-Yuxian basin is located in the eastern margin of the Datong basin. Because a large number of mammalian fossils and ancient human remains were found and excavated at NIHEWAN and the surrounding areas of the eastern basin, it became an important base of geo ecological changes and the origin and evolution study of human of China and Central Asia. Why this land, which is so suitable for mammalian faunas to produce and inhabit, becomes hilly areas with rolling hills, criss-cross ravines and gullies and bad environment in a very short period of time? Research thinks, this is closely related to the uplift of Zhangjiakou-Xuanhua region since Yanshan movement and the rifting of Fen Wei rift system since joy mountain movement. They are controlled and influenced by the deep upper mantle plume. And the changes of the natural environment, such as crustal deformation, magmatic activity, caused frequent disasters, climate change, environmental change, ecological variation, and so on. This paper, based on the theory of mantle plume (mantle branch structure) as a guide, explores the mechanism and evolution of formation and the demise of Yangyuan-Yuxian basin caused by the deep mantle upwelling plume activity.