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 fewdecades 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 diverseresources such as hydrocarbons,metals and construction materials.The potential of craters as plausibleresource contributors to the energy sector is therefore,worthy of consideration,as 42(70%)of the 60craters host energy resources such as oil,gas,coal,uranium,mercury,critical and major minerals as wellas hydropower resources.Among others,19 craters are of well-developed hydrocarbon reserves.Mineraldeposits 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 confinedto 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 andsyngenetic mineral deposits(like Fe,Ni,Pb,Zn and Cu)associated with craters are formed as a directresult of the impact event,whereas epigenetic deposits(e.g.hydrocarbon)are hosted by the impactstructure and result from post-impact processes.In the progenetic and syngenetic deposits,the shockwave 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 centralelevated area(CEA)or the rim,act as traps.In this review,we provide a holistic view of the mineral andenergy resources associated with impact craters,and use some of the remote sensing techniques toidentify the mineral deposits as supplemented by a schematic model of the types of deposits formedduring cratering process.

Non-climate environmental factors matter to Holocene dynamics of soil organic carbon and nitrogen in an alpine permafrost wetland,Qinghai‒Tibet Plateau

Studies on the responses of soil organic carbon(SOC)and nitrogen dynamics to Holocene climate and environment in permafrost peatlands and/or wetlands might serve as analogues for future scenarios,and they can help predict the fate of the frozen SOC and nitrogen under a warming climate.To date,little is known about these issues on the Qinghai‒Tibet Plateau(QTP).Here,we investigated the accumulations of SOC and nitrogen in a permafrost wetland on the northeastern QTP,and analyzed their links with Holocene climatic and environmental changes.In order to do so,we studied grain size,soil organic matter,SOC,and nitrogen contents,bulk density,geochemical parameters,and the accelerator mass spectrometry(AMS)^(14)C dating of the 216-cm-deep wetland profile.SOC and nitrogen contents revealed a general uptrend over last 7300 years.SOC stocks for depths of 0-100 and 0-200 cm were 50.1 and 79.0 kgC m^(-2),respectively,and nitrogen stocks for the same depths were 4.3 and 6.6 kgN m^(-2),respectively.Overall,a cooling and drying trend for regional climate over last 7300 years was inferred from the declining chemical weathering and humidity index.Meanwhile,SOC and nitrogen accumulated rapidly in 1110e720 BP,while apparent accumulation rates of SOC and nitrogen were much lower during the other periods of the last 7300 years.Consequently,we proposed a probable conceptual framework for the concordant development of syngenetic permafrost and SOC and nitrogen accumulations in alpine permafrost wetlands.This indicates that,apart from controls of climate,non-climate environmental factors,such as dust deposition and site hydrology,matter to SOC and nitrogen accumulations in permafrost wetlands.We emphasized that environmental changes driven by climate change have important impacts on SOC and nitrogen accumulations in alpine permafrost wetlands.This study could provide data support for regional and global estimates of SOC and nitrogen pools and for global models on carbon‒climate interactions that take into account of alpine permafrost wetlands on the northeastern QTP at mid-latitudes.

Sedimentary evolution models of Lower Triassic deep-water carbonate rocks of west Qinling Mts.

Based on the study of Lower Triassic deep-water carbonate rock sequence of west Qinling Mts . deep-water carbonate rock sequence is divided into lower fine-grain euxinic deposits of a carbonate gentle slope type and upper bathyal and abyssal sediments of carbonate steep slope type. The upper member is emphatically analysed and synthesized into five fades associations. They comprise four fining- and thinning-upward megacycles, each of them representing a sedimentary column which accumulated after a tensional fault subsidence event, which recorded a whole rifting process of west Qinling ocean trough during Lower Triassic.