The Mojay showing is located on the southern border of 114P/13, four kilometres east of the Alsek River on the west side of a narrow glacial canyon. At this locality, coarse, white marble is intruded by Jurassic-Cretaceous(?), variably foliated hornblende diorite and gabbro. At least four intrusive phases were noted in this area. The contact with host marble is extremely irregular, and numerous dikes with skarn-mineralized (mainly garnet plus epidote plus hornblende plus pyroxene) selvages are present. Northwest-trending rusty weathering, resistant lenses of sulphide-bearing skarn are exposed in the canyon, mainly developed within the dioritic pluton contact zone and numerous marble screens. The sulphides are primarily disseminated pyrrhotite and pyrite. One such zone measures approximately 10 metres by 200(?) metres. Lenses of massive sulphide within these zones consist primarily of pyrite, pyrrhotite, chalcopyrite and bornite(?). The extent and distribution of massive sulphide mineralization is largely unknown, as most outcrops are inaccessible in cliff faces or were mapped only by aerial reconnaissance. One sample returned an analysis of 4 parts per million silver, 550 parts per million cobalt and 523 parts per million copper (Table 1-13-2, No. 151). Although the mineralization seems to be of a skarn type, the consistent northwest trend to these bodies suggest a degree of structural control as well.
There are similar showings in the next valley to the east, where at least three large west-northwest-trending rusty weathering skarn lenses are exposed. One such lens developed within the marble at the contact between the marble and the diorite body, consists of very fine-grained disseminated and massive yprite and pyrrhotite, with slightly coarser, disseminated pyrite and pyrrhotite within the diorite body. Only minor development of calcsilicate skarn was observed here, in contrast to the first locality. Two samples collected from this locality did not yield anomalous assays for silver, copper, lead or zinc.