By: callanbentley
Image: RR/MAGIC
License: Creative Commons Non Commercial ⧉

Uploaded: 22 Mar 2020
Last Updated: 22 Mar 2020

238 megapixels
18,364 x 12,944 pixels
61.2 in X 43.1 in at 300dpi
3,943 pixels per inch

Sample 17 is a striated and faceted stone embedded in a sandy diamictite matrix, from the Cryogenian period Storeelv Formation in eastern Greenland. The erosional surfaces of the pebble suggest that it was in direct contact with mobile basal ice. The flattened (faceted) surfaces of the pebble were formed as the pebble scraped along the bedrock beneath the moving basal ice. The striations that appear as parallel grooves etched into the faceted surface of the pebble record the direction of ice movement.