酒西盆地晚新生代沉积物重矿物分析与高原北部隆升  

Analysis of Tectonic Uplift and Heavy Minerals of Sediments on Jiuxi Basin in the Northern Margin of Tibetan Plateau since the Late Cenozoic

作　　者：宋春晖[1] 孙淑荣[1] 方小敏[1] 孙东[1] 

机构地区：[1]兰州大学西部环境教育部重点实验室&资源环境学院

出　　处：《沉积学报》2002年第4期552-559,共8页Acta Sedimentologica Sinica

基　　金：国家教委重大项目 (0 0 - 0 5);国家重点基础研究发展规划 (G1 9980 4 0 80 9)资助

摘　　要：沉积物的形成是地壳差异升降运动的物质记录。位于青藏高原北缘的酒西盆地晚新生代沉积比较敏感和全面记录了高原北部的构造运动和隆升过程。老君庙剖面晚新生代沉积物重矿物分析表明 13MaBP以来酒西盆地南部沉积物中重矿物具规律性变化 ;依据重矿物具规律性变化和沉积特征 ,揭示了青藏高原北缘晚新生代以来地壳运动经历了稳定期 (13～ 8.2 6Ma)、逐步阶段性隆升期 (8.2 6～ <4 .9Ma)和急剧强烈整体阶段性隆升期 (>3.6 6～ 0Ma)Sediments in basins could record the ascending and descending difference of the earth crust. The sediments of the Late Cenozoic in the Jiuxi basin, located in the northern margin of the Tibetan plateau, have sensitively and completely recorded the uplifting process of northern plateau. The heavy minerals of sediments have the regulatory variety in the Laojunmiao section of Jiuxi basin since 13 MaBP; detailed study of the heavy mineral has revealed four heavy mineral stages of sedimentary evolution. they are: ①stable heavy mineral associations before 12.18 Ma BP , ②relatively stable heavy mineral associations between 12.18 and 8.26 Ma BP, ③unstable heavy mineral associations between 8.26 and 4.9 Ma BP, and ④the very unstable heavy mineral associations since 3.66 Ma BP. The associated mountain erosion and uplift are suggested having experienced three phases on the uplifting process of the northern Tibetan Plateau, that is, tectonic stable (13～ 8.26 Ma BP), gradual staggered uplift (8.26～<4.96 Ma BP), and rapid intense intermittent mass uplift (>3.66～0 Ma BP).

关 键 词：重矿物 构造隆升 晚新生代 酒西盆地 青藏高原 地壳运动 

分 类 号：P534.6[天文地球—古生物学与地层学] P512.[天文地球—地质学]