Publication: Un nuevo meteorito español: Retuerta del Bullaque
(Ciudad Real). Clasificación, mineralogía y preservación
de la morfología
Loading...
Full text at PDC
Publication Date
2013-01
Advisors (or tutors)
Editors
Journal Title
Journal ISSN
Volume Title
Publisher
Consejo Superior de Investigaciones Científicas (España)
Citations
Exportar
Abstract
El meteorito de Retuerta del Bullaque es un nuevo siderito español, encontrado en 1980 cerca de esta localidad de Ciudad Real, en un área colindante al Parque Nacional de Cabañeros (39º27’32”N, 4º22’39”O). Con cerca de 100 kg de peso, se trata de una octaedrita gruesa moderadamente oxidada con regmaglifos. Algunos sectores del borde están recristalizados debido a la fricción con la atmósfera.
Los análisis de ICP-AES (Ni: 7.527 y Co: 0.475 en % en peso) e ICP-MS (Ga: 68.9, Ge: 365, As: 13.7,
W: 0.95, Ir: 1.95 y Au: 1.70 en ppm) permiten clasificar el ejemplar en el grupo principal del complejo
IAB. Químicamente, el meteorito de Retuerta del Bullaque es similar al siderito de Kaalijarv, aunque mineralógica y texturalmente es más parecido a otros sideritos del citado grupo, con menos Ni y Au (como por ejemplo Cañón del Diablo). Retuerta del Bullaque está compuesto principalmente por kamacita, tanto en bandas de Widmanstätten (2.0 ± 0.3 mm) con inclusiones de cohenita, como en sectores
poligonales sin cohenita y con abundantes líneas de Neumann. En ambas zonas, la kamacita contiene schreibersita alotriomorfa e idiomorfa (rhabdita). La taenita forma delgadas lamelas situadas entre los cristales de kamacita y también dentro de plessitas perlíticas. La cohenita lamelar es muy abundante (9.5 % del área total en dos secciones de 77.7 y 41.1 cm2), está parcialmente recubierta de schreibersita y contiene esférulos de kamacita y taenita. La sección más grande muestra varios nódulos de troilita-
grafito (máxima dimensión: 5-18 mm), localizados en las zonas centrales de la kamacita poligonal. Cada nódulo está recubierto por schreibersita + cohenita. Hemos preservado la morfología original del ejemplar mediante técnicas de moldeo y vaciado (basadas en elastómeros, resinas y escayolas modificadas) y utilizado tecnología de escáner láser en 3D.
Retuerta del Bullaque is a new Spanish iron meteorite. Found in 1980, has been recovered from the Province of Ciudad Real, near the northern limit of the Cabañeros National Park (39º27’32”N, 4º22’39”W). The specimen is a coarse octahedrite of about 100 kg in weight, with many concave regmaglyphes in one surface and moderate terrestrial weathering. The atmospheric heat-affected rim (≤1.5 mm) is partially preserved. Analysis by ICP-AES (Ni: 7.527 and Co: 0.475 in wt%) and by ICP-MS (Ga: 68.9, Ge: 365, As: 13.7, W: 0.95, Ir: 1.95 and Au: 1.70 in ppm) we used to classify the specimen as an IAB complex (Main Group). Chemically, Retuerta del Bullaque iron is similar to Kaalijarv iron but its mineralogy and texture are more like other low Ni-Au irons of main group (e.g. Diablo Canyon). The bulk of the specimen is a Widmanstätten kamacite (band-width estimated at 2.0 ± 0.3 mm) with large and tabular crystals of cohenite and polygonal kamacite without cohenite that exhibits abundant Neumann lines. Schreibersite (irregular crystals + rhabdite) is rare in the two sectors. Taenite is present in thick lamellae between kamacite bands and pearlitic plessite. Lamellar cohenite is very abundant (9.5% of the total area into two sections 77.7 and 41.1 cm2), is partially covered of schreibersite and contains kamacite-taenite spherules. The larger sections display irregularly shaped troilite-graphite nodules (max. size, 5-12 mm), located in the central areas of the kamacite polygonal sectors. Each nodule has a rim of schreibersite + cohenite. The original morphology of the specimen was preserved making replicas as molds and casts (using elastomers, resins and modified plasters) and a 3D-laser scan.
Retuerta del Bullaque is a new Spanish iron meteorite. Found in 1980, has been recovered from the Province of Ciudad Real, near the northern limit of the Cabañeros National Park (39º27’32”N, 4º22’39”W). The specimen is a coarse octahedrite of about 100 kg in weight, with many concave regmaglyphes in one surface and moderate terrestrial weathering. The atmospheric heat-affected rim (≤1.5 mm) is partially preserved. Analysis by ICP-AES (Ni: 7.527 and Co: 0.475 in wt%) and by ICP-MS (Ga: 68.9, Ge: 365, As: 13.7, W: 0.95, Ir: 1.95 and Au: 1.70 in ppm) we used to classify the specimen as an IAB complex (Main Group). Chemically, Retuerta del Bullaque iron is similar to Kaalijarv iron but its mineralogy and texture are more like other low Ni-Au irons of main group (e.g. Diablo Canyon). The bulk of the specimen is a Widmanstätten kamacite (band-width estimated at 2.0 ± 0.3 mm) with large and tabular crystals of cohenite and polygonal kamacite without cohenite that exhibits abundant Neumann lines. Schreibersite (irregular crystals + rhabdite) is rare in the two sectors. Taenite is present in thick lamellae between kamacite bands and pearlitic plessite. Lamellar cohenite is very abundant (9.5% of the total area into two sections 77.7 and 41.1 cm2), is partially covered of schreibersite and contains kamacite-taenite spherules. The larger sections display irregularly shaped troilite-graphite nodules (max. size, 5-12 mm), located in the central areas of the kamacite polygonal sectors. Each nodule has a rim of schreibersite + cohenite. The original morphology of the specimen was preserved making replicas as molds and casts (using elastomers, resins and modified plasters) and a 3D-laser scan.