Controls on gold mineralization Forest Hill, Guysborough Co., N.S.

Abstract

Forest Hill is a former Nova Scotia gold mining district. Like most Nova Scotia gold deposits, the gold is concentrated in and along quartz veins lying in the stratification planes within interbedded quartzites and slates of the Meguma Group rocks which have been folded into an anticline which extends EW across the property. This deposit differs from many others in Nova Scotia by its high-grade amphibolite-metamorphism, which is believed to be closely related with Devonian (Acadian) plutonic intrusive rocks that are exposed on the north and south boundaries of the property. The area that includes Forest Hill has also been affected by the Hercynian deformation event. Gold was emplaced during the introduction of pre- or early Acadian quartz veins. The gold was later remobilized, along with cassiterite and scheelite, in some cases into fractures, 'pseudoveinlets' and biotite-garnet-rich stratum located along the hanging wall of the quartz veins. This remobilization appears to be associated with a late residual fluid phase of the granitic intrusions which are closely spatially located to the gold district. The anticlinal structure at Forest Hill played a very important role by funnelling these fluids toward the fold hinge.