Skip to Main Content
Skip Nav Destination
GEOREF RECORD

Melt migration and melt-rock reactions in the deforming Earth's upper mantle; experiments at high pressure and temperature

Vincent Soustelle, Nicolas P. Walte, M. A. Geeth M. Manthilake and Daniel J. Frost
Melt migration and melt-rock reactions in the deforming Earth's upper mantle; experiments at high pressure and temperature
Geology (Boulder) (December 2013) 42 (1): 83-86

Abstract

Crucial to our understanding of melt migration and segregation from source rocks beneath mid-ocean ridges and volcanic provinces is the intimate relationship with ductile mantle deformation. For this reason, numerous experiments and theoretical studies have been performed to simulate the process of melt extraction from deforming mantle rocks, with the emerging view that segregation occurs into melt-rich bands that are inclined relative to the direction of deformation. This is seemingly in contrast, however, to observations made on mantle rocks exposed at the Earth's surface, which display evidence for melt migration in bands that were originally parallel to the direction of deformation. Here, we present experimental evidence that reconciles these contradictory observations. Olivine aggregates containing 10 wt% of a melt that reacts with olivine to precipitate orthopyroxene were deformed at 2 GPa and 1150 degrees C in simple shear experiments. In agreement with previous studies, we observe the development of a melt-preferred orientation that is inclined ( approximately 30 degrees ) with respect to the main compression axis sigma 1. However, the alignment of newly crystallized orthopyroxene aggregates defines a fabric that develops perpendicular to sigma 1 and rotates toward the shear direction with increasing shear strain (gamma of 0.3-2). This misalignment significantly changes the interpretation of evidence for melt channeling and transport in exposed upper mantle rocks: the fabric formed by the phases that have crystallized from a melt during deformation cannot be used directly as a marker for the melt migration direction.


ISSN: 0091-7613
EISSN: 1943-2682
Coden: GLGYBA
Serial Title: Geology (Boulder)
Serial Volume: 42
Serial Issue: 1
Title: Melt migration and melt-rock reactions in the deforming Earth's upper mantle; experiments at high pressure and temperature
Affiliation: University of Bayreuth, Bayerisches Geoinstitut, Bayreuth, Germany
Pages: 83-86
Published: 20131206
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
References: 29
Accession Number: 2014-002357
Categories: Geophysics of minerals and rocks
Document Type: Serial
Bibliographic Level: Analytic
Annotation: GSA Data Repository item 2014019
Illustration Description: illus.
Secondary Affiliation: Universite Blaise Pascal, 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: 201403
Close Modal

or Create an Account

Close Modal
Close Modal