Metamorphic rocks - Slate

Page / - last modified by Roelof Zwaan on 2021/09/30 15:18

Slate

last modified by Roelof Zwaan

on 2021/09/30 15:18

Table of Contents

Slate is a fine-grained foliated metamorphic rock. This rock originates from shale and transformed from shale into slate. When metamorphism continues it forms phyllite, then schist and finally into gneiss.

Characteristics

Slate has a dominant foliation and due to this fact slate falls apart in thin platy pieces. Slate originate from low-grade regional metamorphism at a former sedimentary basin involved in convergent plate boundaries, which means it forms under horizontal forces and minor heating. Slate can be distinguished from phyllite by its grain size. The grain size of slate is much smaller than that from phyllite.

Composition

Slate is mainly composed of quartz and some metamorphosed clay minerals. Most slates are grey in color and range from light to dark. The minerals in slate form at right angles to the compressive forces of the convergent plate boundary to yield a vertical foliation that usually crosses the bedding planes that existed in the shale.

References

NEN-EN-ISO 14688-1:2019

https://geology.com/

Slate

Type	Metamorphic rock
Texture	Platy
Clasts	Very fine grained
Hardness	Medium hard
Color	Grey to dark grey
Minerals	Quartz and mica minerals
Touch	Smooth
Image	Slate

Contents

Characteristics

Composition

References

Slate