ICATE   21876
INSTITUTO DE CIENCIAS ASTRONOMICAS, DE LA TIERRA Y DEL ESPACIO
Unidad Ejecutora - UE
artículos
Título:
Varre Sai: The recent Brasilian fall
Autor/es:
ZUCOLOTTO M.E.; ANTONELLO L; VARELA M.E.; SCORZELLI R; MUNAYCO P.; DOS SANTOS E.; LUDKA, IZABEL
Revista:
EARTH, MOON, AND PLANETS
Editorial:
SPRINGER
Referencias:
Año: 2012 vol. 109 p. 43 - 53
ISSN:
0167-9295
Resumen:
Abstract Varre-Sai, the most recent Brazilian meteorite fall, on June 19th, 2010 at
Varre-Sai, in Rio de Janeiro State, Brazil (205104100S; 41440.8000W). At least eight masses
(total *3.5 kg) were recovered. Most are totally covered by fusion crust. The exposed
interior is of light-grey colour with a few dark shock veins. Five thin polished and etched
sections were prepared from a slice weighing 35 g on deposit at the National Museum/
UFRJ. It consists mostly of chondrules ranging in size from 0.35 to *2.2 mm, and
chondrule fragments enclosed in a crystalline matrix. The matrix consists of tiny isolated
subhedral and anhedral crystals and opaque minerals that are intergrown with broken
chondrules. The chondritic texture is poorly defined with chondrule textures that vary from
non-porphyritic to porphyritic ones. The essential minerals are olivine (Fa25±0.2) and low-
Ca pyroxene (Fa21.66±0.2Wo1.4). Accessory minerals are plagioclase, apatite, FeNi metal
phases, troilite, chromite and magnetite. Mo¨ssbauer spectroscopy analysis confirms that the
mineral phases are olivine, pyroxene, troilite and kamacite/taenite. Chemical data indicate
that Varre-Sai is a member of the low iron L chondrite group. The observed texture and
mineral phases led us to classify Varre-Sai as an equilibrated petrologic type 5. The shock
features of the minerals (undulatory extinction, planar structure and numerous cracks), as
well as plagioclase partial or totally transformed to maskelynite, suggest a shock stage S4.
Also, some post-impact metamorphic processes could be inferred from the meta-sulfide
conjoint grains that show complex mixtures of kamacitetaenitetetrataenite and troilite.
The occurrence of veins crosscutting the studied sections indicates that Varre-Sai wasVarre-Sai, the most recent Brazilian meteorite fall, on June 19th, 2010 at
Varre-Sai, in Rio de Janeiro State, Brazil (205104100S; 41440.8000W). At least eight masses
(total *3.5 kg) were recovered. Most are totally covered by fusion crust. The exposed
interior is of light-grey colour with a few dark shock veins. Five thin polished and etched
sections were prepared from a slice weighing 35 g on deposit at the National Museum/
UFRJ. It consists mostly of chondrules ranging in size from 0.35 to *2.2 mm, and
chondrule fragments enclosed in a crystalline matrix. The matrix consists of tiny isolated
subhedral and anhedral crystals and opaque minerals that are intergrown with broken
chondrules. The chondritic texture is poorly defined with chondrule textures that vary from
non-porphyritic to porphyritic ones. The essential minerals are olivine (Fa25±0.2) and low-
Ca pyroxene (Fa21.66±0.2Wo1.4). Accessory minerals are plagioclase, apatite, FeNi metal
phases, troilite, chromite and magnetite. Mo¨ssbauer spectroscopy analysis confirms that the
mineral phases are olivine, pyroxene, troilite and kamacite/taenite. Chemical data indicate
that Varre-Sai is a member of the low iron L chondrite group. The observed texture and
mineral phases led us to classify Varre-Sai as an equilibrated petrologic type 5. The shock
features of the minerals (undulatory extinction, planar structure and numerous cracks), as
well as plagioclase partial or totally transformed to maskelynite, suggest a shock stage S4.
Also, some post-impact metamorphic processes could be inferred from the meta-sulfide
conjoint grains that show complex mixtures of kamacitetaenitetetrataenite and troilite.
The occurrence of veins crosscutting the studied sections indicates that Varre-Sai was5104100S; 41440.8000W). At least eight masses
(total *3.5 kg) were recovered. Most are totally covered by fusion crust. The exposed
interior is of light-grey colour with a few dark shock veins. Five thin polished and etched
sections were prepared from a slice weighing 35 g on deposit at the National Museum/
UFRJ. It consists mostly of chondrules ranging in size from 0.35 to *2.2 mm, and
chondrule fragments enclosed in a crystalline matrix. The matrix consists of tiny isolated
subhedral and anhedral crystals and opaque minerals that are intergrown with broken
chondrules. The chondritic texture is poorly defined with chondrule textures that vary from
non-porphyritic to porphyritic ones. The essential minerals are olivine (Fa25±0.2) and low-
Ca pyroxene (Fa21.66±0.2Wo1.4). Accessory minerals are plagioclase, apatite, FeNi metal
phases, troilite, chromite and magnetite. Mo¨ssbauer spectroscopy analysis confirms that the
mineral phases are olivine, pyroxene, troilite and kamacite/taenite. Chemical data indicate
that Varre-Sai is a member of the low iron L chondrite group. The observed texture and
mineral phases led us to classify Varre-Sai as an equilibrated petrologic type 5. The shock
features of the minerals (undulatory extinction, planar structure and numerous cracks), as
well as plagioclase partial or totally transformed to maskelynite, suggest a shock stage S4.
