M. E. Varela

Instituto de Ciencias Astronómicas, de la Tierra y del Espacio

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G. Kurat

Natural History Museum Vienna

E. Zinner

Washington University in St. Louis

R. Clocchiatti

Laboratoire de Mesure du Carbone 14

R. B. Scorzelli

University of Basilicata

F. Brandstätter

Natural History Museum Vienna

Shyh‐Lung Hwang

National Dong Hwa University

E. Dos Santos

Universidade Federal dos Vales do Jequitinhonha e Mucuri

D. Massare

Centre National de la Recherche Scientifique

P. Munayco

Universidade Federal de Mato Grosso

S. J. Stewart

Consejo Nacional de Investigaciones Científicas y Técnicas

Cooperative Institutions

Centre National de la Recherche Scientifique

Centro Brasileiro de Pesquisas Físicas

Consejo Nacional de Investigaciones Científicas y Técnicas

Commissariat à l'Énergie Atomique et aux Énergies Alternatives

Max Planck Society

Université Paris Cité

Universidade de São Paulo

CEA Paris-Saclay

Institut de physique du globe de Paris

Max Planck Institute for Chemistry

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Kuratite (IMA 2013-109): The ``Unknown'' Fe-Al-Ti Silicate from the Angrite D'Orbigny

LPI (2014)

Sung-Ki Hwang Peng Shen Huai-Pu Chu T. Chui M. E. Varela

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Citations (20)

Pb-U-Th isotopic evolution of the D’Orbigny angrite

E. Jagoutz Reimund Jotter M. E. Varela Robert E. Zartman G. Kurat

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Citations (14)

Glasses in the D'Orbigny and Cachari Meteorites: A Mössbauer Study

M&PSA (2005)

Y. A. Abdu I. Souzaáazevedo S. J. Stewart A. López M. E. Varela

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The Vaca Muerta mesosiderite: The path under which Fe‐Ni alloy ±C phases could have formed

Meteoritics and Planetary Science (2024)

M. E. Varela Shyh‐Lung Hwang P. Shen L. N. Garcia Marcela E. Saavedra

Abstract The combined SEM and TEM studies on the metal (Fe‐Ni alloy ±C) portion of the Vaca Muerta mesosiderite reveal structural and compositional evidence at micro to nanoscale, which sheds light on the solidification of taenite + graphite as a cement, and later solid‐state precipitation process for the kamacite formation as grain boundary allotriomorph. Besides, it is proposed that the graphite veinlets formed through a complex partial melting process followed by a solidification toward the final eutectic transient coupled with the solid‐state precipitation and later decomposition ordering of taenite. The presence of defects and taenite in graphite signal formation in a liquid environment. The δ 13 C values of graphite in the graphite‐rich areas (e.g., ranging from −0.8 ± 1.7‰ to +15.3 ± 2.5‰) suggest a short‐circuit diffusion path for C isotope fractionation.

10.1111/maps.14120

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Citations (1)

Carbon in glass inclusions of Allende, Vigarano, Bali, and Kaba (CV3) olivines

Geochimica et Cosmochimica Acta (2000)

M. E. Varela Nicole Métrich M. Bonnin-Mosbah G. Kurat

Allende meteorite

Carbon fibers

10.1016/s0016-7037(00)00478-6

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Citations (19)

Glass-bearing inclusions in Nakhla(SNC meteorite) augite: heterogeneouslytrapped phases

Mineralogy and Petrology (2001)

M. E. Varela G. Kurat R. Clocchiatti

Pigeonite

Melt inclusions

10.1007/s007100170037

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Citations (21)

INCLUSIONES MAGMATICAS EN INTRUSIVOS RIODACITICOS DEL DISTRITO MINERO LOS MANANTIALES, PROVINCIA DE CHUBUT

Revista de la Asociación Geológica Argentina (2020)

M. E. Varela Amado Leandro Bengochea

Las inclusiones mazmaticas representan microsistemas que preservan informacion sobre las condicionesfisico-quimicas del magma en el momento que las mismas fueron formadas. Los estudios petrograficos detalladosde las inclusiones de fusion, la caracterizacion de su evolucion despues del entrampamiento y los estudios termometricosde elevadas temperaturas proveen informacion sobre la quimica de la fusion.

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Kuratite, Ca₄(Fe²⁺₁₀Ti₂)O₄[Si₈Al₄O₃₆], the Fe²⁺-analogue of rhönite, a new mineral from the D'Orbigny angrite meteorite

Mineralogical Magazine (2016)

Shyh‐Lung Hwang P. Shen H. Chu Tzen‐Fu Yui M. E. Varela

Abstract Kuratite, ideally Ca 4 (Fe 2+ 10 Ti 2 )O 4 [Si 8 Al 4 O 36 ], the Fe 2+ -analogue of rhönite and a new member of the sapphirine supergroup, was identified from the D'Orbigny angrite meteorite by electron microscopy and micro-Raman spectroscopy. Based on the least-squares refinement of 25 d-spacings measured from selected-area electron diffraction patterns of 11 zone axes, the symmetry of kuratite was shown to be triclinic (space group by analogy to rhönite) with a = 10.513(7), b = 10.887(7), c = 9.004(18) Å, α = 105.97(13), β = 96.00(12), γ = 124.82(04)°, V = 767 ± 2 Å3 and Z = 1 for the 40 oxygen formula. The empirical formula based on eight electron microprobe analyses is (Ca 3.88 Na 0.02 REE 3+ 0.03 Mn 0.03 Mg 0.01 Ni 0.02 Zn 0.01 Sr 0.01 ) ∑4.01 (Fe 2+ 9.98 9.9Ti 2.00 ) ∑11.98 (Si 7.80 Al 3.52 Fe 3+ 0.64 P 0.05 S 0.02 ) ∑12.03 O 39.98 F 0.01 Cl 0.01 . The simplified formula is Ca 4 (Fe 2+ 10 Ti 2 )O 4 [Si 8 Al 4 O 36 ]. Micro-Raman spectroscopy showed four main bands resembling those of lunar rhönite but with higher frequencies due to different chemical composition. Analogous to the occurrence of kuratite in terrestrial basaltic rocks, kuratite coexisting with Al, Ti-bearing hedenbergite, ulvöspinel, iron-sulfide, tsangpoite, Ca-rich fayalite and kirschsteinite in D'Orbigny angrite most probably was formed at >1000°C by rapid cooling of an interstitial melt, which is subsilicic, almost Mg-free but enriched in Al-P-Ca-Ti-Fe.

Triclinic crystal system

Space group

10.1180/minmag.2016.080.043

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Citations (10)

The D'Orbigny Angrite: Evidences for and Against a Final Thermal Event at -1000ºC

LPI (2014)

M. E. Varela Seong-Sik Hwang P.Y. Shen H. Chu Tzen‐Fu Yui

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Cm?-U-Th-Pb Isotopic Evolution of the D'Orbigny Angrite

Meteoritics and Planetary Science Supplement (2003)

E. Jagoutz Reimund Jotter Alfons Kubny M. E. Varela G. Kurat

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Citations (10)