TY - JOUR
T1 - Minerals of the pseudobinary perovskite-brownmillerite series from combustion metamorphic larnite rocks of the Hatrurim Formation (Israel)
AU - Sharygin, V. V.
AU - Sokol, E. V.
AU - Vapnik, Ye
N1 - Funding Information:
This work was supported by grants 05-05-65036 and 08-590405-Ukr from the Russian Foundation for Basic Research, Interdisciplinary Integration Project 105 from the Siberian Branch of the RAS, and Scientific-School Support grant NSh-4922.2006.5.
PY - 2008/10/1
Y1 - 2008/10/1
N2 - Brownmillerite, Fe-perovskite, and two intermediate phases (Ca3Ti(Fe,Al)2O8 and Ca5Ti(Fe,Al)4O13) were found in combustion metamorphichigh-temperature larnite rocks of the Hatrurim Basin, Israel. This is the first finding evidencing the existence of the pseudobinaryperovskite-brownmillerite series in nature. Fe-perovskite contains the Ca2(Fe,Al)2O5 end-member (up to 18 mole %), whereas brownmilleriteCa2(Fe1-xAlx)2O5 with x = 0.15-0.55 is enriched in the CaTiO3 end-member (up to 15 mole %). The intermediate phases are Ca3Ti(Fe,Al)2O8(phase X) and Ca5Ti(Fe,Al)4O13 (phase Y), which have synthetic analogs. In some larnite rocks, the phase X is the only member of theperovskite-brownmillerite series. It is clustered into two compositional groups, Ca3Ti(Fe1.3Al0.7)O8 and Ca3Ti(Fe1.6Al0.4)O8. The phase Y isextremely rare and has the composition Ca5Ti(Fe0.76Al0.24)4O13. The presence of minor Si, Cr, Sr, Zr, and LREE is common for all mineralsof the series. The Fe-perovskite + brownmillerite paragenesis was found in none of the studied rocks, which is consistent with theCaTiO3-Ca2Fe2O3 phase diagram. The rocks bear either one phase or two or three phases (Fe-perovskite + phase X; brownmillerite + phase X ± phase Y). According to the CaTiO3-Ca2Fe2O3 diagram, the minimum formation temperature for the Hatrurim larnite rocks estimated fromthe Fe-perovskite + phase X paragenesis is 1170-1200 °C. This paragenesis is proposed as a new thermometer for metacarbonate rocks ofthe high-temperature region of the spurrite-merwinite facies.
AB - Brownmillerite, Fe-perovskite, and two intermediate phases (Ca3Ti(Fe,Al)2O8 and Ca5Ti(Fe,Al)4O13) were found in combustion metamorphichigh-temperature larnite rocks of the Hatrurim Basin, Israel. This is the first finding evidencing the existence of the pseudobinaryperovskite-brownmillerite series in nature. Fe-perovskite contains the Ca2(Fe,Al)2O5 end-member (up to 18 mole %), whereas brownmilleriteCa2(Fe1-xAlx)2O5 with x = 0.15-0.55 is enriched in the CaTiO3 end-member (up to 15 mole %). The intermediate phases are Ca3Ti(Fe,Al)2O8(phase X) and Ca5Ti(Fe,Al)4O13 (phase Y), which have synthetic analogs. In some larnite rocks, the phase X is the only member of theperovskite-brownmillerite series. It is clustered into two compositional groups, Ca3Ti(Fe1.3Al0.7)O8 and Ca3Ti(Fe1.6Al0.4)O8. The phase Y isextremely rare and has the composition Ca5Ti(Fe0.76Al0.24)4O13. The presence of minor Si, Cr, Sr, Zr, and LREE is common for all mineralsof the series. The Fe-perovskite + brownmillerite paragenesis was found in none of the studied rocks, which is consistent with theCaTiO3-Ca2Fe2O3 phase diagram. The rocks bear either one phase or two or three phases (Fe-perovskite + phase X; brownmillerite + phase X ± phase Y). According to the CaTiO3-Ca2Fe2O3 diagram, the minimum formation temperature for the Hatrurim larnite rocks estimated fromthe Fe-perovskite + phase X paragenesis is 1170-1200 °C. This paragenesis is proposed as a new thermometer for metacarbonate rocks ofthe high-temperature region of the spurrite-merwinite facies.
KW - Hatrurim
KW - Perovskite
KW - brownmillerite
KW - combustion metamorphism
KW - larnite rocks
UR - http://www.scopus.com/inward/record.url?scp=52049105410&partnerID=8YFLogxK
U2 - 10.1016/j.rgg.2008.03.001
DO - 10.1016/j.rgg.2008.03.001
M3 - Article
AN - SCOPUS:52049105410
SN - 1068-7971
VL - 49
SP - 709
EP - 726
JO - Russian Geology and Geophysics
JF - Russian Geology and Geophysics
IS - 10
ER -