mudstones
/ˈmʌdˌstoʊnz/
noun
- Multiple types or pieces of mudstone; fine-grained sedimentary rocks made from hardened mud or clay.
- The construction site unearthed several mudstones from an ancient lake bed.
- Mudstones can vary in color from gray to red depending on their mineral content.
- The region's geology is known for its colorful mudstones.