Changes

The evolution and development of the Nequén Basin c an be considered in three stages.  

The evolution and development of the Nequén Basin c an be considered in three stages.  

* Stage 1. Late Triassic-Early Jurassic: prior to the onset of subduction on its western margin, this part of Gondwana was characterized by large transcurrent fault systems. This led to extensional tectonics whitin the basin and the evolution of a series of narrow, isolated depocentres (Fig. 2).<ref>Manceda, R., & D. Figueroa, 1995, [http://archives.datapages.com/data/specpubs/memoir62/18manced/0369.htm Inversion of the Mesozoic Neuquén rift in the Malargue fold and thrust belt, Mendoza, Argentina], in: A. J. Tankard, S. R. Suarez, & H. J. Welsink (eds), Petroleum Basins of South America, [http://store.aapg.org/detail.aspx?id=476 AAPG Memoir 62], pp. 369-382.</ref>;<ref name=Vergani> Vergani, G. D., A. J. Tankard, H. J. Belotti, & H. J. Welsink, 1995, [http://archives.datapages.com/data/specpubs/memoir62/19vergan/0383.htm Tectonic evolution and paleogeography of the Neuquén Basin, Argentina], in: A. J. Tankard, R. Suárez Soruco & H. J. Welsink (eds), Petroleum Basins of South America, [http://store.aapg.org/detail.aspx?id=476 AAPG Memoir 62], pp. 383-402. </ref><ref>Franzese, J. R., & L. A. Spalletti, 2001, Late Triassic –early Jurassic continental extension in southwestern Gondwana: tectonic segmentation and pre-break up rifting: Journal of South American Earth Sciences, vol. 4, pp. 257-270.</ref>  

* Stage 1. Late Triassic-Early Jurassic: prior to the onset of subduction on its western margin, this part of Gondwana was characterized by large transcurrent fault systems. This led to extensional tectonics whitin the basin and the evolution of a series of narrow, isolated depocentres (Fig. 2).<ref>Manceda, R., & D. Figueroa, 1995, [http://archives.datapages.com/data/specpubs/memoir62/18manced/0369.htm Inversion of the Mesozoic Neuquén rift in the Malargue fold and thrust belt, Mendoza, Argentina], in: A. J. Tankard, S. R. Suarez, & H. J. Welsink (eds), Petroleum Basins of South America, [http://store.aapg.org/detail.aspx?id=476 AAPG Memoir 62], pp. 369-382.</ref><ref name=Vergani> Vergani, G. D., A. J. Tankard, H. J. Belotti, & H. J. Welsink, 1995, [http://archives.datapages.com/data/specpubs/memoir62/19vergan/0383.htm Tectonic evolution and paleogeography of the Neuquén Basin, Argentina], in: A. J. Tankard, R. Suárez Soruco & H. J. Welsink (eds), Petroleum Basins of South America, [http://store.aapg.org/detail.aspx?id=476 AAPG Memoir 62], pp. 383-402. </ref><ref>Franzese, J. R., & L. A. Spalletti, 2001, Late Triassic –early Jurassic continental extension in southwestern Gondwana: tectonic segmentation and pre-break up rifting: Journal of South American Earth Sciences, vol. 4, pp. 257-270.</ref>  

* Stage 2. Early Jurassic-Early Cretaceous: development of a steeply dipping, active subduction zone and the associated evolution of a magmatic arc along the western margin of Gondwana led to back-arc subsidence within the Neuquén Basin. This post-rift  stage of basin development locally accounts for more tan 4000 meters of the basin fill (Fig. 2) (Vergani et al. 1995).  

* Stage 2. Early Jurassic-Early Cretaceous: development of a steeply dipping, active subduction zone and the associated evolution of a magmatic arc along the western margin of Gondwana led to back-arc subsidence within the Neuquén Basin. This post-rift  stage of basin development locally accounts for more tan 4000 meters of the basin fill (Fig. 2) (Vergani et al. 1995).  

* Stage 3. Late Cretaceous-Cenozoic: transition to a shallowly dipping subduction zone resulting in compression and flexural subsidence, asocciated with 45-57 km of cristal shortening<ref>Introcaso, A., M. C. Pacino, & H. Fraga, 1992. Gravity, isostasy and Andean crustal shortening between latitudes 30° and 35°S: Tectonophysics, 205, pp. 31-48.</ref><ref>Ramos, V.A., 1999, Evolución Tectónica de la Argentina, in: R. Caminos (ed.) Geología Argentina. Instituto de Geología y Recursos Minerales, Anales, 29, 715-759. </ref> and uplift of the foreland thrust belt (Fig. 2).<ref name=Veiga_et_al />  

* Stage 3. Late Cretaceous-Cenozoic: transition to a shallowly dipping subduction zone resulting in compression and flexural subsidence, asocciated with 45-57 km of cristal shortening<ref>Introcaso, A., M. C. Pacino, & H. Fraga, 1992. Gravity, isostasy and Andean crustal shortening between latitudes 30° and 35°S: Tectonophysics, 205, pp. 31-48.</ref><ref>Ramos, V.A., 1999, Evolución Tectónica de la Argentina, in: R. Caminos (ed.) Geología Argentina. Instituto de Geología y Recursos Minerales, Anales, 29, 715-759. </ref> and uplift of the foreland thrust belt (Fig. 2).<ref name=Veiga_et_al />  

The Neuquén Basin is characterized by a prograde depositional system, leading to formations of various origins: Loma Montosa Formation, coastal facies; Quintuco Formation, carbonate platform facies; Vaca Muerta Formation, slope facies and high TOC.<ref name=Galeazzi>Galeazzi, S., F. Pose, & A. Gangui, 2014, Estratigrafía Secuencial del intervalo Quintuco- Vaca Muerta en el Engolfamiento Neuquino, Cuenca Neuquina, Argentina: IX Congreso de Exploracion y Desarrollo de Hidrocarburos, Rompiendo Paraigmas, IAPG.</ref>  

The Neuquén Basin is characterized by a prograde depositional system, leading to formations of various origins: Loma Montosa Formation, coastal facies; Quintuco Formation, carbonate platform facies; Vaca Muerta Formation, slope facies and high TOC.<ref name=Galeazzi>Galeazzi, S., F. Pose, & A. Gangui, 2014, Estratigrafía Secuencial del intervalo Quintuco- Vaca Muerta en el Engolfamiento Neuquino, Cuenca Neuquina, Argentina: IX Congreso de Exploracion y Desarrollo de Hidrocarburos, Rompiendo Paraigmas, IAPG.</ref>  

The prograde sequence proceeds transitional way from the Quintuco Formation to the Vaca Muerta Formation. This latter Formation is known as “classic” shale gas/oil play and is constituted of marl and shale, with less than 3500 metres depths, overpressure conditions, thicknesses with high organic content and the adecuate thermal madurity to generate hydrocarbons.<ref name=Galeazzi />

The prograde sequence proceeds transitional way from the Quintuco Formation to the Vaca Muerta Formation. This latter Formation is known as “classic” shale gas/oil play and is constituted of marl and shale, with less than 3500 metres depths, overpressure conditions, thicknesses with high organic content and the adecuate thermal madurity to generate hydrocarbons.<ref name=Galeazzi />

== Stratigraphy of Vaca Muerta Formation in El Trapial area ==

== Stratigraphy of Vaca Muerta Formation in El Trapial area ==