摘要
通过对阳原盆地中井儿洼孔(深200.6m)河湖相岩石地层、生物地层和古地磁等的研究,将第四系河湖相层新命名为阳原群,进一步划分为3个组,即下更新统泥河湾组(深200.6～107.8 m,未见底),由褐灰色粉砂质粘土和粉砂组成;下一中更新统小渡口组(深107.8～20.6m)由灰、灰黑色粉砂质粘土和粉砂组成,内含12段纹层,可作为标志层,底界年龄约1000ka;中一上更新统井儿洼组(深20.6～0m),是本文新命名的组,由黄绿色粉砂和粉砂质粘土组成,底界年龄约200ha。顶部年龄推测为10ka左右。本孔地层划分有助于阳原盆地及毗邻地区区域对比,也为全球变化提供了基础材料。
By means of various methods, the writers analyzed cores from a borehole, 200. 6 m deep, in the Yanyuan basin. In terms of lithostratigraphic, biologic and paleomagnetic features, the Quaternary lacustrine sediments were renamed the Yanyuan Group, which can be divided into three formations. The Lower Pleistocene Nihewan Formation (in depth of 200. 6-107. 8 m), not reaching the bottom of the formation) consists of brown-gray silty clay and silt. The Middle-Lower Pleistocene Xiaodukou Formation ( in depth of 107. 8-20. 6 m) consists mainly of gray and grayish-black silty clay and fine sands. Varves are the marker beds in this Formation. The bottom boundary of the Xiaodukou Formation is 1000 ka B P in age. The Upper-Middle Pleistocene Jing'erwa Formation ( in depth of 20. 6-0 m), newly named in this paper, consists of greenish-yellow silt and silty clay. The age of the bottom boundary is approximately 200 ka BP and that of the top is about 10 ka B P.
出处
《地质学报》
EI
CAS
CSCD
北大核心
2000年第2期108-115,共8页
Acta Geologica Sinica
基金
地质矿产部"九五"重点基础研究项目(编号9501113)
河北省阳原县井儿沟幅1:50000区域地质调查项目
关键词
阳原群
井儿洼组
地层划分
第四纪
湖相层
Yanyuan Group
Jing'erwa Formation
stratigraphic division
Hebei Province
