The petrology of the Myrna Lake and Fraser Lake basic intrusive bodies

Abstract

During 1945 Sherritt Gordon Mines announced the discovery of nickel bearing sulphides on the shore of Lynn Lake in Northern Manitoba. This disclosure caused a staking rush to the Lynn-Barrington Lakes Area during the years l946 to l948. Interest centered upon the basic intrusives of the area, as the Sherritt Gordon ore occurs within such rocks. Despite intensive exploration by geophysical and geological methods no other nickel deposit of commercial size was found, although most of the basic intrusives seem to be of a nature favorable to such deposits. The object of the present study was to carry out a petrological investigation of certain of these basic bodies to ascertain the controlling factors in the occurrence or non-occurrence of the nickel deposits. The Lynn-Barrington Lakes Area comprises five fifteen minute map-areas between longitudes 100 degrees 00 minutes and 101 degrees 15 minutes west and between latitudes 56 degrees 45 minutes and 57 degrees 00 minutes north. The total area enclosed by the five sheets is about 800 square miles. The topography of the area is similar to much of the Precambrian shield; muskegs and lakes fill depressions between rounded hills or steep ridges few of which have a relief of more than one hundred feet...