GEOLOGY
Khao Sok has been very geologically stable over the last 60 million years: while other regions of the world experienced periods of glaciation and shifting climate, Thailand rested in the middle of the relatively stable Indo-Chinese plate, never drifting far from the equator. This long period of stable weather and rainfall patterns have allowed the many species of the area to prosper.
Khao Sok rests near or straddles many features that create different bioregions. The Tenasserim Hills that serve as a continental divide, separating eastern and western regions of the Thai peninsula, run along the edge of Khao Sok National Park. It lies immediately below the Isthmus of Kra, separating the bioregions of peninsular Thailand and Malaysia from the more deciduous, dry regions to the north.
The Kangar-Pattani line south of Khao Sok near the Thai-Malay border separates the jungles of the Orient from the jungles of Indonesia and its surrounding areas. A key distinction of this line is the shift in humidity, as it is markedly higher south of the line.