The Arizona copper camp. [volume] (Ray, Ariz.) 1910-1920, 1917-01-06
Or. WALTER HARVEY WEEDS
REPORT ON THE MAGMA CHIEF
FAVORABLE FOR DEVELOPMENT

canyon above the town of Superior.
This simple monoclinal structure is
broken, but is not obscured by fault
ing. great strike fault runs from
Queen Creek through the town of Su-
perior and the portal of the Magma
tunnel up the gulch which extends
northward from Magma mine This
fault brings limestone of carboniferous
age against diabase and quartzite.
There are also numerous cross frac-
lures running at right angles to the
exposed edges of the limestone bed
The best known of these faults is the
Gated. There are at least six we'll
marked cross faults in the Black Rock
group north of the Magma and two
prominent faults in the Magma Chief
group, besides numerous lesser faults
whose position has not yet been posi-
lively determined.
Owing to difference in composition,
color and texture of the sedimentary
beds and to the pressure Of the under
lying diabase, the recognition of these
fault fractures is not difficult. In the
Magma vein the displacement is about
500 feet and the drop is towards the
south, as it appears to be in most of
the cross faults.
Near the Silver King mine an in
trusive stock, or irregular mass of
quartz dioriae, cuts through the diabase
and the adjacent schists.
naturalization
Ore deposition occurred in and along
the fault fissures mentioned above. In
the Magma mine the fault is filled by
porphyry dixie and the hanging, or
south wall, of this dixie is marked by
large lenticular oreshoots of sulphide
ore
North of the Magma there are sew
eral of these very strong cross veins
in which the limited development work
has not yet disclosed any porphyry
mineralized strike fault or line of
of the devonian limestone and some
times at the exact quartzite contact, is
known as the Lake Superior and Ari-
IONA vein because it has been extern
sively developed by that company, in
the tract between the Magma mine
and Queen Creek This horizon is
traceable for many miles, it's position
with regard to the quartzite varying
but little, and it's dip conforming to
that of the enclosing limestone beds.
The surface naturalization observed
along the vein is similar to that OBJ
served in all the cross veins.
All the mineralized faults show black
manganese and iron stained outcrops
of silicious material. In the limestone
the fracture is shredded" and not
simple so that the actual width of
naturalization varies from place to
place. Comparing the outcrop of the
Magma vein and the L. S. & A. vein
with that of the other fractures, not
ably those seen on the Magma Chief
property there is no recognized diff
ference in nature, appearance or
amount of outcrop naturalization The
L. S. &, A. fissure was opened for gold
ore and a shoot of spongy, gold bear
ing, white silica was treated in small
mill many years ago. Later develop
ment proved the vein to contain great
quantities of leached limonite gossan
with some oxidized copper ore, but the
workings did not extend deep enough
to reach the sulphide zone.
At the Magma mine the actual out
crop where undisturbed shows no OBJ
servable copper minerals, but the
bright green silicate is seen on frac-
lures at few places. Experience and
knowledge of geological conditions in
other districts, indicates that the cross
fractures north of the Magma mine,
more particularly the cross fractures
known as the Watson vein of the
Magma Chief property, have the super
ficial characteristics of we'll mineral
lied veins.
Careful observations during my visits
to the property failed to disclose the
presence of any porphyry on your
claims. Copper ore was seen at two
places, though it was not recognized in
the Watson vein. The two vein fis-
sures particularly observed are lines of
displacement and faulting and are
traceable down into the underlying dia-
base on the Watson claim. In the
light of our present knowledge of the
naturalization of the district, there is
good ground for the belief that develop
ment of the Watson vein is likely to
disclose copper ore and silver ore of
commercial value.
Development on the property is Of
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