Rapakivi Granites and Related Rocks

ISBN-13: 9780128214152 / Angielski

Ilmari J. Haapala; O. Tapani R?m?; Roberto Dall'agnol

Opis

Rapakivi Granites and Related Rocks tells the story of Rapakivi granites, a group of granitic rocks characterized by specific texture (presence of plagioclase-mantled ovoidal to subhedral alkali feldspar megacrysts, two generations of quartz and feldspars) and A-type geochemical composition. The book includes research and abundant geochemical and isotopic data combined with an understanding of geotectonic processes that allow more detailed tectonic and petrological modeling of rapakivi granite magmatism and associated ore mineralization. Well-known examples are found as anorogenic or post-orogenic batholith- to stock-sized intrusive complexes in the Precambrian cratons of Ukraine, Fennoscandia, South Greenland, Canada, United States, Brazil, Venezuela and Siberia. The current knowledge of the rapakivi granites is largely based on the achievements of three International Geological Correlation Programme projects: IGCP–315 (Rapakivi Granites and Related Rocks) in in 1991–1996, IGCP–426 (Granite Systems and Proterozoic Lithospheric Processes) in 1998–2002, and IGCP–510 (A-type Granites and Related Rocks Through Time) in 2005–2009. After these projects, the research has continued actively utilizing enhanced geochemical methods, in situ geochemistry in particular.

Spis treści

1. Historical Background and Definitions 2. Rapakivi Texture and Rapakivi Granite 3. State of the Art: Discussion on Various Aspects of Rapakivi Granite and Related Rocks 4. Intensive Parameters 5. Origin of Rapakivi Granite Magmas 6. Origin of Mantled Alkali Feldspar Megacrysts 7. Metallogeny 8. Granitoids Approaching Rapakivi Granites