292 



RESUME AND THEORETICAL DISCUSSION 



endeavor will be made to set forth that which may now be considered as 

 quite clearly established in reference to the original mode of deposition and 

 character of the auriferous gravel deposits of the Sierra. After that has 

 been accomplished, the way will be clear to take up some of the more difficult 

 and controverted points, the writer hoping that in thus doing he will be able 

 in the discussion to throw light on some of them. 



After these preliminaries, the remainder of this chapter will be devoted to 

 a resume of certain portions of the investigations embodied in the present 

 work, in regard to which it seems desirable that the salient points should be 

 brought together into a convenient form for a rapid review, for such persons 

 as would not desire to make themselves acquainted with the mass of local 

 details with which some of the essential facts are encumbered in the descrip- 

 tive parts of this volume. 



I 



Section II. — What 



of 



In a previous chapter there has already been given a partial discussion of 

 some of the more prominent points connected with the theory of the occurrence 



of the gravels* 



This was done in order that the reader might have the pre- 

 liminary information necessary for understanding the details which were to 

 follow in regard to the nature and distribution of the various formations, to 

 the special study of which this volume is devoted. It now remains to take 

 up the more doubtful points suggested in the course of the investigation, and 

 to devote especial attention to such of these as seem to require such treat- 

 ment, and which the reader who has gone over the details embodied in 

 the preceding chapters and Appendix A will now be better prepared to 

 understand. 



The present section is introductory to such a review and general discus- 

 sion, its object being to clearly distinguish between those points in regard 

 to the theory of the gravels, which are so well made out that it is proper 

 to assume that there will be no difference of opinion about them, and, on 

 the other hand, those which are more obscure and which therefore may 

 suitably be laid before the reader at some length, and not without admitting 

 that there are certain things which cannot yet be made so perfectly clear as 

 to warrant the expectation of entire unanimity of opinion in regard to them. 



* See ante, pp. 53-78. 





i 



