新疆库鲁克塔格南华系砂岩碎屑组成对其物源及盆地演化的指示

发布时间：2018-07-31 17:53

【摘要】：库鲁克塔格南华系记录了塔里木北缘同期的火山—沉积事件和蚀源区物质组成及演化的信息。该区不同剖面内南华系各组砂岩碎屑组分的统计分析显示,贝义西组砂岩在不同剖面内组成差异显著:西山口剖面以岩屑砂岩为主,且岩屑为火山岩岩屑与沉积岩岩屑,物源为再旋回地层,而依格孜塔格剖面以长石砂岩和岩屑长石砂岩为主,岩屑主要为变质岩岩屑,物源为下伏古元古代高级变质岩。砂岩碎屑组成在剖面上垂向的变化表明贝义西组沉积期与照壁山组沉积期间(725 Ma±)存在一个沉积转型事件,导致贝义西组之上的照壁山组、阿勒通沟组及特瑞艾肯组砂岩组成在不同区域趋于一致,转变为代表基底隆起—过渡大陆区物源的典型"长石砂岩"。南华系砂岩碎屑组成与大陆裂谷盆地沉积砂岩相似,且物源区存在由前裂谷地层—过渡裂谷肩部—切割裂谷肩部—克拉通内部的连续演化过程,是库满凹陷早期裂解的岩相学记录。
[Abstract]:The Kuruktag Nanhua system records the volcanic-sedimentary events and the material composition and evolution of the etched source area in the northern margin of Tarim. The statistical analysis of the sandstone clastic components of the South China series in different sections of this area shows that there are significant differences in the composition of the sandstone of the Bei Xi formation in different sections: the Xishankou section is dominated by the lithic sandstone, and the lithoclasts are volcanic and sedimentary lithoclasts. The provenance is recyclically stratigraphic while the Igeztag section is dominated by feldspathic sandstone and lithic feldspar sandstone with metamorphic lithology and material source of Lower Volgoproterozoic high grade metamorphic rocks. The vertical variation of sandstone clastic composition in the section indicates that there was a sedimentary transition event between the sedimentary period of the Bei Xi formation and the Zhaobishan formation (725 Ma 卤), which led to the Zhaobishan formation above the Bei Yi Xi formation. The sandstone composition of the Alethonggou formation and the Terre Aiken formation tends to be consistent in different regions, and it is transformed into a typical "feldspathic sandstone" representing the basement uplift and the provenance of the transitional continental area. The detrital composition of the South China sandstone is similar to that of the sedimentary sandstone in the continental rift basin, and the source area has a continuous evolution process from the front rift stratigraphy to the transitional rift shoulder to the cut rift shoulder to the interior of the craton. It is a petrographic record of early pyrolysis in Kuban depression.
【作者单位】：新疆大学地质与矿业工程学院;中国科学院新疆生态与地理研究所;
【基金】：中国地质调查局项目(1212011120477)~~
【分类号】：P588.2

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