Special Issue dedicated to Francisco Hervé: Global tectonic processes of the ancient southwestern Gondwana margin in South America and the Antarctic Peninsula
Edited by:
- Mauricio Calderón, PhD, Universidad del Desarrollo, Chile
- Paula Castillo, PhD, Universität Münster, Deutschland
- Robert Pankhurst, PhD ScD, United Kingdom
Submission status: Extended until September 30, 2025
Special Issue: Geoethics in Chile and Latin America - Contextual reflections for responsible geoscience
Edited by:
- Luisa Pinto, Universidad de Chile
- Hernán Bobadilla, Politecnico di Milano
- Tania Villaseñor, Pontificia Universidad Católica de Chile
- Pablo Ramírez, Universidad de Chile
- Millarca Valenzuela, Universidad Católica del Norte
Submission status: Open between August 15, 2025, and March 31, 2026
Instituto de Ciencias de la Tierra y Ambientales de La Pampa (CONICET-Universidad Nacional de La Pampa) Argentina
Doctor en Ciencias Geológicas
Ayudante de Primera Petrología (Licenciatura en Geología - Universidad Nacional de La Pampa)
Jefe de trabajos Prácticos Escuela de Campo (Licenciatura en Geología - UNLPam
Gustavo Walter Bertotto
Instituto de Ciencias de la Tierra y Ambientales de La Pampa (CONICET-Universidad Nacional de La Pampa) Argentina
Doctor en Ciencias Naturales
Profesor Adjunto Geoquímica (Licenciatura en Geología - UNLPam)
Alexis Daniel Ponce
Instituto de Ciencias de la Tierra y Ambientales de La Pampa (CONICET-Universidad Nacional de La Pampa) Argentina
Doctor en Ciencias Naturales
Ayudante de Primera Geoquímica (Licenciatura en Geología - UNLPam)
Ayudante de Primera Geosistemas (UNLPam)
Yuji Orihashi
Earthquake Research Institute, University of Tokyo Japan
Ph.D.
Hirochika Sumino
Department of Basic Science, Graduate School of Arts and Sciences, University of Tokyo Japan
Volcanology and inflation structures of an extensive basaltic lava flow in the Payenia Volcanic Province, extra-Andean back arc of Argentina
Mauro Ignacio Bernardi, Gustavo Walter Bertotto, Alexis Daniel Ponce, Yuji Orihashi, Hirochika Sumino
Abstract
The El Puesto lava flow is located in the Payenia Volcanic Province (central-western Argentina), has a length of 70 km and is Middle Pleistocene in age (0.200±0.027 Ma). The flow shows a P-type pahoehoe structure and exhibits several inflation structures, mainly tumuli and also inflation ridges and lava rises. Lava rise pits and radial or annular clefts are common features associated with inflation structures. The gentle slope on which the flow moved (≈0.5°) allowed the lateral coalescence of lobes at the flow front and the development of an external rigid crust that insulated the liquid core. Lava tunnels are frequent and the lava tunnel named “Cueva de Halada” which is located at its medium portion is the best example of a drainage master tube which formed from the cooling of the crust around a stable inflated flow. Tumuli alignments and long inflation ridges reveal the existence of larger tunnels within the flow. Inflation structures may occur in high concentration belts that converge on a single main belt which is assigned to an anastomosed network of internal flow pathways within the main lava body. The development of inflation structures and lava tunnels require low to moderate effusion rates. An average lava supply rate of 1.8x10-4 m3/s and an inflation time of about 15 days were estimated for an average tumulus of this flow. A high and sustained supply of low viscosity lava (η’=1550 - 483 Pa s) was inferred that initially generated a sheet flow of great areal extension. The reduction in effusion rates could then allowed the development of tunnels that carried lava to the distal fronts, generating localized inflation phenomena throughout the lava flow.