144

farther east, at locality C, exposures of the igneous rock occur within a
limited area. Beyond this point, along the strike, no rock outcrops for
a long distance. The igneous body is about 50 feet thick and seems in
the western part to be steeply inclined to the southwest. The mass has
somewhat the appearance of a sill, but at locality A it cuts across the
strata both along the strike and dip and, therefore, is presumed to be a dyke.

DESCRIPTION OF THE ORE OCCURRENCES

The ore consists of hematite and with a small, variable amount of
vein quartz, it occurs in the igneous dyke and bordering strata exposed
between localities A and B, and in the vicinity of locality C. It also
occurs in sedimentary beds revealed in a number of shallow trenches
and rock-cuts at localities D and E on the otherwise nearly exposureless
southwest slopes.

At locality A on the axis of the ridge, the strata bordering the igneous
body are, in part, dense, pale grey, faintly greenish, siliceous rocks, stained
red or brownish on weathered surfaces. In places near the dyke, these
siliceous rocks hold small bodies of hematite varying in size from mere
specks to some that are several inches long. In general shape they are
ovoid, but in cross-section they have either irregularly curving or angular
outlines. The hematite in these bodies is very fine-grained and is dark
greyish black because of the large amount of fine-grained silica present.
The bodies in some places are sparsely distributed; in others they
are closely set, nearly touching one another, and many have outlines that
suggest they are due to the coalescence of two or more bodies. They
do not seem to be connected with one another nor with any fracture or
vein system. Similar bodies were observed in dense, siliceous strata and
in limestone in the trenches on the southwest slope and in the natural
rock outcrops farther to the northwest. These small bodies may be
accretions that formed with the enclosing rock. Near the edge of the
dyke, the dense, siliceous strata in places are traversed by discontinuous,
curving or reticulated, thin, seam-like bodies of nearly pure hematite.
These are seldom more than a few inches in length and one-eighth inch in
breadth. In places they are closely set and except for their curving,
minutely intricate courses, appear as if developed along planes of fracture
in shattered rock. The igneous rock is sheared and much of it is stained
or impregnated with hematite. In places it is distinctly cut by veins
of hematite, some as much as several inches in width. Such veins also
appear in the bordering sediments.

Elsewhere along the edges of the igneous body, the bordering lime-
stone and associated beds are impregnated and replaced by hematite
in varying degrees and to varying distances, but nowhere, except at one
place, is anything developed worthy of being considered iron ore. In
places, short, gash-like veins of quartz cut the sediments and igneous rock.
So far as observed, any hematite appearing in these veins occurs along
fracture planes.

On the axis of the ridge, bordering the dyke on its southern side,
is a body of hematite with a width of 8 feet and an exposed length of the
same dimension. Parts of the body are nearly pure hematite, dark red,
very dense, but much fractured and slickensided. In part, the body shows
vague patches of partly replaced country rock, some of it showing the