黄河三角洲ZK1孔岩心环境敏感粒度组分及沉积环境分析

Analysis on environmentally sensitive grain-size population and sedimentary environment of ZK1 drilling core in Yellow River delta

本文选取黄河三角洲5个钻孔岩心的ZK1钻孔,对其剖面沉积物进行了详细的岩性描述、粒度测试和有孔虫鉴定,分析了ZK1孔粒度参数的垂向分布序列。通过计算粒级—标准偏差的变化获得了ZK1孔沉积物中对沉积环境变化较为敏感的粒度组分的范围为3.75～4Ф和>10Ф。敏感粒度组分含量随深度变化的初步分析、各种粒度参数垂向分布特征及有孔虫资料表明,黄河三角洲ZK1孔的沉积环境大致可分为4段:Ⅰ(0～5.14 m)为1904—1976年上三角洲平原沉积;Ⅱ(5.14～17.41m)为1855年以来的下三角洲平原沉积;Ⅲ(17.41～22.6 m)为1855年以前的陆架沉积;Ⅳ(22.6～24.6 m)为潮坪沉积。

Detailed lithologic description,grain-size testing and foraminifer identification from the ZK1 of the five drilling cores in Yellow River delta have been done,with the analysis of their vertical distribution sequence.The change of grain-size and standard deviation showed the sensitive grain-size population to sedimentary environment variation in ZK1 drilling core are 3.75~4 Ф and 10 Ф.The sedimentary environment of ZK1 in Yellow River delta can be divided into 4 stages through the analysis of sensitive grain-size population contents varied in depth,vertical distribution characteristics of grain-size parameters and foraminifer informations.The first stage（0~5.14 m） is upper delta plain deposition from 1904 to 1976;the second stage（5.14~17.41 m） is lower delta plain deposition since 1855;the third stage（17.41~22.6 m） is continental shelf deposition before 1855;and the fourth stage（22.6~24.6 m） is tidal flat deposition.