BATTLE MOUNTAIN MINES, WEST GROUP, AND OUTLYING PROSPECTS. 479 
and Portland mines. (See PI. V, p. 26.) The fissures of this second zone, which 
may conveniently be distinguished as the northeast fissure zone, dip generally to 
the southwest, but in one or two cases exhibit northeasterly dips. Between these 
two main fissure zones occur some hitherto less important lodes ranging in strike 
from north-south to northwest-southeast. These intermediate lodes have not been 
followed for long distances nor shown to contain large ore bodies. 
Lying immediately southwest of the main shaft is a third group of fissures, 
also striking about X. 30° W., forming a zone from 300 to 400 feet in width. These 
fissures dip generally to the southwest at angles ranging from 60° to 80°. 
occur for the most part in granite, just south 
of the granite-breccia contact, and are not 
persistent, rarely maintaining distinct char¬ 
acter for more than 250 feet in length. These 
fissures may collectively he designated the 
southwest zone. 
They 
GEOLOGICAL FEATURES. 
With the exception that latite-phonolite 
has not, so far as known, been encountered 
in the Ajax workings, the rocks of the mine 
are similar to those in the Portland. 
The main contact between the granite 
and the volcanic breccia of Battle Moun¬ 
tain is well exposed on nearly all the levels 
and has in many places been drifted on for 
considerable distances. It is prevailingly 
steep, dipping north or northeast at angles 
ranging usually from 45° to 85°. The aver¬ 
age dip is probably between 70° and 75°. 
Near the shaft, particularly in the upper 
levels, the contact runs nearly east and west. 
But, as is shown on Pis. II (in pocket) and 
V (p. 26), the Ajax shaft is situated in an 
embayment in the granite between the Port¬ 
land promontory (seep. 27) on the east and 
the northward turn of the contact, which 
carries it through the saddle between Squaw 
and Battle mountains, on the west. This 
northerly turn is noticeable on all of the Ajax workings that have followed the con¬ 
tact far enough to the west and is particularly conspicuous on the lower levels. A 
north-south section through the Ajax shaft showing the steep dip of the contact is 
given in fig. 63. The apparent flatter dip below level 6 is partly real and partly 
due to the obliquity of this part of the contact to the plane of the section. 
Fig. 63.—North-south section through the Ajax shaft, 
showing the dip of the granite-breccia contact. 
