16.23 kg. H5
TKW 240 kg. Fall not observed. Found January 1997, Tiris Zemmour, Mauritania.
Jürgen/jnmczurich writes:
The pictures show an extremely fresh 16.23 kg angular fragment of El Hammami / Hamada du Draa. It is a part of a larger individual, smashed into smaller portions by local Bedouins for motorcycle-transportation. The black dull crust covers about 50% of the fragment. Some prominent metal veins are visible below the crust.
The pictures of the two thin sections ("El Hammami" TS is 22 x 20 mm; "Hamada du Draa" TS is 30 x 20 mm) were taken under cross-polarized light. The pictures are not modified by PhotoShop. Both thin sections display a typical metal vein.
The huge El Hammami / Hamada du Draa fragment is one of my largest chondrite samples and has been in my collection since August 1997. I received it as a part of the "Hamada du Draa" meteorites (see the story below).
The following information on El Hammami / Hamada du Draa is copied from MetBase 7.2:
In 1997 January, an unknown mass, possibly broken apart from a single large stone, was sold to meteorite collectors by nomads near the town of Mhamid, Morocco; this material has since been sold under the names "Mhamid" and "Hamada du Draa" and the nomads claimed that this meteorite was found to the south in Algeria (29°50'N, 5°50'W), in the direction of a fireball seen in 1995 January. In 1997 Sept., the same nomads shipped a fragment of a meteorite that they claimed was seen to fall on 1997 Aug. 10 to Edwin Thompson and in November of the same year, Thompson traveled to Mauritania and collected six fresh-looking stones totaling about 200 kg (indiv. masses of 80, 51, 30, 26, 8, and 4 kg) at the base of the El Hammami Mountains in Mauritania (1000 km SW of Mhamid, Morocco), probably in the place where they fell; classification and mineral analysis of "El Hammami" stones (E.Rubin, UCLA), ol. Fa18.8, pyx. Fs16.7; shock stage S2; contains metal veins; petrologic type 5; classification and mineral analysis of "Hamada du Draa" stones (D.Weber, Univ. Münster), ol. Fa19.2, pyx. Fs17.4; shock stage S2; contains conspicuous metal-rich veins; petrologic type 5/6; some of the material appears weathered and rusts easily, but the bulk is quite fresh, J.N.Grossman, Met. Bull. 82, MAPS, 1998, 33, p.A221. NIR spectral sensitivity, J.L.Hinrichs et al., LPSC, 2000, 31, abs. #1521. Mössbauer study, J.Galazka-Friedman et al., Geol. Quart. Warsaw, 2001, 45 (3), p.319. Cosmogenic radionuclide data ("Hammada du Draa"), V.A.Alexeev et al., LPSC, 2001, 32, abs. #1024; see also, LPSC, 2002, 33, abs. #1016. Magnetic susceptibility, P.Rochette et al., MAPS, 2003, 38, p.251. Experimental study of impact-induced frictional melting, C.H.van der Bogert et al., MAPS, 2003, 38, p.1521. |