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image/svg+xml Jakob Voss, based on art designer at PLoS, modified by Wikipedia users Nina and Beao Closed Access logo, derived from PLoS Open Access logo. This version with transparent background. http://commons.wikimedia.org/wiki/File:Closed_Access_logo_transparent.svg Jakob Voss, based on art designer at PLoS, modified by Wikipedia users Nina and Beao Mineralogy and Petro...arrow_drop_down
image/svg+xml Jakob Voss, based on art designer at PLoS, modified by Wikipedia users Nina and Beao Closed Access logo, derived from PLoS Open Access logo. This version with transparent background. http://commons.wikimedia.org/wiki/File:Closed_Access_logo_transparent.svg Jakob Voss, based on art designer at PLoS, modified by Wikipedia users Nina and Beao
Mineralogy and Petrology
Article . 1995 . Peer-reviewed
License: Springer TDM
Data sources: Crossref
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One hundred years of rapakivi granite

Authors: O. T. R�m�; I. Haapala;

One hundred years of rapakivi granite

Abstract

Rapakivi granites, recently redefined as A-type granites showing rapakivi texture at least in the larger batholiths, occur on all continents and presumably represent the most voluminous continental silicic intraplate magmatism on Earth. Most of the rapakivi granites are Proterozoic (mainly 1.0 to 1.7 Ga) but also Archean (2.8 Ga) and Phanerozoic (0.05 to 0.4 Ga) are known. The magmatic association is bimodal comprising anorthosite to gabbro, diabase, minor Fe-enriched intermediate rocks, and monzonite, beside granite; mingling of silicic and mafic magmas is typical. Geochemically and otherwise, rapakivi granites show the characteristics of the Phanerozoic A-type granites, except that they encompass relatively few peralkaline rocks and that they may occur as very large (up to 40,000 km2) batholiths. Some of the rapakivi granite complexes host important Sn-polymetallic and Fe-Cu deposits. The rapakivi granites crystallized from relatively hot, restite-poor magmas at low (epizonal-subvolcanic) pressure, $$a_{H_2 O} $$ , and $$a_{O_2 } $$ . Mineral assemblages are indicative of a multiphase crystallization history; the conspicuous mantling of the perthite ovoids with plagioclase can be explained by changes in magma composition and/or, P, T, and $$a_{H_2 O} $$ affecting the stabilities of feldspars. The isotopic composition of rapakivi granites is generally compatible with a lower crustal protolith. The latter could have been either a melt-depleted residue or otherwise relatively anhydrous igneous or metaigneous rock. Melting of the protolith commenced under vapor-absent conditions and was induced by heat from the contemporaneous mantle-derived mafic magmas. The widespread rapakivi granite magmatism in the Middle Proterozoic may have been related to the establishment of a major continental mass (supercontinent).

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selected citations
These citations are derived from selected sources.
This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
BIP!Citations provided by BIP!
popularity
This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network.
BIP!Popularity provided by BIP!
influence
This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
BIP!Influence provided by BIP!
impulse
This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network.
BIP!Impulse provided by BIP!
199
Top 10%
Top 1%
Top 10%
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