南海海盆演变与深部海流

Evolution of the South China Sea basin and the deep circulation

南海在距今34 Ma之前的始新世从陆地变为海洋,古水深不断加深,至距今24 Ma之前的中新世/渐新世之交,由于T60构造运动,南海海盆整体进入深海环境。但是,自中新世以来随着吕宋岛弧向欧亚板块碰撞,南海海盆的半封闭程度在距今10.0、6.5、3.0和1.2 Ma之前加剧,导致南海深部海水只能来自巴士海峡海槛深度2600 m以浅的太平洋。此后,巴士海峡两侧的南海与太平洋深部海水交换,由于全球海平面变化,呈现冰期/间冰期模式。

The present-day South China Sea(SCS)was evolved from land to sea in the Eocene 34 million years ago,and its paleo-water was very deep.At the turn of the Miocene/Oligocene,24 million years ago.due to the T60 tectonic movement,the entire SCS basin became a deep-sea environment.Since the Miocene,10.0,6.5 and 1.2 million years ago,along with the collision of the Luzon island arc with the Eurasian plate,the semi-closed degree of the SCS basin increased,so that the SCS deep-water could only come from the Pacific above the sill depth(〜2600 m)of the Bashi Strait.After that,due to the global sea level change,the deep-water exchange between the SCS and the Pacific on both sides of the Bashi Strait displayed the glacial/interglacial mode.