’ UPPER SANDSTONES IN THE BAD RIVER COUNTRY. 233 
satisfactorily proved to be secondary to the augitic constituent. Macroscop- 
ically it is medium-grained, and from black- and white-mottled to nearly 
black in color. The constituents are labradorite, augite, hornblende, titan- 
iferous magnetite, apatite, uralite and diallage; with a little biotite, chlorite 
and quartz. 
In the townships west from Bad River, within the gabbro belt, low 
exposures of a coarse, pinkish granite are often met with, and precisely sim- 
ilar exposures are found in the area occupied by the upper mica-schists 
of the Huronian. This granite is intrusive, cutting both the gabbro and 
the upper Huronian schists. It is a true biotite-granite, consisting of ortho- 
clase, oligoclase, quartz very rich in large bubble-bearing cavities, and 
rather rare biotite. 
Thus far, for the region west of the Montreal River, attention has been 
directed to the Lower Division of the Keweenaw Series, and to the lower- 
most members of its Upper Division. These lower rocks form the mass of 
a highland or range which, on the Montreal, is only some two miles from 
the lake shore, while on Bad River it lies twenty miles back of the coast, 
leaving in front of it a broad lowland, underneath which lies the main mass 
of sandstone of the Upper Division. On the Montreal most of the thickness 
of this upper sandstone is in sight, and on the Potato, Bad and Brun- 
schweiler rivers some hundreds of feet of its lowest portions are to be 
seen. On the Montreal, Potato and Bad rivers it stands vertically or 
nearly so, with a slight inclination to the north, the northern dip flattening 
somewhat in the higher layers. On the Brunschweiler a perceptible flat- 
tening of the whole series has begun. 
Throughout most of the lowland underlaid by these sandstones they 
are covered by red lacustrine clays, but at two points—on Bad River in See. 
25, T. 47, R. 3 W., and on White River in the N. E. 4, Sec. 6, T. 46, R. 4 
W.—they appear in great force, inclining now to the southeastward. Qn Bad 
River, a thickness of 2,000 feet is in sight, trending N. 60° E., and dipping 
S. E. 38°; and on White River, 300 to 400 feet, with a N. 40° E. trend, and 
25° S. E. dip. These southward-dipping sandstones indicate the existence 
of asynclinal in the Upper Division of the series, and explain the wide 
surface spread of the upper sandstones in this region. 
