98 emanations from a ‘granitic’ fluid, with corresponding abstraction of lime. No example of a transition within a single bed from tremolite-actinolite- clinozoisite-garnet skarn into hornblende-plagioclase amphibolite was found in the Wolverine complex, though such a gradation seems probable and has been suggested (Barth, 1928). North of Blackpine Lake, skarn and amphibolite are both interbedded with quartz-mica-feldspar gneiss, and exist side by side for several hundred feet without noticeable change of composition (See Figure 5). It is apparent that the amphibolite is not merely a more highly metamorphosed phase of the skarn ; the two rock types seem to represent somewhat different trends of alteration under similar physico-chemical conditions. Glimmerite Near the edge of the southwest shoulder of the mountain overlooking Blackpine Lake, and on a serrated aréte 3 miles north of this locality, beds up to 3 feet thick composed almost entirely of biotite are intercalated with the quartz-mica-feldspar gneisses. The biotite is in glistening black scales up to 4 mm. in diameter, entirely similar to that found in the biotite- bearing amphibolites. Accessory minerals are those found in the amphibo- lites: hornblende, quartz, plagioclase, apatite, and sphene. The glimmerite appears to be merely a phase of the amphibolite extremely rich in biotite. Pyrrhotite Skarn In several places the skarns and amphibolites northeast of Blackpine Lake are accompanied by deposits of iron sulphides, dominantly pyrrhotite, with variable amounts of pyrite, chalcopyrite, and arsenopyrite. The deposits range from thin seams of coarsely crystalline sulphides intercalated with the skarns and amphibolites, to bodies up to 25 feet wide and 500 feet long consisting of at least 40 per cent sulphide material. The largest of these bodies, on which the Hope group of mineral claims was staked, is described breifly on page 222, The characteristic association of iron sulphide deposits with contact metamorphosed limestone, in relations that appear directly related to metamorphism rather than to later hydrothermal mineralization, has been noted by many workers (Knopf, 1933, p. 538). Goldschmidt (1911, p. 211) found that in such deposits the iron sulphides were usually partly older and partly younger than the skarn silicate minerals. In the Wolverine complex rocks, the pyrrhotite appears to have formed essentially contemporaneously with the silicate minerals, before the conclusion of intrusive action, for dykes of alaskite crossing bands of pyrrhotite-rich skarn show no evidence of mineralization. Granodiorite The most conspicuous feature of the Wolverine complex rocks north- east of Blackpine Lake is a body of granodiorite about 5 square miles in area exposed on the slopes overlooking the lake. Another body about 3 Square mile in area outcrops on the north side of the north peak of the massif northeast of the lake, and smaller bodies of similar material are found on the crest of a ridge 7% miles south of Chase Mountain. For the i