Bisbee daily review., 1908-11-22

Notes on the geology of the Eureka
(Hachita) districts of New Mexico.
taken for the FL Paso Mining Journal
by X. Prather.
'Hachita, Grant county, New Mexi-
CO, is located on the Ell Paso & South
western railway, lit miles west of Ell
Paso, Texas, and like distance from
Bisbee, Ariz. The new camp of Syl-
vanite is about u miles from Hachita
''The rocks of this region consist OF
limestone belonging to the mesozoic
period; a yellow sandstone, and ig-
neous rocks of various kinds, as well
as some matamorphics, mari, shale
and schist are also found IN some
parts of the district
From about the Copper Dick prop
erty to Granite Gap (Which district
includes the town of Sylvanite. the
rock is chiefly an ardesite and often
SO fine-grained that 1t would be
classed as a felsite. This rock is cut
up by dykes and veins and some sam
pies show a good deal of oliyene
through the rocks.
Another marked feature is the
hills which are dark-colored from the
iron deposited through the rocks.
Many samples OF the rock taken
over the district show mineral dissem-
mated through 1t. There is some lime
stone near Sylvanite, but most of the
rock can be classed under the gener-
al name Of porphyry. Towards the
end of the hills, abolt two miles from
Sylvanite, in the direction of Granite
Gap, there is schfst and beyond this
are three small limestone hills. Some
of the rock rings like phonolyte, but
did not see any which would class
as a true phonolyte. Granite Gap
makes an extensive break in the rock
The light colored granite weathers
very easily and 1t has been consider
ably eroded here. The rock on the
other side of this break contains more
quartz through 1t and shows little
mineral. The granite weathers into
huge boulders. Through the granite
are dykes of porphyry, about 10 TO
Is feet wide, running northeast and
southwest. At one place ! noted a
50O-foot break in one of these dykes
These dykes are often quite persis-
tent and some of the veins noted were
found to cut across at right angles
to the dyke
In the main grIlch where the prop
critics are located which are being
worked, the hills are lower and show
the effects of erosion and disintegra-
ton. They are of a yellow color.
THE other part of the district is
about as follows: Opposite Livermore
Springs the hills are of rhyolite-por-
phyry and show practically no miner
al The rock varies in color from
light to dark and shows several flows
An intermediate period is marked by
an igneous conglomerate about 40 feet
thick.
"On the other side of these hills
Of rhyolite-porphyry is a valley and
beyond it other hills Of the same
rocks. Beginning on the Hachita road
not far from the Copper Dick proper
ty is range of limestone hills which
extend across to the plain below They
belong TO the mesozoic period and CON
tain fossils. but I did not determine
any of them. This limestone appears
to contain little mineral, but the veins
of rhyolite-porphyry cutting it at
right angles show some quartz and
agate. Extending parallel to this, and
between the limestone and the rhyo-
lite-porphyry, is a brown sandstone
containing more or less iron. This is
in some places quite compact, and in /
others the grains are not so closely !
cemented together. Beyond these |
limestone hills and near the town of |
Old Hachita, the rocks cover a pref !
ty wide range, from obsidian and |
pitch stone to volcanic conglomerate |
There is limestone and porphyry with /
veins and dykes where the American,
King and other mines are located |
copper, lead, silver, gold and zinc be-
ing the minerals found, together with /
some turquoise.
F. P. Earles, manager of the III
Paso smelter:: Our tests of the
metal in the ore from Sylvanite show
the same to contain teliurium, gold,
as well as bismuth. II is probably
telluride of bismuth. Our tests have
not demonstrated in what manner,
but beyond a doubt we find the gold
with this telluride"
S. ]. varney OF Varney q Dillon,
the assayers at the camp I'VE have
made about lis assays and had about
i've showing only a trace of gold. and
The rock runs up to $4,000. Have had
Dne sample giving $1,000. and about
twenty that run over 800 The rest
AN be calculated between a trace and I
300. II Is one of the greatest miner |
'lized sections ever saw. The Goat .
,uns exceedingly well. We know this
because during the rush men entirely
with rock or mining !
nave br0asbT hand samples and while
We looked for n good many showing !
nothing. the fact is that practically
carries some value. think