North of the city of Reading, near the Berks County towns of Hamburg and Lenhartsville, is an amazing geological formation.

I learned about this place after finding a postcard photograph of the site taken by H. Winslow Fegley, prolific Berks County photographer of the early 20th century.

At the end of the last Ice Age period of glaciation, the Blue Mountains of Berks County underwent periods of freezing and thawing that splintered the cliffs of Tuscarora Quartzite.

Blocks of stone fell in a boulder field pattern stretching some distance from the cliff face.

Streams of water from snow melt washed fine particulates away, leaving only the stone field on which vegetation cannot be supported.

On either side of the exposed Boulder field are forested areas which have grown up over the same Boulder field, but the forested area lay outside the streams which removed all the fine particles on which soil could be formed.

On-line, one can find numerous discussions of the geological history and a more current, free-use, photograph of the area.

The postcard photograph was copyrighted and published by H. Winslow Fegley circa 1920.  The postcard was not mailed.