Abstract The record of igneous activity (magmatism and volcanism) can significantly affect natural resource exploration and exploitation, including the search for hydrocarbons, critical minerals, natural hydrogen and geothermal energy sources, as well as using mafic igneous rocks as storage sites for CO 2 . These effects will vary depending on the nature and timing of the activity, the structural framework and the crustal architecture of the affected country-rock. To understand these effects and the interplay with other factors, we must first know the igneous record's distribution, timing, and petrology. In this paper, we describe a new geospatial database of the igneous rock record designed to provide a baseline digital resource that is application-agnostic and can be applied across the broadest range of research and resource exploration activities. We discuss the challenges we have faced and solved at each of the three main stages of geospatial mapping: database design, database population and database visualization. This includes the importance of a comprehensive audit trail so that users can differentiate between well and poorly-constrained interpretations, helping identify areas requiring additional work and data acquisition. The result is a geospatial database that will facilitate a better understanding of the Earth system and natural resource exploration.

Abstract Intruding magma can create space by uplift and elastic bending of the overburden, which locally fractures the deforming volume and produces flat-topped or dome-like forced folds. Here, I map such fracture networks and quantify their geometry and connectivity across a range of natural and modelled intrusion-induced forced folds. I show that there is a positive relationship between forced fold length and amplitude, and all fracture networks comprise traces, with variable lengths and orientations, that are more intense and denser where fold curvature is greatest. Fracture length populations are typically best described by power-law distributions, but some fit better to log-normal or exponential distributions. Connectivity of fracture networks is low and generally increases with folding, but resurfacing by eruptive products can disrupt this trend. My work supports previous analyses of forced folds and fractures, suggesting that we can use the fracture characteristics of exposed forced folds to predict that of buried forced folds. Due to their geometry and fracture network, intrusion-induced forced folds make ideal fluid traps. As these forced folds are common in many volcanic settings and sedimentary basins, we should consider their potential as exploration targets for water, magmatic-related mineral and metal deposits, and particularly CO 2 storage.

Abstract Cooling subvolcanic igneous intrusions are known to have a tremendous impact on fluid flow in the shallow Earth's crust. However, the long-term post-cooling legacy of subvolcanic intrusions on fluid flow has received much less attention. Here we describe geological examples in the Andean foothills, Argentina, showing that igneous intrusions have long-term effects on fluid flow after their emplacement and cooling. The case study consists of ∼11 Myr-old eroded andesitic intrusions of Cerro Alquitrán and Cerro La Paloma, northern Neuquén Basin, Argentina, at the rims of which large volumes of bitumen are naturally seeping out at the Earth's surface. The intrusions exhibit laccolithic shapes with steep-sided contacts with the host rock. Near the intrusive contacts, the andesite is intensely broken along concentric breccia bands and fracture bands, interpreted as resulting from syn-emplacement brittle magma deformation, which represent high-permeability pathways for the migrating bitumen. Organic geochemical analyses of the bitumen show that the seeping oils were generated from incipiently mature Vaca Muerta sections located in a regional kitchen to the west, implying a lateral migration of ∼10–20 km. The Cerro Alquitrán and Cerro La Paloma intrusions are demonstrative examples highlighting how extinct subvolcanic intrusions have long-term consequences for subsurface fluid circulations in sedimentary basins.

Abstract This contribution presents a detailed geological study of a well-exposed igneous petroleum system at Sierra de Cara Cura, Neuquén Basin, Argentina, which consists of sills, dykes, laccoliths and hybrid intrusion morphologies. The size of the exposed intrusive complex (19 km in north–south direction) is similar to those of sill-clusters hosting producing oil fields of the nearby Río Grande Valley. Most sills (>80%) are preferentially emplaced in the organic-rich rocks such as Vaca Muerta and Agrio Formations. Sills are extensively fractured and represent potentially good fractured hydrocarbon reservoirs. We document several fracturing mechanisms that can lead to heterogeneous fracture distribution. Laccoliths represent very different igneous reservoirs with a typical zonation: the core of the laccoliths are massive and poorly fractured, whereas the rims consist of a breccia formed during laccolith emplacement. The Vaca Muerta and Agrio Formations are thermally altered by the cooling of the sills. The deep parts of the outcropping laccoliths likely altered thermally the shale formations they were emplaced in. Hydrogen Index (HI) and Transformation Ratio (TR) of the organic matter are the best parameters to determine the thickness of the thermal aureole. The Sierra de Cara Cura appears as a world-class field analogue of igneous petroleum systems.

Abstract Cripple Creek is among the largest epithermal districts in the world, with more than 800 metric tons (t) Au (>26.4 Moz). The ores are associated spatially, temporally, and genetically with ~34 to 28 Ma alkaline igneous rocks that were emplaced into an 18-km 2 diatreme complex and surrounding Proterozoic rocks. Gold occurs in high-grade veins, as bulk tonnage relatively low-grade ores, and in hydrothermal breccias. Pervasive alteration in the form of potassic metasomatism is extensive and is intimately associated with gold mineralization. Based on dating of intrusions and molybdenite and gangue minerals (primarily using 40 Ar/ 39 Ar and Re-Os techniques), the region experienced a protracted but intermittent history of magmatism (over a period of at least 5 m.y.) and hydrothermal activity (intermittent over the final ~3 m.y. of magmatic activity). Key factors that likely played a role in the size and grade of the deposit were (1) the generation of alkaline magmas during a transition between subduction and extension that tapped a chemically enriched mantle source; (2) a long history of structural preparation, beginning in the Proterozoic, which created deep-seated structures to allow the magmas and ore fluids to reach shallow levels in the crust, and which produced a fracture network that increased permeability; and (3) an efficient hydrothermal system, including effective gold transport mechanisms, and multiple over-printed hydrothermal events.