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N. P. Peterson

Publications and source records attributed to N. P. Peterson.

12 recordsLinked to original sources
USGS1962

Copper in the United States, exclusive of Alaska and Hawaii

The copper districts in the United States (exclusive of Alaska and Hawaii) are shown on the accompanying map. In compiling the map, the estimated total quantity of copper present before mining was used to assign districts to size categories, and both production and reserves are included without distinction as to the status of exploitation. Four categories have been distinguished: deposits that contain 50+ to 1,000 tons; 1,000 to 50,000 tons; 50,000 to 1 million tons; and over 1 million tons of copper respectively. In many of the smaller deposits copper occurs with other metals, as gold, silver; lead, or zinc, that may be quantitatively and economically more important than the contained copper. Thus, for example, a deposit that contains large values in gold or zinc may contain only a small amount of copper and is shown on this map as a small copper deposit. Five principal morphologic types of deposits have been distinguished on the map by letter symbols. These are disseminated, replacement, vein, massive sulfide, and native copper deposits (see Explanation). They are not strictly genetic types, however, for the disseminated deposits, the massive sulfide deposits, and many of the vein deposits were formed largely or entirely by replacement processes. The symbols show either individual mines or the approximate centers of districts. Some of the more prominent districts are identified by name on the map, and all with over 1,000 tons of copper are numbered to correspond to the Locality Index. As mining district names do not always correspond to locality names, and a name established through common usage may not be the legal name of the mining district, several names are given in the index for some localities. The index is arranged alphabetically by States. Both published and unpublished data were used, and at least one reference is given for each locality if reports on it have been published.

Mineral Investigations Resource Map↗
USGS1962

Geology and ore deposits of the Globe-Miami district, Arizona

The rocks of the Globe-Miami district range from lower Precambrian to Recent. The oldest formation, the Pinal schist, comprises several varieties of schist formed by dynamic and thermal metamorphism of shale and feldspathic sandstone during the early Precambrian Mazatzal revolution. During the later stages of this revolution, the schist was intruded by a complex of dioritic rocks and by plutons of granite and quartz monzonite. There were extensive intrusions of a biotite-quartz diorite, known as the Madera diorite, mainly south of the district. In the northern part of the mapped area, the schist was invaded by an extensive mass, the Ruin granite, which is a coarse-grained rock most commonly of quartz monzonitic composition. There are also smaller sill-like masses of slightly gneissic muscovite granite.

Arizona↗
USGS1954

Copper cities copper deposit, Globe-Miami district, Arizona

The Copper Cities copper deposit in the Globe - Miami district , Arizona , is now in process of development. It is of the "porphyry" type and occurs in a body of quartz monzonite that has been intruded by smaller masses of granite porphyry. The hypogene sulfides are pyrite, chalcopyrite, and a very little molybdenite. Pyritic mineralization extends over a large area of which only a small portion contains an appreciable amount of chalcopyrite. The outcrop of the copper -bearing rock, roughly 1,800 feet square, is bounded on the west, north, and east sides by fault zones. The south boundary is gradational. The pyrite to chalcopyrite ratio of the protore increases rapidly with depth, whereas the copper content decreases but slightly. The ore body is a shallow chalcocite zone formed by supergene enrichment. Bodies of granite porphyry within the copper -bearing area were not as strongly mineralized by hypogene solutions as the quartz monzonite, and in them the chalcocite zone is thin, undoubtedly because the granite porphyry is less pervious to ground water than the quartz monzonite.

Arizona↗