By: magic-gigapans
Image: Robin Rohrback, Mid-Atlantic Geo-Image Collection
License: Creative Commons Non Commercial ⧉

Uploaded: 10 Apr 2020
Last Updated: 27 May 2020

395 megapixels
23,428 x 16,868 pixels
78.1 in X 56.2 in at 300dpi
55,813 pixels per inch

As described by Dr. Ken Rasmussen, Northern Virginia Community College: "This is likely an authigenic chemical precipitate. Possibly iron monosulfide oxidizing to something like limonite, or perhaps a pyrite precipitate."