CAJ | 학술논문

阴山造山带-鄂尔多斯盆地岩石圈层、块速度结构与深层动力过程
음산조산대-악이다사분지암석권층、괴속도결구여심층동력과정
Velocity structure of layered block and deep dynamic process in the lithosphere beneath the Yinshan orogenic belt and Ordos Basin

万方数据

地球物理学报地毬物理學報 지구물이학보

2010年 1期 67-85 ,共19页

滕吉文%王夫运%赵文智%张永谦%张先康%闫雅芬%赵金仁%李明%杨辉%张洪双%阮小敏

등길문%왕부운%조문지%장영겸%장선강%염아분%조금인%리명%양휘%장홍쌍%원소민

阴山造山带%鄂尔多斯盆地%岩石圈层、块速度结构%深层动力过程陰山造山帶%鄂爾多斯盆地%巖石圈層、塊速度結構%深層動力過程
음산조산대%악이다사분지%암석권층、괴속도결구%심층동력과정
Yinshan orogenic belt%Ordos Basin%Layer-block velocity structure in lithosphere%Deep dynamic process

阴山造山带位于鄂尔多斯盆地的北缘,这一地带不仅是构造活动强、弱的变异地域,且为盆、山的耦合地带,故在造山带与盆地地域具有各异的深层动力过程.本文基于高精度人工源地震宽角反射、折射探测和高分辨率的数据采集,通过反演求得了满都拉-鄂尔多斯-榆林-延川长达650 km剖面辖区的岩石圈精细层、块结构.研究结果表明:①沿该剖面由南向北地壳厚度为40～45 km,在不同构造单元其介质、结构均不相同;速度分布、空间结构形态和界面起伏及属性亦存在着明显差异;上地幔顶部速度为8.0～8.1 km/s;②沿剖面存在5条深、大断裂,且将该区切割成为壳、幔结构明显差异的4个构造单元,即鄂尔多斯盆地、盆山耦合地带、阴山造山带、内蒙构造带,它们各自具有固有的深层过程和动力学响应.同时厘定了阴山造山带与内蒙构造带之间的白云鄂博深、大断裂带是古亚洲洋的南界.在这里不仅导致了阴山造山带的形成,而且聚集了诸多的金属矿产资源,地震亦频繁活动.基于上述研究表明,阴山造山带-鄂尔多斯盆地耦合地带的壳、幔结构复杂、呈现出速度结构各异的层、块状展布.显然,在这一错综的成山、成盆、成岩、成矿和成灾地带,有着特异的深层过程和动力机制.
음산조산대위우악이다사분지적북연,저일지대불부시구조활동강、약적변이지역,차위분、산적우합지대,고재조산대여분지지역구유각이적심층동력과정.본문기우고정도인공원지진관각반사、절사탐측화고분변솔적수거채집,통과반연구득료만도랍-악이다사-유림-연천장체650 km부면할구적암석권정세층、괴결구.연구결과표명:①연해부면유남향북지각후도위40～45 km,재불동구조단원기개질、결구균불상동;속도분포、공간결구형태화계면기복급속성역존재착명현차이;상지만정부속도위8.0～8.1 km/s;②연부면존재5조심、대단렬,차장해구절할성위각、만결구명현차이적4개구조단원,즉악이다사분지、분산우합지대、음산조산대、내몽구조대,타문각자구유고유적심층과정화동역학향응.동시전정료음산조산대여내몽구조대지간적백운악박심、대단렬대시고아주양적남계.재저리불부도치료음산조산대적형성,이차취집료제다적금속광산자원,지진역빈번활동.기우상술연구표명,음산조산대-악이다사분지우합지대적각、만결구복잡、정현출속도결구각이적층、괴상전포.현연,재저일착종적성산、성분、성암、성광화성재지대,유착특이적심층과정화동력궤제.
The Yinshan orogenic Belt in the northern margin of Ordos Basin is not only a transition region between strong and weak tectonic activities, but also a basin/mountain coupling zone, so there are different deep dynamical processes in the orogenic belt and basin region. Based on the high resolution data from a wide-angle reflection and refraction seismic sounding, we get the fine lithospheric structure along the profile of Mandula-Ordos-Yulin-Yanehuan as long as 650 km. Some results are summarized as follows: 1. The crust thickness is about 40 to 45 km from south to north in the profile. The property of medium and structure are different in different tectonic units. Obvious differences exist in the velocity distribution, structure pattern, and interface undulation and attributes. The velocity is 8.0～8.1 km/s on the top layer of the upper mantle. 2. There are five deep and big faults in the profile, dividing the region into four tectonic units with obviously different crust-mantle structure beneath the Ordos Basin, the basinmountain coupling belt, Yinshan orogenic belt, and Inner Mongolia tectonic area, which have respectively inherent deep processes and dynamic responses. Furthermore, we define the Bayan Obo fault between Yinshan and Inner Mongolia as the south boundary of Paleo-Asian Ocean.Subsequently, Yinshan orogenic belt and a good many metallic mineral resources were formed and frequent earthquakes happened. Therefore, the structure of the crust and mantle in this coupling region is quite complicated, and is divided into layers and blocks. Obviously, in the forming of mountains, basins, rocks, minerals and disasters, there are special deep process and dynamic mechanism.