太行山中南段古元古代甘陶河群沉积环境分析及盆地演化

Sedimentary Environmental Analysis and Basin Evolution of the Ancient Proterozoic of Gantao River Group in the Mid-Southern Section of Taihang Mountain

太行山中南部的甘陶河群主体为一套近滨环境下形成的陆源碎屑-复理石-碳酸盐岩—基性火山岩夹陆源碎屑建造,根据韵律、岩相组合规律可划分出6种基本层序类型。南寺掌组及南寺组一至三段碎屑沉积岩的物源区为基底隆起构造环境,沉积物特征表明古气候为干燥贫氧还原环境,表现为构造活动强烈,风化作用时间短,并以物理风化为主的特点;南寺组四段正常碎屑沉积岩中碎屑物的物源区为多旋回造山带构造环境,碎屑分选性、磨圆度均较差,碎屑物主要来源于火山岩区,结构成熟度低,其沉积作用处于堆积速度快,构造活动强烈的动荡环境;其间,伴随基底断裂的强烈活动,发育了两期多次基性火山岩喷发。

The main body of the Gantao river in the mid-south section of Taihang mountain is a set of terrigenous clastic-flysch-carbonate-basic vocanic rocks with terrestrial clastic structures formed in the near shore environment, which can be divided into six basic sequence types according to the rhythm and the combination of rock facies.The clastic sedimentary rocks of Nansizhang and the first three period of Nansi groups derived from tectonic settings of basement uplift, and its characteristics indicated that the environment of paleoclimate was dry and anoxic, which was characterized by intense tectonic activity, short duration of weathering, and physical weathering. The clast of normal clastic sedimentary rocks in the fourth period of Nansi group which were derived from the area of volcanic rocks in polycyclic orogenic belt, had poor sorting and roundness, low structure maturity, fast stacking velocity and intense tectonic activities. Along with intense activity of basal fracture, during the deposition process, it has developed two periods of multiple base volcanic eruptions along with intense activity of basal fracture.