新疆库鲁克塔格地区早寒武世磷质岩的形成条件

根据地层层序与岩石学特征,对新疆库鲁克塔格地区下寒武统西山布拉克组磷质岩的形成环境,物质来源和形成机理进行了分析。认为本区磷质岩形成于从浪基面附近至氧化界面附近一个较宽泛的环境带中,具有热液和生物两个方面的物质来源。来自火山和生物的含磷物质由上升洋流带至沉积地点经化学沉淀形成磷质岩。而后又经历了水流与波浪的作用,以及重力产生的滑塌事件的改造。西山布拉克组沉积时期经历了三次海平面的升降变化,磷质岩是早期海平面变化的产物。沉积过程发生在高级别的海侵背景之下。

Forming factors of phosphorite in Lower Cambrian of Kuruktag, Xinjiang

On the basis of the characteristics of stratigraphy and petrology, this study focuses on the forming environment, origin and mechanism of the phosphorite in Lower Cambrian of Kuruktag, Xinjiang. It is considered that the phosphorite in this area formed in a comparatively wide environment from the sites above or below the basement surface of wave to the sites around the oxygenic surface. And there are two sources for the phosphorite 's origins. One is from hot liquid and the other is from living things. Those chemical processes were transported by the raising ocean currents and deposited, and then they underwent the mechanism of stream and wave, as well as the event of slip slide caused by gravity. There were three sea-level change cycles during Xishanbulake stage. The phosphorite was the result of the earlier sea-level change. This whole process of phosphorite sedimentation occurred in the background of high rank of transgression.