ACADEMY OF NATURAL SCIENCES. 387 



Regular Meeting, December 16th, 1867. 

 Vice President Ransom in the Chair. 



Thirty-seven members present. 



The following gentlemen were elected Resident Members : Messrs. 

 William Hamel, P. B. Cornwall, Horace D. Dunn and W. B. 

 Rising. 



Donations to the Cabinet : seven specimens of ores from Greg- 

 ory Yale, Esq., also, a series of samples in bottles, illustrating the 

 chlorination process of extracting gold from the sulphurets, by the 

 same. 



Mr. Goodyear read the following paper : 



Salt Spring Valley and the adjacent region in Calaveras 



County. 



BY W. A. GOODYEAR. 



Having spent some time during the past summer in Copperopolis, and the 

 region lying west and northwest from it, I offer the following observations 

 respecting its topography and geology. 1 will first notice the 



TOPOGRAPHY. 



For a general description of the topography, etc., of Calaveras County, 

 including the main features of the region in question, reference may be made to 

 Prof. J. D. Whitney's Report upon the Geology of California, Vol. I, p. 253. 

 In addition, however, to what is there stated, I will say that Copperopolis lies 

 at the southwestern base of Bear Mountain, the summits of which rise to an 

 altitude of something more than 2,000 feet above the sea. The Gopher Hills, 

 also mentioned in the report, form a well defined and connected, though subor- 

 dinate range, lying to the southwest of, and nearly parallel with the general 

 course of Bear Mountain. This range forms a prominent feature in the topog- 

 raphy of the region for a distance of at least fifteen or eighteen miles southeast- 

 erly from the Calaveras river. Its summits are probably 1,400 feet above the 

 sea, and the lowest break or gap within the distance named is that through 

 which Rock Creek finds its way to the plains below. The valley or depression 

 between the Gopher Hills and Bear Mountain, whose average width is four to 

 six miles, has received the name of Salt Spring Valley. Its general altitude 

 is little less than 1,000 feet above the sea, that of the town of Copperopolis 

 being nine hundred feet according to H. P. Handy's survey of a railroad route 

 from Copperopolis to Stockton. I should mention that for several miles north- 



