The object of this study is to test the assumption that cryogenic weathering (here understood as in‐situ disintegration of rock under cold‐climate conditions including ice as a weathering agent) preferentially breaks up quartz grains. We apply the results of laboratory tests to a Quaternary sediment record. The combination of silt production, relative quartz enrichment in the silt fraction, and quartz grain micromorphology is traced in a multi‐100‐kyr lake sediment archive as indicator data for cryogenic weathering. Constant cryogenic weathering conditions are inferred for at least the last 220 000 years from a lake sediment core of El'gygytgyn Crater, northeast Russia. This is the longest continuous terrestrial archive currently known for the continental Arctic. Quartz enrichment in the fines evolves from seasonal freeze–thaw weathering as demonstrated in laboratory testing where over 100 freeze and thaw cycles crack quartz grains preferentially over feldspar. Microscopic grain features demonstrate that freeze–thaw cycling probably disrupts quartz grains along mineral impurities such as bubble trails, gas–liquid inclusions, or mineralogical sub‐grain boundaries. Single‐grain micromorphology (e.g. angular outlines, sharp edges, microcracks, brittle surfaces) illustrates how quartz becomes fragmented due to cryogenic cracking of the grains. The single‐grain features stemming from the weathering dynamics are preserved even after a grain is transported off site (i.e. in mobile slope material, in seasonal river run‐off, into a lake basin) and may serve as first‐order proxy data for permafrost conditions in Quaternary records.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.