Basin formation and Neogene sedimentation in a backarc setting, Halmahera, eastern Indonesia
- University College, London (United Kingdom)
- R.H.B. New College, Egham (United Kingdom)
It has been proposed that basins in backarc setting form in association with subduction by thinning of continental crust, backarc spreading in oceanic crust, compression, or trapping of pieces of oceanic plate behind an arc. The Halmahera basin in eastern Indonesia developed in a backarc setting but does not fall into these categories; it formed by subsidence of thickened crust made up of imbricated Mesozoic-Paleogene arc and ophiolite rocks. Halmahera lies at the western edge of the Philippine Sea Plate in a complex zone of convergence between the Eurasian margin, the oceanic plates of the West Pacific, and the Australian/Indian Plate to the south. The basement is an imbricated complex of Mesozoic to Paleogene ophiolite, arc, and arc-related rocks. During the Miocene this basement complex formed an area of thickened crust upon which carbonate reef and reef-associated sediments were deposited. The authors interpret this shallow marine region to be similar to many of the oceanic plateaus and ridges found within the Philippine Sea Plate today. In the Late Miocene, convergence between the Philippine Sea Plate and the Eurasian margin resulted in the formation of the Halmahera Trench to the west of this region of thickened crust. Subduction of the Molucca Sea Plate caused the development of a volcanic island arc. Subsidence in the backarc area produced a broad sedimentary basin filled by clastics eroded from the arc and from uplifted basement and cover rocks. The basin was asymmetric with the thickest sedimentary fill on the western side, against the volcanic arc. The Halmahera basin was modified in the Plio-Pleistocene by east-west compression as the Molucca Sea Plate was eliminated by subduction.
- OSTI ID:
- 5617801
- Report Number(s):
- CONF-910403-; CODEN: AABUD
- Journal Information:
- AAPG Bulletin (American Association of Petroleum Geologists); (United States), Vol. 75:3; Conference: Annual meeting of the American Association of Petroleum Geologists (AAPG), Dallas, TX (United States), 7-10 Apr 1991; ISSN 0149-1423
- Country of Publication:
- United States
- Language:
- English
Similar Records
Geotectonic regionalization and evolution of East China Sea and northern South China Sea
Forearc sedimentation in Terraba Trough, Costa Rica, Central America
Related Subjects
INDONESIA
SEDIMENTARY BASINS
PLATE TECTONICS
GEOLOGIC MODELS
GEOLOGIC HISTORY
CARBONATE ROCKS
CONTINENTAL CRUST
OCEANIC CRUST
REEFS
SEDIMENTATION
SUBDUCTION ZONES
TERTIARY PERIOD
ASIA
CENOZOIC ERA
DEVELOPING COUNTRIES
EARTH CRUST
GEOLOGIC AGES
GEOLOGIC STRUCTURES
ISLANDS
ROCKS
SEDIMENTARY ROCKS
TECTONICS
580000* - Geosciences