Crystal chemistry of amphiboles: implications for oxygen fugacity and water activity in lithospheric mantle beneath Victoria Land, Antarctica

2014 ◽  
Vol 167 (3) ◽  
Author(s):  
C. Bonadiman ◽  
S. Nazzareni ◽  
M. Coltorti ◽  
P. Comodi ◽  
G. Giuli ◽  
...  
Keyword(s):  
Oxygen Fugacity ◽  
Crystal Chemistry ◽  
Water Activity ◽  
Lithospheric Mantle ◽  
Victoria Land

Nature and evolution of the northern Victoria Land lithospheric mantle (Antarctica) as revealed by ultramafic xenoliths

2021 ◽  
pp. M56-2020-11
Author(s):  
Massimo Coltorti ◽  
Costanza Bonadiman ◽  
Federico Casetta ◽  
Barbara Faccini ◽  
Pier Paolo Giacomoni ◽  
...  
Keyword(s):  
Lithospheric Mantle ◽  
Evolutionary History ◽  
Major Elements ◽  
Mantle Xenoliths ◽  
Victoria Land ◽  
Ultramafic Xenoliths ◽  
Large Sector ◽  
Subcontinental Lithosphere ◽  
Comparative Manner

AbstractA review of northern Victoria Land ultramafic xenoliths, collected and studied over more than 30 years, was carried out. More than 200 samples were gathered and characterized in a coherent and comparative manner, both for mantle-derived and cumulate xenoliths. Almost 2000 analyses of major elements and more than 300 analyses of trace elements of in situ and separated olivine, pyroxenes, amphibole, spinel and glass were taken into consideration. Particular attention was devoted to mantle lithologies in order to emphasize the composition and the evolution of this portion of the subcontinental lithosphere. The three main localities in northern Victoria Land where mantle xenoliths were found (i.e. Mount Melbourne (Baker Rocks), Greene Point and Handler Ridge), over a >200 km distance, were described and compared with ultramafic xenoliths in three other localities (Harrow Peaks, Browning Pass and Mount Overlord) that are mainly cumulate in nature. Altogether, these data enabled us to reconstruct a long evolutionary history, from old depletion to most recent refertilization and metasomatic events, for this large sector of the northern Victoria Land subcontinental lithospheric mantle.

scholarly journals Oxidation State of the Lithospheric Mantle Beneath Komsomolskaya–Magnitnaya Kimberlite Pipe, Upper Muna Field, Siberian Craton

Minerals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 740 ◽  
Author(s):  
Anna Dymshits ◽  
Igor Sharygin ◽  
Zhe Liu ◽  
Nester Korolev ◽  
Vladimir Malkovets ◽  
...  
Keyword(s):  
Oxygen Fugacity ◽  
Oxidation State ◽  
Siberian Craton ◽  
Lithospheric Mantle ◽  
Redox State ◽  
Kimberlite Pipe ◽  
Good Explanation ◽  
Redox Conditions ◽  
Lateral Heterogeneity ◽  
Physical Processes

The oxidation state of the mantle plays an important role in many chemical and physical processes, including magma genesis, the speciation of volatiles, metasomatism and the evolution of the Earth’s atmosphere. We report the first data on the redox state of the subcontinental lithospheric mantle (SCLM) beneath the Komsomolskaya–Magnitnaya kimberlite pipe (KM), Upper Muna field, central Siberian craton. The oxygen fugacity of the KM peridotites ranges from −2.6 to 0.3 logarithmic units relative to the fayalite–magnetite–quartz buffer (∆logfO2 (FMQ)) at depths of 120–220 km. The enriched KM peridotites are more oxidized (−1.0–0.3 ∆logfO2 (FMQ)) than the depleted ones (from −1.4 to −2.6 ∆logfO2 (FMQ)). The oxygen fugacity of some enriched samples may reflect equilibrium with carbonate or carbonate-bearing melts at depths >170 km. A comparison of well-studied coeval Udachnaya and KM peridotites revealed similar redox conditions in the SCLM of the Siberian craton beneath these pipes. Nevertheless, Udachnaya peridotites show wider variations in oxygen fugacity (−4.95–0.23 ∆logfO2 (FMQ)). This indicates the presence of more reduced mantle domains in the Udachnaya SCLM. In turn, the established difference in the redox conditions is a good explanation for the lower amounts of resorbed diamonds in the Udachnaya pipe (12%) in comparison with the KM kimberlites (33%). The obtained results advocate a lateral heterogeneity in the oxidation state of the Siberian SCLM.

Oxo-amphiboles in mantle xenoliths: evidence for H2O-rich melt interacting with the lithospheric mantle of Harrow Peaks (Northern Victoria Land, Antarctica)

2015 ◽  
Vol 109 (6) ◽  
pp. 741-759 ◽  
Author(s):  
S. Gentili ◽  
C. Bonadiman ◽  
C. Biagioni ◽  
P. Comodi ◽  
M. Coltorti ◽  
...  
Keyword(s):  
Lithospheric Mantle ◽  
Mantle Xenoliths ◽  
Victoria Land
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