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

摘要

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。%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.