LODE MINING IN SOUTHEASTERN ALASKA. 47 
by dikes of felsite, andesite, and uralitic diabase, locally known as diorite. The intimate 
association of the chalcopyrite, which is in general younger than the magnetite, with 
altered limestone, garnet, epidote, and hornblende, as well as its mode of occurrence, 
indicates its deposition from hot solutions, probably pneumatolitic, which were given off 
by the intrusive igneous rocks and which replace to some extent the invaded marble. 
Faulting is of frequent occurrence in the rock complex and has often cut oil' (lie ore bodies. 
The strongest system of fissure planes strikes about north and south and parallels the 
trend of the ore bodies, which pitch at low angles to the south. 
At Hadley a 500-ton smelter has been erected with the necessary adjunct building, 
ore bins, and wharf. At the time of visit about 12,000 tons of ore had been delivered lor 
treatment, and early in December the smelter was reported to have been started. 
The Stevenstown group of claims is located on the crest of the hill above the Mamie min? 
and has been under active exploitation during the last summer. The ore body is a low- 
grade, flat-lying lens of chalcopyrite and magnetite, the upper covering of which has been 
removed by erosion so that at present it appears as a blanket capping the hill. Develop- 
ment consists of two tunnels and upraises, several test pits, open cuts, and surface strip- 
pings. The ore body has been found to be 20 feet thick at several points and often contains 
excellent showings of massive chalcopyrite. At several points surface oxidation of the 
metallic sulphides has developed a thin crust of limonite in which occasional flakes of 
secondary native copper can be observed. The ore body is cut by numerous dikes of 
porphyrite and uralitic diabase, which tend to increase the difficulties of estimating the 
amount of ore in sight. Limestone with epidote and other contact minerals was observed 
limiting the ore body on the east and also underlying it in places. A tramway has been 
extended from this property to the Mamie mine and serves to convey the ore to the 
smelter. 
The Mount Andrew group adjoins the Stevenstowm workings and lies in the same gen- 
eral mineral belt. Four ore bodies have been discovered and are flat-lying magnetite 
masses impregnated with some copper and small values in gold. The country rock is 
limestone, with various types of greenstone and felsite, and is in every way comparable to 
that at the adjacent Stevenstown and Mamie properties. The chief development work 
on this property was accomplished several years ago and consists of two long tunnels 
with several upraises to the surface, also test pits and open cuts. Although no work 
was in progress at the time of visit, a company is reported to have bonded the property 
recently and to have begun active operations. 
Hole in the Wall is a small bight on the north side of the harbor at Hadley. The 
mountain to the north of its abrupt shore has been prospected for copper ore and several 
small chalcopyrite bodies with favorable showings discovered. They are contact deposits 
between greenstone and crystalline limestone, the associated minerals being garnet and 
epidote. 
The properties of the Grindall Mining and Smelting Company are located about 3 miles 
southeast of Kasaan, and although they embrace a number of claims the actual develop- 
ment has been slight and confined chiefly to the Peacock and Tacoma claims. The ore 
bodies are contact deposits, accompanied by a gangue of garnet and epidote. They are 
irregular in shape, sporadic in occurrence, and intersected in many directions by later 
intrusive dikes both of felsite and diabase and by a system of fault planes. Chalcopyrite 
is the principal ore and is associated with magnetite and small amounts of molybdenite. 
On the Peacock- claim the developments consist of two short prospect tunnels not far from 
the shore, while on the adjoining claim several short tunnels and open cuts have been exca- 
vated. At the time of visit considerable ore had been taken from a deposit at tide water 
and placed ready for shipment. 
The Uncle Sam group, originally called the White Eagle group, has received its present 
name by recent locators who have shown great activity in exploratory work. A gravity 
tram connects the mine workings at 500 feet elevation with a dock at tide water and fur- 
nishes economical transportation facilities. The ore bodies are irregular in shape and of t he 
