Meteorite impact craters as hotspots for mineral resources and energy fuels: A global review

The ever-increasing recovery rate of natural resources from terrestrial impact craters over the last few decades across the globe offers new avenues for further exploration of mineral and hydrocarbon resources in such settings. As of today, 60 of the 208 terrestrial craters have been identified to host diverse resources such as hydrocarbons, metals and construction materials. The potential of craters as plausible resource contributors to the energy sector is therefore, worthy of consideration, as 42 (70%) of the 60 craters host energy resources such as oil, gas, coal, uranium, mercury, critical and major minerals as well as hydropower resources. Among others, 19 craters are of well-developed hydrocarbon reserves. Mineral deposits associated with craters are also classified similar to other mineral resources such as progenetic, syngenetic and epigenetic sources. Of these, the progenetic and syngenetic mineralization are confined to the early and late excavation stage of impact crater evolution, respectively, whereas epigenetic deposits are formed during and after the modification stage of crater formation. Thus, progenetic and syngenetic mineral deposits (like Fe, Ni, Pb, Zn and Cu) associated with craters are formed as a direct result of the impact event, whereas epigenetic deposits (e.g. hydrocarbon) are hosted by the impact structure and result from post-impact processes. In the progenetic and syngenetic deposits, the shock-wave induced fracturing and melting aid the formation of deposits, whereas in the epigenetic deposits, the highly fractured lithostratigraphic units of higher porosity and permeability, like the central elevated area (CEA) or the rim, act as traps. In this review, we provide a holistic view of the mineral and energy resources associated with impact craters, and use some of the remote sensing techniques to identify the mineral deposits as supplemented by a schematic model of the types of deposits formed during cratering process

Meteorite impact crater positions based on paleo-positions and its unrestrained latitudinal distribution

The paleo-positions of terrestrial meteorite impact craters along with distance and displacement registered since formation due to plate tectonics were deciphered using GPlates, an interactive GIS-based plate tectonic reconstruction and modeling software. The results of the study are intriguing as several craters have traversed across the globe, both from the Eastern to Western hemisphere and from the Southern to Northern hemisphere, and vice versa. The oldest crater studied was Foelsche, which traversed from the Southern to Northern hemisphere and from the Western to Eastern hemisphere while covering a distance of 39080 km in the past 981 million years and recording a relatively shorter displacement of 10470 km. On the other hand, Jänisjärvi and Suvasvesi South have traveled longer distances (27781 and 29050 km, respectively) and are among the most displaced craters (17400 and 16988 km, respectively). Similarly, the paleo-position, distance, and displacement for all craters, with ages \u3c1100 \u3eMa, were computed in the study. Based on the derived paleo-position, we have accessed the possibility of any selective distribution of craters across different latitudinal segments. As Earth is a planet that recorded dynamic variations in the terrestrial surface area across different geological ages, calculating the same was an arduous task. The land area within each of the three latitudinal segments, viz. 0–30°, 30–60°, and 60–90°, in which a crater formed was calculated for the geological time corresponding to an impact cratering event. This calculated land area within the respective latitudinal zone at each instance of a crater\u27s formation was then compared with the total land area on Earth. The results showed that 0–30° and 30–60° segments have equal crater frequencies whereas the 60–90° segment has a lesser frequency. The latitudinal crater distribution on Earth was then compared with Moon and Mars. The results revealed that there is a non-selective distribution of terrestrial impact craters across different latitudinal segments, indicating a non-perceivable latitudinal dependency for impact events

Deriving a denudation index for terrestrial meteorite impact craters using drainages as proxies

