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利用地热学、流变学和重力学方法 ,计算了南海岩石层温度结构、流变特征及地幔对流格局 .南海莫霍面温度在 6 0 0— 1 0 0 0℃之间 .岩石层底界面温度在 1 1 5 0— 1 3 0 0℃之间 ,有效粘滞系数为 1 0 2 0 — 1 0 2 1 Pa·s,与冰期回弹资料确定的地幔粘度吻合 ,表明南海深部具备产生地幔热对流的物理条件 .研究认为地幔物质由北西向南东方向的运移以及印澳 -欧亚板块的碰撞 ,导致南海北部大陆边缘向洋扩张、离散和断裂解体 .在向洋离散过程中 ,陆 -洋岩石层底部地幔局部对流使中央海盆扩张和北部陆缘发生差异性块断运动 .
Based on the geothermal, rheological and gravimetric methods, the temperature structure, the rheological characteristics and the convection pattern of the mantle in the South China Sea have been calculated.The temperature of the Moho in the South China Sea ranges from 600 ℃ to 10000 ℃ .The rock bottom interface The temperature is between 1 1 0 0 0 and 1 0 0 0 ° C, and the effective viscosity is 1 0 2 0 - 1 0 2 1 Pa · s, which agrees well with the mantle viscosity determined by the glacial springback data, indicating that the mantle The physical conditions of thermal convection show that migration of mantle material from northwest to southeast direction and the collision of Indo-Macao-Eurasian plate lead to oceanic expansion, dispersion and fracture disintegration in the northern continental margin of the South China Sea.In the process of oceanic dispersion, The local convection of the bottom mantle in the oceanic lithosphere causes the central basin to expand and the northern continental margin to undergo differential block-off motion.