【摘要】 重新处理和解释叶县—南漳反射地震剖面,并综合利用油气勘探地震剖面,地震层析、大地电磁测深、地热流、气体测量等地球物理和地球化学数据,得到秦岭造山带岩石圈构造模型。识别出秦岭地壳不同时代的重要构造:(1)加里东期华北克拉通向秦岭微板块的俯冲,并造成中上地壳内华北地壳和北秦岭地壳形成锯齿状楔入构造。(2)印支—燕山期扬子克拉通与秦岭微陆块的对冲走滑软碰撞,形成了以南阳地区为中心由一系列规模宏大的逆冲断层组成的负花状构造。(3)白垩纪后,由正副片麻岩交互成层的结晶基底形成的穹隆。(4)盖在结晶基底上的近透明浅变质元古宙地层形成的褶皱基底。白垩纪后,秦岭地区和中国东部其他地区一样,岩石圈地幔遭受到软流圈上升形成蘑菇云构造,岩石圈活化,严重影响构造演化过程。更多还原

【Abstract】 The authors have constructed a new lithospheric structural model of the Qinling orogen by reprocessing and reinterpreting the seismic reflection profile from Yexian to Nanzhang and integrating and using the geophysical and geochemical data from seismic profiles for petroleum exploration, magnetotelluric sounding, heat flow and gasometry. The following major structures of varying ages have been recognized for the crust under the Qinling orogen:(1) crocodile structure formed by subduction of the North China craton beneath the Qinling microplate in the Caledonian period;(2) negative flower structure composed of a number of huge thrust faults centering around the Nanyang area formed by ramping-up, strike-slip motion and soft collision of the Yangtze craton and Qinling microplate during the Indosinian-Yanshan;(3) a dome of crystalline basement consisting of alternating orthogneiss and paragneiss formed after the Cretaceous; and (4) folded basement formed by nearly transparent Proterozoic low-grade metamorphic strata, overlying the crystalline basement. After the Cretaceous, as was the case with other areas in eastern China, a mushroom cloud-shaped structure was formed in the lithospheric mantle under the Qinling area due to the uplift of the asthenosphere and the lithosphere was reactivated, thus seriously affecting the tectonic evolution.更多还原