We describe two circular morphological features representing depressed areas. This preliminary work is based on visual interpretations from Landsat ETM satellite images and SRTM Radar scans. The two geoforms are located at the north of the Sierras Pampeanas in Argentina. The La Ciénaga circular indentation is 15 km in diameter and Las Cejas is 34 km in diameter. Until now rings of these characteristics, magnitudes and diameters are unknown and unheard of in Argentina.
References
[1]
Instituto Geográfico Militar (1991a) Carta Topográfica 1:250.000 2766-II San Miguel de Tucumán (provincias de Tucumán, Salta, Santiago del Estero y Catamarca). Buenos Aires, Argentina.
[2]
Instituto Geográfico Militar (1991b) Carta Topográfica 1:250.000 2766-III Belén (provincias de Catamarca y Tucumán). Buenos Aires, Argentina.
[3]
Ruíz Huidobro, O.J. (1975) Carta Geológico-Económica Laguna Helada-12c, provincia de Catamarca, escala 1:200.000. Ministerio de Economía, Servicio Nacional Minero Geológico, 146, 68 p.
[4]
González Bonorino, F. (1947) Carta Geológico-Económica Capillitas-12d, provincia de Catamarca, escala 1:200.000. Ministerio de Economía, Dirección General de Minas y Geología, 65, 72 p.
[5]
DalMolin, C.N., Fernández, D. and Escosteguy, L. (2003) Hoja Geológica 2766-IV Concepción, escala 1:250.000 (provincias de Tucumán, Catamarca y Santiago del Estero). Servicio Geológico Minero Argentino, 342, 41 p.
[6]
Summerfield, M.A. (1991) Global Geomorphology: An Introduction to the Study of Landforms. Pearson, Prentice Hall, England, 537 pp.
[7]
French, B.M. (1998) Traces of Catastrophe: A Handbook of Shock-Metamorphic Effects in Terrestrial Meteorite Impact Structures. Lunar and Planetary Institute, Houston, 120 pp.
[8]
Gutiérrez, A.A. (1999) Tectonic Geomorphology of the Ambato Block (Northwestern Pampeanas Mountain Ranges, Argentina). Fourth International Symposium on Andean Geodynamics, 1, 307-310.
[9]
Tsikalas, F. (2005) Mjolnir Crater as a Result of Oblique Impact: Asymmetry Evidence Constrains Impact Direction and Angle. In: Koeberl, C. and Henkel, H., Eds., Impact Tectonics, Springer, Berlin, 285-306. https://doi.org/10.1007/3-540-27548-7_10
[10]
Cunningham, W.D. (2007) Structural and Topographic Characteristics of Restraining Bend Mountain Ranges of the Altai, Gobi Altai and Easternmost Tien Shan. In: Cunningham, W.D. and Mann, P., Eds., Tectonics of Strike-Slip Restraining and Releasing Bends, Geological Society Special Publication, London, 219-238. https://doi.org/10.1144/SP290.7
[11]
Gutiérrez, A.A. and Mon, R. (2008) Macroindicadores cinemáticos en el Bloque Ambato, provincias de Tucumán y Catamarca. Revista de la Asociación Geológica Argentina, 63, 24-28.
[12]
Zampieri, D., Gutiérrez, A.A., Massironi, M. and Mon, R. (2012) Reconciling Opposite Strike-Slip Kinematics in the Transpressional Belt of the Sierra Pampeanas (Argentina). European Geosciences Union General Assembly, Viena, 2 p.
[13]
Chapman, C.R. and Morrison, D. (1989) Cosmic Catastrophes. Plenum Press, New York, 302 p. https://doi.org/10.1007/978-1-4899-6553-0
[14]
Kring, D.A. (1997) Air Blast Produced by the Meteor Crater Impact Event and a Reconstruction of the Affected Environment. Meteoritics & Planetary Science, 32, 517-530. https://doi.org/10.1111/j.1945-5100.1997.tb01297.x
[15]
Dietz, R.S. and French, B.M. (1973) Probable Astroblemes in Brazil. Nature, 244, 561f. https://doi.org/10.1038/244561a0
[16]
Engelhardt, W.V., Matthai, S.K. and Walzebuck, J. (1992) Araguainha Impact Crater, Brazil. I. The Interior Part of the Uplift. Meteoritics, 27, 442-457.
[17]
Rocca, M.C.L. (2003) El Cráter en la Meseta de la Barda Negra, Neuquén: Un potencial nuevo impacto de meteorito en Patagonia, Argentina. Cambridge Conference Network, Vol. 116, 7 p.
[18]
Acevedo, R.D., Valín-Alberdi, M.L. and Villar, L.M. (2002) Hallazgo del mineral fosfuro de Níquel en una octahedrita IAB de Rubín de Celis (Campo del Cielo, Argentina). 1 Congreso Ibérico de Meteoritos y Geología Planetaria, Resúmenes, Museo de las Ciencias de Castilla-La Mancha, Cuenca.
[19]
Acevedo, R.D. and Roca, M.C.L. (2008) Catálogo de los meteoritos hallados en territorio argentino. Actas del 17 Congreso Geológico Argentino, Vol. 3, 1317-1318, San Salvador de Jujuy.
[20]
Cassidy, W.A. and Wright, S.P. (2003) Small Impact Craters in Argentine Loess: A Step up from Modeling Experiments.Workshop on Impact Cratering, 8004 p.
[21]
Bocanera, R. (2006) Algunas observaciones sobre meteoritos y meteoros. Petrotecnia, 80-88.
