Royal Rockhounds Field Trip to the South Fork
In a certain undisclosed location on the South Fork of the Shenandoah River, a small group unloads handmade rafts and prepares to step into the welcome cool water on this hot summer day.
The Royal Rockhounds based in Front Royal are excited about the possibility of finding Suiseki or “Viewing Stones”, mainly from the metabasalts of the Catoctin Formation, in this stretch of the river. Glenn Reusch introduced fellow Rockhounds to the Japanese and Chinese art of contemplating an individual mounted rock specimen that can evoke a spiritual image because it resembles a landscape or a particular thought. The shapes and surface textures of specimens are the result of differential polishing and fluting by the river. In the quest to find a true Viewing Stone, many small attractive stones are collected and brought home.
“The location is north of Luray,” says Glenn with a chuckle, who organized the trip. Though not a secret to rafters and other river recreationists, the group thought it best to minimize impact and keep the actual location private. Suffice it to say that areas where a tributary joins a river are good places to find interesting specimens due to the erosion bringing rocks from higher elevations down to lower sites.
Within the river, gravel bars, islands and the inside curves of a meander are also good places to look for special rocks as the water flow slows and tends to drop a portion of its suspended load.
Conditions have to be right for this type of collecting and Mr. Reusch monitored river levels until the flow was low enough to safely wade in and see the river bottom.
“The river is now at 1.9 feet, though less than 1.5 feet is best,” he says.
“Almost all the color in these rocks is due to different oxidation states of iron in the various minerals” says geologist Bob Luce. “Metamorphism changed the original mineralogical and chemical composition of the rocks; tumbling in the river polished and enhanced surface textures.”
The northern section of the Blue Ridge Mountains is highly metamorphosed having undergone considerable changes in pressure and temperature. Over millions of years, the mountains have been uplifted by continents colliding, pushing them higher than the Himalayas, covered by oceans, experienced volcanic activity and undergone considerable erosion due to their old age. The rocks today tell the story of the changes to these ancient mountains.
“I think everyone loves rocks as a child. I am just lucky to have not outgrown that.” says Mr. Reusch.
Fifteen year old Miles Kolmstetter from Arlington has not outgrown his love of rocks. He is on the trip with his father and grandmother. He places several small conglomerates into his bucket including one particularly bright red piece of jasper, a type of sandstone. He has just completed an internship with the Smithsonian Institute and has taken two field trips with the Royal Rock Hounds.
The group takes field trips each month to explore interesting geology around the area. We look forward to hosting the Rock Hounds at the White House Farm this fall where limestone outcrops occur in the farm fields and sinkholes dot the landscape.
“Rivers are interesting, no matter where you are,” says Chris Cochrane. “Wherever in the world you are and no matter what interest you have – canoeing, biology, rocks – rivers are interesting.”
White House Farm Foundation
Luray, VA 22835