size The geometrical center of the structure is located west of Rochechouart, near the little village of la Judie (see map). The center of the structure according to the nature and distribution of the shock damage in the deposits and according to the negative gravity anomaly in the target stands about further South near Valette. The size of the Rochechouart impact crater reported in the official impact database () lacks geologic significance. As previously mentioned, the initial morphology of the crater is lost and initial diameter and shape of the crater. The reported diameter corresponds to the size of the area where deformation attributed to impact were reported by authors in the 1970s. From the morphology of the crater floor and the distribution of impact deposit it is clear the initial crater is much larger than the zone where outcrops the remnants of the crater fill has been mapped. In the diameter range, terrestrial impact craters are developing a central high, such as Boltysh crater, a impact crater in Ukraine. Like Rochechouart, Boltysh formed exclusively in crystalline basement. The crater is buried yet the deeper structure is known through numerous drill cores and geophysical investigation undertaken during the Soviet period in the search of hydrocarbons. The central high at Boltysh raises about above the level of crater floor in the low around the central high. There is no central high at Rochechouart, but a flat central low suggesting the central uplift has collapsed, a characteristic feature of larger impact craters. The current estimates for the Rochechouart initial crater fall in the range . Rochechouart projectile Owing to the prominence of the siderophile contamination, a cometary projectile seems unlikely. The impactor was an asteroid. The earliest identification works involved the same heavy techniques and the same diagnostic elements (Ir, Os and other siderophile elements) as those that became famous in the early 1980s with the identification of the extraterrestrial signal at the K–T boundary worldwide. Since then the two extreme projectile types, iron meteorite and chondrite, have been argued by the successive workers. The most recent studies seems to agree with a special type of achondrite, a mix by impact of iron meteorite and silicates formerly designated as non magmatic iron meteorites. Planetary surfaces Within the population of terrestrial impact crater Rochechouart provides a quite unique direct access for investigating major questions related to the impact cratering as geological and as