MINES OF BATTLE MOUNTAIN, EAST GROUP. 
443 
be completely recrystallized as a porous, vuggy aggregate of valencianite (secondary 
orthoclase), quartz, fluorite, occasionally a little calcite, pyrite, calaverite (rarely 
visible), and sometimes a little sphalerite and galena. Ore of this type was formerly 
of much greater importance in the Portland mine than now, and was stoped in 
large quantities from the Diamond veins. 
The ore at present most typical of the mine is that occurring in breccia, par¬ 
ticularly in the Captain stopes. This consists of fine-grained gray breccia, con¬ 
taining much finely disseminated pyrite and considerable scattered carbonate, 
which appears to be in most cases dolomite rather than calcite. The calaverite 
occurs in very narrow fissures or joints in this breccia, associated with crystalline 
films of dolomite, with sometimes a little quartz and fluorite. In most places the 
ore shows very little calaverite to the naked eye; but in some of the richer stopes 
the rock, when split open along these joints, reveals an abundance of thin-bladed 
crystals of silvery calaverite that are occasionally 2 inches in length and frequently 
form branching or stellate groups. These crystals are often accompanied by a 
little molybdenite. The value of the ore appears to lie wholly within the narrow 
joints which are seldom individually large enough or persistent enough to be dignified 
even with the name of veinlet. The fine pyrite impregnating the breccia is not 
known to be auriferous, though samples of pyritized breccia often contain $2 to S3 
per ton in gold. The ore of the Hidden Treasure veins has crystallized in larger 
and more open fissures than the Captain ore and gangue minerals are consequently 
more conspicuous. The calaverite occurs with dolomite (often in well-developed 
rhombohedrons), fluorite, and quartz. 
The Lost Anna and Lee veins are characterized by more open Assuring and 
more abundant vein matter than most of the productive Cripple Creek veins. 
They contain abundant pyrite, and in some places galena and sphalerite, associated 
with dolomite, quartz, and fluorite. Calaverite occurs usually in the porous or 
vuggy portions of the vein, and in the Lost Anna vein is sometimes associated , 
with roscoelite. 
The ore of the Anna Lee chimney was soft and oxidized down to the bottom 
of the worked-out ore shoot. 
PAY SHOOTS AND LODE STRUCTURE. 
With the exception of the so-called Anna Lee chimney, all of the ore of the 
Portland mine occurs in the form of lodes; that is, in nearly vertical deposits of 
essentially tabular form. The general plan and distribution of these lodes has 
been already described. Some account will now be given of the shape and structure 
of the ore bodies themseHes. 
Three important types of ore bodies have been recognized: (1) Deposits along 
fissure zones in breccia, (2) deposits along fissure zones in granite, and (3) mineral¬ 
ized phonolite dikes. These three classes are not always distinct, for, as will 
presently be shown, deposits of the third class are not infrequently combined with 
deposits belonging in the first or second class. 
In the first class belong the first eight Captain, the three Hidden Treasure, 
and the four Lee veins of the northern ore zone and a portion of the No. 2 vein 
in the southern zone. These lodes are sheeted zones of varying width, definiteness, 
