150 The American Geologist. 
March, 1903 
DEPOSITS NEAR THE HEAD OF COFFEE CREEK. 
In my paper on the ancient glaciers of this mountain le- 
gion, I have described the large Salmon river glacier as ter- 
minating at a slight morainic ridge which crosses the valley 
about one and one-half miles from the present head of Coffee 
creek. Recently I have become aware of the existence below 
this point of apparent glacial deposits. The creek passes the 
morainic ridge in an insignificant trench no wider at the bot- 
tom than the stream. Then the valley floor suddenly widens 
to a plain 100 to several hundred feet wide, about which the 
stream winds in a shallow ditch. This plain has no boulders 
on its surface. It is composed of the over-wash gravels from 
the glacier at the time it reached the moraine. It is bounded on 
either hand by a sort of discontinuous and irregular terrace 
consisting of boulders, cobbles and other rock debris char- 
acteristic of glacial deposits. Serpentine boulders from the 
east side of the valley higher up, are rather numerous, but 
Courtney granite is not as conspicuous as in the glacial area 
above the moraine. The deposit is too coarse to be due to 
stream action in such a wide and here low grade valley. Many 
of the boulders are quite angular. 
The deposits rise from twenty to seventy-five feet above 
the valley floor. They extend to at least a mile and a half 
below the moraine. At that distance, a Courtney granite er- 
ratic weighing many tons lies on the valley slope. The ter- 
race-like form of these deposits seems to be due to their rem- 
nants of a sheet that once floored the valley, but has been cut 
away in the central portion by the erosion of a broad trench 
which was floored by the over-wash deposits of a subsequent 
glacial stage. Like the supposed older glacial deposits near 
the Nash mine, they do not rise high on the slopes of the val- 
ley, which may be significant as the supposed later glaciers 
appear to have terminated much more abruptly. The generally 
aged appearance of these deposits and the erosion to which 
they have been subjected warrant our reference of them to the 
same period of time as the glacial deposits at the Nash mine. 
DEPOSITS AND GORGES IN THE VALLEY OF THE SOUTH FORK OF 
SALMON RIVER. 
About eight miles from the head of the South Fork of 
Salmon river, in Siskiyou county, there is the Thompson Bar 
