 | Runyon, Simone E., Nickerson, Phillip A., Seedorff, Eric, Barton, Mark D., Mazdab, Frank K., Lecumberri-Sánchez, Pilar, Steele-MacInnis, Matthew (2019) Sodic-Calcic Family of Alteration in Porphyry Systems of Arizona and Adjacent New Mexico. Economic Geology, 114 (4) 745-770 doi:10.5382/econgeo.4661 | Journal (article/letter/editorial) | | intrusions that frequently lack porphyry textures, quartz veins, and potassic alteration, with compelling...magmatic-hydrothermal alteration with potassic alteration, quartz veins, and overlying sericitic alteration, which...in epidote, as well as some inclusions hosted in quartz. Microthermometry was conducted using a USGS-type...density of one to four veins per meter. In areas of quartz leaching, local pockets of andradite-grossular...structurally shallower than the younger biotite-muscovite quartz monzonite (Bradfish, 1979; Skotnicki, 1999). Pervasive |  | | Report (volume) | | found in Paleozoic and Cenozoic orogenic-belt and island-arc settings and are associated with felsic to...(diopside-hedenbergite), wollastonite, chlorite, epidote, quartz, actinolite-tremolite, and (or) calcite. INTRODUCTION...Eric Pier of Pegasus Gold Corporation; Larry Hillesland of West Introduction gold grade of 1 g/t or...Salsigne, France; Pamlico, Nevada; Red Cloud, Nevada; Island Copper, British Columbia; and others. Ertsberg...hornfels and also are present in veins with chlorite, quartz, adularia, and carbonate minerals. Gold is present |  | | Journal (article/letter/editorial) | | ; Z x t l = total crystals; gins = groundmass a quartz xenocrysts b includes both hornblende and phlogopite...silica. These lavas span a range from nepheline to quartz normative compositions and most of them lie to...silica enrichment in residual liquids, resulting in quartz normative compositions. Differentiated minette...Donovan for technical assistance, and L. Ames, K. Hillesland, T. Johnson, B. Lange, L. Simmons, and N. Wiser...J, Whelan P (1989) Early rifting of an oceanic island arc (Fiji) produced shoshonitic to tholeiitic basalts |  | Long, Keith R., DeYoung,, John H., Ludington, Stephen (1998) Database of significant deposits of gold, silver, copper, lead, and zinc in the United States. Open-File Report Vol. 1998 (98-206) US Geological Survey doi:10.3133/ofr98206ab | Report (issue) | | REFERENC Brown, F.R., 1947, Apollo mine, Unga Island, Alaska: Alaska Division of Geological and Geophysical... Ferguson, H.G., and Gannett, R.W., 1932, Gold quartz veins of the Alleghany District, California: U...Geological Survey Professional Paper 309, 310 p. Hillesland, L.L., Wothington, W.T., and Hawkins, R.B., 1994... p. 34-45. Johnston, W.D., Jr., 1940, The gold quartz veins of Grass Valley, California: U.S. Geological...375-381. Logan, C.A., 1927, Amador County, gold quartz mines: California Journal of Mines and Geology |  | | Map | | Mexico began to decline in 1980 after the Three Mile Island nuclear accident (Fig. 5), which resulted in a...except potash, sand, gravel, caliche, borrow dirt, quarry rock, natural petroleum, coal, geothermal resources...deposit in New Mexico Volcanic-epithermal veins Quartz-adularia, quartzalunite, epithermal manganese (25b...to mesothermal veins; gold-bearing breccias and quartz veins; porphyry CuMo-Au; Cu, Pb/Zn, and Au skarns...Mines and Mineral Resources Circular 103, 16 p. Hillesland, L.L., Worthington, W.T., and Hawkins, R.B., | | Long, Keith R., DeYoung,, John H., Ludington, Stephen (1998) Database of significant deposits of gold, silver, copper, lead, and zinc in the United States. Open-File Report Vol. 1998 (98-206) US Geological Survey doi:10.3133/ofr98206ab | Report (issue) | | period are mostly placer gold and low-sulfide gold-quartz veins in California. Period III covers the discovery...years (Goldstrike-Post-Meikle, Twin Creeks, Gold Quarry-Maggie Creek, Pipeline, McDonald, and Jerritt Canyon)...district Cripple Creek Goldstrike-Post Comstock Gold Quarry-Maggie Creek Fairbanks Empire-North Star Hammonton...Gulch Bingham Canyon district Twin Creeks Gold Quarry-Maggie Creek Pipeline Round Mountain McDonald Jerritt...district Oregon Gulch Cripple Creek Twin Creeks Gold Quarry-Maggie Creek Round Mountain Jerritt Canyon NV |  | | Journal (article/letter/editorial) | | 88-2 * Contains phlogopite xenocrysL t Contains quartz xenocryst. The size boundary distinguishing phenocrysts...between 52-7 and 57-6 wt.