摘要
根据对南京江北TZC全新世剖面的野外考察和室内粒度分析,揭示了该地区一万多年以来的成壤环境演变特点。研究结果表明,南京江北地区第一层古土壤为全新世最适宜期(8500～3100aBP)时形成,当时,气候温暖湿润,降水量丰沛,沙尘暴很少发生,成壤极其强烈,其成土母质为末次冰期形成的下蜀黄土,主要是在下蜀黄土堆积成壤基础上的再发育。近3100a来为全新世晚期,季风气候格局发生转变,气候干旱化,沙尘暴频繁发生,在该地区形成了50cm厚的黄土层或表土层。
Field investigation and the grain-size analysis in a loess profile of Holocene in the north bank of the Yangtze River, Nanjing, have revealed the characteristics of the environmental change during the last 10 000 years. The results show that a paleosol layer was formed during the Holocene climate optimum((8 500)～3 100 (aBP)) in the north bank of the Yangtze River, and the climate became warmer and wetter, so the speed of pedogenesis rate was much larger than that of the dust deposition. Therefore, the loess formed in the last glacial became the substance on which the paleosol re-developed. There is a transformation period at 3 100 (aBP), which represents a climate change from the period dominated by the southern monsoon to the period dominated by northern monsoon. A modern loess layer (about 50 cm) has been accumulated since 3 100 (aBP),meaning that the last 3 100 years is a period with intensified dust accumulation.
出处
《海洋地质与第四纪地质》
CAS
CSCD
北大核心
2005年第2期127-132,共6页
Marine Geology & Quaternary Geology
基金
南京大学地球科学系国家重点实验室开放基金
教育部博士点基金(20020284005)
"973"子课题(0209H024)
