Due to the energy transfer during an impact event, the earth surface is extensively modified at the location of the collision. As a consequence, impact structures have the potential to become economically significant sources for quarries, mines, hydroelectric reservoirs, and hydrocarbon reservoirs. While there are several examples of impact structures that have been exploited for building material and water reservoirs, most of the economic interest is regarding the formation of ore bodies (concentrations of metal and metal-bearing minerals) and hydrocarbons. These deposits can vary from small, local operations to some of the world largest deposits making impact craters economically significant. Most of the resource deposits at classified based on the timing and are described as progenetic, syngenetic, and epigenetic.
Progenetic deposits are economic deposits that originate prior to the impact event, but the impact event moved the deposits, in some cases bringing them to the surface or near-surface, making it possible to access the deposit. Processes such as structural displacement (movement of large amounts of mass within subsurface) and brecciation lead to concentration of deposit such as iron, uranium, gold, and hydrocarbons. An example of this kind of deposit is the uranium mining associated with the Carswell impact structure. As the world’s second-largest uranium producing region, the cumulative uranium production in this structure located in Canada is approximately 1.5 billion pounds of uranium oxide. The progenetic deposit at Carswell was brought to the surface by the central uplift of the impact structure and the subsequent erosion.
Syngenetic deposits are economic deposits that originate during the impact event, or immediately afterward, as a direct result of impact processes. The deposits occur as a product of shock metamorphism, melting, and post-impact hydrothermal activity resulting in economic deposits of copper, nickel, diamonds, zinc, lead uranium, platinum, gold, and uranium. Impact diamonds have been observed at the Popigai crater, the world’s largest known diamond deposit, as a product of the shock metamorphism caused graphite to transition to diamond and crystallize from coal. The ore deposits of Sudbury structure in Canada, one of world largest suppliers of nickel and copper ores, are closely associated with the impact melt sheet, dykes, and hydrothermal system caused by the impact event.
Epigenetic deposits are economic deposits that originate as a result of topographic change and structural features that allow for the entrapment of hydrocarbons. Accumulation of hydrocarbons occurs when oil and natural gas from shales migrates and is trapped within the impact structure. In North America, approximately 50% of the know impact structures in hydrocarbon-bearing sedimentary basins have commercial oil and/or gas fields. Examples include the Red Wing Creek structure, USA and Steen River structure, Canada. Although the Vredefort and Sudbury structures are world-class mining regions, hydrocarbon production, especially epigenetic deposits, is the most valuable resource deposits found at impact structures.