Economic Mineral Deposits in Impact Structures: A Review

Rimaal: A Sand Buried Structure of Possible Impact Origin in the Sahara: Optical and Radar Remote Sensing Investigation

“…Typically, fracturing and brecciation resulting from meteorite impacts can cause significant porosity and permeability of the target rocks [3,33], therefore, most the likely produce a good quality oil reservoir. Here, the shock deformation and the generation of central uplift caused by the impact would make a substantially productive reservoir if filled with hydrocarbons [34].…”

Impact cratering — fundamental process in geoscience and planetary science

“…Considering the fact that the surfaces of other planetary bodies (e.g., the Moon or Mars) largely consist of a thick layer of impact debris (the so-called regolith), and asteroids also have suffered multiple impact events and impactite formation, demonstrates that extraterrestrial impactites must be regarded as possible construction materials, and even oxygen sources, for interstellar development and settlement. Closer to home though, numerous terrestrial impact structures have become recognized as important ore deposits (e.g., Grieve 2005;Reimold et al 2005). Essentially three types of impact-related ore and hydrocarbon deposits have been distinguished:…”

“…Examples for this type are the Carswell uranium and Ternovka (Krivoi Rog) iron-ore deposits, respectively . The detrital gold and uranium deposits of the South African Witwatersrand basin, which represents the outer part of the Vredefort impact structure (Gibson and Reimold 2001;Reimold et al 2005) -also fall into this category (but compare section (3) with regard to the Witwatersrand). (2) Ore formations that formed as a direct effect of impact would be considered 'syngenetic deposits', for which the Sudbury nickel and PGE resources are a type example.…”

“…For example, it is believed that the Pb-Zn mineralization in the Siljan impact structure is the result of this process. Economically of much greater significance, however, is the authigenic gold mineralization in the Witwatersrand basin, which is believed to be the result of fluid flow away from the central parts of the Vredefort impact structure, with these hot fluids having dissolved allogenic gold in the Witwatersrand sediments, which was followed by redeposition -and local enrichment -of the resource (Hayward et al 2005;Reimold et al 2005). Extensive hydrocarbon (natural oil and gas) resources have been found and exploited in impact structures, mostly in North and Central America.…”

“…In contrast, the notion that pseudotachylite was of impact-diagnostic value, as promoted repeatedly in the recent literature, must be discouraged, as obviously such friction melt is known from numerous tectonic settings. Also, pseudotachylitelike breccias, in the form of veins or complex occurrences, in impact structures comprise a range of melt and clastic breccia types (Müller-Mohr 1992;Reimold 1995Reimold , 1998Reimold et al 2005), and Reimold in these publications encouraged to use the term 'pseudotachylitic breccia' for such materials (figure 8) -in impact structures -in order to emphasize the genetic difference to tectonic friction melt (Reimold and Gibson 2005b;. It is obvious though that friction melting could easily be a process active during the various stages of impact cratering (as also shown in shock recovery experiments by Kenkmann et al (2000) and Langenhorst et al (2002), but further work on these impact breccias is still required to differentiate between injection of impact melt, friction melt, friction-plus-shock produced melt, and locally produced shock compression melt or melt generated after decompression from peak shock pressure.…”