A Study of Overlapping Spreading Center
Ching-Ming Chang
Abstract
These three articles are all primary based on the bathymetry data in west Philippine
overlapping spreading center (OSC) refers to small offset or deviation, which are not regular transform faults but sometimes mark a petrological segmentation of the ridge; OCS refers to a phenomenon that occurs on fast-spreading ridges when the transform fault does not mark the abrupt termination of both ridge segments, instead, the segments overlap slightly.
Use two examples to supposed kinematic models for propagation of oceanic spreading ridges. In this OSC model, flow in the mantle would be continuous from one spreading center branch to the other, being curved in the overlap area to accommodate the offset.The mantle flow would therefore be more and more decoupled with the brittle crust when approaching the overlap zone, where extensional tectonics can occur. The authors consider that some mantle upwelling is possible due to its specific location, in between two ridge segments and over the main mantle flow.
Reference
Douglas S. Wilson, Kinematics of overlapping rift propagation with cyclic rift failure, Earth and Planetary Science Letters, 96 (1990) 384-392
Jacques Girardeau, Christophe Monnier, Patrick Launeau, and Freˇ¦deˇ¦ ric Quatrevaux, Kinematics of mantle flow beneath a fossil Overlapping Spreading Center: The Wuqbah massif case, Oman ophiolite, Geochemistry Geophysics Geosystems,Article Volume 3, Number 7, 31 July 2002, 10.1029/2001GC000228, ISSN: 1525-2027
MacLeod, C. J., and D. A. Rothery, Ridge axial segmentation in the Oman ophiolite: evidence from along-strike variations in the sheeted dyke complexe, in Ophiolites and their modern oceanic analogues, edited by L. M. Parson, B. J. Murton,and P. Browning, pp. 39ˇV63, 60, Geological Society Special Publication, London, 1992
(Abstract) (Full text)