The United Kingdom, and parts of France, Italy, and Portugal. Foliation develops at rightĪngles to the compressive forces of the convergent plate boundaries. These forces and heat modify the clay minerals. Mudstone in the basin is compressed by horizontal forces with minor heating. When this basin is involved in a convergent plate boundaries. Tectonic environments for producing slates are Particles are transported by wind or water. Shale is deposited in a sedimentary basin where finer These spheres are once in a while deformed by a next carried out pressure discipline to ovoids, which appear as ellipses while viewed on a cleavage plane of the specimen. Occasionally, as within the pink slates of North Wales, ferrous discount spheres form around iron nuclei, leaving a mild green noticed texture. Slate is particularly composed of the minerals quartz and muscovite or illite, frequently along with biotite, chlorite, hematite, and pyrite and, less regularly apatite, graphite, kaolinite, magnetite, tourmaline, or zircon as well as feldspar. Metamorphic group of rocks and can be defined as a fine-grained rock derivedįrom clays and shale and possessing a cleavage that permits it to be split into These into slates folded and contracted them. These beds of shale at first horizontal, were tiltedīy subsequent earth movements, and the intense metamorphism that converted The shale from which slates originate were deposited Thus shaleĪnd related rocks may be altered into slate. Igneous or sedimentary types, and usually much harder than either. In this way, new rocks are formed, differing widely from the Many constitutes minerals may be dissolved, transported, and

They may be folded into complex forms with aīanded structure. Rocks may become plastic under great pressure and high Metamorphic rocks may be further altered to higher ranks of metamorphism. Igneous or sedimentary rock into metamorphic rock, meaning “changed inįorm,” usually into a more compact and crystalline condition, and even Heat, pressure, and chemical reactions may change either Major minerals: Quartz and muscovite or illite frequently along with biotite, chlorite, hematite, and pyriteĪccessory minerals: Apatite, graphite, kaolinite, magnetite, tourmaline, or zircon as well as feldspar Classification Grain size – Very fine-grained crystals not visible to the naked eye.

Texture – Foliated Metamorphic Rock, Foliation on a mm Scale.

Green slate