Professional Paper - United States Geological Survey, Ausgabe 21The Survey, 1904 |
Andere Ausgaben - Alle anzeigen
Häufige Begriffe und Wortgruppen
Abrigo Canyon Abrigo limestone abundant Arizona Bisbee group Bisbee quadrangle Black Gap block bodies Bolsa quartzite calcareous Calumet and Arizona Cambrian Carboniferous chalcocite chalcopyrite Cintura formation Collected by Ransome Copper Queen Cretaceous Cretaceous beds crystalline cuprite Devonian dikes Dividend fault east of Bisbee erosion Escabrosa limestone Escabrosa Ridge Espinal Plain exposed fauna fissures fossils geological Glance conglomerate Gold Gulch Gold Hill granite granite-porphyry intrusive irregular Juniper Flat LIBRARIES STANFORD UNIVERSITY limonite Locality Martin limestone mass metamorphism miles mineral Morita formation Mount Martin Mule Gulch Mule Mountains Mural limestone Naco limestone northeast northwest occurs overlying overthrust oxidized Paleozoic Paleozoic rocks Pennsylvanian Pinal schist porphyry pre-Cambrian probably Productus pyrite quartz Quaternary deposits Sacramento Hill sandstones sediments shales slope southeast southwest species Spirifer Spring Valley STANFORD UNIVERSITY STANFORD UNIVERSITY LIBRARIES stope structure sulphide Sulphur Spring Valley surface syncline topographic unconformity UNIVERSITY LIBRARIES STANFORD upper vicinity zone
Beliebte Passagen
Seite 22 - cloud-burst" visits every tract, and when it comes, the local drainage- way discharges in a few hours more water than is yielded to it by the ordinary precipitation of many years. The deluge scours out a channel which is far too deep and broad for ordinary needs and which centuries may not suffice to efface. The abundance of these trenches in various stages of obliteration, but all manifestly unsuited to the every-day conditions of the country, has naturally led many to believe that an age of excessive...
Seite 38 - These pink beds, which weathering usually shows to have an inherent lamellar or shaly structure, are very fine grained and compact in texture. They effervesce freely with cold dilute acid and are evidently composed chiefly of calcium carbonate. Examination of natural surfaces with a lens, however, shows the presence of minute quartz grains and tiny flakes of mica. * * * "Chert is not uncommon in the Naco formation; it occurs...
Seite 74 - The surface caliche is clearly the result of the upward capillary flow of water from below, induced by the constant and rapid evaporation at the surface in a comparatively rainless region. It is not the result of a flow from springs, or from any source at the surface, or by the lateral movement of water; but is an example of concentration, by evaporation at the surface, of the solutions of nitrate of soda that were deposited in the desiccation of Lake Aubury in the layers of the terraces.
Seite 159 - The oxidized material is not only more porous but much softer and more plastic than the original mineralized limestone and hence greatly weakens by its presence the rocky structure in which it occurs. The overlying limestones, no longer 'adequately supported, fissure and settle down upon the soft plastic ore and gangue. The access of solutions is thus still more facilitated, and the processes of oxidation and solution proceed so much the faster. That part of the surface which is underlain by oxidizing...
Seite 38 - Escabrosa formation, is made up chiefly of light-colored beds, which consist essentially of calcium carbonate. The beds range in thickness from a few inches to 10 feet, but are usually thinner than those of the Escabrosa limestone.
Seite 128 - Ransome,2 it is found in an impure earthy condition mixed with limonite and ferruginous clays or in crystalline masses associated with native copper. The latter occurrence is particularly characteristic of the deeper oxidized zones in the vicinity of chalcocite and other sulphides. In the Calumet & Arizona mine cuprite is found in large crystalline masses. On the...