Skip to Main Content
Book Chapter

A kilometre-scale highly refractory harzburgite zone in the mantle section of the northern Oman Ophiolite (Fizh Block): implications for flux melting of oceanic lithospheric mantle

By
Nami Kanke
Nami Kanke
1
Graduate School of Science and Technology, Niigata University, 2-8050 Ikarashi, Nishi-ku, Niigata, 950-2181, Japan
2
Asaka High School, 5-25-63, Kaisei, Koriyama, Fukushima, 963-8851, Japan
Search for other works by this author on:
Eiichi Takazawa
Eiichi Takazawa
3
Department of Geology, Faculty of Science, Niigata University, 2-8050 Ikarashi, Nishi-ku, Niigata, 950-2181, Japan
Search for other works by this author on:
Published:
January 01, 2014

Abstract

We report the major element compositions of constituent minerals in 278 harzburgites and of 101 whole rocks from the northern Fizh mantle section in the northern Oman Ophiolite to investigate the formation and evolution of oceanic lithospheric mantle. Olivine Fo varies from 90 to 92 whereas spinel Cr# (= Cr/(Cr+Al) atomic ratio) varies from 0.15 to 0.78. The Cr# of spinels in a large number of harzburgites exceeds 0.6, which is the upper bound for abyssal peridotites. In the northern Fizh mantle section, highly refractory harzburgites with spinel Cr# greater than 0.7 are distributed in a 3-km-wide band along a NW–SE-striking shear zone. We infer a two-stage depletion process in the northern Fizh mantle section. In the first stage, asthenospheric mantle was partially melted beneath a mid-ocean ridge, producing a harzburgitic residual column. In the second stage during detachment of oceanic lithosphere an H2O-rich fluid, released from the metamorphic sole due to thermal metamorphism of altered oceanic crust, extensively infiltrated the northern Fizh mantle section where the ridge segment boundary region was previously located. The residual harzburgites were subjected to flux melting, resulting in a highly refractory harzburgite zone with spinel Cr# greater than 0.7.

Supplementary material:

Locality map, names of the wadis and UTM coordinates and further analytical data are available at http://www.geolsoc.org.uk/SUP18679.

You do not currently have access to this article.

Figures & Tables

Contents

Geological Society, London, Special Publications

Tectonic Evolution of the Oman Mountains

H. R. Rollinson
H. R. Rollinson
University of Derby, UK
Search for other works by this author on:
M. P. Searle
M. P. Searle
Oxford University, UK
Search for other works by this author on:
I. A. Abbasi
I. A. Abbasi
Sultan Qaboos University, Muscat, Oman
Search for other works by this author on:
A. I. Al-Lazki
A. I. Al-Lazki
Petroleum Development Oman, Oman
Search for other works by this author on:
M. H. Al Kindi
M. H. Al Kindi
Petroleum Development Oman, Oman
Search for other works by this author on:
Geological Society of London
Volume
392
ISBN electronic:
9781862396685
Publication date:
January 01, 2014

GeoRef

References

Related

Citing Books via

Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal