HEAD OF CALIFOBNIA GULCH. 513 



bodies of Gray Porphyry, whose position and structural relations are very 

 imperfectly known. For these reasons a considerable concentration of ore 

 might naturally be looked for in this region, but it would probably be found 

 more irregularly distributed and less easy to follow than in the normal 

 groups of Carbonate and Iron Hill. The ore currents would no longer 

 have been confined to one or two principal channels, but would have had a 

 variety of contact planes which they might have followed, and whose posi- 

 tion cannot be predicated beforehand. Unfortunately the small amount of 

 exploration already made not only gives but an imperfect idea of the actual 

 geological relations of the various bodies, whose representation on the map 

 and sections may in consequence be somewhat imperfect, but the actual 

 development of ore has been so slight as to afford no indication as to what 

 particular contact is the more likely to contain ore. The normal contact of 

 Blue Limestone and White Porphyry extends eastward from the Pilot fault 

 along the north slope of Printer Boy Hill, until in the Eclipse the limestone 

 commences to wedge out Ore is found in considerable quantity in the Pilot 

 tunnel, apparently along the very plane of the fault, and a certain amount 

 of vein material occurs at the contact in the Lovejoy, Eclipse, and other 

 shafts. On the other side of the gulch the same contact that carries ore in 

 the Adelaide-Argentine, viz, Parting Quartzite and White Porphyry, is found 

 in the Iron Duke and others and is apparently mineralized to a certain 

 extent. 



GOLD DEPOSITS. 



Between Pilot and Mike faults, on the northwest slope of Printer Boy 

 Hill, is a body of porphyry not identical with any other found in the region 

 and which is notable for containing the Printer Boy and Five-Twenty gold- 

 bearing lodes. 



The Printer Boy lode was discovered before the existence of carbon- 

 ate ores in this region was known, and produced a large amount of gold 

 between 186G and 1870, of which no record can be obtained. It is a prac- 

 tically vertical deposit along a jointing or fracture plane in the porphyiy, 

 having a direction a little east of north. It now consists of two claims, the 

 -Upper Printer Boy and Lower Printer Boy, each opened by vertical shafts. 

 MON XH 33 



