伦坡拉盆地始新统牛堡组物源分析

Source Analysis of Niubao Formation in Rumpola Basin

针对青藏高原伦坡拉盆地碎屑岩的物源分析问题,通过岩石学结合镜下薄片观察和Dickinson三角图,综合分析了其物源成因。对其岩石组分观察和碎屑含量投图发现,该区域碎屑岩以砂岩为主,多以石英砂岩和岩屑砂岩,部分石英为多晶石英并具有波状消光的现象;岩屑则以变质岩岩屑和岩浆岩岩屑为主,其中岩浆岩岩屑以中性喷出岩岩屑居多。综合以上分析始新统牛堡组物源来源受到了喜山期第一幕的影响,其物源区发生了强烈的褶皱和断裂作用,并可能伴有中性岩浆的侵入。

In view of the matter source analysis of clastic rocks in the Lunpola Basin of the Qinghai Tibet Plateau,the origin of the source is analyzed comprehensively by means of the petrology combined with the thin section observation under the microscope and Dickinson triangle.The observation of the rock components and the projection of the clastic content show that the clastic rocks in this area are mainly sandstone,mostly quartz sandstone and lithic sandstone,and some quartz are polycrystalline quartz and have wave extinction;The main debris is metamorphic rock cuttings and magmatic rock cuttings,and the majority of magmatic rock cuttings are neutral ejected rock cuttings.The source of Niubao formation in Eocene is influenced by the first act of Himalayan period.The source area of Niubao formation has strong fold and fracture,and may be accompanied by the intrusion of neutral magma.