渤海地球物理场与深部潜在地幔热柱的异常构造背景  

GEOPHYSICAL FIELDS AND BACKGROUND OF EXCEPTIONAL STRUCTURE FOR DEEP LATENT MANTLE PLUME IN BOHAI SEA

作　　者：滕吉文[1] 张中杰[1] 张秉铭[1] 杨顶辉[1] 万志超[1] 张慧[1] 

机构地区：[1]中国科学院地球物理研究所,北京100101

出　　处：《地球物理学报》1997年第4期468-480,共13页Chinese Journal of Geophysics

摘　　要：渤海是中国东部陆缘的一个裂谷型盆地，通过重力、航磁、古地磁、天然地震、地热、应力场、地壳与上地幔结构及地震层析成像等资料，对渤海湾及其周边地带的深部结构、地球物理场效应和深层物理过程进行了综合研究．这一盆地是由NNE－NE向、近EW向和NW向3组断裂组成，这3组断裂与3组地幔隆起带基本相对应，并在渤中坳陷交汇、渤海内部的现代构造运动以水平构造应力场作用下的走滑运动为主要特征，渤海区内地壳厚度仅28-29km，上地幔向上隆起，等温居里面埋深浅（为12km），并为较高区热流值区（56-77mW／m2）．该区岩石层厚度变化显著，庙岛西部中地壳中有一近似圆形的低速体，在120km深度仍为低速异常区．深大断裂可为深部热物质与气态物质上涌的通道．通过综合研究，提出渤海湾很可能是一个潜在的、尚在发展中的地幔热柱．Bohai Sea is located at eastern edge of mainland between 37°07'-41°0° N and 117° 33'- 121°10' E. They are composed of three groups of faults in NNE-NE, EW and NW direction, which cross Tanlu fault. These three groups of faults are consistent with three groups of mantle uplift and convergence in the Bohai center depressed.Bohai and its neighbouring region are the main area of Seismicity and Mesozoic,Cenozoic magmatic activities area. The crustal depth is 28-29km, and the upper mantle is uplift. The isothermal Curie Surie surface is 12km deep and has high heat flow value (56-77mW/m2). There is approximate circle low velocity body existing in the upper mantle near the Miao island, until 120km deep there is low velocity zone existing. The faults are the channel of heating and gaseous state substances. We have comprehensively rcseached deep structure and deep internal processes as well as geophysical field responsibility and formation through Gravity, Airbornmagnetism,Paleomagnetism, Earthquake, Gcothermism, Tectonic stree field, crustal and upper mantle structure and seismic tomography in Bobal Sea and its around region. We advance a new argument: Bobal Sea is not only a tectonic background of deep heating,but also a devoloping mantle plume.

关 键 词：渤海 岩浆活动 地球物理场 地幔热柱 异常构造 

分 类 号：P314.2[天文地球—固体地球物理学] P738[天文地球—地球物理学]