What is Crenulation cleavage?

What is Crenulation cleavage?

Crenulation cleavages are zones of mineral differentiation that are coincident with the limbs of microfolds in crenulated fabrics. They consist of subplanar domains of highly oriented micaceous material that constitute preferred sites of parting in the rock.

What is Crenulation lineation?

The crenulation lineation is the fabric element parallel to the tightly spaced hinges. Many schists exhibit this type of lineation. It generally is a good indication of superposed deformation.

What is Microlithon geology?

Spaced foliation planes are discrete, tabular domains separated by thin slabs of rock without fabric or with a differently oriented, older, primary (original) or secondary fabric. These rock slabs which are thick enough (> ca. 1mm) to be distinguished in hand specimens or outcrop are called microlithons.

What is the meaning of Crenulated?

Definition of crenulated : having an irregularly wavy or serrate outline a crenulated shoreline.

What is slaty cleavage?

Since the nature of cleavage is dependent on scale, slaty cleavage is defined as having 0.01 mm or less of space occurring between layers. Slaty cleavage often occurs after diagenesis and is the first cleavage feature to form after deformation begins.

What is Gneissosity?

gneissose) General petrological term applied to coarse-grained, banded rocks that formed during high-grade regional metamorphism. The banding (gneissose banding, or gneissosity) is a result of the separation of dark minerals (e.g. biotite, hornblende, and pyroxenes) and the light-coloured quartzofeldspathic minerals.

What does schistosity look like?

Schist (/ˈʃɪst/ SHIST) is a medium-grained metamorphic rock showing pronounced schistosity. This means that the rock is composed of mineral grains easily seen with a low-power hand lens, oriented in such a way that the rock is easily split into thin flakes or plates.

What is Isoclinal fold?

A very tight fold, in which the limbs are parallel or nearly parallel to one another is called an isoclinal fold (Figure 12.6). Isoclinal folds that have been overturned to the extent that their limbs are nearly horizontal are called recumbent folds.

What is a crenelated wall?

adjective [usually ADJECTIVE noun] In a castle, a crenellated wall has gaps in the top or openings through which to fire at attackers.

What causes crenation?

When red blood cells are in a hypertonic (higher concentration) solution, water flows out of the cell faster than it comes in. This results in crenation (shriveling) of the blood cell.

Why do gneisses shine?

Answer. Answer: Gneiss is a metamorphic rock formed by changing schist, granite, or volcanic rocks through intense heat and pressure. Schists often have a high luster (they are very shiny) due to large crystals within the rock.

How many types of schists are there?

The specific mineral composition of a schist is indicated by placing the name or names of significant subordinate minerals in front of the word schist; commonly occurring types include biotite schist, muscovite-chlorite schist, garnet-mica schist, staurolite kyanite schist, and hornblende schist.

What does rock behaving plastically mean?

10.7c: At higher confining pressures, a similarly directed external force will cause the deeply buried rock to actually flow and deform without fracturing. This is known as ductile deformation and the rock is said to behave plastically.

  • October 18, 2022