Wyoming County

    Little Rocky Glen is one of the best examples of geological forces in action within the the watershed.  It is the highest outcrop in the area, and is an area of significant Holocene (post-glacial) erosion.  This outcrop was cut and eroded since the glacier left this area about 18,000 years ago.

    If you look carefully, you may find evidence of ripple marks and an incipient pothole.  Frequently when a sizable stream flows over a bedrock ledge, potholes are formed by vortices in the water.  When the vortex comes upon an imperfection in the stream bottom, particles collect there which act as grindstones.    Several potholes may coalesce forming a slot canyon.  At this site, the stream is cutting down through a moderately resistant sandstone. If the bedrock here were shale, the canyon would be much deeper as the shale would be more easily eroded.  Little Rocky Glen is reminiscent of The Seven Tubs, a natural area in Luzerne County which is also eroding through a tough sandstone, but has more erosive tools in the form of water flow and stream gradient. 

 

Photos by J. Stevens and J. Skinner