“赤水—涟源东西向构造带”厘定的地质-地球物理证据

Geological and geophysical evidences for Chishui-Lianyuan E-W strike tectonic zone

中上扬子地块现今深部结构构造的研究,不仅具有科学意义,而且对于研究其与形成演化相关的油气生成、运移、聚集及构造保存和矿产资源的分布赋存规律等更具有重要的社会经济价值。通过地球物理场的详细处理、分离提取技术,结合地表地质的综合分析,发现并厘定了赤水—涟源东西向基底构造带,详述了相关的地质-地球物理证据。结果表明,该构造带是位于中上扬子地块与湘桂地区元古宙也许更早时期南北不同构造块体之间的重要界线,具有从基底到盖层多期次复活演化特点,在空间上有由南往北穿时推进的趋势,而形成演化时间上可主要归为两个时间段:前寒武纪晚期和白垩纪晚期之后。

The study of deep seated structure and tectonics in the mid-upper Yangtze block is important for understanding the genesis,migration and gathering of oil and gas,the conservation of structures,and the occurrence and distribution of mineral resources,which are related to the formation and evolution of the mid-upper Yangtze block.By manipulating geophysical data in detail and combined with the surface geology,we found and collated an E-W trending Tectonic Zone （EWTZ） from Chishui in Guizhou Province to Lianyuan in Hunan Province and presented the geological and geophysical evidences for the existence of the EWTZ.The results showed that the EWTZ was an important boundary tectonic unit between the northern tectonic block and the southern one in the mid-upper Yangtze and Hunan-Guangxi regions since the Proterozoic or earlier.The findings suggested that the EWTZ has multi-phase evolution characteristics from basement rock to cover,as well as a diachronous migration trend from south to north.The formation and evolution of the EWTZ may probably be divided into two stages：the Late Precambrian period and the post Late Cretaceous period.