% SiO2; two-thirds are quartz normative (Tables 2 and 3). According to the Gill...predominantly of pyroxene were found on xenocrysts of quartz in two samples (42 and 108; same flow, Fig. 2)...buffer, more reduced conditions (approaching the quartz-fayalite-magnetite buffer) would change the olivine...of Grove et al. (1982) were conducted along the quartz-fayalite-magnetite buffer; the water-undersaturated |  | | Journal (article/letter/editorial) | | are also an abundant rock type in parts of some island arcs such as the Sunda-Banda arc, Indonesia (Hutchison...are typical of mid-ocean ridge basalts and ocean island tholeiites (BVSP 1981, p. 144), and slightly higher...developed for use with mid-ocean ridge and ocean island basalts, both of which occur in areas where the...of the minettes contain occasional xenocrysts of quartz and feldspar, assimilation of granodiorite was...Center for the age determinations, and L. Ames, K. Hillesland, T. Johnson, B. Lange, L. Simmons, and N. Wiser |  | | Report (issue) | | grained (about 0.1 mm), and consisting mainly of quartz with subordinate amounts of plagioclase, biotite...varying amounts of calcareous material. Detrital quartz 0.03 to 0.1 mm is the principle component in all...the quartzites are subarkose and quartz arenite (fig. 5). Quartz makes up 80 to 87 percent of the...grain size from clay to coarse sand. predominantly quartz and feldspar. Note wide The composition is Small...Small bright grains in interstices between quartz and feldspar are grains of sericite. Note metamorphic | | | Report (issue) | | Ya? Yy Yq Ybgn Granite, granodiorite, and quartz monzodiorite (Eocene) I Yab Yab 65 O Ya?...Evans (1981) Evans and Connor (1993) Hait (1965) Hillesland (1981) Kaiser (1956) Lopez (1982a) 16 Lopez...PROTEROZOIC METAMORPHIC ROCKS Granite, granodiorite, and quartz monzodiorite (Eocene) Kt Kg Ti 75 Amphibolite...Eocene ages for three mineral separates from the quartz monzonite of the Idaho batholith collected at Rattlesnake...disseminations associated with large veins or pods of quartz. Molybdenum or molybdenum-copper minerals. Unknown |  | | Book | | Circle, to a barren so many with called Ellesmere Island. It’s a harsh, dangerous place, carry shotguns...Arctic hare, hopping along just a couple forbidding island Shubin and his colleagues were drawn to this life's...pointed them to a stretch of northern Canad Island. island for the first time in 1999 Shubin and his colleagues...Darwin published The Origin of Species, German quarry workers discovered a fossil of a bird with reptile...walk tations is one we can see any time we German quarry ed, publish was Species of In 1860, just a year |  | | Book | | Sillitoe, R.H., 1989, Gold deposits in western Pacific island arcs: The magmatic connection, in Keays, R.R.,...2010); and (3) accretion of exotic terranes, such as island arcs, microcontinental blocks, 6 COPPER PROVINCES...due to collision of the Melanesian intraoceanic island arc with the leading edge of the Australian craton...In contrast to contractional arcs, extensional island arcs, particularly intraoceanic arcs during their...Accretion of exotic terranes (microcontinents, island arcs, large oceanic plateaus), which may cause |
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