摘要
青藏高原东北部的西宁盆地紧邻柴达木盆地戈壁沙漠,沉积了厚层的、序列完整的黄土物质,对其进行研究可望得到高原古气候演化信息。通过对西宁盆地盘子山黄土剖面酸溶相Sr、CaO含量变化的测试分析,获得了自末次间冰期以来多次不同时间尺度变化的信息,证明Sr、CaO可以作为该地区黄土研究更为灵敏的气候代用指标。
Xining Basin, located in Northeast Qinghai Xizang Plateau, is adjacent to Qaidam Basin and gobi desert, and thick and integrated stratum ofloess or paleosol sequence developed excellently for enrichment of sediments. It is well known that there are much paleo environmental information recorded in loess and paleosol. If research of paleo environmental index is carried out from several sides, especially from loess geochemistry, some important and detailed paleo environmental evolutional information will be uncovered and tested one another. Based on this, content of Sr and Ca is analyzed contained in acid soluble fraction from bottom to top for the Panzishan section, which is obtainedthrough making a well about 17 meters in depth, including the important strata of S1 paleosol that was developed during the last interglacial time. The resultsshow that the change of content of Sr and Ca is well correlated with conversionof loess and paleosol. In loess sediment, the content of Sr and Ca is higher than that in paleosol deposit. It is known that loess is deposited in cold dry time and paleosol developed during warm humid episodes, and a conclusion can bemade that due to the mobile behaviors of Sr and Ca, under cold dry climate, Sr and Ca are stagnant for weak weathering, but under warm humid climate, Sr and Ca are easily eluviated and migrated with water solution. Therefore, the content of Sr and CaO can be utilized as an indicator of climate changes. Moreover,the change of the content of Sr and Ca is more detailed and sensitive than susceptibility. As far as it goes, the mobile behaviors of Sr and Ca contained in acid soluble can be acted as a new quantitative index to evaluate the scope of paleo environmental changes in Xining Basin.
出处
《地球化学》
CAS
CSCD
北大核心
2002年第5期409-414,共6页
Geochimica
基金
中国科学院知识创新工程重大项目(KZCX1-10-01)
国家自然科学基金(49961006)
中国科学院地球环境研究所黄土与第四纪地质国家重点实验室开放基金(SKLLQG0001)
