焉耆盆地原型盆地性质及构造演化特征研究

Study on prototype basin properties and tectonic evolution characteristics of Yanqi Basin

分别从盆地内构造特征、沉积体系发育和地层接触方式、沉积速率分析以及盆内构造耦合关系着手,着重讨论存在争议的焉耆盆地早中侏罗世构造性质。应用平衡剖面技术恢复了早中侏罗世及后各个时期的构造。认为焉耆盆地属于早中侏罗世开始孕育的陆内前陆盆地,经历了前中生代基底形成、中生代前陆盆地雏形、燕山期前陆盆地形成、喜山期前陆盆地定型4个构造演化阶段。盆地内种马场隆起和宝浪苏木等主要构造带为同沉积构造,构造带的演化过程控制了凹陷内沉积体系发育特征及油气圈闭形成。

In lights of the tectonic properties, depositional system development and contact style, sedimentary velocity analysis and tectonic coupling relationship within the basin respectively, the authors mainly stressed on the disputed structure properties of Yanqi Basin in early and middle Jurassic Epoch. The structural framework of each stage was recovered from early and middle Jurassic by utilizing balance-section technology. It was concluded that Yanqi Basin belonged to a intra-continent foreland basin that took its shape during early and middle Jurassic Epoch, undergoing four periods of structural evolution stage： basement formation in pre-Mesozoic, foreland-basin embryonic formation in Mesozoic Period, foreland-basin inoculation in Yanshan period, final setting in Himalayan Period. Several primary structure belts were synsedimentary including Zhongmachang uplift and Baolang-Sumu structural belt, the evolution process along the structural belt controlled the characteristics of sedimentary system development and the formation of hydrocarbon traps.