noun
- plural of argillite; fine-grained sedimentary rocks composed mainly of clay minerals that have been hardened but not metamorphosed
Usage: geological term
Examples
- The geologist collected samples of argillites from the exposed cliff face.
- These argillites formed millions of years ago when clay settled in ancient lake beds.
- The dark gray argillites contained well-preserved fossils of ancient marine life.
- Oil companies often drill through layers of argillites to reach petroleum deposits.
- The construction crew encountered hard argillites while excavating the foundation.
- Students examined thin sections of argillites under the microscope to identify clay minerals.