Meteorite impact craters are morphologic features that can develop characteristic radial, centripetal, and concentric drainage patterns. With age, fluvial activity denudes this morphologic feature, thereby erasing the evidence of a prominent geologic event. Apart from morphology and age, the target lithology and climate also influence crater denudation. In this study, we derive an index, called the Denudation Index (DI), which is a measure of rim degradation caused by fluvial activity. DI was derived by summing the average of first order drainages that retains radial and centripetal patterns to the total number of streams. DI was obtained through the extraction of drainages from digital elevation models (DEM) for 71 craters formed since the Phanerozoic eon. The DI was correlated with the morphology, age, lithology and paleoclimate. Paleoclimatic data corresponding to each crater was generated by reconstructing the crater paleo-positions through GPlates and superimposing the same to the Scotese\u27s Global Climate Model with an interval of 1 Ma. The study revealed that denudation is more prominent in a complex crater\u27s formation on a crystalline target rock than in simple crater on a sedimentary target. Craters in the equatorial rainy climate are more denudating than other climates. Thus, this study provides a new, rather novel, method of expressing the denudation of a crater. Furthermore, this study shows that the drainage network is a unique signature that can be used for depicting the denudation of morphologic features, especially a prominent one like the meteorite impact crater

Terrestrial impact craters track the voyage of lithospheric plates

The paradigm of plate tectonics has aided in the identification of the journey of continents on the globe, their assembly into supercontinents, disruption, and re-assembly. Here, we use meteorite impact craters as proxies for tracking the voyage of lithospheric plates. Employing the provisions in GPlates, an interactive geographic information system-based plate tectonic reconstruction model, we were able to identify the palaeo-position, and velocity of the 174 terrestrial impact craters, formed after 1,100 Ma, across the globe. These parameters of craters were evaluated for independent tectonic plates and were correlated with global tectonic events. For example, the similarity in the velocity of Beaverhead (900 Ma) and Holleford (550 Ma) craters since 550 Ma is traced to the connection between the Eastern Basin and North America Craton commencing 1,100 Ma, and through the South Basin and Range. Likewise, the drastic reduction in the velocity of Spider Crater (700 Ma) in Australia after 600 Ma can be attributed to the subduction between east and west Gondwana. The accelerated motion of the Indian Plate at 63 Ma, when the lithosphere was hovering over the Réunion hotspot, is also explained. With the advent of more improved plate tectonic models and the discovery of more impact craters, improvised interpretations will be possible

A compendium of the best-preserved terrestrial hypervelocity impact crater in a basaltic terrain: The Lonar, India

As impact cratering is regarded as the most fundamental process in the modification of planetary surfaces, it is crucial to investigate and identify terrestrial impact craters with credible evidences to learn more about the planet\u27s evolutionary path. Consequently, terrestrial impact craters are considered as proxies for planetary explorations. However, because of the diversity of the lithologies the terrestrial craters are carved in, those in basaltic rocks, which make up the majority of planets, are thought to be the best candidates. Lonar Impact Crater in India is a well-preserved, simple bowl-shaped impact crater that is etched in tholeiitic basalt of the ~65 Ma Deccan Volcanic Province (DVP). The crater has a diameter of 1.88 km and a depth of ~150 m. Being a basaltic target and situated in warm temperate climatic zone, apart from the modern-day anthropogenic influence, the crater is subjected to denudation. One such study has quantified a cumulative rim erosion of 30 m and an erosion rate at 96–203 mm per kyr, indicating fast denudation of the crater. Several methods were employed to date the impact event and based on the recent in-situ cosmogenic radionuclide dating, the age is determined as 37.5 ± 5.0 ka. The tholeiitic flood basalt target rock at Lonar exhibits high total iron (26.25 wt%) and CaO content (9.97 wt%) with lower contents of Al2O3 (13.21 wt%) and MgO (5.96 wt%). Based on the Ni (~60 to 2500 ppm), Cr (27 to 618 ppm), and Co (38 to 196 ppm) geochemistry of sub-mm sized Lonar spherules, the most likely projectiles associated with the cratering event are the chondritic impactors. The Mesoarchean age (~3.0 to 3.1 Ga), yielded by a few zircon grains separated from an impact melt-bearing breccia together with the exotic quartz grains with impact features like planar deformation feature, which is unfamiliar in a basalt-dominated impactite, proved the incorporation of the deep-seated Archean Peninsular gneiss in the impact event. This demonstrates a depth penetration of 522–570 m for the impact. However, compared to the extent of ejecta seen in comparable younger craters on the Moon and Mars, where ejecta can travel up to distances of ~10R and ~ 15R, respectively, the expanse of spallation from the terrestrial Lonar crater is only visible in a smaller area (~3R). In the entirety, Lonar crater has been explored by many researchers, which have uncovered many aspects of the impact including ejecta particles, structural, magnetic, hydrological, and geophysical characterization. In order to better understand the cratering mechanism and characteristics of Lonar impact crater, this review paper aims to garner information from all the relevant literature and this compendium will act as a comprehensive synthesis that will reshape our understanding of not only Lonar impact crater but also the broader realms of impact cratering science

