柴西红三旱一号地区新生代砂岩成分分析及其区域构造意义

高精度的磁性年代研究表明,柴达木盆地红三旱一号地区下干柴沟组-上干柴沟组年龄为40~26.5 Ma，上、下干柴沟组地层的分界年龄约为35.5 Ma。根据盆地内的沉积物与物源区的相关性，采集了柴达木盆地红三旱一号剖面新生代的砂岩样品，用Dickinson-Gazzi方法进行成分分析统计，反映物源区的变化对沉积区砂岩组分具有明显的影响。对砂岩样品的成分统计模式分析表明，下干柴沟组沉积时期，沉积环境比较稳定，说明此时阿尔金山没有快速隆升，而到了上干柴沟组沉积时期沉积环境变得不稳定。结合区域热年代学资料表明，阿尔金山在渐新世强烈隆升，这可能与阿尔金断裂的快速走滑有关。

The Analyses of Cenozoic Sandstone Component in Hongsanhan No. 1 Area and Its Tectonic Implications

The highly precise magnetochronologic study indicates that the age of Xiaganchaigou and Shangganchaigou Formations in Hongsanhan No.1 area is in the range of 40-26.5 Ma.The dividing age between Xiaganchaigou and Shangganchaigou Formations is 35.5 Ma.According to the relativity of the sediment area and source provenance,Cenozoic sandstone samples,collected from Hongsanhan No.1 section in Qaidam Basin,have been analyzed by using Dickinson-Gazzi method.The results suggest that the sandstone components are sensitive to the provenance tectonic changes.The analyses of the sandstone components suggest that the sedimentary environment was relatively stable during Xiaganchaigou period,and reveal that the Altyn Mountains had not uplifted rapidly at that time.But during Shangganchaigou period the sedimentary environment became unstable,combining with regional thermochronologic data,it indicates that the Altyn Mountains were uplifted strongly in Oligocene,which may be caused by the fast strike-slip movement along the Altyn fault.