Terrain characterization and structural control of the Auca Mahuida volcanism (Neuquén Basin, Argentina)

Geomorphometric parameters (slope, aspect, valley depth, and areal density of cones) derived from a moderate resolution digital elevation model with a grid spacing of 100 m are used in an attempt to interpret the tectonic/structural features related to surface deformation in the Auca Mahuida volcanic terrain (Neuquén Basin, Argentina). The Auca Mahuida (2.03–0.88 Ma) is the southernmost volcanic field of the Payenia volcanic province, in the Andean foreland. The foreland is subjected to an E–W compression related to the eastward migration of the N–S striking thrust front of the Andes. The geomorphometric analysis indicates that the Auca Mahuida consists of a basal, E–W elongated lava field with monogenic vents and a summit, polygenic, also E–W elongated, cone. A N100°E striking fault controls the southern flank of the field, which is also affected by scarps related to erosional and gravity-controlled processes. The drainage network shows a pseudo-radial pattern around the summit cone, and the Auca Mahuida's deepest valley is structurally controlled by a NNW–SSE striking fault affecting the sedimentary basement. The volcanic field lies on a NE to E dipping substratum. The areal distribution of the monogenic cones is consistent with ascent of magmas along E–W striking fractures, and with elastic models of a pressurized hole (magma chamber) subjected to an E–W compression. At Auca Mahuida, the ascent of melts from the mantle is controlled, in the overriding crust, by tectonic structures formed in response to the E–W compression of the Andes.

[1]  O. Galland,et al.  Rise and emplacement of magma during horizontal shortening of the brittle crust: Insights from experimental modeling , 2007 .

[2]  S. Kay,et al.  Upper Cretaceous to Holocene magmatism and evidence for transient Miocene shallowing of the Andean subduction zone under the northern Neuquén Basin , 2006 .

[3]  A. Takada.  The influence of regional stress and magmatic input on styles of monogenetic and polygenetic volcanism , 1994 .

[4]  V. Ramos,et al.  Payenia volcanic province in the Southern Andes: An appraisal of an exceptional Quaternary tectonic setting , 2011 .

[5]  E. Cristallini,et al.  Contemporary stress orientations in the Andean retroarc between 34°S and 39°S from borehole breakout analysis , 2007 .

[6]  S. Kay,et al.  Evolution of an Andean margin : a tectonic and magmatic view from the Andes to the Neuquén Basin (35° -39°S lat) , 2006 .

[7]  S. Kay,et al.  Evolution of an Andean Margin: A Tectonic and Magmatic View from the Andes to the Neuque´n Basin (35°-39°S lat) , 2006 .

[8]  G. Messager,et al.  Geomorphic evidence for Plio‐Quaternary compression in the Andean foothills of the southern Neuquén Basin, Argentina , 2010 .

[9]  A. Roth,et al.  The shuttle radar topography mission—a new class of digital elevation models acquired by spaceborne radar , 2003 .

[10]  A. Tankard,et al.  Petroleum Basins of South America , 2003 .

[11]  E. Llambías,et al.  El volcanismo cuaternario en el retroarco de Payenia: una revisión , 2010 .

[12]  S. Kay,et al.  Overview of the tectonic evolution of the southern Central Andes of Mendoza and Neuquén (35°–39°S latitude) , 2006 .

[13]  Giorgi Khazaradze,et al.  Short‐ and long‐term effects of GPS measured crustal deformation rates along the south central Andes , 2003 .

[14]  E. Cristallini,et al.  Contemporary stress orientations from borehole breakout analysis in the southernmost flat-slab boundary Andean retroarc , 2009 .

[15]  Carlos Carbone,et al.  Fracture evolution in oil-producing sills of the Rio Grande Valley, northern Neuquen Basin, Argentina , 2012 .

[16]  Kazuaki Nakamura,et al.  Volcanoes as possible indicators of tectonic stress orientation — principle and proposal , 1977 .

[17]  P. Cobbold,et al.  Aptian to recent compressional deformation, foothills of the Neuquén Basin, Argentina , 2003 .

[18]  V. Ramos,et al.  Intraplate deformation in the Neuquén Embayment , 2006 .

[19]  E. J. Llambías,et al.  Geochronology of the late Pliocene to recent volcanic activity in the Payenia back-arc volcanic province, Mendoza Argentina , 2012 .

[20]  David D. Pollard,et al.  The stress state near Spanish Peaks, colorado determined from a dike pattern , 1977 .

[21]  Tomislav Hengl,et al.  A Practical Guide to Geostatistical Mapping , 2009 .

[22]  J. Strobl,et al.  SAGA-analysis and modelling applications , 2006 .

[23]  Leonardo Rodríguez,et al.  Synrift geometry of the Neuquén Basin in northeastern Neuquén Province, Argentina , 2006 .

[24]  A. Fornaciai,et al.  Fissural volcanism, polygenetic volcanic fields, and crustal thickness in the Payen Volcanic Complex on the central Andes foreland (Mendoza, Argentina) , 2008 .

[25]  H. Welsink,et al.  Tectonic Evolution and Paleogeography of the Neuquén Basin, Argentina , 1995 .