..., the Salida Greenstone Belt, and the Sangre de Cristo Mountains (1,740–1,725 Ma) were not found in the Sawatch and Mosquito ranges. This observation strongly suggests that the northern edge of the Gunnison-Salida arc terrane underlies the southern portion of the Sawatch and Mosquito ranges. (2) Calc-alkalic...

...., Greenstone Belts: Oxford Monographs on Geology and Geophysics 35 , pp. 781 - 790 . Davies , G.R. , and Macdonald , R. , 1987 , Crustal influences in the petrogenesis of the Naivasha basalt-rhyolite complex; combined trace element and Sr-Nd-Pb isotope constraints : Journal of Petrology , v...

... basement rocks, although a few pyroclastic features persist locally within the felsic members. These metavolcanic rocks are compositionally similar to the much better preserved bimodal section in the Salida area, dated at 1728 ± 6 Ma by Bickford (1986) , which emerges from beneath Paleozoic cover rocks...

... of the Dubois greenstone succession: An Early Proterozoic bimodal volcanic association in west central Colorado: Precambrian Research , v. 15 p. 131 – 155 . David , J. , and Syme , E.C. , 1994 , U-Pb geochronology of late Neoarchean tonalites in the Flin Flon Belt, Trans- Hudson orogen...

...; and the Pecos-Gold Hill greenstone belt, ca. 1750–1700 Ma ( Condie, 1982 ; Reed et al., 1987 ). The oldest or earliest arc system, the Green Mountain magmatic arc ( Fig. 1 ; Reed et al., 1987 ), has been established as the major Paleoproterozoic crustal terrane within the Medicine Bow orogeny ( Chamberlain...

... that resulted in the addition of ∼1000 km of new crust south of the Wyoming craton between 1.8–1.6 Ga. The boundary between Proterozoic and Archean crust is the Cheyenne belt, which has been interpreted by previous workers as a major crustal suture formed when juvenile magmatic arcs collided with the southward...

... in an Archean iron-formation, West Greenland . Mineral. Mag . 50 , 175 – 177 . ——— ( 2000 ): Gahnite in the approximately 3.75 Ga Isua greenstone belt, West Greenland . Mineral. Mag . 64 , 121 – 124 . Araujo , S.M. , Fawcett , J.J. & Scott , S.D. ( 1995 ): Metamorphism...

...), although other shear zones farther south in Colorado are also candidates. Rocks of similar age occur in the Salida-Gunnison area ∼300 km south of the Cheyenne belt ( Bickford et al., 1989 ; Reed et al., 1987 ) but are absent in the type region of the Yavapai province in central Arizona ( Karlstrom...

... in Wilson Park, Fremont County, Colorado : The Mountain Geologist , v. 11 , p. 45 – 58 . Robertson J.M. Condie K.C. , 1989 , Geology and geochemistry of early Proterozoic volcanic and subvolcanic rocks of the Pecos greenstone belt, Sangre de Cristo Mountains, New Mexico : Geological...

... is interpreted to represent a complex collage of predominantly juvenile arc terranes characterized by rocks with Nd model ages between 2.0 and 1.8 Ga ( Bennett and DePaolo, 1987 ). Rocks of the Yavapai province were accreted to the Laurentian margin between 1.78 and 1.70 Ga along a belt stretching from Colorado...

...) , and it parallels multiple, well-documented Proterozoic shear-zone systems along the Colorado Mineral Belt and elsewhere in northern Colorado ( Fig. 1 ). Allen and Shaw (2011) described the detailed kinematic history of the structure including the development of mylonite, ultramylonite, and multiple generations...

... zone Movement sense on granite-hosted gold deposits, but also from its position in granite, farther I, Gneiss fault/shear zone Main Au deposit laterally from greenstone rock types than virtually all other gold lo 1x,ge 8 Figure 1. Map of the Yilgarn craton showing granite and greenstone belts...

... and Morrison, 1998 ), depicting ilmenite-series, magnetite-series, and peraluminous subprovinces of the 1.4–1.5-Ga granite belt across North America to the Baltic region. Although several of these granites in Colorado are fairly homogeneous, Cullers et al. (1992 , 1993 ) have shown two batholiths...

... of the Yavapai province were accreted to the Laurentian margin between 1.78 and 1.70 Ga along a belt stretching from Colorado to Arizona and New Mexico. The final collisional phase of this long-lived, progressive orogenic event occurred between ca. 1.71 and 1.70 Ga ( Karlstrom and Bowring, 1988...

... the crushing and concentrator facilities of the mine. On April 12, we visited the Dome mine-a typical shear-zone­ hosted Au deposit in the Abitibi Greenstone belt. It is located in the vicinity of two major faults (Destor-Porcupine and Dome fault zone). The Au-hearing fluids traveled along faults and contacts...

... succession ( Shonk, 1984 ), but the contact is now sheared ( Knoper and Condie, 1988 ). A similar age range for arc rocks is in New Mexico, where the 1.72 Ga Pecos greenstone belt is in close proximity to the 1.77–1.75 Ga Mopin and Gold Hill successions. The Cochetopa and Pecos rocks are basalt...

... Minter effertiwly rlispell rl th insirlio11s n rl strnngely He accompanied us underground on Friday to see JCl's stibnite-gold recurrent CN.AH (Creeping North American Hydrothermalist) Syndrome ores in the ca. 2.9 Ga Archean Murchison greenstone belt, and to a that re-infects overseas visitors...

.... It was a shock to learn that the Neves Corvo deposit contains more Eve1yone who attended the two-day short course surely walked than half as much metal as that contained in all of the VMS deposits away with much new found knowledge of VMS systems. Not only in the Abitibi greenstone belt. did the short course...

... contributed to my career. I have had many different roles, but my summer student experiences stand out as some of the most critical. As an undergraduate I worked as a research assistant, spending my summer back and forth between the university and the Abitibi greenstone belt in Quebec. In my graduate years, I...

.... 117 – 154 , doi:10.1016/S0301-9268(97)00038-7 . Robertson J.M. Condie K.C. , 1989 , Geology and geochemistry of early Proterozoic volcanic and subvolcanic rocks of the Pecos greenstone belt, Sangre de Cristo Mountains, New Mexico , in Grambling J.A. Tewksbury B.J. , eds...