Consistent olivine Mg# in cratonic mantle reflects Archean mantle melting to the exhaustion of orthopyroxene

Publication Status is "Submitted" Or "In Press: 
LDEO Publication: 
Publication Type: 
Journal Article
Year of Publication: 
2007
Authors: 
Bernstein, S.; Kelemenl, P. B.; Hanghoj, K.
Editor: 
Journal Title: 
Geology
Journal Date: 
May
Place Published: 
Tertiary Title: 
Volume: 
35
Issue: 
5
Pages: 
459-462
Section / Start page: 
Publisher: 
ISBN Number: 
0091-7613
ISSN Number: 
Edition: 
Short Title: 
Accession Number: 
ISI:000250253900019
LDEO Publication Number: 
Call Number: 
Key Words: 
cratonic mantle; dunite xenoliths; residues; archean; spinel peridotite; lithospheric mantle; peridotite xenoliths; garnet peridotite; kaapvaal craton; greenland; evolution; komatiite; beneath; origin; inclusions;
Abstract: 

Shallow (garnet-free), depleted cratonic mantle, occurring as xenoliths in kimberlites and alkaline basaltic lavas, has a high Mg# (100 x Mg/(Mg + Fe) > 92) and is poor in Al and Ca compared to off-cratonic mantle. Here we compile data for many suites of shallow cratonic mantle xenoliths worldwide, and demonstrate a remarkably small range in their olivine Mg#, with an average of -92.8. Via comparison with data for experimental melting of mantle peridotite compositions, we explain consistent olivine Mg# as the result of mantle melting and melt extraction to the point of orthopyroxene exhaustion, leaving a nearly monomineralic olivine residue.

Notes: 

221UXTimes Cited:1Cited References Count:40

URL: 
<Go to ISI>://000250253900019
DOI: 
Doi 10.1130/G23336a.1