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Leucite- and Feldspar-Bearing Systems

  • Alok Krishna Gupta
Chapter
Part of the Springer Geology book series (SPRINGERGEOL)

Abstract

Nephelinites have been considered to be the most perplexing group of igneous rocks by Bailey (1974). Such rocks predominantly contain nepheline and augite with other accessory minerals. They are usually associated with rocks of melteigite–ijolite–urtite series in close proximity to either leucite-bearing mafic lavas, or carbonatites. Sometimes, they are also observed as a highly fractionated group of rocks derived from lavas of alkali basalt –phonolite series; in such cases, sanidine becomes an important phase in addition to augite and nepheline.

Keywords

Bulk Composition Nepheline Syenite Alkali Feldspar Incongruent Melting Primary Phase Field 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Copyright information

© Springer India 2015

Authors and Affiliations

  1. 1.Mineralogy & PetrologyUniversity of AllahabadAllahabadIndia

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