四川理塘甲洼组地层时代与环境演化

基金项目:

中国科学院知识创新工程项目(编号:KZCX2-108)、国土资源部基础研究项目(批准号:20010202、991005)、国家重点基础研究专项经费资助项目(批准号:G1999043401)和中国地调局地质调查项目(批准号:200312300034)共同资助。

AGE OF THE JIAWA FORMATION AND ENVIRONMENTAL EVOLUTION OF LITANG COUNTY,SICHUAN PROVINCE

1. Institute of Geomechanics, Chinese Academy of Geological Sciences, Beijing 100081;
2. S tale Key Laboratory of Loess and Quaternary Geology, Chinese Academy of Sciences, Xi'an 710075, Shaanxi;
3. Open Laboratory of Lake Sediment and Environment, Chinese Academy of Sciences, Nanjiang 210008, Jiangsu;
4. Institute of Geography, Planning Commission of Hebei Province, Sijiazhuang 050061, Hebei, China

摘要: 川西理塘甲洼盆地中的甲洼组是一套厚度在300m左右的松散状河湖相沉积物。磁性地层结果表明,B/M界线位于剖面中部157.0m处,剖面底部记录了奥尔都维正极性亚时。对比Cande和Kent的极性年表,理塘甲洼组的始沉积年代约为2.10MaBP,结束于0.10MaBP.孢粉记录显示该地经历亚高山针叶林植被→高山草甸植被的演变过程,沉积环境经历了河湖相→冲积相的转变过程。
- 甲洼组 /
- 磁性地层 /
- 孢粉 /
- 理塘
Abstract: The Jiawa Formation in the Jiawa Basin, Litang County, Sichuan Province, is a sequence of loose fluvio-lacustrine deposits about 300m deep.According to the magnetostratigraphic, the B M boundary is located at 157.0m depth in the middle part of the section and the Olduvai normal polarity chron is recorded at the bottom.According to Cande and Kent's polarity time scale, it can be inferred that the deposition of the Jiawa Formation stared at about 2.10 Ma BP and ended at about 0.10 Ma BP. On the basis of sporopollen analysis, the vegetation changed from subalpine conifer forest to alpine meadow, and the sedimentary environment varied from fluvial-lacustrine facies to alluvial facies.
- Jiawa Formation /
- magnetostratigraphy /
- sporpollen /
- Litang County