• 责任者：Zhou Yinzhang (Key Laboratory of Orogenic Belts and Crustal Evolution ; Ministry of Education ; School of Earth and Space Sciences ; Peking University ; Beijing 100871 ; China) ; Han Baofu
• 刊名：Geological Bulletin of China
• 出版年：2013
• 卷期：32(2/3)
• 关键词：花岗质片麻岩 ; granitic gneiss ; 内蒙古 ; Inner Mongolia
• 页码：p.318-326
• 图表：illus., 1 table, 26 refs.
• 分类号：0802
• issnNo：ISSN1671-2552
• isbnNo：CN11-4648/P

Micro-continents with Precambrian basement are developed in the Central Asian orogenic belt. In southern Mongolia, the Toto Shan and South Gobi miro-continents are characterized by Neoproterozoic magmatism. The South Gobi micro-continent might extend into China, as evidenced by the discovery of Neoproterozoic granitoid in Yagan area. However, the distribution of the South Gobi micro-continent is not well constrained in China. Regional geological data reveal that there are some Proterozoic rocks in Yingba area of western Inner Mongolia. They are regarded as the relict blocks in and around the Yingba granitoid pluton and are mainly composed of gneiss, quartzite, mica and quartz schist and carbonate. In a Proterozoic block, the felsic gneiss composed ofplagioclase, quartz and biotite gave complex U-Pb age results from the LA-ICP-MS zircon dating. The zircon cores with the igneous origin provided a wide range of ^207Pb/^206Pb ages from 2.SGa to 1.0Ga, while the igneous zircon mantles generated a weighted mean ^206Pb/^238U age of 417.2Ma±3.5Ma, indicating an early Paleozoic tectonic event. In another block, the gneiss is crosscut by leucogranite veins, one of which gave a weighted mean ^206Pb/^238U age of 905.2Ma±6.1Ma. The age is close to the emplacement time （916Ma±16Ma） of Neoproterozoic gneissic granite pluton in Yagan. Therefore, the South Gobi micro-continent extended southward at least to the Yagan- Yingba area in China and were strongly modified and destroyed by the Phanerozoic tectonic-igneous activities.