川东北地区下三叠统飞仙关组白云岩成因分析

在川东北地区下三叠统飞仙关组沉积相模式研究成果的基础上,详细研究了区内鲕粒白云岩、具残余鲕粒结构的粗粉晶-细晶白云岩、泥微晶白云岩、藻纹层白云岩、粗粉晶-细晶白云岩的岩石学特征,并结合碳氧同位素、微量元素、流体包裹体3种地球化学特征资料认为:鲕粒白云岩和具残余结晶鲕粒白云岩为混合水白云石化作用形成;泥微晶白云岩和藻纹层白云岩为回流渗透白云石化作用形成;粗粉晶-细晶白云岩为埋藏白云岩化作用形成。

GENETIC ANALYSIS OF DOLOMITE OF FEIXIANGUAN FORMATION OF LOWER TRIASSIC SERIES IN NORTHEAST SICHUAN

Based on the research of sedimentary facies model of Feixianguan formation of the Lower Triassic Series in northeast Siehuan this paper mainly deals with the petrological characteristics of oolitic dolomite, coarse crystal powder dolomite-fine crystal dolomite with residual oolitic texture, micritic dolomite, alga-laminated dolomite and coarse crystal powder-fine crystal dolomite. Combined with data of C, O isotopic, microelement and fluid inclusion researches the author thinks that oolitic dolomite, coarse crystal powder dolomite-fine crystal dolomite with residual oolitic texture are the result of mixed water do- lomitization, micritic dolomite, alga-laminated dolomite the result of seepage reflux dolomitization and coarse crystal powder dolomite-fine crystal dolomite the result of burial dolomitization.