212 GEOLOGY AND GOLD DEPOSITS OF THE CRIPPLE CREEK DISTRICT. 
re body 
loofeet 
i---i 
Fig. 19.—Plan showing occur¬ 
rence of ore bodies at inter¬ 
section of sheeted zone and 
phonolite dike in Dead Pine 
mine. 
Intersection of a vein with a narrow perpendicular seam gave a couple of carloads 
of good ore. • 
The long Orpha May vein, traceable from near the American Eagle shaft for 
a mile southward into the Modoc property, offers perhaps the best example in the 
camp of the influence of cross fissures on long lodes. Penrose 
states that in the Orpha May mine, the most northerly on 
the lode, the shoots were narrow, but more likely to occur 
wherever cross fissures intersected the vein. In the Rubie a 
long, narrow shoot occurred where an east-west vein inter¬ 
sected the Orpha May. It is illustrated best of all in the 
Last Dollar mine, in which the most important shoot fol¬ 
lows the intersection of cross veins with the main vein. In 
this case some ore is also contained on the former, but rarely 
extends more than 40 feet from the main vein. Further 
interest is given to this occurrence by the difference in ore 
carried on the two kinds of veins, the cross veins being rich 
in pvrite, zinc blende, and tetrahedrite, while only normal 
calaverite ore occurs on the 
main vein. Very similar con¬ 
ditions are observed in the 
Modoc mine, though the dif¬ 
ference in ore is not so marked here. ' 
Between the Isabella lode system and that of 
the Vindicator lie a number of cross fissures, most 
of them having a northeasterly strike. In the 
mines located on these veins a number of interest¬ 
ing occurrences may be observed. In the Empire 
No. 2 vein one pay shoot is clearly the result of 
the intersection with the Buena Vista vein of the 
Isabella system. At the Pinto mine the intersec¬ 
tion of the Pinto dike with the Pharmacist vein 
produces an important and rich shoot (fig. 18). 
Another on the same vein lies at the intersection 
of the Pharmacist and the Zenobia. In the Dead- 
wood mine intersection of vein systems is clearly 
connected with the occurrence of the ore. 
As a rule no influence of cross fissures can be 
observed in the great pay shoots of the Vindicator 
system. In one case, however, at the north end of 
the Findley, a small but rich shoot occurred at the 
intersection with an east-west cross vein. Where the same vein crossed the adjoin¬ 
ing and parallel Sliurtlofl vein the pay contained on the cross vein became locally 
impoverished. 
In the Golden Cycle mine the shoots are not, as far as can be observed, depend¬ 
ent on crossings. Frequently, however, the richest ore occurs at splits in the 
principal veins. This is illustrated in both the Legal Tender and the Revenue 
svstems. 
Fig. 20.—Diagrammatic plan showing occur¬ 
rence of ore body in granite on le^el 5, Ajax 
mine. 
