济阳坳陷非生物成因气聚储的深层构造因素探讨

Probe into Deep-Seated Structural Factors of Abiogenic Gas Accumulation and Storage in Jiyang Depression

通过综合分析深部人工地震探测资料和非生物成因天然气分布特征 ,认为超塑性流动变形机制对于济阳坳陷地壳岩石流变和深部结构调整影响深刻 .地幔物质上涌 ,中、下地壳特别是低速物性体的岩石流变以及表壳伸展破裂 ,制约着含气构造按照表壳脆裂与深部流变的组合样式发展 .岩浆活动受到韧性地壳分层的阻隔 ,通过深熔作用同化岩石圈物质 ,通过侵位地壳改造壳层性质 .在低速体所在层位 ,流体 (包括二氧化碳 )在聚集的同时促进了地壳岩层的变质、弱化 .整个地壳层次上的深部顺层断裂。

A synthetic analysis of deep seismic prospecting data and abiogenic gas distribution preliminarily reveals that superplastic rheological mechanism affects significantly the flow deformation of rocks and adjustment of deep structures of the earth crust in the Jiyang depression. Mantle substance upwelling and flow deformation of rocks in middle and lower crusts, especially in low velocity body, along with stretching breach within the surface crust, restrict the development of the gas bearing structures according to a knockdown style of brittle split in surface crust and flow deformation in depth. Magma function was obstructed by tenacity layer of the crust,and assimilated lithospheric substance through anatexis and transformed the layer nature by virtue of emplacement in the crust. In the layer containing low velocity body, metamorphism and weakness of crust rocks have been promoted as the fluid including gathered CO 2. Deep bedding fault, structural dismantling and expansion of fault root among whole crust arrangement constitute beneficial structural factors for the abiogenic gas accumulation and storage in the study area.