UBC Theses and Dissertations
Potassium-argon age determinations on biotites and amphiboles, Bethlehem Copper Property, B.C. Dirom, Gavin Ewan
Potassium-argon apparent ages obtained on biotite and amphibole from various phases of the Guichon Creek batholith present on the Bethlehem Copper property are reported and their geological significances are discussed in this thesis. Although the individual phases were found to be essentially indistinguishable in terms of their potassium-argon apparent ages, the results obtained indicated with considerable certainty that these phases were emplaced during an interval not greater than 10 m.y. centered around 200 m.y. ago and that no major metamorphic event has occurred in this area since this time. It is also believed that this average apparent age of 200 m.y. may represent a better approximation to the maximum age of the Triassic-Jurassic boundary than that previously reported in the literature. The potassium and argon analytical techniques employed are described briefly, and the analytical precision and accuracy obtained are discussed. Descriptions of the samples collected and samples analyzed are given as an appendix.
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