GOLD OF THE SANTA ANNA—METAMORPHIC SLATE ۱ 61 
geology. Thus, starting from the summit, the first four miles of descent is between the hard 
granites that rise in rounded edges on either side, and the valley between them is fertile and 
well wooded. For the next three miles the granites are more laminated and slaty in their 
structure ; tliey offer less resistance to the wearing action of the stream, which has cut a more 
deep and narrow channel, and commences to descend abruptly, winding about in a series of 
rapids between rocky and angular points of the granite and metamorphic rocks that rise on 
each side like walls. Beyond the granite is the belt of sedimentary strata, consisting of sand- 
stones and conglomerates. Here the hills are lower, the valleys more numerous and open, and 
a view of bold escarpments, formed by the ridges of highly inclined strata, is presented on both 
sides. Still lower down the pass, the sandstones are not so much disturbed, and the outlines of 
the hills become more curved ; and near the lower outcrop of the auriferous slates, the surface 
is gently undulating. The adjoining slates, however, present sharp, angular outlines, cut by 
abrupt and rugged valleys. They are also covered with trees, while on the sandstones the 
vegetation is thin and diminutive. 
SAN FRANCISQUITO PASS TO THE MOJAVE RIVER. 
October 15.—After we had completed the survey of the Pass of San Francisquito, we returned 
to the narrow, elevated valley of Lake Elizabeth, and turned to rejoin the wagon-train and 
escort, which were encamped several miles eastward in a valley where grass and water were 
abundant. The continuation of the sandstone hills, already partly described as extending along 
the Lake Elizabeth valley, was found on our right for about eight miles. Similar formations 
appeared to flank the ridge on the left or north of the trail. Opposite the camping place, 
marked 15th on the map, these sandstones and clay strata were visible on the north, and 
appeared to separate the valley from the Great Basin, and they were continuous in a series of 
low hills for several miles beyond. The debris of micaceous slate, somewhat similar to that 
found in the Pass of San Francisquito, was observed in this vicinity ; and soon after, an outcrop 
was passed. The rocks have a dark bluish-gray color, and hornblende in long, slender, 
imperfectly formed crystals is disseminated throughout some portions, in planes parallel with 
the bedding. Quartz veins were also seen. The bedding of the slates has an inclination 
towards the north of from 30 to 40 degrees. Two or three miles beyond this outerop we 
reached the camp of the main party in the centre of a wet, swampy valley, where the grass and 
water was abundant. "The party having killed a wild cow, fresh meat was abundant, and the 
camp was afterwards known as the Cow camp. It was about thirteen miles southeasterly from 
the entrance to the Pass of San Francisquito. 
The hills immediately south of this camp rise to a very considerable elevation, and are, in 
fact, the lower ridges of the main chain. They were found to be composed of slaty rocks, simi- 
lar to those just described. They assume, by almost insensible gradations, a more granite-like 
structure, and feldspar was abundant in small granular masses, invested with micaceous films, 
80 that the rock, when broken transversely to the lamination, resembled a fine-grained granular 
porphyry. Quartz veins are abundant in this rock, and are generally in narrow seams, very 
near together, and preserving parallelism between themselves and the bedding of the rock. 
Their trend was taken in several places, and found to be N. 70° E., and the dip S. 75°. 
' The resemblance of these rocks to the slates in the Pass of San Francisquito was so striking 
that I could not but consider them as connected and of the same formation. There is little 
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