论文部分内容阅读
通过对河南新郑黄土-土壤剖面的野外考察及室内的磁化率、烧失量、碳酸钙及粒度分析研究,认为:豫西山地山前丘陵台地的完整黄土-土壤剖面,是在气候波动变化的条件下形成的。全新世气候的变化,导致了以风尘堆积为主的成黄土期与以风化成壤作用为主的成壤期互相更迭。在全新世早期,风尘堆积旺盛,形成了过渡性黄土层(Lt),在8500aB.P.～3100aB.P.的全新世大暖期,发育了浊红棕色古土壤(S0)。这一时期降水丰沛,土壤水分充足,导致了古土壤层(S0)及其以下的过渡层(Lt)、马兰黄土层(L1)顶部都受到了明显的淋溶作用影响,而完全脱钙。3100a B.P.之后,气候恶化,沙尘暴活动显著增强,加之黄河下游人类活动影响不断加剧,黄泛平原风沙活动十分强烈,风尘堆积形成了沙质黄土(L0)。1500aB.P.以来,近代黄土持续堆积,由于气候的转暖与人类农业耕作影响在持续堆积的近代黄土L0表层形成了现代土壤(TS)。
Based on the field investigation of Loess-Soil profile in Xinzheng, Henan Province, and the study on the magnetic susceptibility, loss on ignition, calcium carbonate and grain size in Xinzheng, Henan Province, it is concluded that the complete loess-soil profile in the foreland hilly area in the west of Henan Province is characterized by fluctuating climate Formed under the conditions. Changes in the Holocene climate led to the change of the loess period dominated by aeolian dust and the pedogenic period dominated by weathering and pedogenesis. In the early Holocene, dust accumulation was abundant and a transitional loess layer (Lt) formed. During the Holocene megathermal period from 8500aB.P. to 3100aB.P., muddy red-brown paleosol (SO) developed. Precipitation was abundant and soil moisture was abundant during this period, leading to the ancient soil layer (S0) and its underlying transition layer (Lt), the top of the Malan loess layer (L1) were significantly leached, and completely decalcified. After 3100a B.P., climate deterioration and dust storms were significantly enhanced. Coupled with the intensifying human activities in the lower Yellow River, the sand blown activity in the Yellow River floodplains was very strong and dust loosening formed sandy loess (L0). Since modern loess has been continuously piled up since 1500 aB.P., modern soil (TS) has been formed in the continuous accumulation of L0 in the loess surface due to the climatic warming and human farming.