Volcanism vs. hydrocarbon source rocks – Fieldwork in the Rio Grande Valley, Argentina
The thermo-mechanical effects of interactions between magmatic intrusions and organic-rich hydrocarbon source rocks are one of the research topics of the “Physics of Geological Processes” research group at the NJORD Center, which is part of the University of Oslo. These effects are important, because the heat provided by the magma rapidly matures the hydrocarbons, which can either be released to the atmosphere and potentially trigger global climate change, or remain in the subsurface as potential oil and gas reservoirs. If we want to understand how rapidly generated hydrocarbon fluids and gases fracture the rock and migrate through the Earth’s crust, we need to understand the Physics behind these interactions, and document their expression in the field.
In my Ph.D. project a key aspect is to integrate numerical simulations of these processes with observations from fieldwork – and for this reason, I travelled to the Rio Grande Valley in the northernmost part of the Neuquen Basin, Argentina. Thanks to the combination of faulting and dry climate in the Eastern foothills of the Andes, one can find fantastic outcrops of intrusions in this part of the world. Here, we can constrain the geometries of intrusions emplaced in the (geo-) world-famous Vaca Muerta shale over many kilometers, but also to conduct very detailed rock sampling. Such field data are extremely valuable, because they make it possible to constrain our physical models, and document the strong effects that magmatic intrusions can have on source rocks. In cooperation with Octavio Palma from CONICET/Y-Tec, we collected over 150 kg of samples, as well as drone-based photogrammetric models, which will form the foundation of our research project.
In addition to the scientific success of this research travel, we were lucky enough to get the opportunity to visit the Payunia volcanic province. Payunia was not only the perfect place to see all forms of volcanoes within a single day, but also simply one of the most beautiful landscapes I have ever seen. I would like to thank the DEEP Research School for funding this fieldwork, and everyone involved for both their kindness and hard work.
- Ole Rabbel (University of Oslo)