The peridotite ridge province in the southern Iberia abyssal plain; seismic constraints revisited

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doi: 10.1002/2014JB011011
Author(s): Minshull, T. A.; Dean, S. M.; Whitmarsh, R. B.
Author Affiliation(s): Primary:
University of Southampton, National Oceanography Centre Southampton, Southampton, United Kingdom
Ion Geophysical Corporation, United States
Volume Title: Journal of Geophysical Research: Solid Earth
Source: Journal of Geophysical Research: Solid Earth, 119(3), p.1580-1598. Publisher: Wiley-Blackwell for American Geophysical Union, Washington, DC, United States. ISSN: 2169-9313
Note: In English. 36 refs.; illus.
Summary: The west Iberia margin has become the type example of a magma-starved margin in which extension during breakup led to the exhumation of mantle rocks apparently over a broad area. Much of our understanding of this process is based on geophysical and drilling data from the southern Iberia Abyssal Plain, where the seaward part of the region of exhumed mantle is composed of a series of margin-parallel basement ridges. Here we analyze wide-angle and normal-incidence seismic data from a series of intersecting profiles across this peridotite ridge province and develop a three-dimensional picture of its structure. Using these seismic data, we infer a location and age (magnetic anomaly M1; 125-127 Ma) of first-formed oceanic crust in this region that are consistent with Ocean Drilling Program data and data from the conjugate margin. We infer that the peridotite ridge province is about 70 km wide with strong serpentinization (>75%) at the top of the basement reducing to much lower degrees (< 25%) around 2 km below. We map the geometry of some prominent reflectors on the landward margin of the peridotite ridge province that likely represent detachment faults and show that one of these has a domal structure similar to that of detachment faults at slow to ultraslow spreading mid-ocean ridges. Abstract Copyright (2014), . American Geophysical Union. All Rights Reserved.
Year of Publication: 2014
Research Program: ODP Ocean Drilling Program
Key Words: 18 Geophysics, Solid-Earth; 20 Geophysics, Applied; Abyssal plains; Atlantic Ocean; Crust; Galicia Bank; Geophysical methods; Geophysical profiles; Geophysical surveys; Iberian abyssal plain; Igneous rocks; Leg 103; Leg 149; Leg 173; Lithosphere; Mid-ocean ridges; North Atlantic; Northeast Atlantic; ODP Site 637; Ocean Drilling Program; Ocean floors; Oceanic crust; Oceanic lithosphere; Peridotites; Plutonic rocks; Seismic methods; Seismic profiles; Surveys; Ultramafics
Coordinates: N420518 N420518 W0125148 W0125148
Record ID: 2014039009
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from John Wiley & Sons, Chichester, United Kingdom