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Genesis and Characteristics of Malan Loess, Lishi Loess and Wucheng Loess
1, loessofMalan, one of the names of Quaternary loess stage in China, the standard section is located on the north slope of Zhaitang, Mentougou District, Beijing, and the named section is on the second terrace on the right bank of Qingshui River opposite to Zhaitang, Beijing. 1962, Liu Dongsheng and Zhang Zonghu named this loess Malan Loess, because there are Malan terraces on the right bank of Qingshui River nearby. Malan terrace is 30 ~ 40 meters above the river surface, which is composed of loose loess material and gravel layer, but there is no loess deposition on Malan terrace.

2. Lishi Loess belongs to the late Middle Pleistocene, which is distributed in North China, Northwest China and the middle reaches of the Yellow River. Its typical profile is in Lishi County, Shanxi Province, hence its name. Pale red and yellow, the loess in Bijoung is shallow and deeper than that in Malan. It is mainly silty, without bedding, and contains many layers of brown-red paleosol, with calcareous nodules under it, sometimes layered. The thickness of Lishi loess is 90- 100 meters, which constitutes the foundation of the loess plateau.

3. Wucheng Loess Standard Site is located on the gravel layer of Liushugou, a tributary of Shui Xin River in Wucheng Town, Xixian County, Shanxi Province, and has no direct contact with hippie red soil layer. Wucheng loess, the rock color is red, containing reddish-brown buried soil layer. Wucheng loess has no clear bedding and less sand and gravel. It is speculated that there was no strong running water when it formed.

Types of loess:

Loess is divided into primary loess and secondary loess.

Primary loess is primary, distributed in thick layers, covering low watersheds, hillsides and hills, often unconformity contact with bedrock, no stratification, often containing paleosol layer and calcareous nodule layer, with vertical joints developed and often forming steep walls.

Loess-like soil, also known as secondary loess, is a primary loess stratum transported by forces other than wind, which is mainly formed by flood, slope and alluvial. It is accumulated in the front of alluvial fan, low terrace and alluvial plain, with developed bedding, less paleosol and undeveloped vertical joints, so it is difficult to form steep walls.

Refer to the above? Baidu Encyclopedia-Loess, Baidu Encyclopedia-Lishi Loess, Baidu Encyclopedia-Malan Loess, Baidu Encyclopedia-Wucheng Loess