Geology of The Philippines - Palawan and Sulu

Palawan and Sulu

Although they are parts of the Republic of the Philippines, Palawan with the Calamian Islands, plus the Sulu Archipelago with the Zamboanga Peninsula of western Mindanao, are the tops of two protruding north-eastern arms of the Sunda Plate. They are not part of the Philippine Mobile Belt but are in collision with it. The Sulu Trench marks the boundary of the Sulu micro-block with the Sulu Sea basin and the Palawan micro-block. The Palawan Trench marks the subduction boundary between the Palawan microblock and the Spratly Islands plateau of the South China Sea basin. The Palawan/Calamian arm was also known in 1981 as the Palawan block and Palawan microcontinent, and in 1989 as the Palawan Micro-Block.