Due to the economic importance of its hydrocarbon and coal resources, more is known of the Tertiary than of any other part of the stratigraphic succession in Thailand. Tertiary sedimentary rocks occur both on- and offshore and they are generally associated with rift basins formed in extensional, transtensional or strike –slip settings (Fig. 10.1). In the Gulf of Thailand and Central Thailand the rift basins have been covered by extensive post-rift sag basins, while the Mergui Basin is in a post-rift passive margin setting. Thermal subsidence has yet to cover the rift basins of Northern Thailand. The basins trend north-south through the centre of the country onshore, and underlie much of the Gulf of Thailand and Andaman Sea. The Tertiary was a period of considerable tectonic activity and hence the timing of a basin’s subsidence, its location and the nature of its basin-fill and lateral facies variations are all tied to its structural development. The Tertiary structure is discussed by Morley etal. (2011) and further data on the Tertiary stratigraphy and structure are to be found in Ratanasthien (2011) and Racey (2011); the wider plate-tectonic context of the Tertiary structure is discussed by Searle & Morley (2011).
Information on the offshore Tertiary basins has been obtained entirely through hydrocarbon exploration and production activities since the late 1960s, and comprises seismic (both 2D and 3D) and borehole data. A number of the onshore basins in Northern and Central Thailand have
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The Geology of Thailand
This is the first volume in the English language to cover the entire range of the geology of Thailand since the joint Thai—US account by Brown et al. exactly 60 years ago. Over this period there has been a phenomenal growth in interest in this core area of SE Asia. This has been led by geologists in Thailand, but with important and highly significant input from geologists based elsewhere in Asia and in Europe, Australasia and North America. Some of that research was prompted by commercial considerations, since Thailand has important energy and mineral resources, while other research has sought to understand better the stratigraphic and structural history, including the plate-tectonic story which Thailand's rocks reveal. This new volume seeks to bring together all of this knowledge into a single accessible book; it is the work of an international team drawn from Thailand, Japan, Australia, USA, Canada, Germany and the UK.