LODE MINING IN SOUTHEASTERN ALASKA. 
51 
Rich have a schistose and wrinkled structure, overlie the limestones and are it) (urn over- 
lin by a wide belt of greenstone schist, which borders the shore of Hetta Inlet. 
The general structure of the area strikes N. 15° to 30° W. and dips to the west, 1 hough this 
as been interrupted in the vicinity of the intrusive granite boss, where the stratified rock 
eds are usually parallel to its contact. These sediment aries are provisionally referred to 
he Paleozoic. 
The principal ore bodies in Hetta Inlet are on the Copper Mountain, Jumbo, and Green 
: ; M : ; : ; : ; ; xv::x 
Fig. 1. — Geologic .sketch map of Copper Mountain region. 
lonster groups and are confined to the contact areas of the diorite with either limestone or 
[uartzite. The Corbin and Copper City deposits are of a different type, for they occur in 
he greenstone schists along the shore of Hetta Inlet. 
The property of the Alaska Copper Company extends from tidewater at Copper Harbor 
o the crest of the ridge wesl of Copper Mountain. The principal workings arc on the New 
fork and Indiana claims, three-fourths of a mile from the shore, 3,200 to 3,500 feet above 
lea level. At the New York claim the ore body is a band of garnet-epidote rock following 
