MINES OF RAVEN AND GUYOT HILLS. 
329 
narrow cracks or joints, the ore thus resembling that found in the Captain stopes 
in the Portland mine. The ore occuring in “basalt” is apparently of similar 
character, although very little of this ore was visible at the time of visit. 
Usually, however, the calaverite occurs in distinct vein lets of quartz and 
fluorite ranging in width from a fraction of an inch up to about 6 inches. The 
quartz and fluorite often show comb or vug structure, but sometimes form a solid, 
compact vein. The best example of such compact vein matter is furnished by 
the Work vein, much of which consists of a dark-purple fine-grained aggregate of 
quartz, fluorite, and a carbonate—probably dolomite. This material, however, is 
rarely sufficiently auriferous to be ore. Although the calaverite occasional^ pro¬ 
jects into the vugs, it is more commonly entirely inclosed in the gangue minerals. 
An earthy green mineral, determined by Doctor ITillebrand to be a vanadiferous 
silicate, probably roscoelite, is abundant in portions of the Mary McKinney vein 
and usually, though not always, indicates good ore. It occurs particularly near 
the walls of the veinlets and as an alteration product of small fragments of country 
rock inclosed in the quartz and fluorite. 
Tetrahedrite occurs in massive form in the Mary McKinney vein a few feet 
below level 5. It is found in close association with calaverite in little stringers of 
quartz and fluorite in phonolite. Some of the stringers contain a little dolomite, 
and hollow siliceous pseudomorphs after celestite occur in occasional small vugs. 
There can be no question that in this case calaverite, tetrahedrite, quartz, and 
fluorite all crystallized contemporaneously. 
There is very little oxidation in the Mary McKinney mine below a depth of 
200 feet and no oxidized ore is now being produced. 
UNDERGROUND WATER. 
Water was originally encountered in the Mary McKinney at an elevation of 
9,498 feet above sea, or at a depth of only 35 feet below the collar of the shaft. 
In 1899, owing to the lowering of the water by pumping and by the Ophelia and 
Standard tunnels, the level stood at 9,241 feet above sea, or 292 feet below the 
collar of the shaft. About this time level 5 was opened, but owing to the excessive 
water was soon afterwards temporarily abandoned. It was not recovered until 
April, 1901, when the Elkton is reported to have been pumping 1,200 gallons per 
minute in order to regain its level 8 . The water continued to fall and in January, 
1903, stood at 9,023 feet above sea, or about 10 feet below level 5, and was going 
down at the rate of 0.03 foot per day . a 
Upon the opening of the El Paso drainage tunnel on September 6 , 1903, the 
water began to fall more rapidly, the record being as follows: 
Recession of water in Mary McKinney mine after opening of El Paso drainage tunnel. 
- ' Inches. 
First week.29. 00 
Second week.-. 17. 00 
Third week.-.-. 10. 00 
Fourth week.- - 8. 00 
Fifth week. 7. 25 
a mils, V. G., Ninth Ann. Rept. Portland Gold Mining Company, 1903, p. 91. 
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