Gweni-Fada crater

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Gweni-Fada crater
Gweni-Fada crater.jpg
Landsat image of the Gweni-Fada crater; screen capture from NASA World Wind
Impact crater/structure
ConfidenceConfirmed
Diameter14 km (8.7 mi)
Age<345 Ma
<Early Carboniferous
ExposedYes
DrilledNo
Location
LocationSahara
Coordinates17°25′7″N 21°45′8″E / 17.41861°N 21.75222°E / 17.41861; 21.75222Coordinates: 17°25′7″N 21°45′8″E / 17.41861°N 21.75222°E / 17.41861; 21.75222
CountryChad
StateEnnedi-Ouest
Gweni-Fada crater is located in Chad
Gweni-Fada crater
Location of the crater in Chad
Gweni-Fada crater viewed from the International Space Station
Oblique Landsat image of Gweni-Fada crater draped over digital elevation model (x2 vertical exaggeration); screen capture from NASA World Wind

Gweni-Fada is a meteorite crater in Chad, Africa.[1][2]

The Gweni Fada structure was first noted on the map NE 34 X Fada of the IGN (National Geographic Institute France) and aerial photographs in the 1950s of IGN by (Paris X- Nanterre University). In April 1995, at the initiative of CNAR (National Center to Help Research of Chad) a team of French geologists (Pierre Vincent, University of Clermont-Ferrand, Alain and Najia Beauvilain, CNAR Chad) visited the site and reported evidence of shock metamorphism within rock samples they had collected inside the structure.

Centered at 17°25′N and 21°45′E, being slightly wider in the NW-SE direction (cf. topographic map), the asymmetric structure is deeply eroded. A broad depression (ø 12 km) forms a crescent around two thirds of the inner complex zone. On the northern side, an elevated outer ring of outward-dipping sandstones surrounds the depression. In its south, the external depression is absent. The inner zone (ø 10 km) consists of a rugged terrain with hills several hundred meters in height. The latter may be remnants of the central uplift (see topographic map).

The age is estimated to be less than 345 million years (Carboniferous). It is older than that of Aorounga because its coverage of impactite has disappeared as a result of erosion.

Topographic map of Gweni-Fada crater

See also[]

References[]

  1. ^ "Gweni-Fada". Earth Impact Database. Planetary and Space Science Centre University of New Brunswick Fredericton. Retrieved 2009-08-13.
  2. ^ VINCENT P.M., BEAUVILAIN A., 1996. Découverte d'un nouveau cratère d'impact météoritique en Afrique : l'astroblème de Gweni-Fada (Ennedi, Sahara du Tchad). C. R. Acad. Sci. Paris, t. 323, série II a, pp. 987-997.[1]

Further reading[]

  • 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

External links[]

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