COORDINATION OF THE FISSURES. 
51 
riginally containing open spaces ranging from a few inches to a foot 
r more in width, occur closely spaced within a comparatively narrow 
one bounded by less fractured country rock. Such a sheeted zone 
brms a favorable place for the deposition of ore bodies, and, as will 
e shown later, the Camp Bird, Tomboy, and other lodes are chiefly 
I this type, illustrated in figs. 9 and 14. Coordinate fractures of this 
mple character, in which the individual fissures maintain their indi- 
iduality and essential parallelism for long distances, may pass with- 
it any line of demarcation into groups of fissures of the linked type, 
i which the nearly parallel assures are arranged more or less en 
3helon and connected by smaller oblique fractures. This structure 
exemplified to some extent in the Tomboy mine, but is not a com- 
FlG. 
■Horizontal sketch projection of the productive iodes west of Silver Lake. 
)n one in the Silverton quadrangle. With a still further shortening 
the principal parallel fissures and an increase in the number and 
e of the linking fractures the fissure zone becomes a reticulated 
^regation of irregular, curving fractures, which, when filled with 
), constitute what may be conveniently termed a stringer lode. Of 
s class is the North Star (King Solomon) lode. Finally, with yet 
sater increase in the number and irregularity of the Assuring, this 
)e of fissure zone passes by insensible gradations into a breccia 
le, such as a portion, at least, of the Polar Star lode. 
Thus far the discussion has dealt with the parallel coordination of 
;ures into minor systems and with the steps by which such groups 
fissures, when confined to rather narrow zones, maj T pass into other 
s regular structures commonly associated with the deposition of 
