mollisol

The sequence and interlayer regular of the palaeosoil,peat layer and melt-frozen folded layers,as well as lake terraes,lake level s changes, palaevegetation and ostracoda assemblages showing the early holocene climate was cool and dry,the middle holocene was warm and humid,the late holocene was temperate and semi-arid climate in the transitional agricultrue-animal husbandry.

从本区发育的古土壤层、泥炭层、古风沙层、冻融褶曲层序列及其交错分布规律，以及湖岸阶地、湖面变化、古植被和介形类化石组合等方面资料都表明本区经历了早全新世冷干，中全新世温湿，晚全新世温凉偏干的气候变化，在千年尺度上表现出２０００ａ左右的气候变化周期；本区环境演变的干湿冷暖序列，即与中国东部和西部的环境演变具有相似性，也具有与全球变化的同步性特点。