Alteration Types In Granitic Rocks

Types of wall rock alteration now coming to the exact question raised the types are varied and manifold.

Alteration types in granitic rocks.

These areas were differentiated in. Bradley dalton winfield g. 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. 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.

Present study aims to understand the nature of. Features of feldspar alteration in the granitic rocks are similar to those encountered in feldspathic sandstones and should hence be considered in studies on diagenetic changes of siliciclastic. 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. The degree and scales of time in which.

Hydrothermal alteration and related solid and aqueous phase geochemical signatures by dana j. Wyns crystalline rocks or hard rocks are rocks that are generally ancient formed at great depth at several tens of kilometres. And zoning of hydrothermally altered rock the age and type of mineralization and hydrothermal alteration and trends or patterns of veins and faults. Alteration is defined as any alteration of rocks or minerals by the reaction of hydrothermal fluid with preexisting solid phases.

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. Mineral alteration refers to the various natural processes that alter a mineral s chemical composition or crystallography. They have two different origins. Phyllic alteration is associated with porphyry cu deposits but also with mesothermal precious metal ores and volcanogenic massive sulfide deposits in felsic rocks.