Cratonic Basement in Northeastern British Columbia: New U-Pb Geochronological Results and their Significance for Diamond Exploration

This study was pro posed to en hance our un der stand ing of crys tal line base ment in north east ern Brit ish Co lum bia. Seven new U-Pb zir con ages for this area are re ported from sam ples of drill cut tings. Sam ples B5 (1854 ± 6 Ma) and B25 (min i mum age 1.75 Ga; in her ited zir con 1.89– 2.23 Ga) are lo cated within but near the edge of the Nova Terrane, as it is cur rently de fined. Sam ple B2 plots within the Kiskatinaw Terrane and sam ples B11 (1994 ± 7 Ma), B12 (1993 ± 7 Ma) and B14 (1993 ± 7 Ma) plot within the Ksituan Terrane. Sam ple B34 (1859 ± 10 Ma) is lo cated near the Brit ish Co lum bia – Yu kon Bor der, and oc curs within the Fort Simpson Terrane. The sam ples from the Nova Terrane re turned Paleoproterozoic ages and thus did not con firm the pop u lar in ter pre ta tion that as signs an Archean age to the Nova Terrane. The age in di cated by the in her ited zir con from sam ple B25 is sim i lar to the 2.0 and 2.3 Ga ages pre vi ously re ported for the Buf falo Head Terrane, which is be lieved to be re worked Archean base ment. This find ing is im por tant from an ex plo ra tion point of view, since the Buf falo Head Terrane in neighbouring Alberta hosts diamondiferous kimberlites.