Dropstone (center of photo) exposed in a well-bedded glacial clay deposit. The dropstone was likely entrapped in an iceberg that was ice rafted into a glacial lake. After the iceberg melted, the dropstone dropped to the bottom of the lake where it was buried in the fine-grained lake sediment. Notice the deformation of the clay bedding around the dropstone that occured during burial.
North Fork of the Skykomish River, near Index, Washington, USA

Photo Copyright © 2009 Jeffrey M. Schwartz