软流层、中地壳与盆—山系  

Asthenosphere、middle crust and basin-mountain system

作　　者：崔永强[1] 李杨鉴 

机构地区：[1]北京大学地球与空间科学学院,北京100871 [2]化学矿产地质研究院,涿州072754

出　　处：《地球物理学进展》2004年第3期554-559,共6页Progress in Geophysics

基　　金：国家自然科学基金(40172066)资助.

摘　　要：　虽然大量的地学断面研究为我们提供了及其丰富的有关中地壳的信息,但极少有人将中地壳的与盆地、断隆山的形成和演化相联系.大陆层控构造理论认为,上地壳正断层上盘在下降过程中,挤压下伏中地壳塑性层,中地壳塑性层物质在该压力作用下从下降幅度最大、垂向压强最大的箕状盆地翘降端压出,主要流向垂向压力较小、紧邻断层面应变空间的下盘,促使该盘向上倾斜,形成断隆山,组成盆 山系.现今中国东部阴山、秦岭、太行山和燕山等断隆山脉,无不与同时代深沉降的断陷盆地毗邻.松辽盆地和西侧大兴安岭以嫩江断裂为界,断陷盆地和断隆山由晚侏罗世到早白垩世同时开始形成到新生代,伴随松辽盆地大幅度沉降,大兴安岭大幅度隆升.在重力均衡作用下,盆\|山系形成引起莫霍面隆起和上地幔软流层隆升,在沉积盆地和断隆上形成大量金属、非金属和油气矿产.中生代以后,软流层大规模发育.软流层隆升对大型含油气区形成具有决定性意义.Middle crust was hardly thought of the relation with the initiation and evolution of half graben-like rift downcast basin and rift rising mountain, even though abundant information on Middle Crust were provided with many Multidisciplinary geosciences transect. Continental layer-controlled tectonics' theory thinks that, the hanging wall of the upper crust normal fault, during its descending, compressed the underlying middle crust plastic layer, with the strength of the compression being directly correlated the descending magnitude. Therefore, under such a pressure, the plastic material of the middle crust was squeezed out from the tilting descending side of the half graben-like basin where the descending and vertical pressure were maximum, flowing to the footwall with a lower vertical pressure and adjacent to the strain space of the fault plane, tilting the footwall upward to form a rift rising mountain, and finally producing a basin-mountain system. All today's magnificent rift rising mountains in eastern China, such as the Yinshan, Qinling, Taihang and Yanshan, without exception, are adjacent to a certain rift downcast basin of the same age and with deep descending. As a rift downcast basin of Songliao Basin and a rift rising mountain of Daxinganling mountain were delimited by Nenjiang Fault, they initiated in the same period from the late Jurassic period and the early cretaceous to the Cenozoic, alone with Songliao Basin sharply subsided, Daxinganling mountain was greatly uplifted. The thinning of the middle crust plastic layer under the action of the hanging wall of the upper crust normal fault caused the arching of asthenoshere due to a gravitational disequilibrium in that part, creating a mirror relation in tectonic form between the asthenosphere top / Moho and the upper crust bottom of the basin. Under the effect that mantle fluid rised to the basin and mountain, large metallic deposits, non-metallic deposits, oil and gas were forming. The asthenoshere formed in a large scale after Mesozoic. It presents a d

关 键 词：中地壳 软流层 盆—山系 

分 类 号：P631[天文地球—地质矿产勘探] TE132[天文地球—地质学]