Lonar Impact Crater, India: the Best-Preserved Terrestrial Hypervelocity Impact Crater in a Basaltic Terrain as a Potential Global Geopark

Lonar Impact Crater is a simple meteorite impact crater carved out on the ~ 65 Ma old Deccan tholeiitic flood basalts. The crater, though scoured in a basaltic terrain, is still preserved in its most pristine form, with a central crater lake. The geomorphology, geochemistry, geochronology, hydrology, geophysical parameters, and structural aspects of Lonar Crater have been explored in detail, but still continue to contribute valid scientific insights into the geology of terrestrial impact craters. Lonar serves as a potential analog site for studying impact cratering on planetary surfaces with basaltic terrains such as the Moon and Mars. Besides being a highly recognizable impact crater in India, the Lonar crater and its hinterland stand out with its archeological relevance and spiritual influence among the people. The numerous temples in and around the crater premises uphold the cultural significance of the region. The crater and adjacent areas are rich in flora and fauna representing a diverse ecosystem in the vastness of the arid Deccan Flood Basalts. Hence, the astrobleme and its surrounding is declared a Ramsar site and is also a protected wildlife sanctuary. The Indian Government has also declared the crater a National Geological Monument as well as an archaeological monument. Furthermore, the astrobleme is a unique site with socio-cultural and economic significance. With these plethoras of importance, combined with the geological and socio-cultural aspects in its hinterland, together with the most acclaimed UNESCO world heritage centers Ajantha and Ellora caves in the neighborhood, it stands as the right candidate for a UNESCO Global Geopark. However, the crater and its ecosystem are not preserved well enough, and the uniqueness of the crater is diminishing. But after selection as a Ramsar site, the area shows increased vegetation growth. The SWOT analysis conducted in this study accounts for Lonar Crater and its adjoining areas as a potential global geopark. Thus, through this study, we try to propagate the vivid and myriad importance of the Lonar crater and the necessity of protecting this geological monument from both anthropogenic and natural processes and to appraise the necessity for nominating this area as a UNESCO Global Geopark

Geochemical and geochronological evidence of meteorite impact excavating the Archean basement at Lonar Crater, Central India

The effect of meteorite impact on basement rocks remains widely debated at Lonar Crater, Central India. We investigate an impact melt-bearing rock from the ejecta layer of Lonar to assess the potential interaction of the projectile with the underlying Archean basement. The investigated sample is a melanocratic, aphanitic melt rock comprising glassy inclusions, and plagioclase and quartz clasts. Plagioclase and quartz show shock-induced features including diaplectic glass and well-developed planar deformation features (PDFs), respectively. The decrease in shock pressure is thus established with the plagioclase of overlying basalt showing shock features like diaplectic glass whereas the quartz from lower Archean basement showing PDF development. Laser Raman spectroscopy reveals the presence of cristobalite. The impact melt-bearing rock shows major element geochemistry similar to that of Deccan basalt with a tholeiitic trend, but the Harker variation plots reveal an independent field for the melt rock between the two end members: Deccan basalt and Archean basement represented by Peninsular gneiss. The REE geochemistry also reveals more fractionation for the melt rock. Zircon U-Pb data indicate an upper intercept age around 3.0 to 3.1 Ga. Chondrite normalized zircon REE data display a positive Eu anomaly indicating a reheating during the impact event. This indicates that the melt rock sample was generated by the incorporation of Archean basement gneiss components, which is compatible with the estimated depth of excavation for an impact structure of this size. This specifies a depth to basement in the range between 522 and 570 m