Constraining the shock conditions experienced by Haughton crystalline basement rocks: a combined Raman spectroscopy and electron backscatter diffraction study of Anomaly Hill zircons
Faculty Advisor
Date
2020
Keywords
impact structures, crystalline basement rocks, shock
Abstract (summary)
Haughton is a 23-km diameter impact structure on Devon Island, Canada [1, 2]. The target stratigraphy comprised ~1880 m of Lower Paleozoic sedimentary rocks, unconformably overlying the Precambrian Canadian Shield [2]. Near the centre of the structure, is a location characterized by negative gravimetric and positive magnetic anomalies, known as “Anomaly Hill” [3]. Highlyshocked, pumice-like lithic clasts are abundant at this locale, and include gneissic and carbonaterich clasts [4, 5]. In this study, we examined 20 zircon grains from a single crystalline clast collected at Anomaly Hill, to reveal microstructures at the micrometer to nanometer scale. Earlier work on Haughton zircons [6] did not incorporate EBSD, and so, is missing a wealth of information to facilitate the identification of key microstructures including FRIGN (former reidite in granular neoblasts) zircon, non-FRIGN granular textures, neoblasts versus sub-grain rotation formation of subdomains, and various dissociation textures, as described in [7, 8]. The goal of our study is to constrain the shock conditions experienced by crystalline basement rocks at Haughton using zircon, a mineral that is increasingly recognized as a sensitive shock indicator.
Publication Information
Jurak, H. A. M., Walton, E. L., Timms, N. E., Osinski, G. R. (2020) Constraining the shock conditions experienced by Haughton crystalline basement rocks: a combined Raman spectroscopy and electron backscatter diffraction study of Anomaly Hill zircons. 2020 Geoconvention.
DOI
Notes
Presented on September 21-23, 2020 at the "GeoConvention 2020" virtual event.
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