| Reference | ANNUAL REPORT OF THE GEOLOGICAL SURVEY OF ARKANSAS FOR 1892 (PUB. DEC., 1900), VOL V: THE ZN AND PB REGION OF NORTH ARK., BY STATE GEOLOGIST JOHN C. BRANNER, P. 106 USGS RESTON (241) AR5; (LOCAL GEOLOGY PICTURED ON YELLVILLE SHEET IN THAT BOOK |