Geochemistry and Nd isotopes of the Francois Lake plutonic suite, Endako batholith: host and progenitor to the Endako molybdenum camp, central British Columbia

The Endako low-F granodiorite-type porphyry Mo deposit is hosted by the Tri assic to Eocene Endako batholith, which comprises five temporally distinct plutonic suites, only one of which is mineralized. Pre-mineralization suite s range in composition from diorite to granodiorite. The synmineralization Jurassic-Cretaceous Francois Lake suite includes two granodiorite- to monzo granite-bearing subsuites. Postmineralization phases include the Eocene Sam Ross Creek monzogranite. The batholith spans a silica range of 44-80 wt.% and consists of metaluminous to slightly peraluminous, low- to high-K, I-ty pe granitoids; the Sam Ross Creek phase is an A-type granite. Positive epsi lon (Nd)(T) values (+1.1 to +7.2) indicate derivation predominately from ju venile source materials, but with variable input from an older crustal comp onent. Evidence suggests generation of older plutonic suites in a juvenile arc-type setting and younger K-rich felsic suites via recycling of juvenile arc crust without significant mantle-derived contributions. Three distinct Mo-deposition events in the Endako camp are linked to repeated generations of oxidized, highly evolved monzogranitic phases (pre-ore dykes, aplitic N ithi and Casey intrusions) belonging to both Francois Lake subsuites. Late pre-ore dykes with "Casey-like" geochemical signatures, along with massive unmineralized Casey intrusions near the Endako deposit, could reflect repea ted injections from an underlying magma chamber that remained molten during the youngest Mo-deposition event. A genetic link may exist between the Sam Ross Creek phase, a pluton with Climax-type granite characteristics, and E ocene kaolinite alteration in the Endako deposit. Also, potential exists fo r Eocene-age Climax-type Mo mineralization within the Endako mining camp.