440 GEOLOGY AND GOLD DEPOSITS OF THE CRIPPLE CREEK DISTRICT. 
The second zone lies northwest of a line passing through the Portland No. 2 
shaft and the old Anna Lee shaft. Its width is approximately 600 feet and it 
includes the productive portions of the Lee, Hidden Treasure, and Captain veins. 
Inspection of the map (PI. II, in pocket) shows that the existence of these two 
main zones, separated by a comparatively barren zone from 150 to 200 feet in width, 
is a prominent feature of the Portland mine. It is very doubtful, however, whether 
these same zones are persistent and can be recognized in the properties adjoining 
the Portland on the west and east. A long west crosscut and a long northwest 
drift on the Anna Lee basaltic dike, both on the 500-foot level, have failed to find 
any southwest continuation of the remarkable zone in which occur the Captain and 
Hidden Treasure ore bodies. In view of this fact the term zone is perhaps some¬ 
what misleading. The relation of the ore bodies to the mass of the country rock 
might be expressed bv saying that the ore bodies are not distributed generally 
through the latter, but are clustered together in huge, nearly vertical cores. These 
rock cores, within which the lodes are productive, are separated from the surrounding 
relatively barren country rock by rather indefinite boundaries. Their horizontal 
sections are irregular, but are generally elongated in a northeast-southwest direc¬ 
tion, so that in a limited area they have the appearance of zones. 
None of the productive lodes of either of the Portland zones has yet been traced 
into the other zone. The No. 2 and Diamond veins, so productive in the southern 
zone, are not recognized in the northern zone, nor are the numerous and rich lodes 
collectively designated the Captain system known south of the No. 2 shaft. 
The original Portland vein, sometimes erroneously supposed to be the same as 
Stratton’s Independence vein, has been developed in the southern part of the mine, 
and lies just east of the Burns shaft. Its course on the whole is nearly north and 
south, but it is distinctly curved, striking in its northern part a little east of north 
and in its southern part about S. 25° E. It dips at an average angle of 70° to 75° W. 
The Portland vein is not distinct on the 600-foot and lower levels. 
The Bobtail vein strikes about N. 60° W. and dips about 65° SW. This lode 
and the Portland vein cross without any observable displacement of one lode by the 
other. The Bobtail as a rule is a regular, well-defined lode, which outcrops at the 
old Bobtail shaft and crosses the Portland vein on the surface near the portal of the 
adit level. Southeast of its intersection with the Portland vein the Bobtail is not 
very well defined until the 600-foot level is reached. Below this the Portland vein 
in turn dies out or becomes unrecognizable. 
The Diamond veins comprise two or more rather short, generally parallel fissure 
zones lying 225 feet east of the Portland vein. These lodes strike about N. 10° W. 
and dip steeply to the west. The Diamond veins have not been identified with 
certainty on the 500-foot and higher levels. 
The most easterly lode of the southern ore zone is the important No. 2 vein, 
which strikes from N. 20° to 25° W. and is clearly the northern continuation of the 
Independence vein of Stratton’s Independence mine. Unlike the other lodes of 
this zone, the No. 2 vein dips easterly at an angle of 70° to 75°. It is indistinct 
and of no importance above the 500-foot level, but is well marked on the 600-foot 
and lower levels. The so-called Scranton and Rose veins of the 700-foot and 
800-foot levels appear to be merely northern continuations of the fissure zone of the 
