Autor: |
Lorenz, C. A., Ivanova, M. A., Artemieva, N. A., Sadilenko, D. A., Chennaoui Aoudjehane, H., Roschina, I. A., Korochantsev, A.V., Humayun, M. |
Předmět: |
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Zdroj: |
Meteoritics & Planetary Science; Jan2015, Vol. 50 Issue 1, p112-134, 23p |
Abstrakt: |
A relic impact structure was recognized within the strewn field of the Agoudal iron meteorite. The heavily eroded structure has preserved shatter cones in a limestone basement, and remnants of autochthonous and allochthonous breccias. Fragments of iron incorporated into the allochthonous breccia have a chemical composition (Ni = 5.16 wt%, Ir = 0.019 ppm) similar to that of the Agoudal meteorite, supporting a syngenetic origin of the strewn field and the impact structure. The total recovered mass of Agoudal meteorite fragments is estimated at approximately 500 kg. The estimated size of the SE- NW-oriented strewn field is 6 × 2 km. Model calculations with minimal preatmospheric size show that a similar meteorite strewn field plus one small crater with observed shock effects could be formed by fragmentation of a meteoroid approximately 1.4 m in diameter with an impact angle of approximately 60° from the horizontal. However, the most probable is an impact of a larger, 3-4 m diameter meteoroid, resulting a strewn field with approximately 10 craters, 10-30 m in diameter each, plus numerous meteorite fragments. The calculated scattering area of meteorite shrapnel ejected from these impact craters could completely cover the observed strewn field of the Agoudal meteorite. [ABSTRACT FROM AUTHOR] |
Databáze: |
Complementary Index |
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