Petrology of Pre-Cambrian Granites in the Northern Bighorn Mountains, Wyoming

Osterwald, Frank W.

doi:10.1086/626269

Cited by 26 publications

(22 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Especially noteworthy is the research of Hewitt (1956), who during many years of field work in Ontario found that some occurrences of granite and syenite formed by a transformation of metasedimentary and metavolcanic rock. Elsewhere, examples of Si-K metasomatism (granitization) were presented by Osterwald (1955), Whitten (1959), Edelman (1972), Laurent (1973) and Williams (1976). A valuable review of the "granite problem" was prepared by Marmo (1971).…”

Section: Discussionmentioning

confidence: 99%

METASOMATIC TRANSFORMATIONS IN TWO METAMORPHIC COMPLEXES DOMINATED BY HETEROGENEOUS Ca-PYROXENE - HORNBLENDE GRANITE AND SYENITE, OTTER LAKE AREA, QUEBEC, CANADA

Kretz

2009

The Canadian Mineralogist

View full text Add to dashboard Cite

The Bellmount Complex (28 3 5 km) and the Polish Hills Complex (6 3 3 km), found in a high-grade metamorphic terrane in the western Grenville Province of the Canadian Precambrian Shield, consist mainly of granitic-syenitic rocks with highly variable microstructure and mineral proportions. In a 40-meter section, the mean mineral content is Qtz 21 Kfs 55 Pl 14 Cpx 10 Ttn <1 . The atom ratio Mg / (Mg + Fe 2+ ) in Ca-pyroxene and hornblende is equal to 0.6 to 0.7, Na / (K + Na) in discrete crystals of K-feldspar is equal to 0.06, and Na / (Na + Ca) in plagioclase is 0.93. Complex exsolution-induced microstructures formed during cooling to ca. 400°C. The granite and syenite are interlayered with amphibolite, K-feldspar -biotite (veined) gneiss and other rock components. There are signs of metasomatism on the 1 to 10 meter scale within the two complexes. K-feldspar amphibolite formed from Ca-pyroxene granulite with an addition of K, Rb, Sr, and Ba, and removal of Ca and Na, leaving concentrations of Si, Ti, Al, Fe, Mg, P, Sc, V, Zr, Nb, Cs and Hf unchanged. Also, bodies of Ca-pyroxene skarn and Ca-pyroxene -scapolite skarn, possibly formed from dolomite marble with an addition of all major elements except Mg and Ca, and the addition of several trace elements, including V, Zn, Rb, Y, Ba and rare-earths. Furthermore, a mixture of K-feldspar amphibolite and hornblende granite has possibly formed by an alteration of common amphibolite to K-feldspar amphibolite (with an addition of K and Rb), followed by the local transformation of K-feldspar amphibolite to hornblende granite (with an addition of Si and removal of Fe, Mg, Mn and Ca), leaving concentrations of Al, Na, K, Rb, Sr, Y and Ba unchanged. The introduction of elements at numerous places in the two complexes was possibly facilitated by deep fractures of a northeast-trending rift structure, marked by the presence of several bodies of ca.1.15 Ga nepheline syenite.

show abstract

Section: Discussionmentioning

confidence: 99%

METASOMATIC TRANSFORMATIONS IN TWO METAMORPHIC COMPLEXES DOMINATED BY HETEROGENEOUS Ca-PYROXENE - HORNBLENDE GRANITE AND SYENITE, OTTER LAKE AREA, QUEBEC, CANADA

Kretz

2009

The Canadian Mineralogist

View full text Add to dashboard Cite

show abstract

“…In the Bighorn Mountains Osterwald (1955; and Hoppin (1961) have shown that the Precambrian core consists of older gneiss and schist, amphibolite, and rare layers of tuff and agglomerate, and Heimlich (1969) suggested that granitic rocks in the northern Bighorns were formed by granitization of the metamorphic rocks. The gneiss has a northeast-trending fabric and the granitic rocks occupy a northwest plunging synform.…”

Section: 1)mentioning

confidence: 99%

Precambrian uranium-bearing quartz-pebble conglomerates: exploration model and United States resource potential

Houston¹,

Karlstrom²

1979

View full text Add to dashboard Cite

“…The replacement textures could be ascribed to either latemagmatic or metasomatic growth, but several authors (e.g. King, 1947;Osterwald, 1955) have cited similar textures as evidence of metasomatism.…”

Section: Field and Petrographic Evidencementioning

confidence: 99%

The petrology of the Mt Manypeaks Adamellite and associated high‐grade metamorphic rocks near Albany, Western Australia

Stephenson¹

1973

Journal of the Geological Society of Australia

View full text Add to dashboard Cite

Petrology of Pre-Cambrian Granites in the Northern Bighorn Mountains, Wyoming

Cited by 26 publications

References 26 publications

METASOMATIC TRANSFORMATIONS IN TWO METAMORPHIC COMPLEXES DOMINATED BY HETEROGENEOUS Ca-PYROXENE - HORNBLENDE GRANITE AND SYENITE, OTTER LAKE AREA, QUEBEC, CANADA

METASOMATIC TRANSFORMATIONS IN TWO METAMORPHIC COMPLEXES DOMINATED BY HETEROGENEOUS Ca-PYROXENE - HORNBLENDE GRANITE AND SYENITE, OTTER LAKE AREA, QUEBEC, CANADA

Precambrian uranium-bearing quartz-pebble conglomerates: exploration model and United States resource potential

The petrology of the Mt Manypeaks Adamellite and associated high‐grade metamorphic rocks near Albany, Western Australia

Contact Info

Product

Resources

About