柴西红沟子地区晚新生界磁组构的特征和意义  

Characteristics of Late Cenozoic magnetic fabric in Honggouzi area of western Qaidam Basin and their significance

作　　者：高军平[1] 刘胜昌[2] 方小敏[3] 李艾银[2] 张伟林[3] 彭杨宏[2] 

机构地区：[1]兰州大学西部环境教育部重点实验室,兰州730000 [2]兰州大学资源环境学院,兰州730000 [3]中国科学院青藏高原研究所,北京100085

出　　处：《世界地质》2007年第2期180-189,共10页World Geology

基　　金：国家自然科学基金重点项目(40334038);国家自然科学基金委青年科学家群体研究项目(40421101);"973"项目(2005CB42001)资助

摘　　要：柴西地区发育良好的新生代地层是对青藏高原隆升和环境变化的共同响应。对红沟子剖面新近系磁化率各向异性的测量分析认为,沉积物磁组构参数既揭示了沉积盆地及其周缘山地的环境变化特征,又反映了源区构造事件对沉积物及区域环境变化的制约。大量证据表明,柴西地区晚新生代环境变化以及地质构造演化主要经历了三个阶段：Ⅰ阶段（〉16.5-14.2 Ma）构造活动强、气候干燥;Ⅱ阶段（14.2-9.8 Ma）早中期构造稳定、环境变化平稳,晚期构造活动加强;Ⅲ阶段（9.1-4.8Ma）早期构造活动加强,中期构造、环境较稳定,晚期则变化较大。Well-developed Neocene strata in western Qaidam Basin were a response to uplift of Qinghai- Tibet Plateau and their environmental changes. The measurements and analyses on Neocene magnetic anisotropy in Honggouzi section suggest that magnetic fabric parameters not only revealed the environmental change of the sedimentary basin and its peripheric orogenic-belts, but also reflected the constraint of the tectonic events of sedimentary provenance to sediment and regional environmental changes. Many evidences indicate that there were three stages of Neocene environmental changes and geological evolution in western Qaidam Basin. Stage Ⅰ （ 16.5 -14.2 Ma） ： this area appeared as stronger tectonism and aridity; stage Ⅱ （14.2-9.8 Ma） ： it showed stabi- lization of tectonism and environmental change in early-medium stages, strong tectonic activities in late stage, and stage Ⅲ （9.1-4.8 Ma） ： with stronger tectonism in early stage, stable in medium stage and many changes in late stage.

关 键 词：磁组构 新近纪 柴达木盆地 红沟子 

分 类 号：P534.6[天文地球—古生物学与地层学] P318[天文地球—地质学]