华南地块震旦纪晚期—早寒武世古大陆位置暨灯影组蒸发岩成钾条件分析  

Tectonic and Sedimentary Settings of Evaporites in the Dengying Formation, South China Block: Implications for the Potential of Potash Formation

作　　者：王立成[1] 刘成林[1] 张华[1] 

机构地区：[1]中国地质科学院矿产资源研究所,国土资源部成矿作用与资源评价重点实验室,北京100037

出　　处：《地球学报》2013年第5期585-593,共9页Acta Geoscientica Sinica

基　　金：国家"973"计划项目(编号:2011CB403007)资助

摘　　要：海相钾盐的形成需要构造、气候和成钾物源三者的耦合作用,而构造是首要控制因素。华南地块发育震旦晚期—早寒武世灯影组海相蒸发岩,本文通过古大陆位置、古纬度和古气候、古地理以及古海水成分等文献综合分析,提出灯影组沉积时期,华南地块位于印度大陆西北缘,是冈瓦纳大陆的一部分。华南地块灯影组沉积与印度、巴基斯坦、阿曼、伊朗等地的同时期沉积相似,并形成一个巨型的碳酸盐台地,其中发育众多的局限盐盆地蒸发岩,古气温最高可达40℃。同时,通过与巴基斯坦盐岭地区含钾蒸发岩盐岭组的构造-沉积背景对比,表明两者均为冈瓦纳大陆北缘被动大陆边缘盆地沉积,具有相似的蒸发岩沉积序列和形成条件。因此,综合来看,认为华南地块灯影组具有必要的成钾条件。The formation of marine potash salts needs a coupled mechanism of tectonics, palaeoclimate, and source. Tectonic element is the primary controlling factor. A sequence of marine evaporites was developed in the Late Sinian–Early Cambrian Dengying Formation in South China Block （SCB）. An integrated literature analysis of the position of continents, palaeo-altitude, palaeoclimate, palaeogeography, and seawater chemistry indicates that the SCB should be an integral part of Gondwana close to the northwestern margin of India. Deposits of the Dengying Formation are similar to those in India, Pakistan, Oman, and Iran. These deposits were deposited in a giant carbonate platform. Shallow restricted marine evaporites were developed in the carbonate platform with the highest temperature up to about 40℃. A comparison of tectonic and sedimentary setting between SCB and Salt Range indicates that the evaporite-bearing Dengying and Salt Range formations were deposited in a shallow marine environment on the northern margin of the Gondwanaland passive continent and shared the similar evaporitic sequence and formation conditions. It is thus inferred that the Dengying Formation in the SCB has the essential conditions for the formation of potash deposits.

关 键 词：华南地块 灯影组 古大陆位置 蒸发岩 

分 类 号：P534.31[天文地球—古生物学与地层学]