Geology of the Fox orebody, northern Manitoba

Abstract

The Fox Mine is an Aphebian Cu-Zn massive sulphide deposit. This study documents the relationship between the ore body, its host metavolcanic rocks, its alteration zone and the metamorphic history of the area. The Fox Mine area can be divided into four blocks, separated by fualts, which are essentially conformable with the stratigraphy and foliation. The rocks within the area are primarily metavolcanic, ranging from mafic to felsic. Minor amounts of metasedimentary rocks are also present. The metavolcanic and metasedimentary rocks of the area have been intruded by mafic and felsic intrusions of several ages, and have undergone medium-grade (amphilbolite) metamorphism. The ore body is massive, essentially stratiform and stratabound, and exhibits a strong copper-zinc zonation. Zinc is concentrated along the margins, with copper in the center. The ore body shows signs of metamorphism to a level equal to the surrounding silicate rocks... The Fox ore body is compared with other massive sulphide deposits considered to be of volcanogenic origin, and is compatible with this model assuming the deposit has been isoclinally folded. Evidence for this folding is found in the copper-zinc zonal patterns.