DEPOSITS NEAR NEW IDRIA. 309 



rich, and a considerable quantity was extracted and delivered at the New 

 Idria furnaces. Tiie deposits were ver}" irregular and no considerable at- 

 tempt seems to have been made to develop the property in depth. The 

 Aurora or Morning Star mine, to the west of the San Carlos, also yielded ore. 

 Beyond the fact that excavations were made here nothing is visible. Near 

 the falls on San Carlos Creek, in a line coiniecting the New Idria and the 

 Morning Star, a little cinnabar is said to have been found, and traces of ore 

 have been detected at other points, all of which, except the Washington crop- 

 pings, ;ire within the metamorphic area. 



Within a few miles of the area mapped and to the southwest, several 

 mines have been opened and again abandoned. The Picacho is in the usual 

 contorted, highly indurated rocks, partly silicified and partly converted into 

 carbonates. The ore appeared to have occurred in cracks across the strata 

 and along the partings.^ It is said that the first continuous quicksilver fur- 

 nace ever built in the State was erected here by Mr. John Roach. This 

 structure was still in place at the time of my visit, in 1884, and substantially 

 in the same condition as when it was examined by Mr. Goodyear thirteen 

 years earlier. Several pounds of quicksilver still remained in the wooden 

 condenser, showing how slowly quicksilver must volatilize, even at the 

 high temperatures which prevail in this region during the summer. Near 

 Clear Creek also are two mines, or prospects, at which ore associated with 

 rocks of the same type as at the Picacho was extracted. 



' In a prospectus of the company an assay is given according to wliicli, besides mercury, tlie ore 

 contains considerable amonats of botli gold and silver. I did not have an opportunity of verifying 

 this statement, which is not intrinsically improbable. 



