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

Abstract

The last two decades of research have highlighted that volcanism occurring in sedimentary basins can havesubstantial effects on sedimentary formations. In particular, igneous intrusions can trigger the generation of largeamounts 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 Neuqu´en Basin,Argentina, is a well-studied example of a hydrocarbon-producing sedimentary basin hosting massive volcanism.The combination of substantial industry subsurface data and high-quality outcrops makes the Neuqu´en Basin anexceptional geological object to study magma-sedimentary rock interactions and their implications to hydrocarbonsystems. This contribution reviews well-studied examples from the Neuqu´en Basin that illustrate: (1)thermal effects of sills on maturation of the organic matter of the source rock, (2) fracturing processes in igneousintrusions and the host rock, (3) sills as producing fractured reservoirs, (4) intrusion-induced doming as structuraltrap or as potential fractured reservoir, (5) fluid migration along igneous intrusions, (6) reservoircompartmentalization 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 documents various effects of magma-rock interactions in hydrocarbon-bearing sedimentarybasins, and highlights the significant scientific value of the Neuqu´en Basin as a world-class case studyfor unravelling processes of magma-rock interactions in hydrocarbon-bearing sedimentary basins.