The role of magmatic and hydrothermal processes in the chemical evolution of the Strange Lake plutonic complex, Qu�bec-Labrador

A deposit model for carbonatite and peralkaline intrusion-related rare earth element deposits

“…This is a recurring theme of studies at Strange Lake (Boily and Williams-Jones, 1994;Salvi and Williams-Jones, 1990 and at the Nechalacho deposit (Sheard and others, 2012). At Strange Lake, primary ore minerals are clearly magmatic, but the origin of the hydrothermal fluid that reacted with these phases is controversial.…”

“…They are typically a few hundred meters wide in deeper zones to tens of meters in upper zones (Richardson and Birkett, 1996b). However, hydrothermal fluids can play an important role in concentrating REEs in these systems (Boily and Williams-Jones, 1994;Sheard and others, 2012). In some mineralized areas, such as at Strange Lake, late stage pegmatitic dikes intrude the country rock.…”

“…This suggests that important ligands include carbonate, fluoride, and phosphate species; experimental work has shown that chloride species can also be important (Migdisov and others, 2009). Boily and Williams-Jones (1994) evaluated the role of magmatic and hydrothermal processes in the genesis of the Strange Lake deposit and concluded that F-rich parental magma allowed for the high concentrations of REEs and HFSEs as fluorocomplexes and that these complexes were concentrated in late-stage residual magma. Further work by Salvi and Williams-Jones (1996) showed that multiple hydrothermal events occurred at Strange Lake, with an initial transport in an orthomagmatic fluid consisting of Zr, Y, and HREEs as fluorine complexes.…”

Micro-structural and compositional variations of hydrothermal epidote-group minerals from a peralkaline granite, Corupá Pluton, Graciosa Province, South Brazil, and their petrological implications

“…Salvi andWilliams-Jones 1996, Salvi et al 2000). In these media, the Ca contents of the residual fluids seem to play a fundamental role (Salvi and Williams-Jones 1990, 1996, Boily and Williams-Jones 1994, and even low Ca contents lead to the crystallization of fluorite and a fast decrease of the F activity in the fluid phase. As a consequence, the HFSE solubility decreases and they are preferentially incorporated into the mineral structures.…”

Boron isotopic constraints on the Nb and Ta mineralization of the syenitic dikes in the ~ 260 Ma Emeishan large igneous province (SW China)

“…High field strength element (HFSE)-rich peralkaline granites commonly occur as small-scaled dikes, sills or plugs and are considered to have formed from highly fractionated and volatile-rich magmas (Boily and Williams-Jones, 1994;Hadj-Kaddour et al, 1998;Kovalenko et al, 1995). As HFSE-rich peralkaline granites experienced remarkably hydrothermal overprints, the high concentrations of rare earth elements (REE) and HFSE in the rocks are attributed to the remobilization of these elements in hydrothermal fluids (Beus et al, 1962;Kempe et al, 1999).…”