摘要
洞庭盆地周缘广泛发育着第四纪红土地层,我们在野外对典型红土剖面进行了考察,并在岳阳市月山红土剖面进行了取样,在室内对土壤样品进行了磁化率、粘土矿物和粒度等实验分析,从而对洞庭盆地第四纪红土地层的剖面特征进行了研究,在此基础上,对洞庭盆地第四纪古气候变迁进行了探讨。月山红土剖面地层界限清晰,剖面特征明显,与中国南方其它的红土地层具有较好的地层对比性。月山红土剖面磁化率和粘土矿物分析表明:中更新世早期洞庭盆地气候干凉,中更新世晚期转为湿热;晚更新世早期气候仍保持湿热,晚更新世晚期则转为干凉;全新世以来洞庭盆地的气候再次转为湿热。粒度分析表明月山红土剖面第四纪沉积物的沉积环境为洪水盆地中的泛滥平原环境。
There are many Quaternary laterites around the Dongting Basin. The survey on some typical laterite profiles on the field was carried, and sampling in the Yueshan laterite profile, Yueyang City. Some experiments on the soil samples, such as magnetic susceptibilities, clay minerals and size analysises had been done, and the characteristics of the Quaternary laterite profiles in the Dongting Basin were studied, then the Quaternary paleoclimate evolution in the Dongting Basin was discnssed. The Yueshan laterite profile has the distinct stratigraphical facies and the evident profile characteristics, and it has a good stratigraphical correlation with other laterites in the South China. The analyses of magnetic susceptibilities and clay minerals of the Yueshan laterite profile indicate the rules of the Quaternary climate change in the Dongting Basin as follows: the climate of the Dongting Basin in the early stage of the Middle Pleistocene is dry and cold, and the climate of the Dongting Basin in the late stage of the Middle Pleistocene is humid and hot. The climate in the early stage of the late Pleistocene still keep humid and hot, but the climate begin to turn dry and cold in the late stage of the late Pleistocene. The climate of the Dongting Basin turn humid and hot in the Holocene once more. The size analysis indicates that the sedimentary environment of the Yueshan laterite is flood plain in the basin.
出处
《沉积学报》
CAS
CSCD
北大核心
2005年第1期130-137,共8页
Acta Sedimentologica Sinica
基金
国家重点基础研究发展计划项目(2003CB415201)
国家自然科学基金项目(批准号: 40271013)资助
