论文部分内容阅读
腾格里沙漠晚更新世断头梁剖面分析出介形类７属７种，分别为Ｌｉｍｎｏｃｙｔｈｅｒｅｉｎｏｐｉｎａｔａ，Ｄａｒｗｉｎｕｌａｓｔｅｖｅｎｓｏｎｉ，Ｃａｎｄｏｎａｎｅｇｌｅｃｔａ，Ｃｙｐｒｉｄｅｉｓｔｏｒｏｓａ，Ｉｌｙｏｃｙｐｒｉｓｇｉｂｂａ，Ｃｙｃｌｏｃｙｐｒｉｓｓｅｒｅｎａ，？Ｎｅｏｃｙｐｒｉｄｏｐｓｉｓｓｐ．，其中Ｌｉｍｎｏｃｙｔｈｅｒｅｉｎｏｐｉｎａｔａ和Ｄａｒｗｉｎｕｌａｓｔｅｖｅｎｓｏｎｉ为优势种。根据丰度、分异度及百分含量变化情况，研究剖面划分出四个介形类组合，进一步结合年代数据、沉积物及孢粉资料识别出四个气候期。距今约４２０００－２３０００年间研究区总的气候特征是温暖湿润，间有几次幅度较小的变冷期；介形类显示出淡水至中盐水环境，这一特征持续整个沉积时期，没有出现干旱期。
The late Pleistocene faulted beam profile in the Tengger Desert analyzed 7 genera and 7 genera of Ostracoda, which were Limnocythereinopinata, Darwinula stevensoni, Candonaneglecta, Cyprideistorosa, Ilyocyprisgibba and Cyclocyprisserena, respectively. Neocypridopsissp. Among them, Limnocythereinopinata and Darwinula stevensoni were the dominant species. According to the changes of abundance, degree of differentiation and percentage content, the study classified four types of troughs in the section and further identified four climatic periods based on chronological data, sediment and sporopollen. About 42000-23000 years ago, the total climatic characteristics of the study area are warm and humid, with a few occasional cooling periods between them. Ostracoda shows freshwater to medium salt water environment, which lasted for the whole depositional period and did not appear Drought period.