青藏高原地质科学研究的新进展
New progress in the geoscience study of the Qinghai-Tibet Plateau
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摘要: 《青藏高原隆升的地质记录及机制》科研项目实施4年取得一些新进展:证实西昆仑存在两种基底和4期构造变形;大幅度提高了可可西里盆地研究程度,重塑了滇西高原隆升史;厘定了冈底斯构造-岩浆岩带时空结构和地壳生长方式;进一步查明羌塘地区新生代火山岩存在3个亚带和4个活动高峰期;确定南迦巴瓦构造结为一楔入构造,由3个构造单元组成,南迦巴瓦群为元古宇;GPS监测获得高原北部地壳运动速率,发现两个涡旋构造;把高原岩石圈划分为3种类型,识别出3种地球化学端元;获得一批有关高原隆升、盆地沉积、地质年代等的新数据,对高原隆升及对气候影响等提出一些新认识。Abstract: After four years of implementation of the project Geological Records and Mechanism of the U-plift of the Qinghai-Tibet Plateau the following progress has been made:it has been verified that there exist two kinds of basement and four phases of tectonic deformation in the West Kunlun;the degree of research on the Hoh Xil basin has been raised greatly and the history of the uplift of the western Yunnan Plateau has been reconstructed.;the temporal-spatial structure and crustal growth mode of the Gangdise tectono-magmatic belt have been determined;it has been further made clear that three subzones and four culmination phases of volcanic activity exist in the Cenozoic volcanic belt of the Qiangtang area;it has been ascertained that the Namjagbarwa structural node is a wedge structure composed of three tectonic u-nits,and the Namjagbarwa Group is Proterozoic in age;GPS monitoring of the rate of crustal movement in the northern part of the plateau shows two whirl structures;three types of the lithosphere of the plateau have been distinguished and three geochemical end-members recognized;a group of new data about the uplift of the plateau,basin sediments,geologic ages etc.have been obtained and some new views in respect to the influence of the plateau uplift on the climate proposed.