DENHALL-, ^ , _, 
and COPPER DEPOSITS OF MOUNT WRANGELL REGION. 145 
JHiDER -• 
MENDENHALL 
AND 
SCHRADEK. 
distance below the contact the vein is barren. It is irregular in 
width, varying between 2 and 7 feet, and has a strike of about 
N. 40° E. There is no quartz or other vein material associated with 
the ore, although there is sometimes a considerable amount of crushed 
limestone between the walls. The ore is practically pure chalcocite, 
or copper glance, which is exposed in solid masses 2 to 4 feet across 
and 15 feet or more in length. Besides the ore within the fissure 
there are bedded ore bodies running off into the limestone along the 
planes of stratification. The ore is regarded as a replacement of the 
limestone. A selected sample gave over 70 per cent copper and 14 
ounces of silver per ton, with a trace of gold. 
Louise claim, Elliott Creek. — Elliott Creek is a tributary of the Kot- 
sina River and is near the western end of the copper area. The 
Louise claim is on a small branch of Elliot Creek called Rainbow 
Creek. Here, in a shallow open cut, a slickensided face of greenstone, 
forming a well-defined and, so far as exposed, regular foot wall, is 
revealed. This face strikes N. 10° E. ami dips 70° NW. The cut does 
not expose an equally definite hanging wall, but adjacent to the foot 
wall is a crushed zone, which has an extreme width of 15 or 16 feet. 
Within this zone the greenstone is generally irregularly fractured, 
but at the j)resent surface there exists, in the center of this crushed 
mass, a "horse" of solid greenstone 7 or 8 feet wide. It is probable 
that the slickensided foot wall is a fault plane, but since no displace- 
ment was observed in the limestone above, its throw can not be great. 
The mineralization within this belt consists of an impregnation of 
chalcopyrite and bornite, the latter mineral being superficially more 
abundant. The impregnation follows the fractures and partakes of 
their irregularity, the exposed surfaces of the greenstone fragments 
generally showing more or less ore. 
Goodyear claim, Elliott Creek. — Across Rainbow Creek from the 
Louise claim and a few feet below it, an open cut in greenstone reveals 
a well-defined fissure vein 4 to 5 feet wide, striking N. 12° E. and 
dipping 45° SW. The vein can be traced 50 or 75 feet up the slope 
toward the limestone contact before it is buried under the talus. 
The gangue minerals are quartz and calcite, entirely distinct from 
the perfectly definite walls of greenstone, and this gangue carries 
heavy bodies of bornite and a smaller quantity of chalcopyrite. 
While the heavy ore bodies are confined to the vein, the shattered 
hanging wall and the more massive foot wall are impregnated with 
copper sulphides for some distance above and below. 
In the upper part of the open cut a slight horizontal fault has dis- 
placed the vein laterally, so that the hanging wall above the displace- 
ment is continuous with the foot wall below it. 
Eleanor, Davy, and associated claims, Kotsina River. — Two thou- 
sand five hundred feet above the level of the Upper Kotsina River, 
near the crest of a sharp ridge separating two tributaries, Peacock 
Bull. 213—03 10 
