THE STRUCTURE OF ARIZARO, SALTA, ARGENTINA: A NEW SIMPLE TYPE METEORITE IMPACT SITE?

ACEVEDO, R.D.; ROCCA, M.; ALONSO, R.; RABASSA, J; PONCE, J.F.; KLAJNIK, M.

Cairns

Congreso; 75th Annual Meteoritical Society Meeting; 2012

Meteoritical Society Meeting

THE STRUCTURE OF ARIZARO, SALTA, ARGENTINA: A NEW SIMPLE TYPE METEORITE IMPACT SITE? R. D. Acevedo1, M. Rocca2, R. Alonso3, J. Rabassa1,4, J. F. Ponce1 and K. Klajnik5. 1CADIC-Conicet, Ushuaia, 9410, Tierra del Fuego, Argentina. E-mail: acevedo@cadic-conicet.gob.ar 2CABA, Argentina. 3Universidad Nacional de Salta, Argentina, 4Universidad Nacional de Tierra del Fuego, Ushuaia, Argentina, 5Metropolitan Ervin Szabo Library, Budapest, Hungary. Introduction: Recent efforts to identify additional impact cra-ters in Argentina, making use of LANDSAT imagery, Google Earth images and aerial photographs, have found a possible new example in this category in Salta Province: the structure of Arizaro (24º 55? 45.30? S, 67º 27? 09.64? W) located in Puna at 3,650 m.a.s.l. Description: The structure has 185 meters in diameter. Its appearance is that of a bowl-shaped hole with a clear raised rim and a central depression. The structure has been a bit flattened at the rims by the erosion. The interior it is lighter shade and it seems to be full of sands. It is very different from other cavities that are present in the area around. Discussion: The local geology is in no conflict with a possible origin by a meteorite impact. The area is mainly composed of salt deposits, sandstones and gypsum of Tertiary-Quaternary age. Definitely this depression is not a doline. It has a raised rim and dolines never have raised rims. No volcanic features have been so far reported for this site. Furthermore Arizaro?s structure cannot be a volcanic neck or cal-dera. Its morphology is quite different, e.g. has a raised rim and there are no visible lava floods coming from the crater itself. Conclusion: This crater is probably a new young simple-type impact crater on Tertiary-Quaternary sedimentary deposits. Other investigation of this interesting crater is in progress. Acknowledgements: This work was funded by Conicet, Na-tional Geographic/Waitt and The Planetary Society. 75th Annual Meteoritical Society Meeting (2012) 5042.pdf