摘要
利用钻井取心、薄片鉴定、粒度分析、古生物鉴定及测井解释等资料和手段,对济阳坳陷南部古近系孔一段到沙四段底部沉积特征进行研究。结果表明,济阳坳陷在孔一段至沙四段沉积早期处于湖盆裂陷初期,沉积作用明显受季节性洪水注入影响,在东营、惠民两凹陷形成洪水—漫湖沉积体系。其主要岩性特征为:岩石类型以反映氧化环境的浅色碎屑岩类为主,成熟度较低,粒度分布和沉积构造反映其兼有重力流和牵引流的沉积特点,植物碎屑贫乏而生物扰动构造丰富且具周期性,砂体呈环带状分布。该沉积体系分为洪水水道末端、泥坪、砂坪、砂泥混合坪和漫湖风暴等5个微相和侧缘远源、近岸远源两类相层序。
The Paleogene sedimentary characteristics from the 1st Member of the Kongdian Formation to the 4th Member of the Shahejie Formation in the southern Jiyang depression have been studied by core observation, thin section identification, grain size analysis, fossil identification and log interpretation. Results indicate the following： the Jiyang depression was in the initial stage of lake downfaulting from the 1st Member of the Kongdian Formation to the early stage of the 4th Member of the Shahejie Formation and the sedimentation was significantly controlled by inflow of ephemeral flood; a flooded lacustrine sedimentary system formed in the Dongying and Huimin subbasins. The main lithologic characteristic is that the rock types are dominated by light-colored clastic rocks reflecting the oxidation environment with a low maturity. The grain size distribution and sedimentary structure show that the rocks have the sedimentary characters of both gravity currents and tractional currents. Plant fragments are lacking and bioturbation structures are abundant and cyclic. Sandbodies are distributed in a ring shape The sedimentary system may be divided into the side-edge distal and near-shore distal facies sequences and five microfacies, namely, flood channel terminus, mud flat, sand flat, mixed mud/sand flat and flooded lake tempestite.
出处
《中国地质》
CAS
CSCD
2005年第4期655-662,共8页
Geology in China
基金
国家"十五"科技攻关项目(2001BA605A09)
中国石油天然气集团公司"九五"科技工程项目(970206-02-01)资助
关键词
洪水-漫湖
沉积特征
孔一段
沙四段
济阳坳陷南部
flooded lake
sedimentary characteristics
1st Member of the Kongdian Formation
4th Member of the Shahejie Formation
southern Jiyang depression
