After calculating the the depth data of the basement of the oceanic crust, the author finds that the the SW Subbasin is older than the Central Subbasin.

用大洋基底的深度资料计算洋壳的年龄，发现西南次海盆洋壳的年龄也老于中央次海盆。

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These two parts were partitioned by antique basement and Cenozoic oceanic crust. The suture belt of the Ancient South China Sea exists in an area from north Kalimantan to north Palawan.

南北两地中生界被古老基底和新生代洋壳隔开，加里曼丹岛北侧-北巴拉望一线为古南海消亡的缝合带。

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