CLIMATIC CHANGE SINCE LITTLE ICE AGE RECORDED BY DUNDE ICE CAP

The climatic change since the Little Ice Age recorded in the Dunde Ice Cap is presentedin this paper. There have been three cold periods and three warm periods since 1400AD.Among them, the coldest one was in the 17th century. Many evidences verified the three coldand warm variations recorded in the Dundc Ice Cap. But it was found from the comparison between the Dunde Icc Cap climatic record and thewinter temperature record in Shanghai that there was a temporal dfference in climatic changebetween East China and West China. The general trend is that the cooling and warmingprocesses in West China were earlier than that in East China. In the Dunde Ice Cap, it isnow in an anomalous warm period, while it is not as warm as in Dunde Ice Cap recordaccording to the winter temperature in Shanghai. In addition to the possible cause of temporaldifference in climatic change between West China and East China, another possible cause isthat the greenhouse effect of CO_2 may already be recognizable in the Dunde Ice Cap a     

A PRELIMINARY RESEARCH ON WEATHERING PROCESS IN CASEY STATION, EAST ANTARCTIC

The chief aim of this preliminary work is to investigate the weathering process of the bed rock and moraine in Antarctic by the method of sedimentology. Microfractures, the depth of which is less than 1 cm, and macrofissures are formed through frost weathering process. The chemical composition of the weathering products are observably related to their size due to migration process. Weathering materials are relatively rich in rare-earth elements of Ce family. Weathering clay minerals are mainly illite hydromica which can considerably absorb the elements of Ti, K, Cs, Rb, Sc, Sb, As and Fe. The weathering crust of the bed rock has hardly any CaCO_3 component, it belongs to primigenial debris weathering crust, with only a slight As pollution.     

东南极凯西站地区风化过程的初步研究

本文主要用沉积学方法研究南极地区基岩和冰碛砾石的风化作用。寒冻物理风化作用形成宏观裂缝及微裂纹,后者所达深度在1cm以内。不同粒级风化物的化学元素有明显的分异现象。风化物为富铈族稀土的选择配分型。风化粘土矿物以伊利水云母为主,对Ti,K,Cs,Rb,Sc,Sb,As,Fe有较强的吸附作用。基岩风化壳中完全不合碳酸钙,属最原始的碎屑型风化壳、有轻微的砷元素污染现象。     

敦德冰帽中的小冰期气候记录

本文讨论了敦德冰帽中小冰期以来的气候变化,在敦德冰帽记录中,自公元1400年以来,有3次冷期、3次暖期,最冷是在17世纪,但敦德冰帽记录与上海冬温记录的比较发现,中国东西部气候变化又有时间的差异性,总的趋势是西部的变暖、变冷过程早于东部,在敦德冰帽中,目前已处于异常温暖期,而在上海冬温记录中,并没有敦德冰帽记录那么明显,除了中国东西部气候变化可能有时间差异这一原因外,另一可能原因是CO_2温室效应所产生的增温过程,在地处中国西部中纬内陆地区的敦德冰帽地区可能已有所反映。     

我国西藏南部珠穆朗玛峰地区冰雪水中氘和重氧的分布

珠穆朗玛峰和希夏邦马峰北部海拔4550—7027米处的冰、雪、水中,氘和氧-18的含量都比标准平均洋水中的为低,氘在固相比在液相中,对比氧-18一般有较大的相对富集。此外,对同位素高度效应、年龄效应、冰川纵剖面中的同位素组成以及高原湖中的同位素浓度,作了讨论。