西昆仑麻扎—康西瓦一带温泉沟群的形成时代及物源区分析

Age and source regions of the Wenquangou Group in the Mazar-Kangxiwar area, West Kunlun Mountains

温泉沟群出露在西昆仑麻扎-康西瓦构造接合带的南侧,岩性主要为浅变质的碎屑岩,对这套碎屑岩的形成时代和产出构造背景目前还存在着争议。采于这套地层中的大量微体古生物化石表明,其形成时代为早志留世。物质组成、岩石碎屑特征、岩石地球化学特征等的分析结果显示,其物源区主要为活动大陆边缘、过渡陆壳和造山再旋回物源区,形成时的构造环境为深海相残留洋盆。这些分析结果为康西瓦结合带的研究提供了地层学方面的依据。

The Wenquangou Group is exposed in the Mazar-Kangxiwar junction zone, West Kunlun Mountain. It is made up of low-grade metamorphic clastic rocks. There are different views about the age and tectonic setting of this suite of metamorphic clastic rocks. Plenty of microfossils collected from this sequence of rocks indicate a Early Silurian age. Analysis of the material composition, characteristics of rock clasts and rock geochemistry of this sequence of rocks indicate that its source regions of the simple metamorphic clastic rocks are mainly active continental margins, transitional continental crust and orogenic recycling source regions. The tectonic environment of the Wenquangou Group is an abyssal relict ocean basin. These analytical results furnish stratigraphic evidences for the study of the Kangxiwar-Mazar junction zone.