New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1880-08-02

canic rock which according TO Professor Newbeuy
who visited the district last autumn was poured
out and consolidated during the tertiary period.
How great the extent of this deposit from north
west TO southeast -. do not know but Its width
IA at least five miles and its length is probably ff-
teen or twenty. Extending into the trachyte for
nation from the southwest aud follOwing its general
direction s a tOngue-shaped mass of granite about
three-fourths of a mile wide and at least seven or
eight miles long. When the trachyte was poured out
this granite apparently formed a ridge which rose
above the level of the fluid of the surrounding
volcanic rock and therefore not covered by It,
That 1t does not now stand higher than the sur
rounding country does not disprOve tins theory
because there are everywhere to be tound evidences
of terrible commissions since the trachyte was de-
posited which have completely changed the face Of
this entre region. The mines here are found both
In the granite and also IN the trachYte. Winding
through the porphyry IN serpentine course there Is
also a stream of obsldlan, as it is called here.
volcanic glass mixed with trachyte and quartz
boulders. This stream where it has been examined,
varies from few feet - many rods IN width, and
In crevces of the boulders which form the mass Of
il were found last week. the Hecla claim, some
very rich specimens of horn silver
The natural color of the trachyte 10 yellowlsh-
white When it contains silver it IS also generally
stained with black oxide of manganese and red OK
ide of iron. THIS rock in many places seems to me
to have been subjected 20 the action OF water be-
tween the time 1t was thrown out by volcanic
action and the period when 1t was broken up and
! impregnated with mineral solutions | am led TO
this conclusion by the fact that several mines and
| prospect holes which have visited have found
| portons of the rock as distinctly stratfed any
CLAW slate | ever saw. The layers of rock came
apart one from another in the hand, and presented
smooth faces Of qualification | have never
this fact mentioned in any report have read about
the mines of this region, and it may not BE- Import
ant. though il certainly IS interesting.
TIE Distribution or SILVER.
At Silver Cliff and north of here, especially, the
tracbyte rock has been shaken up and fractured in
all directions and in many places the crevices have
been filled with iron and manganese, which has be-
cone oxdzed, and with chloride OF silver. This Is
the free milling ore which is found in the Racine
Bow and silver Cliff Mines owned by the Silver
Cliff Company, in the Plata Verde. and IN all the
mines that lie directly north of this town and adj
inning it. | shall write detailed descriptions of
several of the more important of them IN letters that
are 10 follow. Generally the chloride Of silver is so
widely distributed through the rock and is so small
in onantity that IL cannot be with the naked
ave nor even with a powerful magnifying glass
That II IL there however. Is conciusyely proved by
assays. Captain Turner, of Galveston, Texas, an
old California miner. who has spent several