W. P. Blake on the Gold Region of California and Oregon. 81 
Copper pyrites is also found in a vein about seven miles below 
the summit level of the New Pass, which leads from the Great 
Basin to the valley of San Francisquito. This vein outcrops on 
the southern slope of a granite hill on the north side of the Pass, 
and is about 90 feet above the bed of the creek. The ore resem- 
bles in its luster and color the variegated copper pyrites, but is 
much softer. 1t is found in strings and narrow veins distributed 
through a hard quartzose gangue about fifteen feet thick: the 
thickest seam of ore, however, does not exceed two inches; 
but when several such were closely combined a thickness of eight 
inches of good ore was seen v 
his vein has been prospect cted and a small quantity of ore 
broken out. It is about sixty miles distant from Los Anggie PY 
the trail. 
Native Copper and Red Oxyd of Copper. When visiting 
Camp Yuma at the junction of the Colorado and the Gila rivers 
in Dec., 1853, several large masses of superior copper ore were 
shown to me b the officers of the fort. ‘This ore was brought 
from the adjoining State of Sonora, Mexico, and the vein is re- 
ported to be near Altar. It is within the limits of the strip of 
territory recently acquired by purchase and is therefore now in the 
United States. B peciggame teat ueptly brought in by emigrants 
who cross the Col at the hey below the fort. The ore is 
pe ally the red Poxyd of copper associated with the pure metal 
o 2 crusts of carbonate. The specimens that I saw ought 
6 yield about ninety p.c. of pure copper. This is probably the 
ore that has recently excited so much attention in California, and 
has been reported to be highly charged with gold. 
alaveras Co.—Native Copper a ilver—A specimen of 
pure copper combined with silver is reported to have been found 
ina placer mine near Mokelumne Hill. ‘The specimen was ex- 
hibited in several places and sent to San Francisco, but 1 have 
not been able to obtain any reliable ee concerning it, or 
the circumstances under which it was 
RON oRES.— Mariposa Co., Bae oe —Limonite.—An 
outcrop of hydrous sesquioxyd of iron or limonite occurs near 
the banks of this creek, on the right of the road going south. It 
€ ore outcrops in great solid blocks from two to four feet in 
diameter : it is compact, of a dark brown - and breaks with 
a smooth conchoidal fracture. The position and peculiarities of 
pyrites, and that it forms the “gossan” of a vein of sulphuret be- 
w the surface. The mass does not, however, present that 
ahi a and friable condition in which gossan is generally 
ound. 
; - Seconp Serres, Vol. XX, No, 58.—July, 1855. i 
