| 川西高原甘孜黄土地层学 |
| |
| 关键词:loess stratigraphy susceptibility Late Quaternary Qinghai-Xizang Plateau |
| 基金项目:地质矿产部“九五”重点基础研究项目,中国科学院黄土与第四纪地质国家重点实验室基金 |
|
| 摘要点击次数: 7095 |
| 全文下载次数: 3884 |
| 摘要: |
| The Ganzi Loess Stratigraphy in the West Sichuan Plateau |
| There is a wide distribution of the eolian loess in West Sichuan Plateau. A preliminary study of the loess strata in Ganzi area was carried out in this paper, in which two profiles situated at Xinshiqu and Mandi in the southwest suburbs of the Ganzi City were measured, with 23.7 m and 26.0 m thick respectively. According to the characteristics of lithology and magnetostratigraphy, susceptibility, CaCO 3 content and thermoluminescent dating, the loess sequence can be divided into three stratigraphical units as paleosol S 0, loess L 1 and paleosol S 1, which were formed in the postglacial period, last glaciation and last interglaciation respectively. The compound paleosol S 1, with 5.1 m thick, is composed of three secondary stratigraphical units as paleosol S 0SS 1, loess S 0LL 1 and paleosol S 0SS 2. The loess L 1 can be subdivided into seven secondary stratigraphical units, including loesses L 1LL 1, L 1LL 2, L 1LL 3, L 1LL 4 and compound paleosols L 1SS 1, L 1SS 2 and L 1SS 3. The paleosol S1 is not exposed thoroughly in the profiles and can be only subdivided into two secondary stratigraphical units, namely paleosol S 1SS 1 and loess S 1LL 1. The Blake subchron recorded in the S 1LL 1. The deposition of the Ganzi loess began at the early of Late Pleistocene, about 120 kaBP. The susceptibility of loess stratais that regarded as a measurement reflected strength of pedogenesis and rate of sedimentation is usually a classical proxy index indicated the summer monsoon changes in the Loess Plateau , and it can show the summer monsoon changes in the Qinghai_Xizang Plateau as well. The evolution of plateau monsoon and the change of climate environment can been brought to light by the susceptibility of the Ganzi loess strata in the last 120 ka, in which six strengthening of the summer monsoon circulation are shown by the higher values of susceptibility and six weakening are shown by the lower values. |
| JIANG Fu-chu,WU Xi-hao,XIAO Hua-guo,ZHAO Zhi-zhong,TIAN Guo-qiang,LIU Ke.1997.The Ganzi Loess Stratigraphy in the West Sichuan Plateau[J].Acta Geoscientica Sinica,18(4):413-420. |
| 查看全文 查看/发表评论 下载PDF阅读器 |
|
|
|
|
|