Thailand: Gulf of Thailand Coast

Introduction

The east coast of peninsular Thailand is dominated by a wide depositional lowland, interrupted by ridges that run out from the interior mountains to protrude as headlands (Pitman 1982). Along the Gulf coast, as far north as Petchaburi, Tertiary sediment are confined to small basins, and Tertiary orogenic movements resulted in the subsidence of the Chao Phraya depression, north of the Bight of Bangkok.

The Gulf of Thailand began to form as a result of late Cretaceous to early Tertiary subsidence, which emphasised the north-south tectonic trends, and formed a series of pronounced depositional basins occupied by Quaternary marine sediment. Tjia et al. (1977) reviewed Quaternary sea level changes in this area, and concluded that there is good evidence that the sea rose temporarily above its present level in Holocene times. There are several emerged coastlines, marine terraces, and river terraces indicative of the recent northwest tilting of the peninsula and the smooth...