塔里木盆地塔中隆起带二叠系火山岩识别及其喷发模式

Identification of Permian volcanic rocks in Tazhong uplift,Tarim Basin and its eruption pattern

基于塔里木盆地塔中隆起带西端的K1三维工区地震和钻井资料,统计分析了火山岩的厚度、岩性特征,建立了本区火山岩地震识别模式,通过连井地震剖面分析了火山岩的剖面特征,利用时间切片剖析了纵向上火山机构的演变特征,应用不连续性检测技术确定了火山口平面展布。综合火山岩的钻井、地震剖面和时间切片等点-线-面-体的特征,建立了研究区的火山喷发模式。研究区的钻井钻遇二叠系火山岩的厚度为285~1133 m,识别出大型火山机构7个,多数火山口呈圆形或近圆形,火山机构在剖面上呈蘑菇状、伞状和漏斗状特征,火山通道呈管状。这些证据表明,该区火山喷发模式以中心式喷发为主,如此密集分布的火山机构群说明本区是塔里木大火成岩省的喷发中心之一。

Based on the seismic and drilling data of the K13D survey area in the western Tazhong uplift,Tarim Basin,the thickness and lithological characteristics of the volcanic rocks were statistically analyzed,and the seismic identification models of the volcanic rocks were established.The profile characteristics of volcanic rocks were analyzed by seismic connecting-well profiles,the evolution characteristics of volcanic edifices were analyzed by time slice vertically,and the plane distribution of volcanic craters were determined by using the discontinuity detection technology,while the magma eruption model in the Tazhong uplift zone was established through the combination of point-line-plane-body analysis of drilling,seismic profiles and time slices.The thickness of the Permian volcanic rocks ranges from 285 m to 1133 m at the well points,and 7 large craters are identified.Most of the craters were circular or nearly circular,while the volcanic structures are mushroom-shaped,umbrella-shaped and funnel-shaped,with tubular-shaped volcanic channels.These evidences indicate that the volcanic eruption pattern in this area is dominated by central type eruption.Such a densely distributed group of volcanic structures indicates that this area is one of the eruption centers of the Tarim large igneous province.