中祁连陆块三叠纪—侏罗纪地层变形特征  

Deformation Features of Triassic and Jurassic Strata in Mid-Qilian Orogenic Belt

作　　者：刘世宝 范文科 李永红 窦光源 祁昌炜 党洪量 

机构地区：[1]青海省地质调查局,青海西宁810001 [2]青海煤炭地质一0五勘探队,青海西宁810007

出　　处：《现代地质》2015年第5期1103-1109,共7页Geoscience

摘　　要：利用砂箱模拟实验进行应变测量以模拟中祁连陆块不同时代地层的变形过程,基于这些应变测量数据,对中祁连陆块三叠纪—侏罗纪地层的变形特征开展了详细研究。结果显示,中祁连侏罗纪地层的变形特征和三叠纪地层明显不同。三叠纪地层为一套滨浅海沉积的砂岩、灰岩、泥岩组合,泥岩为绿色或含碳质、钙质胶结;侏罗纪地层为内陆河湖沉积的泥砂岩,为含煤地层。三叠纪砂岩主要为长石石英细砂岩,而侏罗纪砂岩为泥质砂岩,杂砂岩,岩屑较多。三叠纪地层在晚印支期造山过程中主要发育褶皱和断裂,褶皱轴面直立,褶皱枢纽为对称的南北挤压而形成的近东西走向,整体表现为脆性断块运动特征;侏罗纪地层则遭受燕山期强烈挤压形成紧闭褶皱。Through sandbox modeling experiment the strain data were measured to analyze the deformation fea- tures of Triassic and Jurassic strata in mid-Qilian orogenic belt. The results show that the deformation feature of Jurassic is obviously different from that of Triassic. Triassic is a set of offshore sediments with sandstone and limestone and mudstone, and the mudstone was green with carbonaceous and calcareous cementation; Jurassic is a set of lacustrine sediments mainly composed by mudstone and sandstone and bearing coal. Triassic sandstones are mostly feldspar-quartz fine-sandstones, and Jurassic sandstones are argillaceous sandstones or graywaekes with a lot of cuttings. During the late period of Indosinian movement, Triassic shows brittle fault-block motion features and develop fractures and folds, of which the axial planes are vertical, and the hinges strike east to west resulting from north-south direction extrusion; Jurassic develop tight folds because of the intensive squeezing action in Yanshanian.

关 键 词：中祁连陆块 变形特征 应变 

分 类 号：P542[天文地球—构造地质学] P618.02[天文地球—地质学]