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2005
Curray, JR.  2005.  Tectonics and history of the Andaman Sea region. Journal of Asian Earth Sciences. 25:187-228.   10.1016/j.jseaes.2004.09.001   AbstractWebsite

The Andaman Sea is an active backarc basin lying above and behind the Sunda subduction zone where convergence between the overriding Southeast Asian plate and the subducting Australian plate is highly oblique. The effect of the oblique convergence has been formation of a sliver plate between the subduction zone and a complex right-lateral fault system. The late Paleocene collision of Greater India and Asia with approximately normal convergence started clockwise rotation and bending of the northern and western Sunda Arc. The initial sliver fault, which probably started in the Eocene, extended through the outer arc ridge offshore from Sumatra, through the present region of the Andaman Sea into the Sagaing Fault. With more oblique convergence due to the rotation, the rate of strike-slip motion increased and a series of extensional basins opened obliquely by the combination of backarc extension and the strike-slip motion. These basins in sequence are the Mergui Basin starting at similar to 32 Ma, the conjoined Alcock and Sewell Rises starting at similar to 23 Ma, East Basin separating the rises from the foot of the continental slope starting at similar to 15 Ma; and finally at similar to 4 Ma, the present plate edge was formed, Alcock and Sewell Rises were separated by formation of the Central Andaman Basin, and the faulting moved onshore from the Mentawai Fault to the Sumatra Fault System bisecting Sumatra. (c) 2005 Elsevier Ltd. All rights reserved.

2003
Alam, M, Alam MM, Curray JR, Chowdhury ALR, Gani MR.  2003.  An overview of the sedimentary geology of the Bengal Basin in relation to the regional tectonic framework and basin-fill history. Sedimentary Geology. 155:179-208.   10.1016/s0037-0738(02)00180-x   AbstractWebsite

The Bengal Basin in the northeastern part of Indian subcontinent, between the Indian Shield and Indo-Burman Ranges, comprises three geo-tectonic provinces: (1) The Stable Shelf; (2) The Central Deep Basin (extending from the Sylhet Trough in the northeast towards the Hatia Trough in the south); and (3) The Chittagong-Tripura Fold Belt. Due to location of the basin at the juncture of three interacting plates, viz., the Indian, Burma and Tibetan (Eurasian) Plates, the basin-fill history of these geotectonic provinces varied considerably. Precambrian metasediments and Permian-Carboniferous rocks have been encountered only in drill holes in the stable shelf province. After Precambrian peneplanation of the Indian Shield, sedimentation in the Bengal Basin started in isolated graben-controlled basins on the basement. With the breakup of Gondwanaland in the Jurassic and Cretaceous, and northward movement of the Indian Plate, the basin started downwarping in the Early Cretaceous and sedimentation started on the stable shelf and deep basin; and since then sedimentation has been continuous for most of the basin. Subsidence of the basin can be attributed to differential adjustments of the crust, collision with the various elements of south Asia, and uplift of the eastern Himalayas and the Indo-Burman Ranges. Movements along several well-established faults were initiated following the breakup of Gondwanaland and during downwarping in the Cretaceous. By Eocene, because of a major marine transgression, the stable shelf came under a carbonate regime, whereas the deep basinal area was dominated by deep-water sedimentation. A major switch in sedimentation pattern over the Bengal Basin occurred during the Middle Eocene to Early Miocene as a result of collision of India with the Burma and Tibetan Blocks. The influx of elastic sediment into the basin from the Himalayas to the north and the Indo-Burman Ranges to the east rapidly increased at this time; and this was followed by an increase in the rate of subsidence of the basin. At this stage, deep marine sedimentation dominated in the deep basinal part, while deep to shallow marine conditions prevailed in the eastern part of the basin. By Middle Miocene, with continuing collision events between the plates and uplift in the Himalayas and Indo-Burman Ranges, a huge influx of elastic sediments came into the basin from the northeast and east. Throughout the Miocene, the depositional settings continued to vary from deep marine in the basin to shallow and coastal marine in the marginal parts of the basin. From Pliocene onwards, large amounts of sediment were filling the Bengal Basin from the west and northwest; and major delta building processes continued to develop the present-day delta morphology. Since the Cretaceous, architecture of them Bengal Basin has been changing due to the collision pattern and movements of the major plates in the region. However, three notable changes in basin configuration can be recognized that occurred during Early Eocene, Middle Miocene and Plio-Pleistocene times, when both the paleogeographic settings and source areas changed. The present basin configuration with the Ganges - Brahmaputra delta system on the north and the Bengal Deep Sea Fan on the south was established during the later part of Pliocene and Pleistocene; and delta progradation since then has been strongly affected by orogeny in the eastern Himalayas. Pleistocene glacial activities in the north accompanied sea level changes in the Bay of Bengal. (C) 2002 Elsevier Science B.V All rights reserved.

