Bulk compositional analysis of quartz–hosted fluid inclusions from the South Mountain Batholith, Nova Scotia

Abstract

The objective of this research is to further develop and assess the evaporate mound analysis protocol as an exploration tool, and apply the methodology to a batholith–wide survey of secondary quartz–hosted fluid inclusions in the mineralised South Mountain Batholith (SMB) of Nova Scotia. Results indicate a multi–element (Cl, Na, Ca, K, F, S, Mn, Fe, Zn, Cu, Pb) diversity in hydrothermal fluids hosted in felsic intrusive bodies sampled at a regional scale. Significant was the detection of F (avg. 23 wt. % of the total mound) as an anion in many evaporate mounds, and novel is its widespread occurrence in barren areas. Contact–style, or fault–related, mineralisation associated with externally–derived fluids is recognizable in regional–scale (i.e., 1 sample per 100 km²) application of evaporate mound analysis, but an equivalent hydrothermal/magmatic signature in the bulk composition of fluid inclusions, at the regional–scale of observation, eludes detection despite an exhaustive analytical protocol and sampling density throughout various phases of the SMB.