鄂、湘、粤、桂二叠纪构造煤特征及其成因分析

CHARACTERISTICS OF TECTONICALLY DEFORMED PERMIAN COAL IN HUBEI,HUNAN,GUANGDONG AND GUANGXI PROVINCES AND ANALYSIS OF ITS ORIGIN

我国南方构造煤发育,具有特殊的煤岩特征和复杂的成因。本文分析了区内二叠纪各主要煤田构造特征和构造煤发育情况。构造煤宏观上光泽暗淡,煤岩成分破碎或揉皱,结构构造复杂,常见不规则的滑动镜面和构造裂隙。微观上显微组分有破裂从初裂到破碎,揉皱从弱到强的变化特点。根据构造煤的变动特征,将构造煤的宏观类型分为五种,显微类型定为七种,详细地描述各种构遣煤的特点。本文认为不同构造应力的作用是形成构造煤的主要原因。在短期应力作用下煤层表现为塑性和脆性形变,易产生褶皱和破碎;而当煤层受到长时间的应力作用,在高温高压影响下,煤物质就具有流变性质,形成流动形变特征。

The tectonically deformed coal with special petrographical features and compli- cared origin developed in South China.This paper analyzes the structural characters and development of tectonically deformed Permian coal in main coalfields in the studied area.Macroscopically,coal is dull in lustre,and the ingredients are crushed or corrugated.The texture and structure are complicated.Irregular sliding planes and structural fissures are commonly found.Microscopically,macerals are charac- terized by cracks varying from initial cracks to fracture and by varying degree of corrugations.According to deformation of the coal it can be classified into 5 kinds of marcro-litho-types and 7 kinds of micro-litho-types.The characteristics of each kind of coal are described in detail.The paper considers that the main reason for forming the tectordcally deformed coal is the effect of structural stress. Under the effect of short-term stress,coal shows plastie and brittle deformation, forming folding and fracture.Under the effect of long-term stress,high pressure and high temperature,coal shows rhcological character.