Low-Ca contents and kink-banded textures are not unique to mantle olivine: evidence from the Duke Island Complex, Alaska

2011 ◽  
Vol 104 (3-4) ◽  
pp. 147-153 ◽  
Author(s):  
Chusi Li ◽  
Joyashish Thakurta ◽  
Edward M. Ripley
Keyword(s):  
Mantle Olivine ◽  
Duke Island

scholarly journals Petrogenesis and Tectonic Significance of the ~276 Ma Baixintan Ni-Cu Ore-Bearing Mafic-Ultramafic Intrusion in the Eastern Tianshan Orogenic Belt, NW China

Minerals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 348
Author(s):  
Minxin You ◽  
Wenyuan Li ◽  
Houmin Li ◽  
Zhaowei Zhang ◽  
Xin Li
Keyword(s):  
Orogenic Belt ◽  
Olivine Gabbro ◽  
Early Permian ◽  
Eastern Tianshan ◽  
Nw China ◽  
Tianshan Orogenic Belt ◽  
Tectonic Significance ◽  
Ultramafic Intrusion ◽  
Back Arc ◽  
Duke Island

The Baixintan mafic-ultramafic intrusion in the Dananhu-Tousuquan arc of the Eastern Tianshan orogenic belt is composed of lherzolite, olivine gabbro, and gabbro. Olivine gabbros contain zircon grains with a U-Pb age of 276.8 ± 1.1 Ma, similar to the ages of other Early Permian Ni-Cu ore-bearing intrusions in the region. The alkaline-silica diagrams, AFM diagram, together with the Ni/Cu-Pd/Ir diagram, indicate that the parental magmas for the Baixintan intrusion were likely high-Mg tholeiitic basaltic in composition. The Cu/Pd ratios, the relatively depleted PGEs and the correlations between them demonstrate that the parental magmas had already experienced sulfide segregation. The lower CaO content in pyroxenites compared with the Duke Island Alaskan-type intrusion and the composition of spinels imply that Baixintan is not an Alaskan-type intrusion. By comparing the Baixintan intrusion with other specific mafic-ultramafic intrusions, this paper considers that the mantle source of the Baixintan intrusion is metasomatized by subduction slab-derived fluids’ components, which gives rise to the negative anomalies of Nb, Ti, and Ta elements. Nb/Yb-Th/Yb, Nb/Yb-TiO2/Yb, and ThN-NbN plots show that the Baixintan intrusion was emplaced in a back-arc spreading environment and may be related to a mantle plume.

Fingerprinting the water site in mantle olivine

Geology ◽  
2005 ◽  
Vol 33 (11) ◽  
pp. 869 ◽  
Author(s):  
Andrew J. Berry ◽  
Jörg Hermann ◽  
Hugh S.C. O'Neill ◽  
Garry J. Foran
Keyword(s):  
Mantle Olivine

scholarly journals Rapid magma ascent recorded by water diffusion profiles in mantle olivine

Geology ◽  
2006 ◽  
Vol 34 (6) ◽  
pp. 429 ◽  
Author(s):  
Sylvie Demouchy ◽  
Steven D. Jacobsen ◽  
Fabrice Gaillard ◽  
Charles R. Stern
Keyword(s):  
Water Diffusion ◽  
Magma Ascent ◽  
Mantle Olivine ◽  
Diffusion Profiles

scholarly journals Trace-element geochemistry of mantle olivine and application to mantle petrogenesis and geothermobarometry

2010 ◽  
Vol 270 (1-4) ◽  
pp. 196-215 ◽  
Author(s):  
Jan C.M. De Hoog ◽  
Louise Gall ◽  
David H. Cornell
Keyword(s):  
Trace Element ◽  
Trace Element Geochemistry ◽  
Element Geochemistry ◽  
Mantle Olivine

Serpentinization and chloritization of metamorphosed lherzolites in Darreh-Deh (east of Nain Ophiolite, Central Iran): Calcium source for rodingitization and tremolitization

2020 ◽  
Vol 196 (3) ◽  
pp. 179-191
Author(s):  
Nargess Shirdashtzadeh ◽  
Ghodrat Torabi
Keyword(s):  
Crystal Lattice ◽  
Calcium Content ◽  
Mineral Chemistry ◽  
Amphibolite Facies ◽  
Central Iran ◽  
Coarse Grained ◽  
Potential Source ◽  
Calcium Source ◽  
Mantle Olivine ◽  
Microprobe Data

The petrography and mineral chemistry of the metamorphosed lherzolite in Darreh-Deh massif (east of Nain Ophiolite, Central Iran) is investigated in order to find the calcium source for rodingitization and tremolitization. In comparison with olivine and orthopyroxene, the clinopyroxene has lower modal content and is more alteration-resistant. The microprobe data and petrography of these lherzolites indicate that Ca2+ cations can be released during serpentinization of orthopyroxene (with ~18 vol% and CaO~2.7 wt%) and clinopyroxene (with ~6 vol% and CaO~ > 20 wt%). In contrast, per- vasive serpentinization of mantle olivine with ~70 vol% and CaO~0.02–0.07 wt% is another expected source for producing Ca2+ rather than metamorphic olivine with CaO~ < 0.02 wt%. The released Ca2+ cannot be completely accommodated in crystal lattice of produced serpentine (with CaO~0.02–0.06 wt%), talc and chlorite (with CaO~0.015 wt%), but it can participate in formation of Ca-bearing tremolite (CaO~13 wt%), as a result of serpentinization of clinopyroxenes or subsequent metamorphism of peridotites at amphibolite facies and in formation of coarse-grained clinopyroxene blades and tremolite during rodingitization. Therefore, the calcium content in clinopyroxene, orthopyroxene and olivine of a plagioclase–free peridotite is a potential source of Ca2+, depending on the degree of serpentinization or chloritization.

Hematite and magnetite precipitates in olivine from the Sulu peridotite: A result of dehydrogenation-oxidation reaction of mantle olivine?

2008 ◽  
Vol 93 (7) ◽  
pp. 1051-1060 ◽  
Author(s):  
S.-L. Hwang ◽  
T.-F. Yui ◽  
H.-T. Chu ◽  
P. Shen ◽  
Y. Iizuka ◽  
...  
Keyword(s):  
Oxidation Reaction ◽  
Mantle Olivine
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