GENERAL GEOLOGY

Detailed explanation-1: -Gneiss Gneissic banding is a metamorphic foliation in which visible silicate minerals separate into dark and light bands or lineations. These grains tend to be coarse and often folded. A rock with this texture is called gneiss.

Detailed explanation-2: -Foliated metamorphic rocks such as gneiss, phyllite, schist and slate have a layered or banded appearance that is produced by exposure to heat and directed pressure. Non-foliated metamorphic rocks such as hornfels, marble, quartzite and novaculite do not have a layered or banded appearance.

Detailed explanation-3: -Metamorphic rocks can be divided into two groups. Foliated rocks have visible layers or bands. Gneiss (nice) is a foliated metamorphic rock that comes from granite, an igneous rock. Gneiss usually has visible bands of light and dark minerals.

Detailed explanation-4: -Foliated rock is a special type of metamorphic rock that has distinct, repetitive layers. These layers form as the conditions (heat and pressure) change for each layer of the rock.

Detailed explanation-5: -Foliated rocks have platy or elongate minerals aligned in roughly parallel planes or in wavy bands or planes. Nonfoliated rocks may show colored bands that reflect minute impurities in the rock, but the dominant minerals show no visible alignment.