The White Pine news. [volume] (Treasure City, Nev.) 1868-1906, 1906-08-17
Prof. Andrew c. Lawson, OF the California State
University issues Bulletin on Geological Con-
iitiOns In Robinson District, Where Rich
Ore Is Drawing Eastern Capital

middle, and in the vicinity of Pilot
Knob at the west end. Besides these,
however, there are numerous prospects
and mining locations throughout the
district.
The extremes of altitude in the dis
trict are 6,440 and l040 at the east of
the district
The paper treats in detail of the
Palaozoic rocks, of the Carboniferous,
the fossils and other characteristics of
the formation.
From an analysis of about one thous-
and samples taken from five thousand
feet of drifts shafts and crosscuts in
the Ruth mine, the PROFESSOR found in
teresting conclusions. His expert
ments showed that on an average the
ore of the mine contained 10 per cent
of pyrite, 8 25 per cent of iron and 2.61
per cent of chalcocite. The average
copper content of the ore was finally
estimated to be about 3 per cent.
There is large body of this class of
ore, and some of it in patches run as
high as 10 per cent in copper There
are no we'll defined limits to the ore
body except the oxidized zone above
the dyke of the minette on the north
east
: The conclusion is that it is quite prob
: able that the porphyry on the north
e side of the dyke below the zone of OK
y idation is impregnated with chalcocite
: just as 1t is on the south side. In fact,
s the general conditions of deposition
S lend much support to the belief that a
G large part of the porphyry mass below
s the zone of oxidation will be found to
|, carry more or less copper and will be
/. we'll worth prospecting, particularly
s where the Gaping of quartz blout is
/, strongly developed
u COPPER FLAT is LIKE RUTH.
At Copper Flat the general coudi-
. tions are analogous to those at the
Ruth. There is the same porphyry in
trusive in Carboniferous limestones,
and although, as the map shows, this
area of porphyry is separate from that
of the Ruth, yet the two may be con-
n tinuous in depth The fact that, on its
n western border, the porphyry of the
: Ruth are plunges beneath the lime
s stone, while that of Copper Flat, on
v it's eastern border, passes similarly be-
!. meath the limestones in the opposite
a direction, renders this subterranean
continuity of the porphyry of the two
t areas quite probable. On the hills
S about Copper Flat there are remnants
/ of a once extensive body of quartz
e blout. In general it is difficult to spec
: ify any significant difference in the
general conditions affecting the por-
n phyry and those which prevail at the
S Ruth. Yet in one important particular
e the porphyry regarded as an ore of cop
n per is very different from that at the
: Ruth. This difference lies in the fact
that, in the zone Of oxidation, the cop
a per ores, over a very considerable acre
age at least. have not been leached out
q of the porphyry, but have been fixed
: in the form OF carbonates. Over ar
t area of perhaps ten acres numerous
4 prospect pits have been sunk in the
+, porphyry and show very general i'm
t pregnation of the rock with green and
S blue carbonates and carrying on the
average an attractive percentage OF
: copper, said to range up to per cent.
S Many of these pits are fairly deep ano
e the dumps about them show that the
: copper carbonate extends to their bot
: tom. Not having had access to the
record of these prospect pits or to the
t assays of the samples taken from them
n the writer can form no very exact idea
S as to the depth and value of the ore
: The exposures are, however. excellent
S and enough is apparent at the surface
z to warrant the statement that there Is
: vast tonnage in sight, both of unoxi
t died and of oxidized ore, that could bt
d mined by steam shovel methods.
C Continuing his discussion, the profes
Tra,, or, r,a no fbreal