博格达南缘二叠系古土壤类型及其在层序地层研究中的应用

Types of Permian Paleosols and Their Significance in Sequence Stratigraphy in the Southern Part of Bogeda Range

古土壤是在地质时期经成壤作用改造原岩而形成土壤。野外实地详细考察和室内研究表明,博格达南缘二叠系中发育4类古土壤,即有机土壤,发育于土壤剖面的近顶部,属于潮湿古环境的产物;泥质土壤,主要发育于淋滤带和淋滤带底部泥质沉淀带,形成于长期淋滤和比较潮湿的古环境;铁质土壤以富含铁质结核为特征,是长期淋滤和潮湿古环境的标志;钙质土壤以富含钙质结核为特征,是干旱—半干旱古环境的标志。通过古土壤的研究能够精细地划分层序旋回和恢复沉积古环境。

Paleosols were formed on the basis of the reconstruction of primary rocks in the pedogenic process during the long geologic period. The 4 types of Permian paleosols were developed in the southern part of Bogeda range based on the fine research of outcrop and the inside job. The histosot was located on the top of the paleosol section, resulted from the watery paleoenvironment. The argillisol was precipitated within the bottom of eluviation belt, resulted from the long eluviation and the moist ancient climate. The spodosol was characteristic of the ferruginous concentric ball due to the long-term eluviation and the dankish climatic environment. The calcisol was characteristic of the abundant calcic conglomeration from the half-arid to arid ancient climatic environment. The sequence cycles can be divided carefully and the ancient climatic environment can be recovered veraciously according to the paleosol section.