【摘要】 以地震资料解释成果为基础,从平面和剖面上识别楚雄盆地的扭动构造,并结合区域古地磁资料、应力场特征以及盆地沉积演化,分析研究区不同构造期的扭动变形机制及其演化。结果表明,中生代以来,楚雄盆地受到特提斯构造域向北和滨太平洋构造域向西的推挤力,2个推挤力在不同构造期分别占主导地位,并致使红河断裂左行、右行走滑交替,控制着楚雄盆地的构造和沉积演化;印支期金沙江洋关闭、思茅—印支地块与扬子板块拼合后,金沙江—红河碰撞带东侧的楚雄盆地不属于前陆盆地,板块拼合过程中红河断裂走向与推挤方向形成小角度斜交,主要发生走滑运动,未产生大规模造山,随后在晚印支期南北向挤压应力场中形成楚雄裂陷盆地;研究区南部楚雄—牟定一带沉积厚度的剧烈变化源于楚雄—建水断裂和牟定断裂中生代走滑运动产生的拉分效应;楚雄盆地的火成岩分布往往与大型基底断裂的后期扭动作用有关,这有利于圈定火成岩分布范围,在油气勘探中应有针对性地加以回避。更多还原

【Abstract】 Chuxiong basin locates at the southwestern margin of Yangtze Plate and Central Yunnan Secondary Block of the South Sichuan-Yunnan rhombic block. It is bounded by the Red River Fault in the southwest corner and Xiaojiang Fault in the east border. SinceMesozoic, the basin suffered from a pair of extrusion force with northward direction from the Tethys tectonic domain and westward direction from Marginal Pacific tectonic domain. Each force dominated alternately in different tectonic stages and results in left or right-lateral strike-slips of the Red River Fault which controlled the tectonic and depositional evolution of the Basin. The wrench tectonics was identified according to the planar and sectional characteristics with the results of seismic interpretation in Chuxiong basin. On that basis, the dynamic deformation mechanism of the wrench tectonics in each tectonic stage was analyzed combining Paleomagnetic data and stress field of each stage as well as depositional evolution of the basin. It is concluded that:1 The Chuxiong basin was not a foreland basin which located on the east side of Jinshajiang collision belt after the conjunction of Indochina block into Yangtze Plate. The Red River Fault was mainly in strike-slip motion because of the small angle between the strike of the fault and the movement direction of Indochina block, and didn’t give rise to large scale mountain orogenesis. Thereafter, the Chuxiong basin was evolved into a rifted basin in the SN directional extrusion force of the late Indosinian period.2The abrupt change of sedimentary thickness in the region of Chuxiong-Mouding was influenced by the pull-apart effects during the striking-slip movement of Chuxiong-Jianshui Fault and Mouding Fault. 3The distribution of igneous rock in the basin is closely related to the shear movement of the large-scale basement faults in the later stage, which makes it easy to be outlined and to be avoided in the hydrocarbon exploration.更多还原