Editing Rochechouart impact structure (section)

== Shape and size ==
The geometrical center of the structure is located {{cvt|4|km|mi}} 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 {{cvt|1|km|mi}} further South near Valette.<ref name=":8">{{Cite journal|last=Lambert P.|title=The Rochechouart crater: Shock zoning study|journal=Earth and Planetary Science Letters|volume=35|issue=2|pages=258–268|bibcode=1977E&PSL..35..258L|year=1977|doi=10.1016/0012-821X(77)90129-7}}</ref><ref>{{Cite journal|last=Pohl J., Ernstson K., and Lambert P.|date=1978|title=Gravity measurements in the Rochechouart impact structure (France)|journal=Meteoritics|volume=13|pages=601–604|bibcode=1978Metic..13..601P}}</ref>

The size of the Rochechouart impact crater reported in the official impact database ({{cvt|23|km|mi|disp=semicolon}}) lacks geologic significance. As previously mentioned, the initial morphology of the crater is lost, as are the initial diameter and shape of the crater. The reported {{cvt|23|km|mi}} diameter corresponds to the size of the area where deformation attributed to impact was reported by authors in the 1970s.<ref name=":8" /><ref name=":7" /><ref name=":3" /> From the morphology of the crater floor and the distribution of impact deposit it is clear the initial crater was much larger than the {{cvt|12|km|mi}} zone where outcrops the remnants of the crater fill has been mapped. In the {{cvt|4|-|25|km|mi}} diameter range, terrestrial impact craters are developing a central high, such as Boltysh crater, a {{cvt|24|km|mi}} impact crater in Ukraine.<ref name=":9">{{Cite journal|last=Gurov E. Kellley S.P. Koeberl C. and Dykan N.I.|date=2006|title=Sediments and impact rock fillings in the Boltysh impact crater|journal=In Charles Cockell, Christian Koeberl, Iain Gilmour- Eds, Biological Processes Associated with Impact Events, Springer Science & Business Media|pages=335–358|doi=10.1007/3-540-25736-5_15}}</ref> 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 {{cvt|1|km|mi}} above the level of crater floor in the low around the central high.<ref name=":9" /> 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 {{cvt|40|+/-|10|km}}.<ref name=":7" /><ref name=":11" />