Reference | {Deposit:: USGS. BULLETIN 359, 1908, PP.43 TO 61.}{Deposit:: USGS. BULLETIN 995-D ,1953, PP. 135 TO 148.}{Deposit:: PA. GEOLOGICAL SURVEY, BULLETIN M50, 1964, PART 3, SHEET 1.}{Deposit:: PA. SECOND GEOLOGICAL SURVEY, ATLAS TO D3, 1883, SHEET X.} |