The Philippine plate was subducted beneath the South China Sea plate, and at high pressure and temperatures became magma which then burst to the surface in a string of volcanoes. The East Coastal Range, Orchid Island, Green Island, the Batan Islands, the Babuyan Islands, and the island of Luzon all resulted from the same system of volcanic activity.
海岸山脈、綠島、蘭嶼，接著菲律賓巴丹、巴布亞、呂宋島，串成火山島弧。專門關政治犯的綠島在未經「綠化」前，因土地泛紅被稱為火燒島。