Hyperspectral imaging of drill core from the Steen River impact structure, Canada: Implications for hydrothermal activity and formation of suevite‐like breccias

Abstract

Hyperspectral imaging can be used to rapidly identify and map the spatial distributions of many minerals. Here, hyperspectral mapping in three wavelength regions (visible and near‐infrared, shortwave infrared, and thermal infrared) was applied to drill cores (ST001, ST002, and ST003) penetrating a continuous sequence of crater‐fill breccias from the Steen River impact structure in Alberta, Canada. The combined data sets reveal distinct mineralogical layering, with breccias derived predominantly from sedimentary rocks overlying those derived from granitic basement. This stratigraphy demonstrates that the breccias were not appreciably disturbed following deposition, which is inconsistent with formation models of similar breccias (suevites) by explosive impact melt–fluid interaction. At Steen River, volatiles from sedimentary target rocks were an inherent part of forming these enigmatic breccias. Approximately three quarters of terrestrial impact structures contain sedimentary target rocks; therefore, the role of volatiles in producing so‐called suevitic breccias may be more widespread than previously realized. The hyperspectral maps, specifically within the SWIR wavelength region, also delineate minerals associated with postimpact hydrothermal activity, including ammoniated clay and feldspar minerals not detectable using traditional techniques. These nitrogen‐bearing minerals may have originated from microbial processes, associated with oil‐ and gas‐producing units in the crater vicinity. Such minerals may have important implications for the production of habitable environments by impact‐induced hydrothermal activity on Earth and Mars.

Hydrothermal Alteration of the Ocean Crust and Patterns in Mineralization With Depth as Measured by Micro‐Imaging Infrared Spectroscopy

“…Laboratory imaging spectroscopy at the sample scale is rapid and non‐destructive and has numerous applications in the geological sciences (Greenberger, Mustard, Ehlmann, et al., 2015 ). The technique is becoming more common for measurement of drill core owing to the potential for rapid, non‐destructive determination of mineralogy (e.g., Aymerich et al., 2016 ; Hunt et al., 2020 ; Kruse et al., 2012 ; MacLagan et al., 2020 ; Mathieu et al., 2017 ; Speta et al., 2013 , 2015 ) and has garnered considerable interest in the mining industry. Here, we have collected imaging spectroscopy data of all core sections recovered by OmanDP totaling 3.2 km and, for the first time, set up and used the instrument aboard the Japanese IODP drilling vessel Chikyu .…”

Through the impact glass: Insight into the evolution of melt at the Mistastin Lake impact structure

“…At the Steen Lake impact structure, the wide range of impact melt composition was used to propose early segregation (MacLagan et al. , ). The composition range of impact glasses is also shown to vary considerably with glass from the Wanapitei impact structure (Grieve and Ber ) and the Zhamanshin impact structure (Feldman and Sazonova ).…”

“…), Steen River impact structure (MacLagan et al. , ), and Tenoumer impact structure (Schultze et al. ), where incomplete mixing explains impact melt rock heterogeneities.…”