塔里木盆地与天山山脉晚新生代盆山耦合机制

The Late Cenozoic Basin/Mountain Coupling Mechanics of the Tarim Basin and the Tianshan Mountains

根据塔里木盆地北缘地质构造几何学和运动学资料、油气勘探地震剖面、人工地震测深、地震层析成像以及地热资料,提出了塔里木盆地、准噶尔盆地岩石圈地幔在天山岩石圈之下碰撞并发生拆沉的盆山耦合机制的概念模型。由于印藏碰撞,青藏高原的北部前缘岩石圈地幔与塔里木盆地岩石圈地幔形成V字形碰撞结构,推动塔里木地块的高强度岩石圈向北运动并俯冲到天山岩石圈之下,以水平俯冲作用在中天山北缘岩石圈之下与准噶尔盆地向南俯冲的岩石圈地幔碰撞,并发生后剥拆离。塔里木岩石圈俯冲的过程中,形成库车再生前陆盆地和再生前陆冲断带以及再生天山山脉。冲断量约为塔里木俯冲量的20％。这一盆山耦合模型可以解释盆地构造、盆地沉降、山脉隆升、岩石圈深部构造和热特征。

Based on the data of tectonic geometry and kinematics, oil and gas exploration seismic profiles, seismic sounding reflection, seismic tomography and geothermy, the authors bring forward a conception model of coupling mechanics of the Tarim block＇s and the Junggar block＇s lithosphere mantles collision and delamination under the Tianshan Mountains. Due to India-Asian collision, the north frontier lithosphere mantle of the Tibet Plateau collided with the Tarim lithosphere mantle in V-shape, which pushes the high strength Tarim lithosphere to move northward and to subduct horizontally under the Tianshan Mountains. The subducted lithosphere mantle of the Tarim block collided with the southward subducted lithosphere mantle of the Junggar block and then delaminated in the back peel style under the Tianshan Mountains. While the Tarim block lithosphere mantle was subducting, the Kuqa rejuvenation foreland basin and rejuvenation Tianshan Mountains were formed. The thrust slip in the Kuqa rejuvenation foreland thrust belt accounts for 20% of the Tarim block subduction. This basin and mountain coupling mechanics model may reasonably interpret the features of the basin structures, basin depression, mountain uplift, lithosphere structure and geothermy in this region.