Skip to Main Content
GEOREF RECORD

Tectonic versus magmatic extension in the presence of core complexes at slow-spreading ridges from a visualization of faulted seafloor topography

Hans Schouten, Deborah K. Smith, Johnson R. Cann and Javier Escartin
Tectonic versus magmatic extension in the presence of core complexes at slow-spreading ridges from a visualization of faulted seafloor topography
Geology (Boulder) (July 2010) 38 (7): 615-618

Abstract

We develop a forward model of the generation of faulted seafloor topography (visualization) to estimate the relative roles of tectonic and magmatic extension in the presence of core complexes at slow-spreading ridges. The visualization assumes flexural rotation of 60 degrees normal faults, a constant effective elastic thickness, Te, of young lithosphere, and a continuous infill of the depressed hanging wall by lava flowing from the spreading axis. We obtain a new estimate of Te=0.5-1 km from the shapes of the toes of 6 well-documented oceanic core complexes. We model an 80-km-long bathymetric profile in the equatorial Atlantic across a core complex and the ridge axis at 13 degrees 20'N and estimate the variation in tectonic extension, which yields the variation in the fraction of upper crust extension, M, by magmatic diking at the ridge axis. Core complex formation appears to be stable for all values of M<0.5. The visualization shows how gabbro emplaced at the base of the lithosphere during extension by magmatic diking is partitioned to each side of the spreading axis, and predicts a high probability of finding gabbros in the domes of core complexes.


ISSN: 0091-7613
EISSN: 1943-2682
Coden: GLGYBA
Serial Title: Geology (Boulder)
Serial Volume: 38
Serial Issue: 7
Title: Tectonic versus magmatic extension in the presence of core complexes at slow-spreading ridges from a visualization of faulted seafloor topography
Affiliation: Woods Hole Oceanographic Institution, Department of Geology and Geophysics, Woods Hole, MA, United States
Pages: 615-618
Published: 201007
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
References: 22
Accession Number: 2010-064226
Categories: Solid-earth geophysicsOceanography
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. sects., sketch maps
N13°19'60" - N13°19'60", W44°00'00" - W44°00'00"
N22°40'00" - N22°40'00", W45°00'00" - W40°00'00"
Secondary Affiliation: University of Leeds, GBR, United KingdomCNRS-IPGP, Groupe de Geosciences Marines, FRA, France
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Reference includes data from GeoScienceWorld, Alexandria, VA, United States. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States
Update Code: 201035
Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal