Giambiagi L.,IANIGLA CCT MENDOZA |
Mescua J.,IANIGLA CCT MENDOZA |
Heredia N.,Instituto Geologico Y Minero Of Espana |
Farias P.,University of Oviedo |
And 7 more authors.
Journal of Iberian Geology | Year: 2014
The tectonic style of the eastern morphostructural units of the Central Andes between 32°20' and 33°20'S is strongly influenced by pre- Andean structures, especially those developed during the late Carboniferous-Early Permian San Rafael orogeny of the Gondwanan orogenic cycle. Moreover, in the study area pre-Carboniferous rocks were deformed in Late Devonian-early Carboniferous times by the Chanic orogeny. In this paper we argue that the Cordón del Plata and the Southern Precordillera ranges, first order features of the eastern ranges of the Andes, have been shaped in large part by the Permian event. Our data suggest that the double verging character of the Andean Precordillera fold- thrust belt is mainly the result of the reactivation of Gondwanan structures which conform a fold-thrust belt with distinct characteristics north and south of 33°S. The northern sector of this belt corresponds to a bivergent system, while the southern sector had a widespread east vergence. The vergence of the Chanic structures is more difficult to determine, but we infer a westward vergence in the Frontal Cordillera and western sector of Precordillera, and an eastern vergence in the eastern sector of the Precordillera. The sharp disappearance of the Precordillera morphostructural unit south of 33°S is inferred here to be related to the distribution of inherited Permian structures.
Branham Jr. R.L.,IANIGLA CCT Mendoza
Planetary and Space Science | Year: 2010
Comet C/1845 D1 (de Vico) is one of a large number of comets with parabolic orbits. Given that there are sufficient observations of the comet, 291 in right ascension and 269 in declination, it proves possible to calculate a better orbit. The calculations are based on a 12th order predictorcorrector method. The comet's orbit is hyperbolic and, from calculated mean errors, statistically different from a parabola. BulirschStoer integration, although more flexible and of comparable precision, proves considerably more laborious. © 2010 Elsevier Ltd.