2008 "Clinker" outcrop


I visited a strange outcrop of the Pennsylvanian Conemaugh Formation on August 6, 2008, with Mr. Larry Bolt, now retired from Maryland State Highway Administration. The outcrop is on the southeast side of MD Route 36, between Barton and Lonaconing in Allegany County, Maryland, roughly along the axis of the George's Creek Syncline (GPS 39.536794,-79.005625). The outcrop contains "clinkers" which are rocks that have been partially melted and then relatively rapidly cooled, and these were caused by an underlying coal bed which had caught fire and caused the melting and partial collapse of overlying shale. The first photo shows a panorama with the outcrop on the right side, and the second shows a fairly large clinker that had rolled out of the outcrop. You can look at the clinker as a stereo pair or anaglyph, and I collected a sample there as well (cfc1).

I visited the Grand Canyon on October 26, 2008.