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

Uploaded: 13 May 2020
Last Updated: 26 May 2020

319 megapixels
27,996 x 11,384 pixels
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Gravel deposits that overlie the eroded roots of the metamorphic Appalachian belt in Washington, DC. These gravels are well-rounded and poorly sorted, and contain clasts sourced to the Antietam Formation in the Blue Ridge. The age of the gravels is not entirely clear. They may be as old as Cretaceous, or perhaps "Tertiary" terrace gravels.