%0 Journal Article %T A STUDY OF LOESS IN SOUTHEASTERN SHANXI,CHINA
晋东南黄土 %A 曹家欣 %A 石宁 %A 张建中 %J 第四纪研究 %D 1995 %I %X Southeastern Shanxi Province is situated in the eastern margin of the Loess Plateau, China. The famous Yushe basin is within this area, which is the transitional zone from the Loess Plateau to North China Plain. In this area the loess rests unconformably either on the Yushe Group or Triassic strata. The Yushe Group is a suit of fluvio-lacustrine deposits of Pliocene to the early stage of Early Pleistocene. The southeastern Shanxi loess can be divided into 5 Layers: (1) older red loam (Early Pleistocene), (2) younger red loam (the late stage of Early Pleistocene to the early stage of Mid-Pleistocene), (3) upper Lishi Loess (the middle-Late stage of Mid-Pleistocene), (4) Malan Loess (Late Pleistocene) and (5) Holocene loess;the total thickness amounts to about 50m. The Lishi Loess and the Malan Loess are much more widespread than the red loam.The red loam is a kind of specific sediments in southeastern Shanxi and is chiefly composed of silts. It is dark-red and brownish-red, quite homogeneous in lithology and commonly nonstratified. It is widespread in the Yushe basin and ad-jacent areas. It was first studied by P. Teilhard de Chardin and C.C. Young in 1933 and was called "R" loam for short.In this paper, the red loam is subdivided into two layers: (1) older red loam and (2) younger red loam. The older red loam is about 20m thick, contains 910 paleosol bands and has rich Fe-Mn nucleus but no calacareous concretions. Along the Zhuozhang River valley, the older red loam is underlaid with a gravel bed, in which mammalian fossils such as Equus sp. and Trogontherium sp. etc. were found. Besides, in Xiazhuang village a Myospalax tingi fossil was found on a section between the Yushe Group and the older red loam. The younger red loam is lighter in colour than the older red loam and about 10-15m thick, contains 2-4 paleosol beds, and is underlaid with well-developed calcareous concretions. The older red loam and younger red loam contain on an average 66.27% in silt, 10.71 % in fine sands and 23.02% in clay.The Lishi Loess rests on the red roam. It is 10-20m thick and contains 35 brownish-red paleosol beds and rich calcareous concretions. The concretions is the largest at the boundary between the Lishi Loess and the red loam.The Malan Loess is even more widespread in southeastern Shanxi and rests onthe Lishi Loess. It is less than 10m thick and contains small scattered calcareous coneretions.According to the loess section for paleomagnetic measurement shows that the older red loam accumulated at about 2.5-1.5Ma B. P., the younger red loam accumulated at about 0.9-0.6MaB. P. The Lishi Loess and the Malan Loess should be deposited during Brunhes. Lishe Loess at about 0.6-0.1Ma B.P. A correlation is that the older red loam corresponds to the lower part of the Wucheng Loess (Early Pleistocene)and the younger red loam corresponds to the lower part of the Lishi Loess. In fact,the Lishi Loess in southeastern Shanxi corresponds to the upper part of the Lishi Loess i %K 黄土 %K 地层 %K 沉积环境 %K 物质来源 %U http://www.alljournals.cn/get_abstract_url.aspx?pcid=E62459D214FD64A3C8082E4ED1ABABED5711027BBBDDD35B&cid=621CF755B1A341E5&jid=EA07051745CDC8D89D5F01A3A4CFE6A9&aid=0704A347AD3707E5&yid=BBCD5003575B2B5F&vid=23CCDDCD68FFCC2F&iid=0B39A22176CE99FB&sid=AE09EACBCD1B2A13&eid=28F8B56DB6BEE30E&journal_id=1001-7410&journal_name=第四纪研究&referenced_num=2&reference_num=0