manicouagan

Gweni-Fada

 Crater Name  Location  Latitude  Longitude  Diameter (km)  Age (Ma)  Exposed  Drilled  Target Rock**  Bolide Type***
 Gweni-Fada  Chad  N 17° 25'  E 21° 45'  14  < 345  Y  N  S  -
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1. Aerial Photograph

2. Landsat 2.8 metre resolution

3. DEM image Provided by Dr. Carlos Roberto de Souza Filho

4 & 5. Image Provided by Dr. Carlos Roberto de Souza Filho

References
Koeberl, C., Reimold, W. U. , Cooper, G. , Cowan, D. and Vincent, P. M., Aorounga and Gweni Fada impact structures, Chad: Remote sensing, petrography, and geochemistry of target rocks, Meteoritics & Planetary Science, 40, No 9/10 P. 1455 - 1471. 2005.
Koeberl, C., Reimold, W.U., Vincent, P. M., Brandt,D., Aorounga and Gweni Fada Impact Structures, Chad, Central Afr.: Petrology and Geochemistry of Target Rocks, LPSC XXIX, Lunar and Planetary Institute, Houston, TX, (CD-ROM). 1998.
Vincent P.M., Beauvilain, A., Découverte d'un nouveau cratère d'impact météoritique en Afrique: l'astroblème de Gweni-Fada (Ennedi, Sahara du Tchad) (in French). Comptes Rendus de l'Académie des Sciences, v. 323, pp. 987-997. 1996.
Vincent P.M., Beauvilain, A., The circular structure of Gweni-Fada, Ennedi: A second meteorite impact crater in Northern Chad? (abstract). 4th International Workshop of the ESF Scientific Network on "Impact Cratering and Evolution of Planet Earth". The Role of Impacts on the Evolution of the Atmosphere and Biosphere with Regard to Short- and Long-Term Changes, pp. 156-157. 1995.
Vincent, P. M., The circular structure of Gweni-Fada, Ennedi: A second meteorite impact crater in Northern Chad? (abstract). 4th International Workshop of the ESF Scientific Network on "Impact Cratering and Evolution of Planet Earth". The Role of Impacts on the Evolution of the Atmosphere and Biosphere with regard to Short- and Long-Term Changes, p. 156-157. 1995.
* pre-1977 K-Ar, Ar-Ar and Rb-Sr ages recalculated using the decay constants of Steiger and Jager (1977) Ages in millions of years (Ma) before present.

** Abbreviations: C - Crystalline Target; C-Ms - Metasedimentary Target; M - Mixed Target (i.e.sedimentary strata overlying crystalline basement); S - sedimentary target (i.e. no crystalline rocks affected by the impact event). From Osinski. G. R., Spray J. G., and Grieve R. A. F. 2007. Impact melting in sedimentary target rocks: A synthesis. In The Sedimentary Record of Meteorite Impacts, Geological Society of America Special Paper. Editors: Evans K. Horton W., King D., Morrow J., and Warme J. Geological Society of America: Boulder, in press.

***From Koeberl,C. Identification of meteoritic components in impactites. 1998, Koeberl, C. The Geochemistry and Cosmochemistry of Impacts. 2007 and PASSC Files. (IAB, IIIAB, IIIB, IIID - Iron Meteorite)