USGS Professional Paper 1697 - Alaska Resources Library

The Orange Hill deposit contains an inferred reserve of
320 million tonnes grading 0.35 percent Cu and 0.02 percent
Mo, and the Bond Creek deposit contains an inferred
reserve of 500 million tonnes grading 0.30 percent Cu and
0.02 percent Mo (Richter and others, 1975a,b). The Nabesna
pluton intrudes Late Jurassic and Early Cretaceous flysch of
the Gravina-Nutzotin belt. Associated skarn deposits contain
disseminated andradite garnet, pyroxene, pyrite, chalcopyrite,
bornite, and magnetite and massive pyrrhotite, pyrite, chalcopyrite,
and sphalerite. Also associated with the Nabesna
pluton are the mined Nabesna Fe-Au and the Rambler Fe-Au
skarn deposits (Weyland, 1943; Nokleberg and others, 1987;
Newberry and others, 1997a).
Baultoff, Horsfeld, Carl Creek Porphyry Cu Deposits
The Baultoff, Horsfeld, and Carl Creek porphyry Cu
deposits (Richter and others, 1975b) occur in three nearby
areas in the northern Wrangell Mountains. The deposits
consist of pyrite and chalcopyrite that occur both in veinlets
and as disseminations in altered Cretaceous granitoid plutons
composed of quartz diorite, quartz diorite porphyry, or granite
porphyry. The altered areas associated with the deposits have
dimensions as much as 1,000 by 2,000 m. Alteration minerals
are chlorite, sericite, albite, pyrite; local actinolite veins and
disseminations also occur. The deposits contain an estimated
resource of 240 million tonnes grading 0.2 percent Cu,