Reference | {Deposit:: ANNUAL REPORT OF THE GEOLOGICAL SURVEY OF PENNA. FOR 1886, P}{Deposit:: SPENCER, ARTHUR (1908), MAGNETITE DEPOSITS OF THE CORNWALL T}{Deposit:: PENNA., USGS BULL. 359}{Deposit:: GORDON, SAMUEL (1922), THE MINERALOGY OF PENNA., S.P. NO. 1,}{Deposit:: Y OF NAT. SCI. OF PHILA.} |