U.S. Geological Survey Photographic Library
ID. Stose, G.W. 1580Click on photo for higher resolution. Rhyolite flow breccia, from a point 2 miles southeast of South Mountain Sanatorium; angular fragments of red rhyolite cemented into a breccia by quartz. Polished specimen. Franklin County, Pennsylvania. 1927. Plate 31 in U.S. Geological Survey. Folio 225. 1929. Image file: /htmllib/btch334/btch334j/btch334z/sgw01580.jpg |