[22]
Bland, P.A., De Souza, F.C.R., Hough, R.M., Pierazzo, E., Coniglio, J., Pinotti, L., Jull, A.J.T. and Evers, V. (2001) The Río Cuarto Crater Field Revisited: Remote Sensing Imagery Analysis and New Field Observations. 64th Annual Meteoritical Society Meeting, 5319 p.
[23]
Ameghino, F. (1914) Aerolito fósil. Obras completas y Correspondencia Científica: Tomo, 2, 276-279.
[24]
Herrero Ducloux, E. (1914) Nota sobre el meteorito carbonoso de Nogoyá. AnalesMuseo Nacional de Historia Natural, Buenos Aires, 26, Mineralogía, Petrografía, 3, 99-116.
[25]
Herrero Ducloux, E. (1925) Nota sobre el meteorito de La Colina. Anales MuseoNacional de Historia Natural, Buenos Aires, 33, 287-295.
[26]
Herrero Ducloux, E. (1926) Nota sobre el meteorito de Santa Isabel. Revista Facultad de Ciencias Químicas La Plata, 4, 23-29.
[27]
Herrero Ducloux, E. (1940) Nota sobre el meteorito de Gualeguaychú. Anales Museo Argentino de Ciencias Naturales. Buenos Aires. 40, Mineralogía. Petrografía, 14, 123-127.
[28]
Pastore, F. (1925) Aerolito de La Colina. Anales Museo Nacional de Historia Natural. Buenos Aires 33, Mineralog., Petrogr. Vol. 6, 297-306.
[29]
Herrero Ducloux, E. and Pastore, F. (1929) El meteorito de Renca. Revista Facultad Química Farmacia La Plata, 5, 111-120.
[30]
Herrero Ducloux, E. and Pastore, F. (1930) El Meteorito de Ishtilart. Anales Museo Argentino de Ciencias Naturales. Buenos Aires 36, Mineralogía. Petrografía, 9, 313-330.
[31]
Olsacher, J. (1951) Condrita de Achiras. Boletín Academia Nacional de Ciencias de Córdoba, 39, 261-267.
[32]
Olsacher, J. (1951) Condrita de Quebrada de la Aguada. Boletín Academia Nacional de Ciencias de Córdoba, 39, 268-273.
[33]
The Permanent Commission on Meteorites of the International Geological Congress (1961) Meteorites Not Included in the Prior-Hey Catalogue of Meteorites, 1953. The Meteoritical Bulletin, 21, 1-3.
[34]
The Permanent Commission on Meteorites of the International Geological Congress (1962) Meteorites Not Included in the Prior-Hey Catalogue of Meteorites, 1953. The Meteoritical Bulletin, 24, 1-6.
[35]
The Permanent Commission on Meteorites of the International Geological Congress (1962) Meteorites Not Included in the Prior-Hey Catalogue of Meteorites, 1953. The Meteoritical Bulletin, 25, 1-3.
[36]
The Permanent Commission on Meteorites of the International Geological Congress (1964) Discovery of Arbol Solo Stony Meteorite, Argentina. The Meteoritical Bulletin, 32, 1-6.
[37]
Teruggi, M.E. (1968) El Meteorito condriticoChajari. Revista del Museo de La Plata, 6, 21 p.
[38]
Giacomelli, L.O. (1969) Guía de Meteoritos de la Argentina. Revista Museo Argentino de Ciencias Naturales, Geología, 7, 1.
[39]
Graham, A.L. (1986) Fall of the La Criolla, Stony, Argentina. The Meteoritical Bulletin, 64, 310.
[40]
Wlotzka, F. (1994) The Meteoritical Bulletin, No. 77. Meteoritics, 29, 891-897. https://doi.org/10.1111/j.1945-5100.1994.tb01104.x
[41]
Grossman, J.N. (1998) The Meteoritical Bulletin, No. 82. Meteoritics and Planetary Science, 33, A221-A239. https://doi.org/10.1111/j.1945-5100.1998.tb01336.x
[42]
Grossman, J.N. (1999) The Meteoritical Bulletin, No. 83. Meteoritics and Planetary Science, 34, A169-A186. https://doi.org/10.1111/j.1945-5100.1999.tb01762.x
[43]
Weisberg, M.K., Smith, C., Benedix, G., Herd, C.D.K., Righter, K., Haack, H., Yamaguchi, A., ChennaouiAoudjehane, H. and Grossman, J.F. (2010) The Meteoritical Bulletin, No. 97. Meteoritics and Planetary Science, 45, 449-493. https://doi.org/10.1111/j.1945-5100.2010.01036.x
[44]
Sasso, A. and Clark, A. (1999) El Grupo Farallón Negro: Evolución magmática, hidrotermal y tectónica e implicancias para la metalogenia de cobre-oro en el retroarco andino, Catamarca. In: Zappettini, E.O., Ed., Recursos Minerales de la República Argentina, Instituto de Geología y Recursos Minerales SEGEMAR, Anales, Vol. 35, 1437-1450, Buenos Aires.
[45]
Bossi, G.E. and Wampler, M. (1969) Edad del Complejo Alto de las Salinas y Formación El Cadillal según el método K-Ar. Acta Geológica Lilloana, 10, 141-160.
[46]
Melosh, H.J. (1989) Impact Cratering. Oxford University Press, 245 p.
[47]
Elston, W.E. (1992) Does the Bushveld-Vredefort System (South Africa) Record the Largest Known Terrestrial Impact Catastrophe? International Conference on Large Meteorite Impacts and Planetary Evolution, Canadá, 23-24.
[48]
Crawford, D.A. and Schultz, P.H. (1992) Enhanced Magnetic Field Production during Oblique Hypervelocity Impacts. International Conference on Large Meteorite Impacts and Planetary Evolution, Canadá, 18-20.
