Sedimentary evolution of the Bounty Trough; a Cretaceous rift basin, southwestern Pacific Ocean

Author(s): Carter, Lionel; Carter, Robert M.
Author Affiliation(s): Primary:
New Zealand Oceanographic Institute, Wellington, New Zealand
Other:
James Cook University, Townsville, Queensl., Australia
Volume Title: South Pacific sedimentary basins
Volume Author(s): Ballance, Peter F., editor
Source: South Pacific sedimentary basins, edited by Peter F. Ballance. Sedimentary Basins of the World, Vol.2, p.51-67. Publisher: Elsevier, Amsterdam - London- New York - Toyko, Netherlands. ISBN: 0-444-88287-1
Note: In English. 76 refs.; illus. incl. sects., geol. sketch maps
Summary: The Bounty Trough began as a Cretaceous failed rift within submerged continental crust, east of New Zealand. Up to Oligocene times, the 350 km x 1000 km trough was starved of terrigenous sediment and received mainly biopelagic material. This changed with the onset of mountain building related to development of the Pacific-Australian plate boundary in the Miocene. Terrigenous input commenced and increased, with the increasing tempo of the orogeny which continues today. However, the principal control of terrigenous supply to the trough was glacio-eustatic fluctuations of sea level. During times of low sea level rivers draining the rising mountain ranges extended eastwards across the emergent continental shelf and discharged directly into the trough. Part of the sediment load contributed towards shelf progradation whereas detritus escaping this depocentre either was spread as a hemipelagic blanket or was transported along the floor of the Bounty Trough by turbidity currents constrained within the 950+ km long Bounty Channel. These flows overspilled the channel to produce extensive levees whereas those completing the journey fed the abyssal Bounty Fan on the floor of the S.W. Pacific Basin. The main phase of fan growth began in the late Pliocene concomitant with the onset of glacio-eustatic lowerings of sea level. These bouts of high sediment influx were punctuated by times of pervasive biopelagic deposition coinciding with interglacial periods. Under conditions of raised sea level, a reduced terrigenous supply was diverted from the Bounty Trough by the onset of an effective along-shelf transport regime.
Year of Publication: 1993
Research Program: DSDP Deep Sea Drilling Project
IPOD International Phase of Ocean Drilling
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Australasia; Basins; Bounty Trough; Cenozoic; Cretaceous; DSDP Site 594; Deep Sea Drilling Project; Eustasy; Geophysical profiles; IPOD; Leg 90; Mesozoic; New Zealand; Oligocene; Otago Fan Complex; Pacific Ocean; Paleogene; Plate boundaries; Plate tectonics; Provenance; Rifting; Sedimentary basins; Sedimentation; Seismic profiles; South Island; South Pacific; Southern Alps; Southwest Pacific; Structural controls; Terrigenous materials; Tertiary; West Pacific
Coordinates: S463128 S453129 E1745653 E1745652
Record ID: 1994045664
Copyright Information: GeoRef, Copyright 2017 American Geosciences Institute. Reference includes data supplied by Institute of Geological and Nuclear Sciences Limited (GNS Science), Lower Hutt, New Zealand