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Controls on extrusion at mid-ocean ridges

W. Roger Buck, Suzanne M. Carbotte and Carolyn Z. Mutter
Controls on extrusion at mid-ocean ridges
Geology (Boulder) (October 1997) 25 (10): 935-938


A magma lens can erupt to form extrusives only if it is under greater pressure than the static pressure in a column of magma reaching from the lens to the surface. The excess pressure results partly from overburden pressure caused by the presence of high- and low-density rocks (dikes and extrusives, respectively) above the lens. The thicker the pile of low-density extrusives, the lower the average overburden density. Thus, extrusion above a lens should be self-regulating, in that thickening the extrusive layer reduces the driving pressure for subsequent eruptions. Flexural stresses may affect extrusion by altering the pressure on a magma chamber. For ridges lacking an axial valley, we predict that deeper magma lenses should correlate with thicker extrusive layers, consistent with recent observations.

ISSN: 0091-7613
EISSN: 1943-2682
Serial Title: Geology (Boulder)
Serial Volume: 25
Serial Issue: 10
Title: Controls on extrusion at mid-ocean ridges
Affiliation: Lamont-Doherty Earth Observatory, Palisades, NY, United States
Pages: 935-938
Published: 199710
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
References: 37
Accession Number: 1997-071759
Categories: Solid-earth geophysicsIgneous and metamorphic petrology
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus.
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States
Update Code: 199723
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