Shale Rock: Geology, Composition, Uses
Shale forms when the mudstone becomes laminated and fissile. If shale is subjected to heat and pressure, it can metamorphose into slate. Slate can become phyllite, then schist, and eventually gneiss. Key Takeaways . Shale is the most common sedimentary rock, accounting for about 70 percent of the rock in the Earth''s crust. Shale is a finegrained rock made from compacted mud and clay. The