Also, some post-impact metamorphic processes could be inferred from the meta-sulfide
conjoint grains that show complex mixtures of kamacitetaenitetetrataenite and troilite.
The occurrence of veins crosscutting the studied sections indicates that Varre-Sai was*3.5 kg) were recovered. Most are totally covered by fusion crust. The exposed
interior is of light-grey colour with a few dark shock veins. Five thin polished and etched
sections were prepared from a slice weighing 35 g on deposit at the National Museum/
UFRJ. It consists mostly of chondrules ranging in size from 0.35 to *2.2 mm, and
chondrule fragments enclosed in a crystalline matrix. The matrix consists of tiny isolated
subhedral and anhedral crystals and opaque minerals that are intergrown with broken
chondrules. The chondritic texture is poorly defined with chondrule textures that vary from
non-porphyritic to porphyritic ones. The essential minerals are olivine (Fa25±0.2) and low-
Ca pyroxene (Fa21.66±0.2Wo1.4). Accessory minerals are plagioclase, apatite, FeNi metal
phases, troilite, chromite and magnetite. Mo¨ssbauer spectroscopy analysis confirms that the
mineral phases are olivine, pyroxene, troilite and kamacite/taenite. Chemical data indicate
that Varre-Sai is a member of the low iron L chondrite group. The observed texture and
mineral phases led us to classify Varre-Sai as an equilibrated petrologic type 5. The shock
features of the minerals (undulatory extinction, planar structure and numerous cracks), as
well as plagioclase partial or totally transformed to maskelynite, suggest a shock stage S4.
Also, some post-impact metamorphic processes could be inferred from the meta-sulfide
conjoint grains that show complex mixtures of kamacitetaenitetetrataenite and troilite.
The occurrence of veins crosscutting the studied sections indicates that Varre-Sai was*2.2 mm, and
chondrule fragments enclosed in a crystalline matrix. The matrix consists of tiny isolated
subhedral and anhedral crystals and opaque minerals that are intergrown with broken
chondrules. The chondritic texture is poorly defined with chondrule textures that vary from
non-porphyritic to porphyritic ones. The essential minerals are olivine (Fa25±0.2) and low-
Ca pyroxene (Fa21.66±0.2Wo1.4). Accessory minerals are plagioclase, apatite, FeNi metal
phases, troilite, chromite and magnetite. Mo¨ssbauer spectroscopy analysis confirms that the
mineral phases are olivine, pyroxene, troilite and kamacite/taenite. Chemical data indicate
that Varre-Sai is a member of the low iron L chondrite group. The observed texture and
mineral phases led us to classify Varre-Sai as an equilibrated petrologic type 5. The shock
features of the minerals (undulatory extinction, planar structure and numerous cracks), as
well as plagioclase partial or totally transformed to maskelynite, suggest a shock stage S4.
Also, some post-impact metamorphic processes could be inferred from the meta-sulfide
conjoint grains that show complex mixtures of kamacitetaenitetetrataenite and troilite.
The occurrence of veins crosscutting the studied sections indicates that Varre-Sai was25±0.2) and low-
Ca pyroxene (Fa21.66±0.2Wo1.4). Accessory minerals are plagioclase, apatite, FeNi metal
phases, troilite, chromite and magnetite. Mo¨ssbauer spectroscopy analysis confirms that the
mineral phases are olivine, pyroxene, troilite and kamacite/taenite. Chemical data indicate
that Varre-Sai is a member of the low iron L chondrite group. The observed texture and
mineral phases led us to classify Varre-Sai as an equilibrated petrologic type 5. The shock
features of the minerals (undulatory extinction, planar structure and numerous cracks), as
well as plagioclase partial or totally transformed to maskelynite, suggest a shock stage S4.
Also, some post-impact metamorphic processes could be inferred from the meta-sulfide
conjoint grains that show complex mixtures of kamacitetaenitetetrataenite and troilite.
The occurrence of veins crosscutting the studied sections indicates that Varre-Sai was21.66±0.2Wo1.4). Accessory minerals are plagioclase, apatite, FeNi metal
phases, troilite, chromite and magnetite. Mo¨ssbauer spectroscopy analysis confirms that the
mineral phases are olivine, pyroxene, troilite and kamacite/taenite. Chemical data indicate
that Varre-Sai is a member of the low iron L chondrite group. The observed texture and
mineral phases led us to classify Varre-Sai as an equilibrated petrologic type 5. The shock
features of the minerals (undulatory extinction, planar structure and numerous cracks), as
well as plagioclase partial or totally transformed to maskelynite, suggest a shock stage S4.
Also, some post-impact metamorphic processes could be inferred from the meta-sulfide
conjoint grains that show complex mixtures of kamacitetaenitetetrataenite and troilite.
The occurrence of veins crosscutting the studied sections indicates that Varre-Sai was