Bisbee daily review., 1919-09-14

of the huge chimney of hig grade gray copper, bearing sensational values in gold, by the Arizona-Tuc- son Copper Company, in the Tucson mountains, within eight miles of Tucson, to the southwest, and the subsequent close analysis of the for nation disclosed in the discovery work. has totally upset the accepted geology of the whole range. Gener- ally accepted as comparatively late formation, the mining possibilities of the Tucson mountains have been dis credited by most engineers. The re- search conducted few weeks ago by Frank Craycroft, one of the classifi- cation experts on the list of en- gineers called Cpcn from time to tine by the government, demon strates the under lyins structure of the Arizona Tucson Copper property is old granite oTerIaid by a series of Cambrian lime, next a series ofl carboniferous lines and shales the latter being high metamorphosed by numerous doming lifts extending south and east of the parent lift. This with the col-relative date re- ported by MT. Craycroft, entirely precludes the possibility of the ear. ly termination of the ore body and supplies the logical conclusion that the chimney or vent will enrichen as it proceeds downward
 The immediate response to the report of Mir. Crayroft has been ac tivity in locations throughout the Tucson mountains, particularly in the vicinity of the property of the Arizona-Tucson Copper Company. The property of the company has been visited and checked over by practically all Of the leading en- gineers of the state. The general consensus of opinion seems to be that in the discovery Tucson has al property which may be safely reck- oned upon in connection with the copper output of the state as we'll as Pima county.
 A Accompaniment and manway shaft is being sunk on the property now, the work of exploration by glory hole methods, being discard ed on the report of MT. Craycroft of the geological structure, verifying the work of T. E. Kelso, general manager and engineer in charge, who uncovered the big body of ore.
 Describing the structure of the property, MT. Craycroft declares iI consists of a series of doming up- lifts extending from a granite core at which point old granite, probably Archaen occurs.
 "Overlying this granite" reported MT. Craycroft, "is a series of Cam brian lime, and next series of car boniferous metamorphoses by the numerous doming lifts"
 The Cambrian lime he found ex- posed and showing considerable naturalization, particularly where the erosion had denuded the struc- ture to the Cambrian strata.
 The Cambrian lime series had been missed apparently in establish ing the theory of the formation, heretofore, because of the difficult ty' in tracing the series under the remnants of the besalt flow, to- gether with the shale andesites and outwash of erosion, which covered the series. MT. Craycroft declares the Carboniferous Hines and shales are of considerable thickness.
 In connection with the property of the Arizona-Tucson Copper com pany, it is asserted by MT. Cray croft that the Cambrian will enter in the operations at no great depth from the surface. This was indi- cated by the lime traced under the shale andecites.
 As heavy erosion has occurred" !" he reported. due to the breaking and shattering of the structure by intrusive action, as clearly shown on the Ivy May claim of the prop erty, there can be no great depth to reach it."
 The discovery and classification Of an alaskite, the first action, was made on the Ivy May property, by MT. Craycroft, who declared it t<frac- tured the underlying structure. per. mitting the ascending solutions, car Tying the iron hematitie, predomin- ant in the shale andesite, in some places. to thoroughly permeate the surrounding area. This was evinc- ed by the voids in the migdaloio basalt remnants overlying the ande- site being filled with feldsite.
 This action deposited the gold values as we'll as iron in my opin. ion," concluded MT. Craycroft. "The later action, a rhyolite, following the facture course of the former and the thermal solutions carrying the copper, made their replacement or deposition in the hematite, dis seminated by the previous action.
 So thorough a replacement of the hematite with copper. he declared shows conclusively the confinement of the solution flow to a small area. This opinion. MT. Craycron sustains by study of the surface area.
 He found the alaskite as well as the silicious rhyoiite carried appar ently equal values in copper and both filled an irregular fracture ol vent, apparently pear-shaped in the outside lines of the fracture with a main center core approximately one hundred meet long by thirty-five tC