Foliation (geology) - Wikipedia
Alignment of tabular minerals in metamorphic rocks, igneous rocks and intrusive rocks may form a foliation. Typical examples of metamorphic rocks include porphyroblastic schists where large, oblate minerals form an alignment either due to growth or rotation in the groundmass.
Foliation | Types, Causes, & Facts | Britannica
Foliation, planar arrangement of structural or textural features in any rock type but particularly that resulting from the alignment of constituent mineral grains of a metamorphic rock of the regional variety along straight or wavy planes. Foliation is …
Metamorphic Rocks | Pictures of Foliated and Non-Foliated Types
Foliated metamorphic rocks have a layered or banded appearance that is produced by exposure to heat and directed pressure. Examples of foliated rocks include: gneiss, phyllite, schist, and slate. Non-foliated metamorphic rocks …
Metamorphic Rocks – Formation, Types, Examples - Science …
Feb 24, 2024 · Two Types of Metamorphic Rocks. Foliated Metamorphic Rocks: Form under directed pressure, leading to the alignment of minerals in layers. Examples include slate, schist, and gneiss. Non-Foliated Metamorphic Rocks: Form without directed pressure, thus lacking a layered texture. Examples include marble and quartzite. Textures of Metamorphic Rocks
Overview of Metamorphic Rocks – Laboratory Manual for Earth …
Metamorphic rocks with a foliation pattern defined by the layering of platy minerals (such as muscovite or biotite micas) are called schist. The rock name is commonly modified to indicate what mica is present. For example, Figure 5.5 is muscovite schist with garnet present, so the correct name for this rock is a garnet muscovite schist.
6.3: Metamorphic Textures - Geosciences LibreTexts
Foliated metamorphic rocks are named based on the style of their foliations. Each rock name has a specific texture that defines and distinguishes it, with their descriptions listed below.
10.2: Foliation and Rock Cleavage - Geosciences LibreTexts
Aug 22, 2024 · Foliated metamorphic rocks have elongated crystals that are oriented in a preferred direction. This forms planes of weakness, and when these rocks break, they tend to break along surfaces that parallel the orientation of the aligned minerals (Figure 10.10).
7.2: Classification of Metamorphic Rocks - Geosciences LibreTexts
Apr 24, 2024 · The various types of foliated metamorphic rocks, listed in order of the grade or intensity of metamorphism and the type of foliation are: slate, phyllite, schist, and gneiss (Figure \(\PageIndex{4}\)). As already noted, slate is formed from the low-grade metamorphism of shale, and has microscopic clay and mica crystals that have grown ...
Metamorphic Rocks – Introduction to Earth Science - Virginia Tech
Explain what foliation is and how it results from directed pressure and recrystallization. Explain the relationships among slate, phyllite, schist, and gneiss in terms of metamorphic grade. Define index mineral. Explain how metamorphic facies relate to plate tectonic processes.
Gneiss: Metamorphic Rock - Pictures, Definition & More - Geology.com
Gneiss is a foliated metamorphic rock identified by its bands and lenses of varying mineral composition. Some of these bands (or lenses) contain granular minerals that are bound together in an interlocking texture.