对湖北郧县辽瓦店剖面的沉积学特征及磁化率、粒度、Rb、Sr含量等理化指标进行了研究。结果表明:辽瓦店剖面自下而上具有马兰黄土(L_1)一过渡层(L_t) 古土壤(S_0)全新世黄土(L_0)表土(TS)地层序列;不同地层单元的风化成壤差异明显,其成壤强弱顺序为古土壤S_0成壤最强、全新世黄土 L_0和过渡层L_t次之、马兰黄土 L_1最弱。成壤强弱的变化揭示出该区晚更新世末期(11 500 a BP以前)气候干冷,全新世早期(11 500?8 500 a BP)气候处于晚更新世干冷向全新世中期暖湿的过渡阶段,全新世中期(8 500?3 100 a BP)气候最为温暖湿润,全新世晚期(3 100 a BP以来)气候转为干冷且逐渐恶化的变化过程。
英文摘要:
The Liaowadian (LWD) profile in Yunxian, Hubei of China was surveyed in details. Investigations into this soil profile, including pedo-stratigraphy, chronology, were carried over the first river terrace of the upper Hanjiang River valley. Magnetic susceptibility, particle-size distribution, the contents of Rb and Sr were analyzed in laboratory. The result shows that LWD profile recorded the environment features and evolution with the stratigraphic series TSL_0S_0-L_tLi. Different degree of weathering intensity in different stratigraphic units is paleosol S_0>Holocene loess L_0>modern TS>transitional loess layer L_t>Malan loess layer Li. The climate was dry and cold before 11 500 a BP and dust falls led to the formation of Malan loess layer Li. And between 11 500 a BP and 8 500 a BP, the climate got warmer, and was characterized by dry and wet, and dust falls led to the formation of Transitional loess layer L_t. During 8 500 a BP to 3 100 a BP,Yunxian basin experienced its warmest period with a warm and humid climate during Holocene, and dust falls led to the formation of S_0. During the late Holocene, namely 3 100 a BP, the climate was deteriorating very quickly. It turned from warm to cold, and precipitation began to decline.