Reports of explorations and surveys, to ascertain the most practicable and economical route for a railroad from the Mississippi River to the Pacific Ocean: Vol. 5, Pt. 2

GEOLOGY.
The outcropping layers of hard sandstone were visible in the hills on each side, the intermediate portion (between the hills) having been removed by denudation. At the highest part of
the outcrop of slates, a quartz vein, five feet thick, stands out above the general surfac, and
UNCONFOR,ABILITY O F S.I,bhILATES ANDm' I SADTONE.
UNCONFORMABILITY OF SLATES AND SANDSTONE.
forms a wall-like mass of fragments. These, being milk-white, contrast strongly with the black
slate on each side. This quartz has preserved the surrounding slate from abrasion by currents
of water, and thus it stands at the summit of a little eminence.
Numerous continuous outcrops of quartz veins of great thickness could be seen on the slopes
of the higher ridges, several miles distant. Even where the surrounding rocks were buried in
soil, the presence of the veins was shown by great loose blocks of the quartz lying in long lines
on the surface.
A quartz vein outcropping near "Burns' creek" was associated with a bed of compact
hydrated peroxide of iron, the whole being nearly twenty-five feet thick. The quartz was much
stained with iron, and the whole outcrop presented a dark chestnrut-brown color, except where
REMNANT OF A STRATUMI OF SANDSTONE.
covered with mosss and lichens, these being of the most brilliant and various colors. Large
blocks of the iron ore, and slate permeated with it, were lying around the outcrop; many of the
14