浑善达克沙地全新世沉积特征与环境演变

SEDIMENTARY CHARACTERISTICS AND ENVIRONMENTAL EVOLUTION OF OTINDAG SANDY LAND IN HOLOCENE

浑善达克沙地全新世沉积主要有风成砂－古土壤和河湖相－古土壤－风成砂沉积序列，其中保存了大量粒度，化学元素，孢粉及披毛犀化石等环境变化证据。据此可把全新世气候划分为８个旋迥，经历了升温波动期（１０～７．１ｋａＢ．Ｐ．）、温暖期（７．１～３．２ｋａＢ．Ｐ．）和温干冷干频繁波动期（３．２ｋａＢ．Ｐ．至今）三个演变阶段。

Holocene deposits of Otingdag Sandy Land mainly consist of aeolian sand- paleosol andfluvial-lacustrine-paleosol-aeolian sand sequence. There are a lot of evidences of environmentalvariations existed in it , including grain size variation,chemical element composition, pollen-sporeassemblage and rhinoceros fossil etc.,Besed on these evidences the climate of Holocene can be dividedinto eight cycles and three evolutional stages , namely temperature-rising fluctuation period(10～7.1ka B.P.),warm period(7.1～3. 2 ka B.P. ) and warm-dry and cool-dry fluctuation period(3.2 kaB.P. ～ present).