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CaCO3含量可以明确指示黄土-古土壤层序的发生及其气候变化,因而被称之为有效的气候代用指标之一。临夏盆地黑林顶剖面出露一套连续完整的晚新生代(11.6～5.0Ma)河湖相地层,对该套地层CaCO3含量进行测定,结果揭示,在11.6～8.6Ma,CaCO3含量基本保持相对稳定,平均含量为10.1%。从8.6Ma后,其含量明显减少,平均含量为8.4%。对该剖面磁化率和色度指标以及周边地区气候记录进行对比,认为CaCO3在8.6Ma时期的转变不能简单地运用气候变化进行解释,而很可能与青藏高原阶段性快速隆升带来的碎屑物质的大量快速沉积有关。
CaCO3 content can clearly indicate the occurrence of the loess-paleosol sequence and its climate change, and is therefore called one of the effective climatic proxy indicators. A continuous and complete series of Late Cenozoic (11.6-5.0 Ma) fluvial-lacustrine facies outcrops from the Heilin Top section of Linxia Basin. The CaCO3 content in this formation was measured. The results showed that the content of CaCO3 remained basically unchanged from 11.6 to 8.6 Ma Stable with an average content of 10.1%. After 8.6Ma, its content was significantly reduced, with an average content of 8.4%. Comparing the magnetic susceptibility and chromaticity indices of the section with the climatic records of the surrounding areas, it is considered that the transition of CaCO3 during the 8.6 Ma period can not be simply explained by climate change but is likely to be related to the debris brought by the rapid uplifting of the Qinghai-Tibet Plateau A large number of rapid deposition of matter related.