Mineralogical and geochemical analysis of the Benjamin River South Cu-Mo-Au porphyry system in northeastern New Brunswick, Canada: A fertile adakitic magmatic system linked to slab failure

The Benjamin River South porphyry system (BRS) lies within the mid-Paleozoic Appalachian realm of Ganderia, representing an area of approximately 80 km 2 in northeastern New Brunswick. This region hosts the hypabyssal Blue Mountain Granodiorite Suite (BMGS) including BRS porphyries, which contains multiple, locally auriferous porphyry Cu-Mo occurrences associated with several cupolas ranging in size from 60 to ~600 m in diameter, situated northeast of the main Blue Mountain Granodiorite. These mineralized cupolas intrude into two Siluro-Devonian-aged volcano-sedimentary rock units (Benjamin and Bryant Point formations;). The adjacent slightly older Benjamin River Intrusive Complex, dated at 418 ± 1 Ma (U-Pb zircon), is cogenetic with the host regional rift-related bimodal volcano-sedimentary suite. The mineralized cupolas of the BRS porphyries (BMGS-BRS) were dated by U-Pb zircon (400.7 ± 0.4 Ma); these Early Devonian intrusive tonalite-granodiorite phases (to andesitic textured), which host the mineralization are light cream to tan colored, plagioclase and hornblende-biotite- porphyries within a variably f.g.- to m.g. hypidiomorphic granular groundmass. In the samples with only minor alteration-mineralization (