我国几个地区浊积岩系的特征

近年来,由于找寻沉积矿床、研究沉积环境和大地构造的需要,浊积岩(在构造意义上称为复理石)的研究有相当快的发展。作者对东北某地早第三纪浊积岩、秦岭中段三迭纪浊积岩和浙西奥陶纪浊积岩进行了野外观察和室内工作。本文就它们的识别特征、沉积环境和构造环境进行概要的讨论,可能对区测填图和普查找矿等方面工作有所俾益。

ON THE FEATURES OF TURBIDITE SEQUENCES IN SOME REGIONS OF CHINA

Turbidite sequences are developed in strata of Lower Tertiary of North-East China, Trias of Qin Ling and Upper Ordovician of West Zhejiang Province. In this study, the sedimentary structures, textures, petrographic features, petrochemistry and other characteristics are analyzed. Based on these analyses, it can be assumed that the turbidite-bearing basins belong to a sort of marginal basins originated by extension at different times. The Tertiary turbidite basin of North-Bast China was initially extended about 46 m.y. ago with the extrusion of basalt, being a transitional member from alkaline basaltic to tholeiitic series. Following this, thick turbidite sequence was deposited. In the basin mollass sequence was developed subsequently and the basin has been subjected to contract by compressive action. The Trias and Ordovician turbidite basins are developed on basements composed of carbonate terrains, and formed by extention. Along these lines of evidence the tectonic history is restored.