硅质岩与二叠纪硅质沉积事件研究现状及进展  

Research Status and Advances in Chert and Permian Chert Event

作　　者：姚旭[1] 周瑶琪[1] 李素[1] 李斗 

机构地区：[1]中国石油大学(华东)地球科学与技术学院,山东青岛266580

出　　处：《地球科学进展》2013年第11期1189-1200,共12页Advances in Earth Science

基　　金：国家自然科学基金项目"东特提斯洋二叠纪硅质沉积事件研究"(编号:41272123);中央高校基本科研业务费专项资金"华北;扬子地区古生代硅质岩分布规律"(编号:13CX06016A)资助

摘　　要：硅质岩分布于造山带和沉积盆地的特殊沉积相带,是岩石大地构造学研究的重要载体,其成因信息具有重要的古地理、古海洋意义。对硅质岩的研究历史及进展进行了回顾,重点阐述了国内外层状及非层状硅质岩的研究现状及研究进展。结合我国二叠纪硅质岩分布特征,分别论述了洋脊、洋盆及陆缘3种沉积环境下硅质岩的硅质来源、沉积环境、成因机理等方面的研究成果。以全球二叠纪硅质沉积事件的成因机理为切入点,讨论了东特提斯地区二叠纪硅质岩的研究现状及存在问题,提出我国二叠纪硅质岩的成因机理与联合古陆西北缘硅质沉积事件截然不同,可能是由于热源(热水系统)而非冷源(海洋冰川)导致的二叠纪硅质富集。我国扬子地区完全能够建立研究二叠纪硅质沉积事件的典型剖面。Cherts are concret research objects for petro-tectonic framework and are widespreadly distributed in special sedimentary environments along orogenic belts and depositional basins. Cherts hold abundant origin-related information, which plays important role in palogeographie and paleooceanograpic study. This paper reviewed the history and the advancement of research on chert, especially paying more attention to the research progress about both bedded chert and nodular chert in domestic and international research areas. Combined with Permian cherts distribution in China, we discuss research aehivements of silica sources, sedimentary environments and original mechanism from cherts deposited in different sedimentary environments such as oceanic rift, oceanic basin and con- tinent shelf. ＂Permian Chert Event＂ （PCE） has been used to discribe the widespread biogenic Permian cherts that occurred around the eastern margins of Panthalassa and Paleotethys Ocean. Research results on Permian cherts in eastern Paleotethys Ocean, particularly the Yangtze areas, are examined here, which suggest Permian cherts are not typically biogenic in origin but severely influenced by hydrothermal sedimentation. The seasonal melting of sea ice is assumed engine for PCE in northwest edge of Pangea Supercontinent, but that dose not work in China. There- fore, a hypothesis different form thermohaline circulation and upwelling is proposed here： there would be a periodi- cal hydrothermal fluid system in the eastern Paleotethys Ocean, providing the source of silica for the development of Permian Chert Event on both south and north continent shelves. What is more, some intensively studied Permian outcrops in the Yangtze areas have the potential to be the typical outcrops for PCE research in China.

关 键 词：硅质岩 成因机理 二叠纪硅质沉积事件 热水系统 

分 类 号：P588.244[天文地球—岩石学]