INVESTIGADORES
RABASSA jorge Oscar
congresos y reuniones científicas
Título:
Geophysical characterization of circular structures in Chubut and Mendoza (Argentina): Impact vs. Volcanism
Autor/es:
PREZZI, C.V.; ORGEIRA, M.J.; RISSO, CORINA; ACEVEDO, R.D.; PONCE, J. F.; NULLO, FRANCISCO; MARTÍNEZ, O.A.; RABASSA, J; MARGONARI; LILIANA; CORBELLA, H.
Lugar:
Cancún
Reunión:
Congreso; AGU Meeting of the Americas; 2013
Institución organizadora:
American Geophysical Union (AGU)
Resumen:
ABSTRACT BODY: This work focuses on two main objectives. One of them is to provide information to
discern the genesis of the circular structures present in Bajada del Diablo (Chubut, Argentina) considered as
impact craters, and the other one is to contribute to a better knowledge of the circular structures located in
the volcanic fields of Llancanelo and Payunia (Mendoza, Argentina). Chubut circular structures have been
attributed to the collision of an extraterrestrial body, possibly an asteroid. However, doubts persist about their
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attributed to the collision of an extraterrestrial body, possibly an asteroid. However, doubts persist about their
genesis because of the lack of direct geological evidences. Since detailed geomorphological studies have
ruled out an origin by wind deflation, the prevailing alternative hypothesis attributes these circular structures to
a volcanic process. On the other hand, the study of the volcanic fields of Payunia and Llancanelo (Mendoza)
will contribute to the knowledge of the mechanics of hydromagmatic processes in the area, and the origin of
circular structures morphologically similar to those located in Chubut. In the Payunia volcanic field at least 27
cones with evidences of hydromagmatism, in a field of more than 800 pure magmatic cones, have been
recognized. This study tries to determine if a relationship between the observed volcanic circular structures
and participation of water during the eruption exists. Magnetic and gravity field surveys of the circular volcanic
structures in Llancanelo and Payunia volcanic fields were performed in order to determine their relationship
with the type of eruption. Electromagnetic, magnetic and gravity field surveys were also carried out in Chubut
circular structures. The comparative analysis of geological and geophysical results obtained in the circular
structures of Chubut and those obtained in the circular structures in the volcanic areas of Llancanelo and
Payunia suggest an impact origin for the circular structures of Chubut.