Western Bavaria, Germany

A limestone formation evidencing branches of striated lines that are the result of an asteroid impact on Earth. Striations are featured on three faces the specimen and further accenting is provided by a variegated tan patina
193 x 131 x 127 mm. (7½ x 5 x 5 inchin.s) and 2,111 g. (4⅔ lbs)

Evidence of an asteroid impact, impactites are terrestrial rocks that were impacted by asteroids or comets. They differ to tektites (see lot 39) in that they were not liquefied and ejected into the upper atmosphere before returning as molten glass. Simply expressed, impactites are earth rocks that were melted, shattered or shocked. At times, new minerals are formed as a result of these high-pressure events such as microdiamonds. Impactite may be found on or beneath the floor of the crater, in the rim, or in ejecta (material launched from the crater following an impact). As might be imagined, impact craters are identified as a result of the presence of impactite, as well as other diagnostic impact products such as shatter cones, impact glass and other chemical, mineralogical and isotopic evidence.
Shatter cones are conical structures produced following intense mechanical shock from either an asteroid impact — or an underground nuclear explosion. The current example came from the 4-km wide Steinheim depression in southwestern Germany. Interestingly, scientists have determined that the Steinheim impact was probably part of a binary asteroid-impact event whose “travel companion” created the nearby, and far larger, 24-km diameter Nördlinger-Ries Crater. This larger impact is also believed to be the source of moldavites, beautiful green-colored impact glasses (otherwise referred to as tektites) found in the Czech Republic — which implies molten glass having been splashed a distance of hundreds of miles — from an event that occurred about 15 million years ago. Most impact craters were once thought to have been volcanic in origin; scientists have today documented 190 impact craters on Earth. Now offered is a select shatter cone from one such asteroid-impact event.

Christie's would like to thank Dr. Alan E. Rubin at the Institute of Geophysics and Planetary Physics, University of California, Los Angeles for his assistance in preparing this catalog note.