510 THE BLUE LEAD THEORY. 
Exceptions to this statement may be found, of course, and bodies of gravel are by no means rare 
whose general color to-day is largely due to the original character of the rocks from which they 
were derived. But the general rule is as stated above. 
Another objection to the whole blue lead theory, and one which to my mind is insuperable, 
lies in the simple fact that this theory presupposes or of necessity involves a great subsequent 
upheaval of the whole Sierra Nevada, as it is evident that at no time since the upheaval of the 
range could any river have flowed far in a southeasterly direction along its southwestern slope. 
Moreover, the subsequent upheaval which this theory requires is not merely a moderate lifting, by 
which the altitude of a previously existing range might have been somewhat increased, but a grand 
and general uplift, essentially creating and calling into new existence the Sierra as a mountain- 
range ; for, otherwise, the same objection would still hold good against the direction of its rivers. 
However low may be the crest of a range of mountains, if it exist as such at all, or if the country 
has even a very light general slope, the rivers do not run far in the directions of the contour 
lines. 
Now I do not know of any evidence whatever to prove that any such upheaval as this has 
occurred since the gravel period. On the contrary, there is abundance of evidence which appears 
to me very strong as tending to show not only that no such upheaval has occurred, but also that 
no considerable disturbance of any kind whatever has occurred in the auriferous slates or in the 
mass of the range itself since the earliest gravel period. Indeed, I do not believe that since that time 
there has been sufficient disturbance of the bed-rock in any part of the Sierra where I have been 
to influence to any perceptible extent the general flow of even the smaller streams. The streams, 
both large and small, have changed their beds indeed, but it has been in another way and from 
another cause. 
A fact which, in connection with other things, appears to me conclusive as evidence that no 
considerable disturbance of the bed-rock has occurred since the gravel period, is the almost total 
absence of local disturbances since that date. It is difficult to believe that any considerable 
general disturbance of such a range of mountains could occur at any time without producing at 
the same time numerous smaller and local disturbances in the way of faults, dislocations, bendings 
of the strata, ete. 
If such disturbances as these had occurred since the deposition of the gravel banks, then these 
banks themselves would have been correspondingly disturbed and faulted, and their sections would 
exhibit it when they came to be worked. Such things do indeed exist, but they are extremely 
rare ; and I do not know of a single instance where such a disturbance exists of so great a magni- 
tude that it may not be reasonably attributed to earthquake shocks not greatly exceeding, perhaps, 
in violence some which are already on record as having occurred within the State. I may say 
that, in all my travels in the gravel region, I met with but a single case of such a disturbance (the 
one at Yankee Jim’s) in which I considered the proof absolute and unquestionable that the dis- 
location was more recent in date than the gravel period, and here the amount of displacement was 
only some twelve or fifteen feet. Other possible localities are King’s Hill, between Indian and Shirt 
Tail cafions, the Dardanelles, Flora’s claim below Volcanoville, the Castle Hill ridge a little way 
above Georgetown, and Spanish Hill near Placerville, though I consider some of these as very doubt- 
ful, to say the least, and there has certainly been no great displacement in any case. Moreover, the 
bedding of the gravel is almost everywhere horizontal, or very nearly so ; and, excepting at Yankee 
Jim’s and perhaps two or three of the other localities named, I never saw this bedding distinctly 
broken or otherwise disturbed or bent to such an extent as could not be readily accounted for by 
the action of the shifting streams which deposited it, or else by special and wholly local causes, as 
in the cases where the gravel rests upon the limestone. , 
When these things are considered in connection with the facts respecting the present directions 
and grades of the ancient channels in the bed-rock, wherever these have been distinctly and defi- 
nitely traced, and with a multitude of other facts in the distribution and structural arrangement 
of the gravel itself, all pointing in the same direction, I consider it proved beyond all reasonable 
