During metamorphism the mineral content and texture of the protolith are changed due to changes in the physical and chemical environment of the rock. Metamorphism can be caused by burial, tectonic stress, heating by magma, or alteration by fluids.

What processes result in mineral flattening during metamorphism?

Which processes result in mineral flattening during metamorphism? dissolution followed by crystallization.

Which of the following describes the orientation of slaty cleavage and mineral grains in relationship to the stress applied?

Which of the following describes the orientation of slaty cleavage and mineral grains in relationship to the stress applied? Slaty cleavage is parallel to the direction of the weakest stress applied. & Mineral grains are oriented parallel to the direction of the weakest stress applied.

Why do bands of minerals form when rocks undergoing metamorphism are put under high grade stress?

Gneiss As metamorphic grade increases, the sheet silicates become unstable and dark colored minerals like hornblende and pyroxene start to grow. These dark colored minerals tend to become segregated in distinct bands through the rock, giving the rock a gneissic banding.

Why do minerals rearrange metamorphic rocks?

Rocks change during metamorphism because the minerals need to be stable under the new temperature and pressure conditions. The need for stability may cause the structure of minerals to rearrange and form new minerals.

What happens to a rock during metamorphism?

The process of metamorphism does not melt the rocks, but instead transforms them into denser, more compact rocks. New minerals are created either by rearrangement of mineral components or by reactions with fluids that enter the rocks.

What type of stress that occurs during metamorphism results in aligned and elongated minerals What does the rock develop as a result of this stress?

Metamorphism and Deformation

The result of compressional stress acting on rocks that behave in a ductile manner (ductile behavior is favored by higher temperature, higher confining stress [pressure] and low strain rates) is the folding of rocks.

How can a rock change during metamorphism quizlet?

How does the mineral composition of rock change during metamorphism? hot magma inside the earth heats up the rocks and causes them to produce new minerals. The closer to the magma the rock is the more it changes. Or the rocks change when pressure builds up due to shifts in the Earth’s crust.

What is the result of differential stress pressure on rocks?

The result of differential stress (pressure) on rocks can: cause mineral crystals to align parallel to each other.

When the mineral assemblage of a rock changes due to high temperature and pressure the rock undergoes?

Sedimentary rock. When the mineral assemblage of a rock changes due to high temperature and pressure, the rock undergoes recrystallization.

What are some of the ways in which geologists can determine the temperatures and pressures or depths of metamorphism?

Therefore, by studying the mineral composition of a metamorphic rock, geologists can determine the temperature at which the rock has formed. Metamorphic mineral assemblages are natural geothermometers. The depth at which metamorphism occurs depends on the geothermal gradient.

Which of the following sets is arranged in order of increasing metamorphic grade?

The sequence slate鈫抪hyllite鈫抯chist鈫抔neiss illustrates an increasing metamorphic grade. Geologists use index minerals that form at certain temperatures and pressures to identify metamorphic grade.

How are metamorphic rocks formed quizlet geology?

Happens when rocks get buried by new rocks formed on top of them. The weight on top of rocks forces them deeper into the earth where they become exposed to heat. The heat and pressure cause the rock to change into a new rock.

Why are mineral bands in metamorphic rocks light and dark colored quizlet?

Why are mineral bands in metamorphic rocks light and dark colored? There is enough heat and pressure to induce recrystallization of any tabular minerals in the rock. Why does quartzite not exhibit foliated texture? There are very few or no tabular minerals in quartzite.

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

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 of pressure during metamorphism.The types of fluids (mostly water) that are present during metamorphism.The amount of time available for metamorphism.

How do minerals change without melting?

This is a really cool way that a mineral can change its atomic structure without melting. So as we change pressure and temperature a different atomic structure becomes stable and the mineral changes. Another example is diamond.

How and why rocks are altered by regional metamorphism?

Regional metamorphism results in intense alteration of the mineralogy and texture of rocks, usually to the point where original sedimentary structures are destroyed. Regional metamorphism is primarily due to tectonic forces associated with the interaction between lithospheric plates.

When rocks are affected by weathering and erosion they change into which of the following?

Weathering (breaking down rock) and erosion (transporting rock material) at or near the earth’s surface breaks down rocks into small and smaller pieces. These smaller pieces of rock (such as sand, silt, or mud) can be deposited as sediments that, after hardening, or lithifying, become sedimentary rocks.