About This Item

Share This Item

The AAPG/Datapages Combined Publications Database

Southeast Asia Petroleum Exploration Society (SEAPEX)

Abstract


Offshore South East Asia Conference, 1976
Pages 42-43

Pre-Tertiary Framework of Southeast Asia

Richard W. Murphy

Abstract

Southeast Asia is redefined to embrace the 6000 km arc between the China-Burma-India border at 28° 16′ N., 97° 23′ E, and the eastern shore of Geelvinck Bay at about 2° S, 136° E. Its western and southern margins are formed by the Tripura Foldbelt-Andaman chain-Java Trench, and the eastern flank by the Taiwan-Batan Islands-Mindanao Trench alignment. At the close of Mesozoic time the core of this crustal block was in the same general position relative to Eurasia, the Indian Ocean west of Ninetyeast Ridge, and the Pacific Ocean as it is today. Australia, the Vogelkop, the Sula Spur, and the lesser Banda Arc were, in contrast, either not in existence or else not in their present position.

Five major types of geotectonic elements are contained:

  1. The pre-Tertiary Sunda core.

  2. Rafted continental splinters from this core:

    The Palawan-Busuanga microcontinent (the South China Sea block), the South Arm of the Celebes, and possibly Sumba.

  3. Additive Tertiary orogenic elements:

    The Tripura-Andaman-Mentawai-Java Ridge belt, the eastern Banda arcs, northern and eastern Celebes and the Halmahera complex, and the entire Philippines east of westernmost Mindoro and Panay.

  4. Additive microcontinents emplaced from the northern Australian continent:

    The Vogelkop-Bomberai-Lengguru block and the Sula Spur.

  5. Marginal seas of Tertiary (and Late Cretaceous) origin:

    Andaman Sea, South China Sea, Sulu Sea, Celebes Sea, and Banda Sea.

Key topics of critical importance in understanding pre-Tertiary Southeast Asia are:

  1. Locus and sequence of formation of the Paleozoic-Mesozoic orogenic elements grouping around present-day or now-removed Precambrian nuclei. Attention is focused on the age, dimensions, petrotectonic assemblage, vergeance, and contact relations of the distinct blocks.

  2. Horizontal and vertical Tertiary crustal movements - especially those involved in the formation of intracratonic basins and marginal seas - and the amount to which the pre-Tertiary face of Southeast Asia has been distorted by them.


Pay-Per-View Purchase Options

The article is available through a document delivery service. Explain these Purchase Options.

Watermarked PDF Document: $14
Open PDF Document: $24