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在西南日本的南海海槽,菲律宾海板块正以约正交于大陆边缘的方向俯冲到欧亚大陆之下(图1)。尽管其东北部的区域构造即涉及在太平洋板块处上述两板块(菲律宾海和欧亚板块)的相互作用和海沟-海沟-海沟三连点的区域构造极其复杂,但是,南海海槽现在的构造背景是比较简单的。近海中四国盆地的一重要特征是一个古扩张脊,其走向大约相当于板块会聚的方向(图1)。该扩张脊在15-12Ma时停止活动(Qkino等人,1994)。由于它和邻近的大洋地壳已消亡,它们在海沟处的年龄变老,因此俯冲板块是冷的。与俯冲大洋板块年龄有关联的俯冲带的短暂热状态是此次模拟研究的重点。
In the South China Sea trough in southwestern Japan, the Philippine Sea plate is subducting below Eurasia (Figure 1) approximately perpendicular to the continental margin. Although its northeastern regional structure involves the interaction of the above two plates (Philippine Sea and Eurasian Plate) at the Pacific Plate and the extremely complicated structure of the trenches-trenches-trench triplet, the present structure of the South China Sea Trough The background is relatively simple. An important feature of the offshore Shikoku basin is an ancient dilapidated ridge that runs approximately the same direction as the plate convergence (Figure 1). The dilatation ridge ceased to function at 15-12 Ma (Qkino et al., 1994). As it and the adjacent oceanic crust have died out, they age at the trench and age, so the subducting sections are cold. The transient thermal state of the subduction zone associated with the subducted oceanic plate age is the focus of this modeling study.