Eureka daily sentinel. [volume] (Eureka, Nev.) 1871-1887, 1882-03-17
METALLIFEROUs VEINS.
Professor LIE COnte Gives His Opin-
ion Upon Their Formation.

ion Upon heir Formation.
At a recent meeting Of the San Fran
cisco Academy of Sciences. Professor
California read a paper on the subject of
the formation of the "Metalliferous
Veins" in which he gave the results Of
the joint investigations of Professor W.
D.. Rising and himself on the active for
nation of a metalliferous vein now in
progress in Lake County, on the ground
Of the Sulphur Bank Quicksilver Com
pany. Professor LIE Conte said metal
liferous veins were still forming there, as
they were also now at Steamboat Springs,
in Nevada. He has watched the opening
Of the Sulphur Bank Quicksilver mine
since 1877. He spoke Of the Coast Range
as very complex in its formation, being
cretaeeous and tertiary, and ascribing its
birth to the end Of the miocene period.
1t differs widely from the Sierra
Nevada formation. which is a very simple
one. North OF San Francisco the Coast
Range is composed of eruptive rocks. The
country rock is all oyerlaid with lava. st.
Helena and Uncle Sam, each 1000 feet
high, were once volcanoes. At Clear Lake
volcanoes have flooded the surface over
strata of sandstone and shale. In this
region have been many hot springs. or
solfataras, emitting carbonate suiphurets.
The time Of volcanic activity was at the
beginning Of the pliocene and continued
much later, perhaps through a portion OF
the quartenary period. The sulphur bank
at the surface resembles ashes, but lower
down pure silica is found. Sulphur ap-
pears first near the surface, but does not
continue deeper than q few feet. Deeper
the vein turns to ~cinnabar, though blue
clay is found and much free %sulphuric
acid. Silica, half consolidated, is found
10 a cheesy condition, streaked with Gin
nabar and iron pyrites. The work OF the
miner is now interfering with natures lab
oratorv, for a metalliferous vein is in pro-
cess Of decomposition in a assure between
sandstone and shale, whose strata stand
nearly erect. Carbonic acid bubbles up
so as to frequently extinguish candles. A
paste of cinnabar, silica and iron pyrites
was found in all stages, sometimes gelatin
Gus, then cheesy and quite solid. Some
brought away in a cheesy state soon solidi-
fied. These two different kinds OF chemi-
cal action are taking place; the primary is
q solfataric action coming up through ifs
sures in the lava cap from below, and a
secondary action is working from above.
The deposit of sulphur Is SUPERFICIAL.
Water descends from above, bearing many
things in solution. He said the original
volcanic rock is changed by acid vapors,
ETC., into pure chalky silica or quartz In a
pure plastic state, also into chalcedonic
state. The latter condition is when it de-
posts from a hot liquid, colling rapidly.
Under other conditions it forms in six
sided crystals when deeper from the SUR
face.
The Bodie Free Press says: II Profess
sor LIE Conte should visit Mono County he
would find at Bridgeport veins OF metallif-
erous quartz forming, through the action
Of hot springs, in the plainest and most
unmistakable manner. We consider the
Bridgeport Hot Springs one OF the great
est natural curiosities on the Pacific Coast,
and one of the most instructive. upon the
subject OF the formation Of metalliferous
veins,