广东北江第四纪沉积物发育土壤的矿物特性

本文分析了粤北武水、北江、横石水和连江各级阶地及河漫滩上各时代沉积物发育土壤的粘粒矿物和原生矿物。结果表明,不同河流流经地区不同,物质来源不同,其矿物组成有别;同一河段,形成于早更新世的三级阶地(T₃)上的土壤矿物组成与形成较晚的各级阶地差异甚大,这是母质来源和风化成土条件不同所致;二级阶地(T₂)、一级阶地(T₁)及河漫滩(T₀)上的土壤矿物相似,只是风化程度有异,随着阶地升高,形成年代愈老,富铝化程度愈强烈;但各级阶地之间差异程度不均等,T₂至T₁之间变幅大,T₁至T₀之间差异较少,这是时间因素和古气候波动性叠加所致。

MINERALOGY OF SOILS DEVELOPED FROM THE QUATERN ARY SEDIMENTS OF THE NORTH RIVER OF GUANGDONG PROVINCE

This paper deals with clay minerals and primary minerals of soils which developed on sediments on the terraces and valley flat of ferent periods Wushui,the North River,Hengshishui and Lian River in Northern Guangdong.The result obtained showed that disparity in mineral composition depended upon differetzt sources of sediments in river valleys.In the same river valley,composition of soil minerals in the third terrace (T_a) which was developed from the Early pleistocene differed greatly from that in other terraces.It resulted from different conditions of weathering and soil formation and different sources of sed.imentary matter.In the Second terrace (T₂),the First terrace (T₁) and the valley flat (T_o),the composition of soil minerals were similar and sedimentary matter was basically the same,only weathering degree was different.The higher the terrace and the older the age of soil formation the stronger the allitic degree was.However,the disparity degree among the terraces was not the same.Because of time factor combined with climatic fluctuation T,diffened greatly from T₂ but less from T_o.