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FORMER VIEWS OF GEOLOGISTS IN REGARD TO THEM. 71 
article written by Mr. C. 8. Capp, and published previous to 1859,* he de- 
scribes the so-called “ Blue Lead,” to which allusion has already been made, 
and traces it from Sebastopol in Sierra County across the North Yuba, thence 
to the Middle Fork of that river, by Forest City, Chip’s Flat, Centreville, and 
Minnesota. Here, he says, “it is obliterated by the Middle Fork of the Yuba, 
but is believed to be again found at Snow Point on the opposite side of the 
river; and again at Zion Hill, several miles beyond.’+ Of this “lead” he 
says, “it is evidently the bed of some ancient stream, because it is walled in 
by steep banks of hard bed-rock, precisely like the banks of rivers and ravines 
in which water now runs, and because it is composed of clay which is evi- 
dently a sedimentary deposit, and of pebbles and black and white quartz, 
which could only be rounded and polished as they are by the long-continued 
action of swiftly running water.” 
These views, however, met with much opposition on the part of the miners 
and others. Mr. B. P. Avery, afterwards editor of the Overland Monthly and 
United States Ambassador to China, thus wrote, in 1859, in reference to Mr. 
Capp’s description of the “ Blue Lead”: ‘It is remarkable that the ma- 
jority of our miners, who are commonly men of intelligence and practical 
knowledge in their pursuit, should have discarded entirely, if they ever enter- 
tained, when speculating upon the origin of our gold fields, the more rational 
theory of marine influence, for one of purely local causes. They overlook 
all the facts which go to prove a total submergence of this coast at some 
remote period, and settle down upon the narrow idea that the immense 
gravel beds which contain so large a portion of our mineral wealth, and 
which extend at least four hundred miles north and south, having an aver- 
age breadth of probably not less than sixty miles, were deposited by rivers, 
which anciently ran here, and changed their channels from time to time, 
until they paved the whole country with cobble stones. These deposits 
have been cut through by modern streams, running a different course, and 
hence the present cafions and ridges. Of the ancient rivers, the one that 
deposited the blue lead has alone left distinctive marks of its course. Now, 
unfortunately for the plausibility of this theory, the blue lead is found all 
the way from the summit of the Sierra to the foot-hills. Instead of being 
confined to a certain altitude, and a certain line, it exists in every alti- 
* This article probably appeared in the San Francisco Bulletin ; it is quoted by Mr. Hittell in the book 
above mentioned, published in 1861, but without indication of date or origin. 
+ See Map at the end of this volume, which, however, does not extend north of the Middle Yuba. 
