中伊朗盆地库姆组层序充填与新特提斯海演化

Sequence Filling and New Tethys Evolution of Qum Formation,Central Iran Basin

中伊朗盆地形成和发展受特提斯洋张力以及阿拉伯板块和伊朗板块边缘聚力的复合控制,其演化经历了基底裂谷(Z1)、被动边缘(Z2-T2)、裂谷盆地(T3)、弧后前陆(J-N11)、陆内坳陷—挤压改造(N12-Q)等不同阶段,层序充填包括1个一级层序、3个二级层序,显示明显的纵向叠加、横向复合的复式特点。作为中伊朗盆地弧后前陆演化阶段沉积产物,库姆组层序充填总体呈现碳酸盐岩、火山岩-火山碎屑岩、陆源碎屑岩"混积"的特点。库姆组包括S1、S2、S3、S44个三级层序,其充填演化经历了Chattian期、Aquitanian早期、Aquitanian晚期、Burdigalian期4次三级海平面变化事件,最大海平面时期(mfs)位于Burdigalian早期。

In the light of genetic sequence stratigraphy, this paper deals with sequence filling and New Tethys evolution of Qum Formation in central Iran Basin. The authors suggest that this basin possesses typical composite characteristics of superposition in vertical direction and complexity in horizontal direction. Its formation and evolution were controlled by both the tensile force from Tethys and the converging force from Arabic and Iranian plates and underwent orogenic rifting （Z1）, passive continental margin （Z2-T2）, rifting basin （T3）, back-arc foreland basin （J-N1^1）, and intracontinental depression and reworking （N1^2-Q） stages. The filling process formed the four sedimentary sequences of S1, S2, S3 and S4 and experienced four sea level events, namely, Chattian, early Aquitanian, late Aquitanian and Burdigalian stages.