Technical Report for the Fort Knox Mine - Kinross Gold

Fort Knox Mine Technical Report14.0 DATA VERIFICATIONAll drill data, including collar locations, down-hole surveys, and data intervals arecollated in Excel spreadsheets. Survey and log data are hand-entered into thespreadsheets, while assay data are downloaded in digital format from the assay lab thensubsequently merged into the spreadsheets. Collar locations are initially recorded in thelocal grid by the GPS surveying system. Collar locations and downhole surveys are alsorigorously reviewed via manual verification methods for erroneous data by the technicalstaff of FGMI. Following input of data into Excel spreadsheets, the data are output to aMineSight-ready ASCII file and subsequently imported into the MineSight softwarepackage. The resulting assay and survey files in the MineSight directory include:Assay file is identified as knx011.07d and,Survey file is named knx012.07d.Gold grade and lithology data are entered into the “au1” and “lith” fields within the assayfile. The majority of the drillhole data has had a minimum of 10% double-entry checksperformed for data validation purposes.The processes of data verification as described above are acceptable due diligenceroutines to assure the reliability of the Fort Knox data set. The authors feel comfortablethat the presented data reflect actual conditions of the in-situ situation.14.1 Drill Hole Data RejectionTwelve RC holes displayed down-hole contamination when compared to adjacent holes,blast hole drilling, and their respective drill logs, and select intervals were rejected fromthe assay data set. Gold values for the rejected data were converted to -1 (as if missing).This process resulted in the rejection of 806 intervals. Prior to 2004, computer programsrecording down hole “cyclicity” and “decay”, as well as excessive sample weight, wouldbe used as guides for geologists to reject suspect intervals as aberrant gold values. Asmining production has progressed and production blastholes have allowed forverification of the presence of gold, these rejected intervals have been reviewed and45