Results 141 to 150 of about 2,559 (173)

The Jaala-Iitti rapakivi complex. An example of bimodal magmatism and hybridization in the Wiborg rapakivi batholith, southeastern Finland

Mineralogy and Petrology, 1994
The dyke-like 1.63 Ga Jaala-Iitti rapakivi complex forms a 25 km long and up to 2 km wide intrusive body at the northwestern margin of the Wiborg rapakivi batholith cutting both the granites of the batholith and the surrounding 1.9 Ga Svecofennian crust.
P. T. Salonsaari, I. Haapala
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The Genesis of the Rapakivi Granites

Geologiska Föreningen i Stockholm Förhandlingar, 1937
(1937). The Genesis of the Rapakivi Granites. Geologiska Foreningen i Stockholm Forhandlingar: Vol. 59, No. 4, pp. 503-524.
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The Problems of the Rapakivi Granites

The Journal of Geology, 1938
The rapakivi granites of Fennoscandia, characterized by Johannsen as "abnormal," include coarse-grained rocks having a peculiar ovoidal texture, controlled by the form of their potassium feldspars, which formerly served to define the whole group. When, however, it was realized that associated with the ovoidal varieties there are related granites having
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Rapakivi granites, South Greenland: hydrothermal alteration of igneous layering

Journal of the Geological Society, 1990
Igneous layering is developed in the Proterozoic rapakivi granite suite of South Greenland in an area on the south-easternmost coast of the island of Angnikitsoq. The layering at this locality is unusual in that it is defined by interstitial phases. We suggest that large-scale hydrothermal alteration has converted a fine-grained pyroxene cumulate, in ...
ADRIAN A. FINCH, R. JOHN REAVY, TIM N. HARRISON, PETER E. BROWN   +3 more
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Petrology of rapakivi granites in Salmi massif

International Geology Review, 1968
Crystallization of rapakivi is accompanied by a progressive decrease in the alkali content of the high-temperature granitic magma and by the concurrent increase in its iron content, during the crystallization of potassium feldspar which is followed by the crystallization of biotite.
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Rapakivi Granite of Ezhimala Complex and its Significance

Journal Geological Society of India, 1982
Abstract The field characters, chemistry and the spatial association of the 678 m.y. old Rapakivi granite with gabbros and anorthosites suggest that these litho-units have developed through bimodal magmatic processes whereby heat derived from basic magma parental to the anorthositic rocks caused partial melting at or near the base of the
M. M. Nair, K. T. Vidyadharan
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Granitoids of rapakivi granite-anorthosite and related associations

Precambrian Research, 1991
Abstract Mid-Proterozoic anorthosite-mangerite-charnockite-rapakivi granite (AMCG) magmatic suites have commonly intruded Proterozoic orogenic belts within 100 Ma or less to as much as 600 Ma after cessation of calc-alkalic crustal generation processes. High FeO (FeO+MgO) , high Na2O+K2O, low Al2O3, and reduced redox condition of the granitoids
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Petrogenesis of the Proterozoic rapakivi granites of Finland

1990
The rapakivi granites (1.7 to 1.55 Ga) of southern Finland occur as epizonal batholiths (e.g., the Wiborg, Åland or Ahvenanmaa, Vehmaa, and Laitila batholiths) and stocks cutting the medium- to high-grade metamorphic Svecofennian (1.9 to 1.8 Ga) crust.
Ilmari Haapala, O. Tapani Rämö
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Rapakivi texture from the O’Leary Porphyry, Arizona (U.S.A.)

Bulletin Volcanologique, 1980
The rhyodactic O’Leary Porphyry which forms the Pleistocene (0.233±0.37 m.y.) volcanic domes of O’Leary Peak and Darton Dome in the San Francisco Volcanic Field (northern Arizona, U.S.A.) contains sanidine phenocrysts with oligoclase mantles (rapakivi texture).
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Geology, Petrography and Petrology ofthe Rapakivi Granites; The Rapakivi Granites of Finland

İri alkali feldispatm plajiyoklas tarafından çevrelenmesiyle oluşan dokuyu gösteren granitler "Rapakivi Granitleri" olarak adlandırılmaktadır. Çoğunlukla Proterozoyik 1.8-1.0 milyar yıl yaşlı olan rapakivi granitleri, Ukrayna, Baltık ülkeleri, güney Grönland, orta-kıtasal ve batı ABD, Venezüella, Brezilya, Bostwana ve diğer birçok ...
ARSLAN, Mehmet, ASLAN, Zafer
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