内蒙古达来诺尔湖湖泊沉积物中敏感粒度组分沉积环境及地层分析

对达来诺尔湖北岸岸边(DL-0)、湖中心(DL-1)和湖南岸(DL-2)3个点的岩心沉积物进行了详细的岩性分析、粒度分析和粒度参数垂向分布序列分析。对沉积环境变化较为敏感的粒度组分的分析发现DL-0与DL-1和DL-2井岩心沉积物敏感粒度组分的峰值有较大差别,其粒度分布范围相差较大,表明湖北岸岸边、湖中心和湖南岸的沉积物来源和沉积环境的时空差异。敏感粒度组分含量随深度变化的初步分析表明,湖北岸岸边(DL-0)和湖中心(DL-1)两个点的沉积环境较为稳定;而位于湖南岸(DL-2)点的沉积环境变化比较大,包含了5个明显的沉积波动旋回,并对达来诺尔湖由北至南进行了沉积地层分析。在达来诺尔湖水下1.5m内主要是粒径0~200μm的颗粒,岩性为粘土、粉砂和砂,以粘土和粉砂为主,随着深度的增加,黏土含量增大,粉砂和砂含量减小。

Sedimentary environmental and stratigraphic analysis of the sensitive grain size components from the Dalai Nur Lake deposits, Inner Mongolia

The detailed analysis of lithology,grain size and vertical distribution of the grain-size parameters are made for the samples collected from the sites DL-0 at the northern bank,DL-1 at the central part and DL-2 at the southern bank of the Dalai Nur Lake,Inner Mongolia. The peak values of sensitive grain size components are found to be quite different,indicating the spatio-temporal differences of provenances and sedimentary environments in the above-mentioned well sites. The sites DL-0 and DL-1 indicate stable sedimentary environments while the site DL-2 indicates variable sedimentary environments in which five depositional cycles are recognized. The clay,silt and sand ranging in grain size from 0 to 200 μm occur mostly at the depth of 1.5 m below the lake level of the Dalai Nur Lake. With the increase of the depths,the clay contents increase while the silt and sand contents decrease.