GEOLOGY

Detailed explanation-1: -Regional metamorphism usually produces foliated rocks such as gneiss and schist.

Detailed explanation-2: -Slate is a fine-grained metamorphic rock that shows no obvious compositional layering, but can easily be split into thin slabs and plates. It is usually formed by low-grade regional metamorphism of mudrock.

Detailed explanation-3: -Answer and Explanation: Gneiss is only formed by regional metamorphism. Gneiss can be formed by the regional metamorphism of different types of rocks such as granite or shale. It is a high grade metamorphic rock which means it is formed at high temperatures and pressures.

Detailed explanation-4: -Igneous and sedimentary rocks can change into metamorphic rocks under great heat and pressure. For example, clay changes to slate and limestone changes to marble.

Detailed explanation-5: -Thus, regional metamorphism usually results in forming metamorphic rocks that are strongly foliated, such as slates, schists, and gniesses. The differential stress usually results from tectonic forces that produce compressional stresses in the rocks, such as when two continental masses collide.