摘要
潜江组盐层间的层段(盐间段 )由砂岩和非砂岩两部分组成。其中非砂岩分布广泛 ,主要由单层厚度为毫米—厘米级、累积厚度达几十厘米至几米的含盐韵律组成 ,并多为复成分的蒸发盐矿物、碳酸盐矿物及陆源的粘土和细碎屑矿物组成的混积岩。过去 ,人们对盐间段非砂岩的研究主要基于对岩性的认识 ,对于其沉积特征和沉积环境方面的研究较薄弱。文中通过对潜江凹陷西北部王场构造 3口井共约 1 51m岩芯的精细研究 ,对盐间段沉积特征和沉积环境进行了系统分析。认为潜江组盐间段湖盆环境为常年性较深水分层盐湖 ,大体可分为微咸水湖、半咸水湖、咸水湖和盐湖 ,水体深度自下而上逐渐变浅。
The intervals between salt beds in the Qiangjiang Formation of Upper Eocene-Lower Oligocene of Paleogene consist of sandstones and non-sandstones. The non-sandstones are widely distributed and mainly composed of miltimeter-scale to centimeter-scale of single bed, a total of several decimeters to several meter thick salt-bearing rhythms,most of which are polymictic mixed rocks composed of evaporite minerals, carbonate minerals and terrigenous clays and fine clastic minerals. For a long time, the study of the non-sandstones between salt beds has been limited to the lithological characters and less attention has been paid to sedimentary characteristics and sedimentary environments. Through the detailed study of a total of 151 m thick in Wangchang Structure of northwestern Qianjiang Sag on the cores of three wells, this paper gives a systematic analysis of the sedimentary characteristics and environments of the intervals between salt beds, and suggests that the lake basin was a perennial relatively deepwater meromictic salt lake which can be roughly divided into brackish-water lake, semisalt-water lake, salt-water lake, and brine lake when the intervals between salt beds were deposited. During the peroid of Qianjiang Formation,the water depth of lake basin was gradually from deeper to shallower.
出处
《古地理学报》
CAS
CSCD
2003年第1期29-35,共7页
Journal of Palaeogeography:Chinese Edition
关键词
沉积环境
江汉盆地
潜江组
含盐岩系
沉积特征
沉积环境
混积岩
Jianghan Basin, Qianjiang Formation, salt-bearing series, sedimentary characteristics, perennial meromictic salt lake