2002
Curray, JR, Emmel FJ, Moore DG.  2002.  The Bengal Fan: morphology, geometry, stratigraphy, history and processes. Marine and Petroleum Geology. 19:1191-1223.   10.1016/s0264-8172(03)00035-7   AbstractWebsite

The Bengal Fan is the largest submarine fan in the world, with a length of about 3000 km, a width of about 1000 km and a maximum thickness of 16.5 km. It has been formed as a direct result of the India-Asia collision and uplift of the Himalayas and the Tibetan Plateau. It is currently supplied mainly by the confluent Ganges and Brahmaputra Rivers, with smaller contributions of sediment from several other large rivers in Bangladesh and India. The sedimentary section of the fan is subdivided by seismic stratigraphy by two unconformities which have been tentatively dated as upper Miocene and lower Eocene by long correlations from DSDP Leg 22 and ODP Legs 116 and 121. The upper Miocene unconformity is the time of onset of the diffuse plate edge or intraplate deformation in the southern or lower fan. The lower Eocene unconformity, a hiatus which increases in duration down the fan, is postulated to be the time of first deposition of the fan, starting at the base of the Bangladesh slope shortly after the initial India-Asia collision. The Quaternary of the upper fan comprises a section of enormous channel-levee complexes which were built on top of the preexisting fan surface during lowered sea level by very large turbidity currents. The Quaternary section of the upper fan can be subdivided by seismic stratigraphy into four subfans, which show lateral shifting as a function of the location of the submarine canyon supplying the turbidity currents and sediments. There was probably more than one active canyon at times during the Quaternary, but each one had only one active fan valley system and subfan at any given time. The fan currently has one submarine canyon source and one active fan valley system which extends the length of the active subfan. Since the Holocene rise in sea level, however, the head of the submarine canyon lies in a mid-shelf location, and the supply of sediment to the canyon and fan valley is greatly reduced from the huge supply which had existed during Pleistocene lowered sea level. Holocene turbidity currents are small and infrequent, and the active channel is partially filled in about the middle of the fan by deposition from these small turbidity currents. Channel migration within the fan valley system occurs by avulsion only in the upper fan and in the upper middle fan in the area of highest rates of deposition. Abandoned fan valleys are filled rapidly in the upper fan, but many open abandoned fan valleys are found on the lower fan. A sequence of time of activity of the important open channels is proposed, culminating with formation of the one currently active channel at about 12,000 years BP. (C) 2003 Elsevier Science Ltd. All rights reserved.

1994
Curray, JR.  1994.  Sediment Volume and Mass beneath the Bay of Bengal. Earth and Planetary Science Letters. 125:371-383.   10.1016/0012-821x(94)90227-5   AbstractWebsite

Rates of sediment accumulation and the amount of sedimentary fill in depocenters lying downstream of erosion in the Himalayas and Tibet can provide some insight into tectonics and geological history. The objective of this paper is to put on record the best estimates which are possible with existing data of the volume and mass of sediments, sedimentary rock and metasedimentary rock beneath the sea floor of the Bay of Bengal. The sedimentary section in the Bay of Bengal is divided into two parts: (1) Eocene through Holocene, sediments and sedimentary rocks which post-date the initial India-Asia collision: volume - 12.5 X 10(6) km3; mass = 2.88 X 10(16) t; this is most of the Bengal Fan, including its eastern lobe, the Nicobar Fan, plus some of the outer Bengal Delta; (2) Early Cretaceous through Paleocene, pre-collision sedimentary and metasedimentary rocks: volume = 4.36 X 10(6) km 3; mass = 1.13 to 1.18 X 10(16) t; these are interpreted as continental rise and pelagic deposits.

1991
Curray, JR.  1991.  Possible Greenschist Metamorphism at the Base of a 22-Km Sedimentary Section, Bay of Bengal. Geology. 19:1097-1100.   10.1130/0091-7613(1991)019<1097:pgmatb>2.3.co;2   AbstractWebsite

Reinterpretation of seismic refraction and reflection data in the Bay of Bengal suggests a maximum thickness of sedimentary deposits of more than 22 km beneath the Bangladesh continental shelf. Revised correlation of an early Eocene unconformity-which is interpreted as representing the time of the India-Asia collision-subdivides these deposits into (1) a Cretaceous and Paleocene continental-rise section up to 6 km thick off the Indian margin and (2) 16 km of overlying Bengal Fan sediments and sedimentary rocks derived mainly from erosion of the region uplifted following the collision. Pressure and temperature conditions within the deeply buried continental rise are in the field of greenschist facies metamorphism. The resulting metasedimentary rocks would have velocities and densities compatible with the refraction data and isostatic calculations.