Title

Tectonics of unusual crustal accretion in the Parece Vela Basin

Document Type

Article

Publication Date

1-1-2011

Abstract

© Springer Science+Business Media B.V. 2011. Despite its rapid intermediate-spreading rate, the Parece Vela Basin (PVB) shows unusual characteristics that indicate a depressed magmatic budget, such as the occurrence of numerous oceanic core complexes (OCCs) and rugged terrain, exposing abundant peridotites and gabbros. Based on the geologic interpretations of crust with analogous features on global mid-ocean ridges, we propose three possible mechanisms that can account for these unusual characteristics: (1) presence of a cold and/or refractory mantle domain, (2) declining spreading rate during the later phase of the second-stage spreading of the PVB, and (3) a transform sandwich effect. Recent numerical modeling for formation of OCC suggests that there is a minimum as well as a maximum magmatic supply necessary to produce longlived detachment fault. In the western PVB, a cold and/or refractory mantle domain inhibited a large amount of mantle melting within an intermediate-spreading ridge, attaining the limited window of the condition of magma supply demonstrated in the numerical model in an otherwise robust magmatic environment. In the central PVB, a transform sandwich effect and/or declining spreading rate inhibited a large amount of mantle melting within an intermediate-spreading ridge, also attaining the limited window of the condition of magma supply demonstrated in the numerical model in an otherwise robust magmatic environment.

Publication Source (Journal or Book title)

Modern Approaches in Solid Earth Sciences

First Page

149

Last Page

168

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