This paper reports results from magnetotelluric measurements made along an approximately 300-kilometre northwest-southeast trending profile that crossed the major geological structures of central Baffin Island. The main goal of this survey was to determine the sub-surface geometry of major geological boundaries, particularly between Archean Rae Craton rocks and overlying Paleoproterozoic continental-margin units. The paper describes data acquisition methods & problems encountered and presents a preliminary model that describes much of the magnetotelluric response observed along the profile.

The Goldcorp high grade zone at the Red Lake mine in northern Ontario is currently the best Canadian example of high-grade gold mineralization. It provides an opportunity to define the fundamental geological parameters controlling the formation of high-grade gold ore and to assist in developing exploration guidelines for such mineralization. This report updates an ongoing study of the Red Lake high grade zone, beginning with a review of the local geological setting and a description of the southeast-trending structural lineament known as the Red Lake mine trend, defined by folds, faults, and an associated corridor of alteration & mineralization. The report then describes the structure, veins, ore zones, and alteration assemblages in the high grade zone and discusses the chronology of gold replacement, gold remobilization, and the geological controls on formation of the high grade zone.