青藏高原陆相火山岩区填图新进展——以松多地区新生代火山机构为例

20世纪90年代以来,为了区别传统的沉积岩区填图方法,中国陆相火山岩区地质调查工作普遍采用"火山构造-火山岩相-火山岩性"三位一体的思路与工作方法,并取得重要进展。以西藏松多地区1∶5万区域地质调查工作为例,探讨该方法在高原地区新生代火山岩研究中的应用。结合遥感影像与剖面测制,通过野外地质观察与镜下岩性特征分析,对火山机构进行相带划分,从而恢复古火山的基本格架、重溯火山作用过程。同时,松多地区新生代火山机构的建立,为冈底斯岩浆带发育的林子宗火山岩与下伏地层的区域性不整合提供了新的证据,进一步限定了印度-亚洲大陆碰撞的起始时间。

New progress of mapping in the continental volcanic terrain: A case study of Cenozoic volcanic edifice in Sumdo area, Tibetan Plateau

In order to distinguish from the traditional mapping method suitable for sedimentary area, the researchers have widely used "volcanic structure-volcanic lithofacies-volcanic lithology" trinity mapping method in the continental volcanic rock area of China since the 1990s, and have made important progress. This paper discussed the applicability of this mapping method in the 1:50000 Sumdo geological mapping program for plateau area of Cenozoic volcanic rocks. Combined with remote sensing images and measured section, the authors divided the volcanic facies by field geological and microscope observation, thus restoring the basic framework of the ancient volcanic and retracing the volcanism process. The establishment of Sumdo Cenozoic volcano edifice provides new evidence of regional unconformity between Linzizong volcanic rocks and underlying strata, which further limits the starting time of the India-Asian continent collision.