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Abandoned Paleocene spreading center in the northeastern Indian Ocean: evidence from magnetic and seismic reflection data

DRS at CSIR-National Institute of Oceanography

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Title Abandoned Paleocene spreading center in the northeastern Indian Ocean: evidence from magnetic and seismic reflection data
 
Creator Krishna, K.S.
Rao, D.G.
 
Subject palaeomagnetism
plate tectonics
seismic reflection profiles
spreading centres
fracture zones
hotspots
 
Description Magnetic data from the northeastern Indian Ocean reveal east-west trending magnetic lineations 28 through 34, an abandoned spreading center (ASC) and part of the Cretaceous Magnetic Quiet Zone (CMQZ), which are used to reconstruct past tectonic processes involved in the evolution of the ocean. Offsets in the magnetic lineations outline the existence of four N-S trending fracture zones: 80 degrees E, Indira, 84.5 degrees E, and 86 degrees E. The 84.5 degrees E Fracture Zone (FZ) acts as a boundary separating oceanic crust with different magnetic isochron patterns. The pairs of magnetic lineations 30 through 32n.2 between the 86 degrees E FZ and the Ninetyeast Ridge reveal an ASC of about 65 Ma age; parallel to approx. equal to 0.5 degrees S latitude. the structure of the ASC is well-identified in seismic reflection data as an undulating basement topographic rise covered by up to 2 km of Bengal Fan sediments. The spreading center might have initiated its activity along with other spreading centers of the Wharton Ridge and India-Antarctica Ridge, after the first major plate reorganization of the Indian Ocean (about 95 plus or minus 5 Ma), but ceased shortly after formation of anomaly 30 (about 65 Ma). Then it jumped southward between anomalies 32n.2 and 33. The jump captured the oceanic crust of anomalies 30 through 32n.2 that initially formed on the Antarctica plate, but were later transferred to the Indian plate. The spreading centers in the vicinity of the Ninetyeast Ridge jumped several times southward, to maintain a close proximity to the Kerguelen hotspot
 
Date 2009-01-09T08:22:30Z
2009-01-09T08:22:30Z
2000
 
Type Journal Article
 
Identifier Marine Geology, Vol.162; 215-224p.
http://drs.nio.org/drs/handle/2264/1673
 
Language en
 
Rights Copyright [2000]. All efforts have been made to respect the copyright to the best of our knowledge. Inadvertent omissions, if brought to our notice, stand for correction and withdrawal of document from this repository.
 
Publisher Elsevier