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Evolution of the Late Cretaceous crust in the equatorial region of the Northern Indian Ocean and its implication in understanding the plate kinematics

DRS at CSIR-National Institute of Oceanography

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Title Evolution of the Late Cretaceous crust in the equatorial region of the Northern Indian Ocean and its implication in understanding the plate kinematics
 
Creator Desa, M.
Ramana, M.V.
Ramprasad, T.
 
Subject gravity anomalies
magnetic anomalies
fracture zones
crustal structure
 
Description Analysis of 3100 km of newly acquired marine magnetic data, constrained by satellite and shipborne free air gravity anomalies, in the corridor between the 86°E fracture zone (FZ) and Ninetyeast Ridge, north of the equator reveals the evolutionary history of the Late Cretaceous crust characterized by anomaly 34 through 31 (83.5-68.7Ma) under complex tectonic settings. Seafloor spreading model studies suggest that the crust, particularly between the chrons 33R and 33 (79.0-73.6 Ma), was formed with variable and slightly higher half-spreading rates (4.8-7.1 cm yr sup(-1)) than the crust of similar age either in the regions west of 86 degrees E FZ or east of the Ninetyeast Ridge or the Southern Crozet Basin. Further, the interpretation of magnetic anomalies suggests the presence of fossil spreading ridge segments and extra oceanic crust on the Indian plate that has been transferred from the Antarctica plate by discrete southward ridge jumps. These ridge jumps are caused by thermal instability of the spreading centre as the Indian plate moved northward over the Kerguelen mantle plume. The present study indicates that the spreading ridge-plume interaction is the prime mechanism for these ridge jumps, which have occurred since 75.8 Ma. The newly identified magnetic anomalies 34 through 31 and the inferred approx. N3 degrees E trending FZs refined the plate reconstruction models for that period
 
Date 2009-06-02T11:35:59Z
2009-06-02T11:35:59Z
2009
 
Type Journal Article
 
Identifier Geophysical Journal International, vol.177(3); 1265-1278
http://drs.nio.org/drs/handle/2264/3352
 
Language en
 
Rights Copyright [2009]. 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 The Royal Astronomical Society