The principal mine of this district, and the one which gave the camp its
fame, is the Carbonate Mine. It was discovered by a man named Collins,
who was working in a lime quarry near by. Collins found croppings of
ore—limonite and manganese—containing silver. He developed the property
somewhat, but it finally passed into other hands, and is now owned by a
Los Angeles company, which has opened the mine quite extensively.
The formation which incloses the vein has a general trend northeast and
southwest, the dip at the main workings being not over 20°. Here an
inclined shaft has been sunk to a depth of 225 feet on the vein. At the
bottom the shaft has attained a vertical depth of about 100 feet. Two
veins of ore, consisting principally of silicious and earthy iron oxide
and black oxide of manganese with carbonate of lime, sometimes
crystallized, extend from the surface to the bottom of the incline.
These veins are very irregular in size, varying from a mere seam to
upwards of 2 feet in places.
The value lies in the lead carbonate and silver which accompany the
gangue minerals. The two veins are curiously formed at contact with
massive blue limestone and mica schist. The schist is from 1 to 4 feet
in width, the ore lying both above and below it, the whole being
inclosed between hanging and foot walls of crystalline limestone. At
various points in the workings is a light-colored, much decomposed rock,
resembling felsite, which has the appearance of having been injected
between the strata in a thin sheet. It is a notable fact that where this
buff-colored, granular appearing rock occurs in contact with the vein an
enrichment of the ore is noticeable, and its absence is marked by the
low value of the ore or no ore at all. In this incline, at a depth of 40
feet, a short drift has been run in on ore of good grade. At 180 feet
from the collar of the shaft the discovery was made that caused this
mine, and, in fact, the entire camp, to become at once the scene of
excitement.
At this place a small wedge of crystalline, granular quartz and calcite
appeared, and with it flakes of free gold. Just below the point of this
discovery the wedge widened to several inches, and the rock was a mass
of glittering sheets and shot-like pieces of gold. Assays of the
material gave fabulous returns. The ore was broken down on canvas, and
every ounce of it sacked on the spot. This was followed down some
distance, but gradually thinned out below the 200-foot level, where
drifts were run, one 50 feet northeast, the other 40 feet southwest.
From these drifts considerable rich quartz was obtained.
In the southwest drift the formation is badly displaced and broken and
the vein is lost, a fault having thrown it, but whether up or down could
not be determined, as the adjacent rock was so badly fractured. Ore was
found at the face and along the sides of some of the cuttings, and some
free gold was found on the 200-foot level in the southwest drift. All
work on this part of the mine had been suspended some time prior to my
visit, the mine having been enjoined.