【摘要】 为了研究南海北部张裂大陆边缘的地壳热结构,利用船载测量磁力数据,通过功率谱方法反演南海北部陆缘居里等温面,并结合深地震剖面、区域断裂及大地热流分布,讨论了深部热结构状态.结果显示研究区居里面深度在13～26km之间,在上下陆坡转换带处与莫霍面相交,北东向断裂多位于居里面梯度带上,北西向断裂多具有分割、错断的特点,居里面深度和大地热流值具有相关性.结果揭示了陆架、上陆坡地区磁性体可能主要位于上地壳和下地壳上部,下陆坡及洋壳区地壳与地幔顶部有被磁化的迹象.磁静区位于居里面上隆区边缘,F3断裂和F4断裂之间可能是残留古洋壳.潮汕凹陷和台西南盆地中央隆起是发生底侵的主要区域,F2断裂为其北界.更多还原

【Abstract】 In order to investigate thermal state of crust in northern continental margin of the South China Sea,we calculated the Curie point depths with the shipboard magnetic anomaly by employing the method of power-density spectrum analysis.Combining with the seismic section,faults,and the heat flow distribution,the deep thermal structure was discussed in the study area.The result shows that Curie point depths were between 13 and 26km.NE-directed faults were mostly distributed in the gradient belt of Curie point isotherm,while NW-directed faults had the features of segmentation and fragment.The correlations were apparent between the Curie point depths and heat flow data.It reveals that magnetic bodies in shelf and upper slope were mostly distributed over upper crust and upper part of lower crust;and the crust and the top of mantle in under slope and the oceanic areas were subject to magnetization.Magnetic quiet zone was located at the margin of the uplift of the Curie point isotherm.Residue ancient oceanic crusts extended from F3 fault to F4 fault.Chaoshan depression and centre uplift of the Southwest Taiwan basin were the main areas of underplating,and F2 fault was the north boundary.更多还原