Sulfur isotopic systematics of granitoids from southwestern New Brunswick, Canada: implications for magmatic-hydrothermal processes, redox conditions, and gold mineralization

Calculation of Rare Earth Element Patterns in Magmatic Fluids: Evidence for Origin of the Lake George Sb-Au-W-Mo Ore Deposit, New Brunswick, Canada

“…This also suggests that hydrothermal fluid(s) causing alteration as well as mineralization (sericite; see [19]), and gold mineralization are derived from the progressively cooling voluminous magma. This interpretation is supported by the prior studies of fluid inclusion, mineral chemistry, stable isotopes, and lithogeochemistry [13,20,[22][23][24].…”

“…A use of the estimated abundance data of REE in MVPs presented in this contribution means that both REE and H 2 O are derived from the cooling granite magma(s), but does not provide for evidence for the source of Au, Cu, and S. Sulphur isotopes in conjunction with fluid inclusions may better constrain sulphur source in the study of the Lake George deposit [13,20]. It is known that magmatic pyrrhotite is present in the Lake George granodiorite, suggesting that most of the Au and Cu partitions into early sulphide liquid because their partition coefficients between sulphide and granite melt are very high.…”

“…This deposit is temporally and spatially associated with the Early Devonian Lake George granodiorite stock [14][15][16][17][18][19][20]. The occurrence of Au-bearing quartz-carbonate veinlets and stockworks associated with W-Mo mineralization within the granodiorite stock, quartzfeldspar dyke, and the proximal metamorphic aureole strongly suggests that associated Au mineralization is related to the hydrothermal system associated with this hypabyssal intrusion [15][16][17]19], analogous to intrusion-related gold systems [13,[20][21][22][23][24]. Table 1 presents the procedures for calculating REE concentrations in magmatic volatile phases described above using the Lake George granodiorite as an example.…”

Using Rare Earth Elements (REE) to Decipher the Origin of Ore Fluids Associated with Granite Intrusions

“…The styles of Au mineralization include Au-bearing quartz-carbonate veins, veinlets, and stockworks that are present within the granodiorite stock, quartz-feldspar dyke, and proximal metamorphic aureole, respectively; these are associated with earlier W-Mo mineralization. These characteristics suggest that the Lake George granodiorite intrusion and related hydrothermal systems may have ultimately resulted in Au mineralization [28][29][30][31]33], resembling intrusion-related Au systems [7,[34][35][36]. Table 4 lists the analyses of the Lake George and Bakircay granodiorites, Cl contents either from bulk analysis or from fluid inclusion salinity data, calculated Cl molality (m v Cl ), calculated k REE P , and REE concentrations of magmatic fluids.…”

“…Cl increases (Table 4) deposit was the largest antimony producer in North America until the mid-1990s. It is temporally and spatially associated with the Early Devonian Lake George granodiorite stock [28][29][30][31][32][33][34]. The styles of Au mineralization include Au-bearing quartz-carbonate veins, veinlets, and stockworks that are present within the granodiorite stock, quartz-feldspar dyke, and proximal metamorphic aureole, respectively; these are associated with earlier W-Mo mineralization.…”