. The prospector's field-book and guide in the search for and the easy determination of ores and other useful minerals. copper was drawnfrom the rich ores, containing up to 40 per cent, ofmetal as mined, and further explorations may againreveal in the future similar deposits to replace thosenow exhausted ; but at present and in the immedi-ate future reliance must be placed on the enormouslow grade ore bodies now being worked, especiallyin North America. The geology of copper is more varied than thatof many other metals, as it occurs in rocks of almostevery age. In Cornwall the slates are more
. The prospector's field-book and guide in the search for and the easy determination of ores and other useful minerals. copper was drawnfrom the rich ores, containing up to 40 per cent, ofmetal as mined, and further explorations may againreveal in the future similar deposits to replace thosenow exhausted ; but at present and in the immedi-ate future reliance must be placed on the enormouslow grade ore bodies now being worked, especiallyin North America. The geology of copper is more varied than thatof many other metals, as it occurs in rocks of almostevery age. In Cornwall the slates are more pro-ductive than the granites, while in our mines in theEastern States the new red sandstone, the carbon- COPPER. 167 iferous limestone, and silurian rocks furnish found in the metamorphic limestone, nearslate (Fig. 49). In the Lake Superior region, wherelarge deposits of native copper are found, the rocksare sandstones and shales underlying green-stone ora kind of trap, and in some places seem to be igne-ous (Figs. 50, 51). Ruby copper ore occurs in Ari-zona between quartzose and hornblendic rocks and. Section of the copper bed at the Dolly Hide mine, Maryland, a,Slate, b, b, b, b, Ore beds or segregations of ore. c, c, c, c, Crystalline lime-stone (metamorphic). limestone. It occurs in both, lodes and deposits,and the best way for the prospector to prepare foractual discovery is to make himself well acquaintedwith the copper compounds, whether ores or min-erals. They may indicate true ores, although theycontain little copper. To become ready in the detection of copper as anore the following facts should be kept in mind, as 168 PROSPECTOR S FIELD-BOOK AND GUIDE. furnishing suggestions for skillful practice. (, 50, and 51.) It is well to remember, especially when exploringa new country, that copper is frequently associatedwith rocks of a dark color, which are very often Fig. 50.
Size: 1762px × 1419px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjectprospec, bookyear1903
