Pegmatite investigations in Colorado, Wyoming, and Utah, 1942-1944

Hanley, J.B.; Heinrich, E. Wm.; Page, Lincoln R.

doi:10.3133/pp227

Cited by 25 publications

(10 citation statements)

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“…2). Hanley et al (1950), Heinrich (1958), Peterson (1964), and Haynes (1965) conducted early studies of the South Platte district. More recently, Simmons and his colleagues have produced numerous contributions on the detailed mineralogy and geochemistry of this district (Simmons, 1977;Simmons and Heinrich, 1975;1980;Brewster, 1986;Lee, 1986;Wayne, 1986;Simmons et al, l986,1987a, 198%;Simmons and Hanson, 1991).…”

Section: Mineralogy and Intensive Parametersmentioning

confidence: 99%

A review of the Pikes Peak batholith, Front Range, central Colorado: A "type example" of A-type granitic magmatism

Smith

Noblett

Wobus

et al. 1999

Rocky Mountain Geology

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The N 1.08-Ga Pikes Peak composite batholith of central Colorado is a type example of an Atype granitic system. From the 1970s through the 199Os, details of the field relations, mineralogy, major and trace element compositions, and isotopic geochemistry of Pikes Peak rocks were documented, and they reveal the existence of two chemical groups, a potassic and a sodic series. The potassic series (~6 4 -7 8 wt % SiO,) includes the Pikes Peak Granite, which is mostly coarse-grained biotite f hornblende syenogranite and minor monzogranite that dominates the batholith. The potassic series also includes fine-to medium-grained biotite granite found in numerous, small, late-stage plutons throughout the batholith. The sodic series is found in seven plutons comprised of a wide range of rock types ( N 44-78 wt % SiO,), including gabbro, diabase, syenite/quartz syenite, and fayalite and sodic amphibole granite.Differences in petrologic and geochemical characteristics between the sodic and potassic series indicate different petrogenetic histories. Major and trace element and strontium and oxygen isotopic data were used by some workers to hypothesize that mantle-derived alkali basalt underwent crystal fractionation and reaction with lower crustal rocks to generate syenitic magmas of the sodic series, which subsequently underwent further fractionation to produce sodic granites. Recent studies involving estimates of oxygen fugacities, along with additional trace element and neodymium isotopic data, also support a basalt fractionation model for the sodic series, but suggest only minor crustal involvement. Gabbros and diabase dikes associated with the sodic series appear to have been derived from mantle sources that previously had been affected by a subduction event, based on neodymium isotopic and trace element data.Some workers propose that the potassic series also formed by fractionation of syenitic and/ or basaltic magmas coupled with reaction with intermediate rather than lower crust. Other workers propose a model in which genesis of the potassic series was dominated by partial melting involving tonalitic sources, with fractionation and-perhaps magma mixing playing subordinate roles in generating compositional diversity among the potassic granitoids. The Pikes Peak batholith thus formed by emplacement of at least two petrogenetically different granite types, which were emplaced close together in space and time and which exhibit geochemical characteristics typical of A-type granites.

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Section: Mineralogy and Intensive Parametersmentioning

confidence: 99%

A review of the Pikes Peak batholith, Front Range, central Colorado: A "type example" of A-type granitic magmatism

Smith

Noblett

Wobus

et al. 1999

Rocky Mountain Geology

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“…Quirke and Kremers (1943, p. 571-580) supported the idea that pegmatites were formed by crystallization of solutions moving through open systems. Recently many writers (Cameron, Jahns, McNair, and Page, 1949, p. 104;Page and others, 1953, p. 20-24;Hanley, Heinrich, and Page, 1950, p. 8;Jahns, Griffitts, and Heinrich, 1952, p. 45) have shown that the internal structure of pegmatites supports the concept that pegmatite zones developed by fractional crystallization and incomplete reaction in a restricted system. Stockwell (1933, p. 38-39) had earlier expressed essentially this same concept to explain the origin of Manitoba pegmatites, which, he believes, show a definite order of solidification progressing inward from the walls.…”

Section: Originmentioning

confidence: 92%

Geology, of the High Climb Pegmatite, Custer County, South Dakota

Sheridan¹

1953

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“…Some of the thousands of pegmatites scattered throughout Colorado outside the Mount Antero region have produced aquamarine; these include the Rose Dawn mine, Micanite district; Big Boulder and Crystal Silica mines, Crystal Mountain district; Bluebird pegmatites, Unaweep Canyon district; Mount Ethel district (near Stove Prairie); Devils Hole district; and Clear Creek district (Hanley, Heinrich and Page 1950;Meeves et al 1966). Occasional discoveries will continue to be made, with the Micanite (Fremont County), Mount Ethel (Larimer County), and Crystal Mountain (Larimer County) districts having the best potential.…”

Section: Coloradomentioning

confidence: 96%

Aquamarine in the United States

Jacobson

1993

Rocks & Minerals

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Pegmatite investigations in Colorado, Wyoming, and Utah, 1942-1944

Cited by 25 publications

References 0 publications

A review of the Pikes Peak batholith, Front Range, central Colorado: A "type example" of A-type granitic magmatism

A review of the Pikes Peak batholith, Front Range, central Colorado: A "type example" of A-type granitic magmatism

Geology, of the High Climb Pegmatite, Custer County, South Dakota

Aquamarine in the United States

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