The Unusual Fusion Crust of Tamdakht (H5) Fall
Résumé
Meteoroids enter Earth’s atmosphere at cosmic speeds reaching up to tens of kilometers per second [1]. During this violent event, their surface is subjected to heating due to the friction with air molecules, which results in its rapid melting, leading to the formation of a usually black and thin layer, upon cooling, called fusion crust [2]. The study of meteoritic fusion crusts provides invaluable insight into the physical and compositional variations generated during this transitional stage, from the interplanetary space to the surface of Earth. Tamdakht is an H5 ordinary chondrite that fell in Morocco on December 20, 2008 [3]. It is an important fall, the TKW is up to 500 kg with numerous pieces and so far largest on was 82 kg [4]. Fusion crust of Tamdakht is interesting because of thickness of some specimens fusion crust [5]. Throughout this work, we aim to explore the physical characteristics, the textures and the mineralogical components of the fusion crust of numerous Tamdakht meteorite pieces, in order to establish a criterion that can be useful to understand the process of fusion crusts formation. [1] Love S. G. and Brownlee D. E. (1991). Icarus, 89, 26–43. [2] Genge M. J. and Grady M. M. (1999). Meteoritics and Planetary Science, 34, 341–356. [3] Chennaoui Aoudjehane et al. 2009. Meteoritics & Planetary Science 44, Nr S7:A50. [4] https://www.lpi.usra.edu/meteor/metbull.php?code=48 691. [5] Chennaoui Aoudjehane H, A. Mazurier, A. El Albani, B. Devouard, P. Rochette, O. Boudouma, T. Shisseh (2017), Meteoritics & Planetary Science 48, abstract #6140. [6] Thaisen K. G. and Taylor L. A. (2009). Meteoritics and Planetary Science 44, 871878.