Original paper
Phlogopitization at Amba Dongar Carbonatite Alkalic Complex, India
Viladkar, S. G.
Neues Jahrbuch für Mineralogie - Abhandlungen Band 162 Heft 2 (1991), p. 201 - 213
20 references
published: Jan 16, 1991
DOI: 10.1127/njma/162/1991/201
ArtNo. ESP154016202005, Price: 29.00 €
Abstract
At Amba Dongar, two types of micas - phlogopitic biotite and phlogopite - formed out of pyroxenes in sodi-potassic fenites and nephelinites during K-metasomatism. The phlogopitization of pyroxene in these two types of rocks requires the addition of large amounts of K and small amounts of Mg and Fe. The fenitizing solutions responsible for large scale phlogopitization were derived from a calcitic carbonatite (sövite and alvikite) magma. It has been suggested that the Mg/Fe ratio of the host pyroxenes is the controlling factor in the formation of phlogopitic biotite or phlogopite.
Keywords
Carbonatite • phlogopite • fenite • fenitization • Amba Dongar