It is commonly associated with other types of alteration, such as albitization
, sepentinization etc.
Wide range of anorthite contents in the plagioclase is due to albitization
of microcline took place at around 300[degrees] to 400[degrees] C, followed by an acidic stage in which crystals of micas, fluorite and thick tabular albite crystallized from weakly enriched [CO.
In the depocentre of the basin, a low-grade metamorphic event (hydrothermalism) took place, leading to some mineralogical changes in the original petrofacies, including silicification, chloritization and the albitization
On the other hand, upper limit of the time interval for emplacement of investigated dykes is defined by the origin of uranium hydrothermal mineralization, which caused chloritization and albitization
of granodiorite porphyries.
Four distinct alteration types are recognized: albitization
, potassic alteration, carbonatization, and silicification.
The hydrothermal clay mineral assemblage was apparently controlled by late magmatic albitization
and the bulk chemistry of albite-topaz granites.
During these alteration events, albitization
and hydrogen ion metasomatism caused not only tungsten greisenization at Krantzberg but also uranium-tungsten-tin mineralization at Etemba 135 and tin-tungsten mineralization at Anibib 136, approximately 20 km west of Krantzberg (Pirajno and Schlogl, 1987).
of the original plagioclase, chloritization of biotite and enrichment in hematite are common.