西昆仑阿什库勒火山地质、活动历史与岩浆演化研究

青藏高原北部新生代高钾钙碱性系列火山作用过程, 作为板块俯冲、碰撞及高原形成、演化过程中深部地质作用事件的浅部响应, 是探索新生代以来高原岩石圈物质组成、壳幔结构及其相互作用方式以及高原隆升机制的"重要窗口"，长期以来一直受到国内外地学界的广泛关注。本项目将开展对阿什库勒火山岩为代表的青藏高原内最新期的北部昆仑火山群火山地质研究，查明第四纪火山活动历史，完成研究区内重要火山锥体的1:2000火山机构图。同时，系统采集火山岩样品，开展火山岩岩石学、岩相学、显微构造学、岩石地球化学及同位素年代学的综合分析, 研究火山岩源区岩浆活动特征、形成时代和演化过程，弥补藏北高原西部由于恶劣工作环境而造成的第四纪火山学研究的不足。

The high K2O volcanism of northeastern Tibet in the Cenozoic era, as an" important window", playes the essential roles in studying the composition of plateau lithosphere, the structure of the crust-mantle, and the uplifting mechanism of the Tibetan plateau. The petrogenetic and geodynamic significance of the Cenozoic volcanism in the north Tibetan plateau has remained focal and controversial issue in the past. Ashikule volcanic group which was developed in the western Kunlun mountain of north Tibet, is composed with 10 major volcanoes and tens of sub-volcanoes, and covers a total area of about 200km2 at the average altitude around 5,000m, one of the highest volcano groups in the world. Because of the high topographic elevation, inclement climate and inaccessibility this area is one of those poorly-studied geological regions on the earth. In this proposed study, we will conduct detailed field investigation of geological and geomophological features of volcanic rocks and volcanic craters in Ashikule basion, find out the eruption history of the volcanic activity, and compile high-scaled geologic map of the study area. We will also collect series of volcanic rocks samples to carry out laboratory analysis in petrology, petrography, micro-texture, rock geochemistry, isotopic geochemistry and isotopic chronology to understand the timing, magmatic process and evolution of the volcanic activity in the study area. The results of this study are expected to fill up the insufficient data regarding to the Quaternary magmatism in the study area, and provide new evidence for the study of tectonic evolution of north Tibet.