The Auriferous Gravels of the Sierra Nevada of California Volume 6, No. 1
This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1880 edition. Excerpt: ...the detailed descriptions given on the preceding pages, is often several hundred feet in thickness and spread over wide areas. And in endeavoring to give a satisfactory explanation of the position and magnitude of the older gravel deposits, we shall have brought up for consideration a great number of minor problems, the solution of which is involved with that of the other main questions. The nature of these problems will become evident during a perusal of the following sections of the present chapter, and it will not be desirable to take the space which would be necessary for stat-ing them, in advance of their presentation in the proper order as developed in the ensuing pages. SECTION III.----T he General Dz'slm'lmlz'012 qf the Del: -ilal and Volcanic lllalerials on lhe West Slope of llze Sierra Nevada. In proceeding to a general discussion of the phenomena of the gravel deposits, it will be desirable, in the first place, to give an account of their geographical distribution, and of the various materials of which they are made up. In considering the position of the hydraulic mines of California, one could hardly fail to be struck at once with the fact that they are concentrated within quite a limited space as compared with the whole area of the State. It will also be apparent that gravels which' are auriferous in character occur where no hydraulic mining has been attempted; and, furthermore, that large deposits of superficial detritus exist where no mining at all is carried on. Each of these conditions has its special and rather complicated set of causes, the nature of which has already been explained, to some extent, in the preceding pages,"" but in regard to which a few words must be added in the present connection....
- 189 x 246 x 18mm | 603g
- 13 Sep 2013
- Illustrations, black and white