【摘要】 利用东北地区1°×1°深至400km的三维Vp(km/s)值数据,选择互相垂直的2条有代表性的剖面,初步建立研究区构造圈、均匀层基本结构模型;利用8套沿不同经纬线的剖面Vp值分布,勾绘出研究区深至过渡层的结构模型谱;进一步综合得到研究区三维岩石圈结构模型。东北地区的B″层可能由3部分组成,即下部的低速带,中上部的中速、低速相间互层带和上部的增速带,B″层底界面是区分B″与B’″层的稳定的标志,上部的增速带速度与B’下部速度值接近,按照传统认识,那里是岩石圈底界面的位置,东北地区B″层顶界面形态可能存在不连续或剧烈变化的部位。B″层上中部的宽广的分布边界形态及其变化,可能反映软流圈对周围地球物质的同化熔蚀作用;软流圈物质上涌为固体矿产提供物源,也对油气矿产形成起加速作用。岩石圈结构是壳幔物质相互作用的动态平衡结果,它包含软流圈层对上覆地球物质的影响,并对油气、固体矿产存在一种动力控制作用。更多还原

【Abstract】 A model of basic structure of the tectosphere and uniform layer in the study area is preliminarily constructed by using 3D VP (km/s) values with a grid of 1°×1°to the 400 km depth in Northeast China and selecting two representative sections perpendicular to each other and a structure model spectrum to the depth of the transition layer in the study area is depicted by using eight VP value sections along different longitudes and latitudes. Through further integration of the data, a 3D lithospheric structure model is obtained. Layer B″in Northeast China likely consists of three parts, the low-velocity zone in the lower part, alternating medium-velocity and low-velocity zone in the middle-upper part and accelerated velocity zone in the upper part. The lower boundary of layer B″is a stable indicator for distinguishing between B″and B″′. The velocity value of the accelerated zone in layer B″is close to the velocity value in the lower part in layer B′. According to the conventional view, the place near the zone is the position of the basal interface of the lithosphere. From the shape of the top interface, it is inferred that there probably exist loci of discontinuous or abrupt changes in layer B″in Northeast China. The wide boundary form and its change in the upper and middle parts of layer B″may reflect the corrosion and assimilation of Earth’s material in the surroundings by the asthenosphere. The upwelling of the asthenospheric material provides the source for solid mineral resources and also accelerates the formation of petroleum resources. The lithospheric structure is the result of dynamic balance reached by crust-mantle interaction, which involves the effect of the asthenosphere on the overlying Earth’s material and has a dynamic controlling effect on petroleum and solid mineral resources.更多还原