柴达木盆地新近纪层序地层划分及岩相古地理分析-古生物与地层学专业论文 word格式.docx

摘要
本文采用沉积学、层序地层学、岩石学及测井、地震等多学科相结合的方法与手段, 研究了柴达木盆地新近纪沉积特征,分析了沉积类型,并建立了层序地层格架,进而以构造层序为基础,分析了柴达木盆地的岩相古地理特征,具体成果如下:
首先进行了柴达木盆地新近纪地层厚度变化与分布研究,明确了各时期地层厚度展布规律,即总体呈现东西展布,南北分带的特点;对柴达木盆地第三纪沉积地层进行了层序地层分析,划分出了 6 个构造层序和 14 个三级层序;在对沉积相标志特征和组合类型进行深入分析的基础上,运用地质、钻井、测井资料和数据对研究区的沉积相类型和组合方式进行了分析,结合物源方向分析,通过测井-录井相分析,建立了测井-录井相与沉积相之间的对应转化关系,确立了该区具有冲积扇、河流、三角洲和湖泊 4 种沉积
体系类型,冲积扇、辫状河、曲流河、扇三角、三角洲、辫状河三角洲和湖泊 7 种沉积
相和 11 种微相类型;根据柴达木盆地新近纪各时期砂泥分散体系及特征、砂砾岩分布反映出的物源区、重矿物分析、古气候分析以及古水流分析,结合重点钻井沉积相的划分, 对柴达木盆地新近纪进行了全盆地岩相古地理图的编制,特别是对第三纪各时期古地理特征做出了新的认识,即柴达木盆地在路乐河组时期由于燕山运动晚期及喜山运动早期的影响,盆地主要以旋转扭张为主,形成盆地内多个沉积-沉降中心的特点,且沉积-沉降中心总体上有由南向北、由西向东迁移的规律。
关键词:柴达木盆地,新近纪,层序地层,岩相古地理
Abstract
This article uses Sedimentology, Sequence Stratigraphy, Petrology, logging , seismic bination of multi-disciplinary to reseach Sedimentary Features and analyze the Deposition types of Neogene in Qaidam basin ,then Establishes sequence stratigraphic framework and further based on Tectonic sequence analyzes lithofacies palaeogeography Features of Qaidam basin , Concrete results are as follows :
Firstly we make a research for Changes and distribution in stratigraphic thickness of Neogene in Qaidam basin,and make sure that the stratigraphic thickness shows Things Spread and North-South sub-zone in the make a sequence stratigraphy analysis in Qaidam basin of tertiary,and divide it to six tectonic sequences and fourteen sequences; Based on the deep analysis for signs characteristic of sedimentary facies and bination types,using geology ,drilling,logging and data to analyze sedimentary facies types and bined with analysis of Source direction,through analysis of logging and drilling facies , we establish the relationship between logging-drilling facies and sedimentary facies,and we think there are four types of depositional systems, alluvial fan,river, delta and lake;seven types of sedimentary facies, alluvial fan facies, braided river facies, meandering river facies, fan delta facies, delta facies, Braided river delta and lake f