大别山北麓黄土地球化学特征及其古气候意义

GEOCHEMICAL AND MORPHOLOGICAL CHARACTERISTICS OF THE LOESS-PALEOSOL ON THE NORTHERN SLOPE OF THE DABIE MOUNTAIN AND THEIR IMPLICATIONS TO PALEOENVIRONMENTAL CHANGE

通过对大别山北麓GS剖面系统的氧化物地球化学的测试及综合分析,讨论该地区中更新世以来GS剖面的氧化物地球化学分布特征及其所记录的古气候变迁规律。综合分析表明:大别山北麓富含硅、铝、铁,三者之和高达85%,该区中更新世以来以湿热气候为主;氧化物地球化学分布特征和变化规律可推断该地区中更新世以来经历了8次暖湿期与8次干凉期的交替过程;氧化物比值分析验证该地区经历多次干冷—温湿大幅度的波动,同时伴随着成壤程度、淋溶和化学风化强弱多次旋回。

Based on systematic geochemical and synthetic analyses of oxides of the GS loesses on the northern slope of the Dabie Mountain, this paper deals with geochemical features of oxides and movement regularity of paleoclimate of this area in Middle Pleistocene. The total amount of silicon,aluminum and iron reaches 85% in that area, and hence the authors hold that the climate has been mainly wet and hot from Middle Pleistocene till now in this area. From the distribution characteristics and movement regularity of oxides, it can he concluded that this area has experienced alternately eight times of warm and wet climate and the same times of dry and cold climate since Middle Pleistocene. Analyses of the ratios of oxides reveal that this area has experienced repeated remarkable changes from dry and cold to warm and wet, accompanied by several cycles of formation degree, eluviation and chemical weathering of soils.