Table of Contents
- 1 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?
- 2 What is the term for a metamorphic rock which show mineral alignments that are more or less parallel to one another?
- 3 What is meant by regional metamorphism?
- 4 What does the term protolith mean?
- 5 What causes Metasomatism?
- 6 How are grains in rock grown in place?
- 7 How does a rock change from one mineral to another?
- 8 Why are high pressure minerals found in metamorphic 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.
What is the term for a metamorphic rock which show mineral alignments that are more or less parallel to one another?
TEXTURES Textures of metamorphic rocks fall into two broad groups, FOLIATED and NON-FOLIATED. Foliation is produced in a rock by the parallel alignment of platy minerals (e.g., muscovite, biotite, chlorite), needle-like minerals (e.g., hornblende), or tabular minerals (e.g., feldspars).
What does the term Protolith mean?
A protolith (from Ancient Greek πρωτο (prōto) ‘first’, and λίθος (líthos) ‘stone’) is the original, unmetamorphosed rock from which a given metamorphic rock is formed. For example, the protolith of a slate is a shale or mudstone.
What is meant by regional metamorphism?
Regional metamorphism is metamorphism that occurs over broad areas of the crust. Most regionally metamorphosed rocks occur in areas that have undergone deformation during an orogenic event resulting in mountain belts that have since been eroded to expose the metamorphic rocks.
What does the term protolith mean?
What is Brainly metamorphism?
Metamorphism is the change of minerals or geologic texture in pre-existing rocks, without the protolith melting into liquid magma. The change occurs primarily due to heat, pressure, and the introduction of chemically active fluids.
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.
How are grains in rock grown in place?
Grains in rock have grown in place within the solid rock. New minerals that grow only under metamorphic temperatures and pressures. Parallel alignment of platy minerals, and/or the presence of alternating light and dark colored minerals.
What makes a metamorphic rock have a foliation?
A fine-grained metamorphic rock with a foliation caused by the preferred orientation of very fine-grained mica. The metamorphic texture that exists where platy grains lie parallel to one another and/or elongate grains align in the same direction.
How does a rock change from one mineral to another?
Changes one mineral into another mineral with same composition but different crystal structure. A rock is squeezed more strongly in one direction than in others in the presence of water. Rock is squeezed or sheared at elevated temperatures. Minerals that recrystallize or grow during metamorphism but have no foliation.
Why are high pressure minerals found in metamorphic rocks?
It occurs because of sudden pressure exerted by faults or meteorite impacts. The results are often the fracturing and granulation of rocks and sometimes the creation of high-pressure minerals such as coesite or stishovite, both polymorphs of quartz.