What is hydrothermal alteration in geology?
Hydrothermal alteration is defined as any alteration of rocks or minerals by the reaction of hydrothermal fluid with preexisting solid phases.
What are the types of alteration?
Types of alterations
- Potassic alteration.
- Phyllic (sericitic) alteration.
- Propylitic alteration.
- Argillic alteration.
- Silicification.
- Carbonatization.
- Greisenization.
- Hematitization.
What is an alteration zone?
Alteration zones can be created around a number of the structural features (faults, shear zones, plugs, dykes and unconformities), and are defined as either alteration haloes, where the pre-existing rock property values are enhanced or depleted, or as replacement zones, where the original rock property values ar …
What is alteration in geology?
[… in rocks] Any change in the mineralogic composition of a rock brought about by physical or chemical means, esp. by the action of hydrothermal solutions; also, a secondary, i.e., supergene, change in a rock or mineral.
Where does hydrothermal alteration occur?
geothermal systems
Hydrothermal alteration occurs in geothermal systems and involves the replacement of the primary mineral assemblage by alteration minerals. Changes in temperature, pressure, and chemistry of the system usually induce extensive alteration of the host rock.
Where is hydrothermal alteration most common?
oceanic crust
Hydrothermal alteration of the oceanic crust is widespread and locally thorough in oceanic crust (Scambelluri et al., 1995), resulting in the pervasive serpentinization of ultramafic rocks as witnessed in many ultramafic sections in ophiolites.
What is hydrothermal alteration mapping?
Hydrothermal alteration zones are considered an important guide for mineral exploration and can act as a potential zone of mineralization. The minerals in alteration zones have very diagnostic absorption features in visible–near infrared (VNIR) and shortwave infrared (SWIR) regions of the electromagnetic spectrum.
What the meaning of hydrothermal?
or relating to hot water
Definition of hydrothermal : of or relating to hot water —used especially of the formation of minerals by hot solutions rising from a cooling magma.
What is hydrothermal fluid?
Hydrothermal fluids are natural heated water solutions wherein variety of elements, compounds and gases may be dissolved. They are generated by diverse crustal and mantle geological processes including basinal fluid interaction, magmatic differentiation and mantle degassing.
What causes hydrothermal activity?
Magma beneath the surface provides the heat; ample rain and snowfall seep deep underground to supply the water; and underground cracks and fissures form the plumbing. Hot water rises through the plumbing to surface as hydrothermal features.
What is alteration in biology?
changes in the structure and function of cells, tissues, and organs in response to harmful outside influences (mechanical, thermal, electrical, chemical, and others).
How is hydrothermal formed?
Hydrothermal deposits refer to the accumulation of minerals in fractures and cavities resulting from the circulation of hot waters in the Earth’s crust. Magma releases hot fluids (water and gases) as it cools but can also heat circulating groundwater.
What do hydrothermal processes form?
Hydrothermal processes therefore accompany (1) the transformation of sediments into sedimentary rocks (diagenesis) and of sedimentary rocks into metamorphic rocks, (2) the formation and crystallization of magmas, and (3) the interaction of meteoric, connate, and ocean water with igneous rocks during their rise.
What is a result of hydrothermal activity?
Hydrothermal vents are usually associated with emission of gases such as helium, methane, and hydrogen sulfide; and deposition of large quantities of metallic compounds on the seafloor. In fact, hydrothermal activity is often identified by detection of anomalies of such emissions and depositions.
What is meant by hydrothermal activity?
hydrothermal activity Any process associated with igneous activity involving the action of very hot waters.
What is alterations in gene structure called?
An alteration in the DNA structure or sequence of a gene is called a mutation. A mutation is any change in the DNA sequence of an organism.
What do you mean by hydrothermal process?
Hydrothermal method is a chemical reaction in water in a sealed pressure vessel, which is in fact a type of reaction at both high temperature and pressure.