阿中地块南缘晚元古代火山岩地质特征及构造环境分析

阿中地块南缘晚元古代索尔库里群基性火山岩与滨浅海相细粒陆源碎屑岩、成熟度较高的石英砾岩和碳酸盐岩共生,这套火山-沉积岩发生浅变质强变形作用改造,其形成于大陆裂谷构造环境,基性火山岩为大陆裂谷拉斑玄武岩,火山岩-火山碎屑岩上覆岩系--碳酸盐岩中含大量小型叠层石,通过区域对比证明该套地层时代为晚元古代青白口纪,其沉积建造、岩相古地理环境与塔里木北缘库鲁克塔格地区同时代地层特征相似,说明青白口纪时南、北塔里木就有了统一的盖层.

Analysis of geological feature and tectonic environment for Neoproterozoic volcanic rocks in southern margin of Middle Altun Plot, Xinjiang, China

The Neoproterozoic basic volcanic rocks in the southern margin of Middle Altun Plot are (coexisting) rocks of continent-derived fine-grained clastic rock in littoral-shallow marine facies, quartz (conglomerate) and carbonate rock with higher maturity. These volcanic-sedimentary rocks formed in (continental) rift tectonic environment are changed by faint metamorphism and intensive deformation. The basic volcanic rocks belong to continental rift tholeiite and limestone overlaid with volcanic rock and (volcanic) clastic rock contained abundant pint-sized stromatolite. It is testified that the stratum age is (Qingbaikouan) Period of Neoproterozoic Era. The sedimentary formation and paleogeographic environment are similar to the same age stratum in Kuruktag at the northern margin of Tarim massif. This indicates that the south and north Tarim massifves have unitive covering strata in Qingbaikouan Period.