Preliminary Insights from Volcanic Facies Analysis 1

Ba salt of the Chil cotin Group (CG), sit u ated in the In te rior Pla teau phys io graphic re gion of cen tral Brit ish Co lum bia, cov ers an area of nearly 36 500 km. Its dis tri bu tion is en tirely within the re gion of BC that is most af fected by mountain pine bark beetle (MPBB) in fes ta tion (Fig 1). The CG is im me di ately un der lain by Pa leo zoic-Me so zoic base ment rocks with high min eral po ten tial (e.g., Quesnel Trough) and Cre ta ceous-Eocene sed i men tary rocks of the Nechako Ba sin with hy dro car bon po ten tial. Pre vi ous work ers (e.g., Mathews, 1989) have sug gested that the CG can reach thick nesses of ap prox i mately 200 m and av er age ap prox i mately 100 m. In ad di tion, the CG is it self par tially over lain by late Qua ter nary gla cial de pos its of vari able (lo cally ≥200 m) and usu ally of un known thick ness (e.g., Kerr and Levson, 1997).