ISSN:
0016-7835
Keywords:
Key words Cumulate
;
Mineral chemistry
;
High-pressure fractionation
;
Suprasubduction
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geosciences
Notes:
Abstract The Mersin ophiolite, represented by approximately 6-km-thick oceanic lithospheric section on the southern flank of the Taurus calcareous axis, formed in the Mesozoic Neo-Tethyan ocean some time during Late Cretaceous in southern Turkey. The ultramafic and mafic cumulates having over 3 km thickness consist of dunite±chromite, wehrlite, clinopyroxenite at the bottom and pass into gabbroic cumulates in which leucogabbro, olivine-gabbro and anorthosite are seen. Crystallization order is olivine (Fo91–80)±chromian spinel (Cr# 60–80), clinopyroxene (Mg#95–77), plagioclase (An95.6–91.6) and orthopyroxene (Mg#68–77). Mineral chemistry of ultramafic and mafic cumulates suggest that highly magnesian olivines, clinopyroxenes and absence of plagioclase in the basal ultramafic cumulates are in good agreement with products of high-pressure crystal fractionation of primary basaltic melts beneath an island-arc environment. Major, trace element geochemistry of the cumulative rocks also indicate that Mersin ophiolite was formed in an arc environment. Coexisting Ca-rich plagioclase and Fo-rich olivine in the gabbroic cumulates show arc cumulate gabbro characteristics. Field relations as well as the geochemical data support that Mersin ophiolite formed in a supra-subduction zone tectonic setting in the southern branch of the Neo-Tethys in southern Turkey.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s005310050103
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