Bisbee daily review., 1904-06-14
Warrefl rlining District
The Use of the
 Diamond Drill
THE AVAILABILITY OF THE DRILL FOR USE IN THE WARREN cisTRlcT-GENER SuR- vEY OF THE DRILL AND ITS PRACTL
 CA6iliTY
 HERE.

Arizona the use of the diamond drill is rapidly increasing. and it is probably a fact that more drills are now work ing here than in any other section of similar area in the United States. There has been a great deal of discus sion, pro and con, as to the availability of diamond drills for operations in the formation of the Warren district, and some experienced companies will not use it at all. The Copper Queen Con. solidated Mining Company is one of these. MT. Walter Douglas, its sup erintendeni, told me that they had us ed drills a number of years ago, bu.. that they had been unsuccessful in finding ore bodies tha, had subsequent. ly been cut by drifts following the drill holes. and that they did not care 10 enter upon the exploration of the.r mines by that method.
 The use of drills in the Warren dis. trict is due 10 the initiative of the Junction Development Company. Now the Junction ground is all conglomer- ate on surface, and it's possible value for copper depended on the conclu- sion that might be reached as to whether or not the copper-bearing lime rocks Of the district dipped be- meath this conglomerate toward the porphyry contact or whether the con glomerate continued in depth. h this case the use Of drill to determ- inc the question was not only permis- sible; it was business sagacity. for the ground, if lime, mlght be exceed ingly rich, and could be secured at low price, while the cost of drill ex- ploraticn, to determine the formation merely, was far less than that of a shaft. The Junction's drill explora- tions did show that lime dipped under the conglomeIate. and there is now possibility that fine mine may be developed there.
 Mining methods adopted by the Lake Superior people operating the Junction had been so wonderfully sue cessful in the case of their Calumet & Arizona, Calumet & Pittsburg and oth. CT earlier developments, that many others, exploring the same field, were ready to follow their methods without applying the proper reasoning to their own conditions. They did not appre- ciate that the diamond drill in Bis bee was valuable for negative. not positive, results So diamond drilling became more or less of fad. Drills are at work in properties where they can be of little value They do worse; they may condemn ground deserving Of better exploration than the drill can give. Another reason for explora- ton by the drill, and this time in ground admittedly lime, has been on financial accounts. Some mining companies here have been so hamper ed by the lack of sufficient funds with which to explore by the much more expensive work of shaft sinking. that they have taken up drills as last re- sort, hoping that something might happen before their funds were ex- hausted, and that. if it did they might secure additional money with which to explore by shafts and drifts This is the excuse for the operation of drills On several prospects in the dis trict.
 Really, the only successful way to explore in this district, except under such conditions as I have outlined above. is by shaft and tunnel. Ere quently it has been found that large and valuable ore lenses have been opened. by following weak and narrow stringers of ore to their conclusion. There is about as much hope of cut ting these stringers with drill as finding needle in a haystack.s Ores are sometimes such that neither cores nor sludge give much indication of their presence. The ore lenses are irregular in shape, and no surface sign IS assurance of their outlines, or act ual position. IL is exceedingly easy 1 not only to miss them by the small i hole bored by drill, but to fail in noting from its results the slightest ! evidence of their presence.
 Diamond drill work at Bisbee is conducted, if statements of operators are conclusive. at costs varying from s2.50 to s and more per foot. Tn ! the opinion of one of the leading drill men of the United tates, who has been making examination of the region. a | fair price for considerable time will be near the latter figure The ground is not easy The glance conglomerate is very hard and irregular in texture, lime is broken and variable in quality, much of it is extremely cherty, and the wear from the stones is consider able, The type of drills generally | used is the Sullivan H or c. with the A rods, cutting hole l 1916 in. and making core little better than one inch in diameter. In one or two cases
 E rods have been adopted for an H
 dr.ll. but this is mistake of judgment on the part of the operator. A few
 S drills are operated underground in order to test the mineral bearing pos
 abilities in a deeper carboniferous
 lime stratum. hitherto untouched ir
 the Warren district. This is the
 case with drill or two operated ir