What are the main factors that control metamorphic processes?

The main factors that control metamorphic processes are:

• The chemical composition of the parent rock.
• The temperature at which metamorphism takes place.
• The pressure applied, and whether the pressure is equal in all directions or not.
• The amount and type of fluid (mostly water) that is present during metamorphism.

What are the 5 factors that influence metamorphism?

Factors Controlling Metamorphism

• Temperature and pressure. Temperature and pressure are important factors in determining the new minerals that form in a metamorphic rock.
• Water.
• Geostatic pressure.
• Differential stress.
• Figure 1.
• Differential Stress.
• Compressive stress.
• Figure 2.

What causes hydrothermal metamorphism?

Hydrothermal metamorphism occurs when hot, chemically active, mineral laden waters interact with a surrounding preexisting rock (called the country rock). Most hydrothermal metamorphism takes place at low pressures and relatively low temperature, as the phase diagram shows.

What changes occur in hydrothermal metamorphism?

The hydrothermal metamorphism results in alteration to such Mg-Fe rich hydrous minerals as talc, chlorite, serpentine, actinolite, tremolite, zeolites, and clay minerals. Rich ore deposits are often formed as a result of hydrothermal metamorphism.

What is the 6 factors that control metamorphism?

Factors that Control Metamorphism

• Chemical Composition of the Protolith. The type of rock undergoes metamorphism is a major factor in determing what type of metamorphic rock it becomes.
• Temperature.
• Pressure.
• Fluids.
• Time.
• Regional Metamorphism.
• Contact Metamorphism.
• Hydrothermal Metamorphism.

What are the 4 factors controlling the mineral assemblage of metamorphic rocks?

The mineral assemblages that occur in metamorphic rocks depend on four factors:

• The bulk chemical composition of the original rock.
• The pressure reached during metamorphism.
• The temperature reached during metamorphism.
• The composition of any fluid phase that was present during metamorphism.

What causes Metasomatism?

In the metamorphic environment, metasomatism is created by mass transfer from a volume of metamorphic rock at higher stress and temperature into a zone with lower stress and temperature, with metamorphic hydrothermal solutions acting as a solvent.

What is hydrothermal metamorphism and where does it mostly occur?

Hydrothermal Metamorphism (Fig. 8.3): typically occurs along mid-ocean ridge spreading centers where heated seawater percolates through hot, fractured basalt. Chemical reactions between the heated seawater and basalt result in metamorphism of the basalt.

What is the main factor that affects regional metamorphism?

Temperature, hydrostatic pressure, and shearing stress, together with the chemical activity of percolating pore fluids, are the major physical variables governing the process of regional metamorphism.

What are the factors that affect the change in a rock during metamorphism?

The main factors that control metamorphic processes are: The temperature at which metamorphism takes place. The amount and type (direction) of pressure during metamorphism. The amount and type of fluid (mostly water) that is present during metamorphism. The amount of time available for metamorphism.

What is metamorphism discuss the factors that control metamorphism in detail?

The main factors that control metamorphic processes are: The mineral composition of the parent rock. The temperature at which metamorphism takes place. The amount and type (direction) of pressure during metamorphism. The amount and type of fluid (mostly water) that is present during metamorphism.

What are the factors controlling mineral formation?

Physical and chemical conditions include factors such as temperature, pressure, presence of water, pH, and amount of oxygen available. Time is one of the most important factors because it takes time for atoms to become ordered. If time is limited, the mineral grains will remain very small.

What determines the geochemical behavior of gold in hydrothermal systems?

The geochemical behavior of gold in hydrothermal systems The occurrence of gold mainly depends on temperature, pressure, pH values, Cl − concentration, and fugacity of H 2S in a hydrothermal system.

What is metasomatism in hydrothermal rocks?

Hydrothermal Rocks. Metasomatism is the process by which hot‐water solutions carrying ions from an outside source move through a rock mass via fractures or pore space. Some of the rock mass is usually dissolved away, and the ions introduced by the water are incorporated into the new minerals that precipitate.

How are hydrothermal rocks different from metamorphic rocks?

Thus, these rocks are distinct from metamorphic rocks, which are created by solid‐state mineral transformations. In fact, many hydrothermal rocks (such as those that form from hot springs and geysers or crystallize as veins in cracks in other rocks) actually build up in layers, much as sedimentary rocks do.

What are mineral assemblages formed during hydrothermal alteration?

Mineral assemblages formed during hydrothermal alteration reflect the geochemical composition of ore-forming fluids. Gold is mainly transported in solution as Au–Cl and Au–S complexes.