EASTERN SANDSTONE AT TORCH LAKE. oot 
quartzes of the quartziferous porphyries, although one might expect to do 
so. In his description of this quarry quoted below, Mr. Wadsworth speaks 
of the grains of the sandstone as furnished with crystalline outlines, and 
regards these outlines as showing the derivation of the quartzes from a quartz- 
porphyry. My sections fail to show any such outlines, but if they occur, 
they are probably rather in the nature of those of the crystal grains so 
frequently met with in the Potsdam sandstone of the Mississippi Valley, 
in which case the crystalline outlines are the result of a secondary deposi- 
tion of quartz upon the surfaces of the originally rolled grains. Rare peb- 
bles of quartz of some size are contained in this sandstone, and patches and 
lines of red clayey substance, which do not show any persistent inclination 
in any one direction. The clayey material often expands into large bunches 
of red clay, forming the usual clayholes, so characteristic everywhere of the 
Eastern and Western horizontal sandstones. 
My description of the rock of this quarry differs from one published 
by Mr. Wadsworth, in which he says— 
In the sandstone quarry at the head of the incline on the Hecla and Torch Lake 
Railroad, the sandstone layers have been regarded as being nearly horizontal. The 
joint planes that form the floors of the quarry are nearly so, having only a slight dip 
to the northwest; but these joint planes cannot be the bedding planes, for we find 
on close examination that numerous layers of coarser material, pebbles, clay masses, 
ete. occur in the rock. These layers extend for long distances through the sandstone, 
and are always parallel, having the same dip, which is N. 45° W. 15°. These of 
course, from their character and regularity, must mark the old planes of bedding, 
while the generally supposed bedding planes are secondary joint planes cutting the 
bedding planes at a small angle. This sandstone has been leached and acted upon 
by water the same as that below the Douglas Houghton Falls, and its feldspathic 
material converted into clay or entirely removed. Part of the materials composing 
the sandstone, especially in the coarser portions, are similar to those in the 
sandstone at Marquette. The quartz grains are partly water-worn, but a large 
proportion are seen to be short crystals formed of the hexagonal prism, terminated 
on both ends by the pyramid, or the usual form found in the acidie porphyritic 
rocks. It appears, then, as the facets of these crystals are comparatively unworn, 
that they were derived from the destruction or decomposition of trachytic and rhy- 
olitic rocks (granitic and quartz-porphyries), the feldspathic material having been 
removed since by water, leaving a quartzose sandstone. It is a question worthy of 
examination whether any other sandstones have been formed from acidic voleanic 
material, from which nearly all the other parts of the rock have been removed by perco- 
lating waters; especially as other sandstones have been said to be composed of quartz 
crystals. 
