Alteration Types In Granitic Rocks

They have two different origins.

Alteration types in granitic rocks.

Alteration is defined as any alteration of rocks or minerals by the reaction of hydrothermal fluid with preexisting solid phases. Hydrothermal alteration and related solid and aqueous phase geochemical signatures by dana j. And zoning of hydrothermally altered rock the age and type of mineralization and hydrothermal alteration and trends or patterns of veins and faults. This alteration grades into the potassic type by increasing amounts of k ak k feldspar and or biotite and into the argillic type by increasing amounts of h ah clay minerals.

Purulia district of west bengal is geologically dominated mostly by proterozic hard granite gneiss rocks including soft phyllite and mica schist of singhbhum group as part of chotanagpur plateau. Types of wall rock alteration now coming to the exact question raised the types are varied and manifold. Wyns crystalline rocks or hard rocks are rocks that are generally ancient formed at great depth at several tens of kilometres. It corresponds to the outcropping of the lower part of the fractured horizon of an alteration profile.

Mineral alteration is essentially governed by the laws of thermodynamics related to energy conservation relevant to environmental conditions often in presence of catalysts the most common and influential being water h 2 o. Present study aims to understand the nature of. Phyllic alteration is associated with porphyry cu deposits but also with mesothermal precious metal ores and volcanogenic massive sulfide deposits in felsic rocks. Mineral alteration refers to the various natural processes that alter a mineral s chemical composition or crystallography.

The chemical and textural characterization of various types of plagioclase alterations allows elucidation of the granitic hydrothermal systems. About 10 types are being named as under though numerous permutations and combinations often tend to produce mixed variables. Bradley dalton winfield g. These areas were differentiated in.