‘119 
“The banks of Pit River, both above and below the 
mouth of Canoe Creek, are partially formed by regularly 
stratified, sedimentary deposits: the first seen since leaving 
the valley of the Sacramento. They appear on both sides 
of Pit River, at intervals, for several miles, being in many 
places interrupted or covered by beds of trap. They are, 
perhaps, best exposed in the cafion formed by the passage of 
the river through ‘Stoneman’s Ridge,’ the most conspicuous 
of the lines of upheaval, which form what is known as the 
lower cafion of Pit River. They here exhibit a thickness of 
about fifty feet, but are considerably tilted up, and are covered 
by a thick bed of trap, which has been poured out over them. 
They exhibit narrow and parallel lines of deposition, but 
are very homogeneous, and can hardly be said to form more 
than two distinct beds. Of these, the upper is white, resem- 
bling very pure Kaolin, derived from the decomposition of 
erystaline Felspar. The lower bed is light brown, or dirty 
white in color, and has a slightly gritty feel between the fin- 
gers. Thesestratarest upon a thick bed of rolled and round- 
ed fragments of traps, porphyry and basalt, of all sizes, from 
masses of two and even three feet in diameter, to pebbles. 
They are generally as large as one’s head, and great numbers 
are each a foot in diameter. The surface of this bed of bowl- 
ders is, perhaps, twenty feet above the present surface of the 
stream; but it bears indubitable evidence of having, at one 
time, been covered by it, or, at least, the’stones composing it, 
so large and clear, have been rounded where they lie by a cur- 
rent or waves of water. The appearance presented by this 
bed of bowlders, is different from that of any of the beds 
of volcanic conglomerate, which are so common in many 
parts of California and Oregon, or of the stratified conglome- 
rates of the Sacramento Valley, and it is undoubtedly of local 
origin. The trap which formed the greater part of the bank 
above, is evidently of recent date; more recent than the 
infusorial marls, and the marls more recent than the conglom- 
erate, and the conglomerate an accumulation of rolled stones 
and pebbles, which belongs to the present epoch. The trap 
which overlies the infusorial marls, composes a large part of 
