【摘要】 中拐地区位于准噶尔盆地西北缘,是在石炭纪—早二叠世挤压应力场作用下形成的宽缓鼻状古隆起。石炭—二叠纪火山岩是主要的含油层系之一,到目前为止已发现了多个油气藏和出油气点,显示出良好的勘探前景。根据系统、精细的地震资料解释,中拐地区在石炭—二叠纪时期主要存在4期构造运动,分别对应4个不整合面:1)石炭系与二叠系之间;2)二叠系佳木河组与下乌尔禾组之间;3)二叠系下乌尔禾组与上乌尔禾组之间;4)二叠系上乌尔禾组与三叠系百口泉组之间。通过对中拐地区石炭—二叠纪火山岩的全岩元素分析表明,该区域主要为中-酸性的安山岩、英安岩和流纹岩及火山角砾岩和凝灰岩为主,其中SiO₂的含量普遍较高,平均含量达到了67%,判定中拐地区的石炭—二叠纪火山岩喷发环境应位于岛弧体系的大陆内侧,在喷发过程中经历过陆壳的熔融作用。结合前人对周缘火山岩的研究,认为石炭—二叠纪时期中拐地区由岛弧环境逐渐进入陆内演化阶段,三叠纪开始进入稳定的沉积演化时期。更多还原

【Abstract】 Zhong-Guai area is located in the Northwest margin of Junggar Basin,it is a broad nose palaeohigh formed in compressional stress field of Carboniferous Early Permain Period. Carboniferous-Permain volcanic rock is one of the mainly oil-bearing series,until now many hydrocarbon reservoirs and oil entry points are discovered,and showing good exploration prospects.According to systematic and elaborate seismic data interpretation,Zhong-Guai area have four tectonic movements in the Carboniferous-Permian period,corresponding to four unconformity respectively:1 ) Between the Carboniferous and Permian system;2 ) Between the Jiamuhe and Xiawuerhe Formation of Permian system;3 ) Between the Xiawuerhe and Shangwuerhe Formation of Permian system;4 ) Between the Xiawuerhe Formation of Permian system and Baikouquan Formation of Triassic system.The rock element analysis shows that the research area are mainly neutral-acidic andesites,quartz andesite,rhyolite,volcanic breccia and tuff,the content of SiO₂ are generally high,the average content is 66.840%.It is considered that the volcanic eruption environment of Carboniferous-Permain system in research area is inside mainland of island arc system,in the eruption process it experienced the molten role of continental crust.Combining previous study of circumferential volcanic rocks,it is considered that the evolution of Zhong-Guai area in Carboniferous-Permain period is from island arc to intracontinent,and in Triassic period it began to enter into the stable sedimentary evolution period.更多还原