湖南下二叠统海泡石及其主要伴生粘土矿物的扫描电镜研究  

THE USE OF SCANNING ELECTRON MICROSCOPY IN THE STUDY OF LOWER PERMIAN SEPIOLITE AND ITS MAIN ASSOCIATED MINERALS IN HUNAN

作　　者：刘德镒 

机构地区：[1]湖南地质研究所二叠纪课题组

出　　处：《沉积与特提斯地质》1990年第1期46-55,共10页Sedimentary Geology and Tethyan Geology

摘　　要：海泡石是一种富镁的纤维状粘土矿物,为链-层状结构的含水硅酸盐。在自然界中分布不广,很少形成单独的大量堆积。但是因为它具有一系列有别于其他粘土矿物的极其有用的物理化学性能,因此,有着广泛的工业用途。海泡石的成因大体分为两类,一是热液蚀变产物,常呈纤维状或“石棉”状,集合成脉状产出,规模较小,工业意义不大。另一类为沉积成因(包括成岩作用或新生作用而成),往往成为土状海泡石粘土,集合成层状、似层状或透镜状产出,规模一般较大,工业矿床多属此类成因。中国的海泡石粘土矿床都分布在中国南方,而且主要集中在下二叠统,其中湖南约占80％,所以被誉为“海泡石之乡”。在我国“科学的春天”里,湖南有关野外队先后发现了四个矿床和十来个矿点或矿化点。湖南地质研究所参加了地质矿产部“七五”The sepiolite clay deposits of hunan are all confined to the upper members of the Lower Permian Qixia Formation. These deposits may be classified into the marl type, 'Ca-Mg shale' type and clay type according to lithology and sepiolite contents. By means of scanning electron microscopy, this paper deals with the form and mineralogy of sepiolite and its bearings on the main associated clay minerals, as well as the formation and enrichment of sepiolite during weathering and reworking. Four types of sepiolite are recognized in terms of the occurrence, form and genesis. Sepiolite in marls and Ca-Mg shales is thought to be formed by neoformation; Earthy sepiolite is the weathering products of the sepiolite-bearing rocks; paper sepiolite owes its origin to leaching, and 'asbestiform' sepiolite is a kind of The infilling material within vein walls. Both talc and montmorillonite were derived from sepiolite. The former is usually associated with sepiolite, and its content is inversely proportional to that of sepiolite. The scale, tenor and quality of sepiolite clay deposits are controlled mainly by weathering and reworking.

关 键 词：海泡石矿床 粘土矿物 下二叠统 成岩作用 热液蚀变 地质矿产部 纤维状 矿化点 地质研究所 化学性能 

分 类 号：P642[天文地球—工程地质学]