Evaluation of crystallization and emplacement conditions of the McKenzie Gulch porphyry dykes using chemistry of rock-forming minerals: Implications for mineralization potential

摘要: Abstract Electron microprobe analyses of rock-forming minerals in the Middle Devonian (386.2 ± 3.1 and 386.4 ± 3.3 Ma) intermediate to felsic porphyry dykes McKenzie Gulch (MG) area, northern New Brunswick, Canada are used constrain important intensive parameters, such as oxygen fugacity (fO2), temperature, pressure, dissolved water (H2Omelt) content, emplacement conditions. Biotite compositions plot just above nickel-nickel oxide (NNO) buffer at fO2 values ~−12.22, which together with presence magnetite indicate oxidizing conditions during crystallization. On a FeOtotal–MgO–Al2O3 discrimination diagram, biotite calc-alkaline field, consistent petrochemical observations, whereas terms log(XF/XOH) versus log(XMg/XFe), plots moderately contaminated I-type suggesting possible interaction these magmas host rocks their evolution. Pressure temperature magma estimated from aluminum-in-hornblende barometry amphibole–plagioclase thermometry suggest that hornblende phenocrysts crystallized temperatures between ~700° 810 °C pressures 4 6 kbar. Depth estimates based on resided depths ~13 ≥19 km prior final upper crust. The content fed indicates they were highly hydrous (up ~5.0 wt%), phases biotite. High magmatic is prerequisite for formation magmatic-hydrothermal ore deposits can be assess prospectivity slab failure suites skarn mineralization.