豫中黄土地区全新世土壤剖面成壤环境变化研究

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)。

Holocene Pedogenic Environmental Change in the Loess Region in the Middle Part of the Hennan Province

Pedological and stratigraphic observation indicated that GDZ profile was Holocene loess-palaesoil profile sequence.Magnetic susceptibility,loss-on-ignition,CaCO3 content and clay content analysis in the profile of loess-soil at Xingzhen identified the climatic change,which brought about by monsoon change.This change resulted in the alternation of dust accumulation and pedogenic period.The cinnamon soil developed during the Holocene Climatic Optimum that was dated to 8,500a B.P.~3,100a B.P.in China.It indicated that the climatic optimum,abundant precipitation and obvious eluviations on the top of Malan Loess(L1) and transitional loess(Lt).The analytical data indicated that increased climatic aridity at 1150 B.C.in China and these resulted in accumulated eolian loess.The recent loess buried the palae-soil and then people's cultivation on the top of recent loess impelled the form of Top Loess(Ts).