The geology and ore deposits of the Bisbee quadrangle, Arizona

Abstract

The first attempt to describe the geological environment of the ores was that of Wendt, in 1887, followed thirteen years later by the more comprehensive account by Douglas. Both of these papers, however, touch on the geology and structure of the Mule Mountains in the very briefest way, being concerned mainly .with the ore bodies and with the process of ore extraction. Dumble's reconnaissance notes, pub• lished in 1902, although necessarily fragmentary, are really the first step toward any general knowledge of the broader geological features, and to him is due the first .recorded recognition of the exten~ive Cretaceous deposits of the Bisbee region.The papers just referred to, with some mineralogical notes, and two other works of general nature which have been drawn upon for historical data, are included in the following brief • bibliography:

Geology and geochemistry of the West Ore Body and associated skarns, Copper Canyon porphyry copper deposits, Lander County, Nevada, with a section on electron microprobe analyses of andradite and diopside

“…Systematic zoning of the garnetite with its surrounding rocks, the relatively coarse-to mediumgrained garnets themselves ( fig. 14), their occurrence In a high-temperature hydrothermal environment (Theodore and Blake, 1975), and their overall petrologic similarity to many other similar rocks in or near porphyry copper deposits that replace carbonate (Ransome, 1904;Lindgren, 1905;Knopf, 1918;Spencer, 1917;Gale, 1965;Moolick and Durek, 1966;Eastlick, 1968;James, 1971;Himes, 1972; and many others) all suggest to us these rocks grew in part at the expense of some carbonate. Certainly there is some textural evidence that garnet and pyroxene at Copper Canyon may have grown from a carbonate-rich host.…”

Diagenetic significance of carbon, oxygen and strontium isotopic compositions in the Aptian-Albian Mural Formation in Cerro Pimas area, northern Sonora, Mexico.

“…Regionally, the Mural Formation overlies and underlies thick fluvial successions comprising of reddish brown sandstone, siltstone and conglomerate of Morita and Cintura Formations, respectively. These formations along with the Glance Conglomerate that underlies the Morita Formation compose the Bisbee Group and its outcrops extend from northern Sonora into southeastern Arizona and southwestern New Mexico in USA (Ransome, 1904;Bilodeau and Lindberg, 1983;Mack et al, 1986;Dickinson et al, 1989; Jacques-Ayala, 1995; Lawton et al, 2004 The fossiliferous clastic and carbonate strata of the Mural Formation were deposited on a sharp ravinement surface developed on the Morita Formation during a major marine transgression. Lawton et al (2004) defined six members in the Mural Formation in north-central Sonora, viz.…”

Tectonics of southeastern Arizona

“…Both east of the Mule Mountains and in the Pedregosa Mountains, later movement of segments of other faults of the northwest-trending system cut this stray east-trending branch of the Sawmill Canyon fault system. In the Mule Mountains, another major branch of the fault splays off to the southeast, where a part, near Bisbee, is known as the Dividend f~ult (Ransome, 1904, andHayes andLandis, 1964). It has been projected by Ludano Lucarelli (1967) 25 km into Sonora on the basis of studies of aerial photos.…”

“…Second-order faults trending southwest from the chief conduit funneled off the fluids and provided access to the favored host rocks of the upper part of the Abrigo Formation, the Martin Formation, and the lower part of the Escabrosa Limestone (Ransome, 1904;Trischka, 1938). The distribution of types of mineral is inadequately known to provide clues of direction of movement of the fluids; but the deposits are richest close to the Dividend fault, and they decrease in grade southwest and south away from the fault and stock, suggesting a component of movement in those directions.…”

“…before Early Cretaceous time. Ransome (1904) and Hayes (1970a) have proposed that such an upland existed in the area now occupied by the main part of the Mule Mountains to the northwest, and that it was genetically related to the emplacement of the Juniper Flat stock, of Jurassic age, and to movement on the Dividend fault (Hayes and Landis, 1964). In essence, the entire Paleozoic sequence was eroded from the northeastern uplifted block, and the resulting detritus was in part deposited as the prism of conglomerate and fanglomerate on the southwestern or downthrown block.…”