Alteration Types In Granitic Rocks

The chemical and textural characterization of various types of plagioclase alterations allows elucidation of the granitic hydrothermal systems.

Alteration types in granitic rocks.

Bradley dalton winfield g. Hydrothermal alteration can be isochemical like meta morphism and dominated by mineralogical changes or it can be metasomatic and result in significant addition or removal of elements. Hydrothermal alteration and related solid and aqueous phase geochemical signatures by dana j. 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.

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. They have two different origins. Alteration is defined as any alteration of rocks or minerals by the reaction of hydrothermal fluid with preexisting solid phases. These areas were differentiated in.

Phyllic alteration is associated with porphyry cu deposits but also with mesothermal precious metal ores and volcanogenic massive sulfide deposits in felsic rocks. Types of wall rock alteration now coming to the exact question raised the types are varied and manifold. About 10 types are being named as under though numerous permutations and combinations often tend to produce mixed variables. 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. Present study aims to understand the nature of. It corresponds to the outcropping of the lower part of the fractured horizon of an alteration profile. The degree and scales of time in which.