Extension crack caved out through ablation
Buchwald also mentioned evidence for extensive reheating of several Gibeon specimens for a short period of time, probably as a result of local energy release during the violent atmospheric rupturing. „It may be more than a coincidence that the most reheated specimens seem to come from the periphery of the strewn field and thus represent material thrown 100 – 200 km away from the central area.“ During the research for this article the author had the opportunity to acquire a previously undiscribed specimen of the Gibeon meteorite which provides additional evidence for a violent atmospherical break up of the Gibeon body.
The specimen discussed here was found by Manfred Gollub on his farm between Maltahöhe and Gibeon in 1985 and sent to Germany under the name of its find location. (“Maltahöhe” is not a synonyme for Gibeon but a field name for an individual mass of the Gibeon fall. This Gibeon individual is not to be mixed up with the meteorite Maltahöhe, which is an IIICD iron (see also Meteoritical Bulletin, No. 71, p. 258)). With dimensions of 42 x 36 x 6.6 cm the meteorite forms a flat oval shield narrowing towards frayed edges. Due to the thin profile of the shield shape the Maltahöhe mass weighs only 29.96 kg.
One slightly concave surface is completely covered with small regmaglypts which show an average extension of 2 cm and an average depth of ~1.2 cm. The regmaglypts are distributed in a random pattern rather than in a radial orientation. Their depth increases towards the centre of the concavity, which is located ~ 8 cm off the geometrical centre and on the expanded end of the shield. The other surface is slightly convex, and apart from a 15 cm long groove, shows little plastic sculpting. Opposite the concavity from the regmaglypted side the convex surface shows a narrow apex which also constitutes the centre of gravity of the mass. No obvious flight marks are visible on this surface other than the groove.
Though no fusion crust is preserved, the overall erosion on the Maltahöhe mass can be considered as very moderate. Regmaglypts are still clearly defined, extension cracks show only superficial caving or smoothing and the common exaggeration of features as well as any sharp edges or spikes on either surface, which are usually attributed to soil etching, are absent.