4]

diorite in contact with a mixture of magnetite and garnet cut by a dense dyke. The magnetite-garnetite is exposed over a width of 3 fect and for a length of 10 feet. Below this occurrence granodiorite is exposed at frequent intervals along the course of the stream. Above it are outcrops of a dark, siliceous, altered sediment or volcanic rock and at a place 70 feet south of the trail at locality No. 2 is an outcrop about 15 feet long and a few feet wide of intermixed magnetite and garnet. A third small outcrop of magnetite is visible 15 feet farther downstream. The two last-mentioned outcrops are possibly part of one body having a length of at least 25 feet; its width may be considerably less. Fragments of magnetite occur upstream for some 25 feet, but presumably are from some other, now concealed, source.

One hundred and sixty feet east, at locality No. 3, a small outcrop of magnetite occurs on the trail and much loose magnetite is visible within a radius of 15 feet. Eastward along the trail are several outcrops of porphyrite and of granodiorite and 380 feet to the east at localities 4 and 5, Just north of the trail, magnetite has been exposed by stripping over a curving area 110 feet long with a maximum breadth of 15 feet. Fifty feet east of locality 4, magnetite is exposed over an area of 4 feet by 8 feet at locality 6 on the north side of the trail. Twenty-five feet south, at locality 7, stripping has shown the presence of nearly pure magnetite over an area about 25 feet in diameter. Thirty feet farther south, at locality 8, is a magnetite outcrop measuring 4 feet by 6 feet, and 30 feet east of this, at locality 9, magnetite is exposed over an area 10 feet in diameter. Very little country rock is visible at any of the magnetite exposures of localities 4 to 9 which extend over a length of 175 feet with no intervening or nearby exposures of either rock or ore.

East of the above-mentioned outcrops, porphyrite and granodiorite are exposed at a few places on the hill-side. Three hundred and twenty-five feet southeast of locality 6, a small outcrop of magnetite lies on the trail at locality 10. Uphill, 35 feet from this locality, magnetite outcrops at locality 11 over an irregular area 15 feet wide by 20: feet long. At the southeast and northeast angles of this outcrop, country rock is visible, but elsewhere the magnetite passes under drift. Country rock is also visible 20 feet northwest of the magnetite at locality 10 and possibly belongs to the same body as the magnetite at locality 11. If the two occurrences are part of one mass, now largely concealed, it has a length of at least 50 feet and a breadth at one place of 20 feet. ;

Southeast along the trail, at a distance of 110 feet from locality 10, beyond an exposure of a dense, igneous rock, is an outcrop of magnetite measuring 2 feet by 2 feet. This is locality 12.

ECONOMIC CONSIDERATIONS

The mineral bodies to which belong the various outcrops of magnetite or of magnetite, garnet, etc., have developed along or near the edge of a large body of granodiorite which invades a complex assemblage of sedi- ments and extrusive and intrusive volcanic rocks. The magnetite bodies have replaced the various types of country rock, including the granodiorite. Owing to the scarcity of natural outcrops and the small amount of mining work done, the form and dimensions of the individual magnetite deposits are unknown and no inferences of any value regarding dimensions can be drawn save that all the individual outcrops do not belong to one continuous