Riachão Ring

 Crater Name  Location  Latitude  Longitude  Diameter (km)  Age (Ma)  Exposed  Drilled  Target Rock**  Bolide Type***
 Riachão Ring  Brazil  S 7° 43'  W 46° 39'  4.5  < 200  Y  N  S  -

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

2, 3 & 4. Image Provided by Dr. Carlos Roberto de Souza Filho


Bland, P. A., Artemieva, N. A. , de Souza Filho, C.R., The Production Rate of Small Craters on Earth, and the Expected Crater Population in South America. 67th Annual Meteoritical Society Meeting. 2004.
Crosta, A. P., Impact Craters in Brazil: How Far We've Got. 2004.
Crosta, A. P., Impact structures in Brazil. In: Pohl, J., ed., Research in Terrestrial Impact Structures, Friedr.Viewig & Sohn, Braunschweig/Wiesbaden, pp. 30-38. 1987.
de Souza Filho, C.R., Bland, P. A., Proven, Probably and Possible Impact Craters in South America Revealed by Aster and SRTM Data and Image Processing Techniques. 67th Annual Meteoritical Society Meeting. 2004.
Dietz, R. S., McHone, J. F. Jr., Meteorite craters and astroblemes, some new possible examples (abstract). EOS, v. 55, p. 336. 1974.
Grieve, R. A. F., The record of impact on Earth: Implications for a major Cretaceous/Tertiary impact event. Geological Society of America, Special Paper 190, pp. 25-37. 1982.
Gurov, E. P., Gurova, E. P., Impact structures on the Earth's surface (in Russian). Geologicheskii Zhurnal, v. 47, pp. 117-124. 1987.
Masaitis, V. L., Danilin, A.N., Maschak, M.S., Raykhlin, A.I., Selivanovskaya, T.V. and Shadenkov,Ye.M., The Geology of Astroblemes (in Russian). Leningrad, Nedra, 231 p. 1980.
McHone J F., Dietz, R. S., Earth's multiple impact craters and astroblemes (abstract). Lunar and Planetary Science, v. XXIII, pp. 887-888. 1992.
McHone, J., Riachao ring, Brazil: A possible meteorite crater discovered by the Apollo astronauts. National Aeronautics and Space Administration (NASA) Special Publication SP-412, pp. 193-202. 1979.
McHone, J. F. Jr., Dietz, R. S., Astroblemes in Brazil (abstract). Geological Society of America, v. 10, pp. 136-137. 1978.
Romano, R., Crosta, A. P., Brazilian Impact craters: A review, Lunar and Planetary Science XXXV. 2004.
Short, N. M., Lowman, P. D. Jr., Earth observations from space: Outlook for the geological sciences. National Aeronautics and Space Administration (NASA) Report X-650-73-316, 89 p. 1973.
* 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)