The impacts of volcanism on hydrocarbon-bearing sedimentary basins - Examples from the world-class Neuquén Basin case study, Argentina

Olivier Galland , Sabina Chiacchiera, Hernán de la Cal, Dougal Jerram, Ezequiel Lombardo, Joaquin Octavio Palma, Gisel Peri, Ole Rabbel, Juan B. Spacapan, Maria Dolores Vallejo, Daniel Yagupski, Alain Zanella

The last two decades of research have highlighted that volcanism occurring in sedimentary basins can have substantial effects on sedimentary formations. In particular, igneous intrusions can trigger the generation of large amounts of greenhouse gases in organic-rich host rocks, leading to dramatic climate change and mass extinctions. Volcanism can also have significant impacts on hydrocarbon-bearing sedimentary basins. The Neuquén Basin, Argentina, is an outstanding example of hydrocarbon-producing sedimentary basin hosting massive volcanism. The combination of substantial industry subsurface data and outstanding outcrops makes the Neuquén Basin a world-class geological object to study magma-sedimentary rock interactions and their implications to hydrocarbon systems. This contribution reviews well-studied examples from the Neuquén Basin that illustrate: (1) thermal effects of sills on maturation of the organic matter of the source rock, (2) fracturing processes in igneous intrusions and the host rock, (3) sills as producing fractured reservoirs, (4) intrusion-induced doming as structural trap or as potential fractured reservoir, (5) fluid migration along igneous intrusions, (6) reservoir compartmentalization induced by dykes, (7) generation of bitumen dykes in vicinity of intrusions, and (8) improvement of geophysical imaging using large-scale outcrops.
All in all, our review (1) documents various effects of magma-rock interactions in hydrocarbon-bearing sedimentary basins, and (2) highlights the great scientific value of the Neuquén Basin as a world-class case study for unravelling processes of magma-rock interactions in hydrocarbon-bearing sedimentary basins.