lias

A geologist examines a lias rock formation in a cliff face.

Definition

1. Noun (Geology):
   • A stratigraphic unit: "lias" refers to a specific series of rock layers, typically the lower part of the Jurassic system, composed of blue or grey limestone and clay. It is also known as the Lower Jurassic or Lias Group.
   • A type of limestone: In a narrower sense, "lias" denotes a hard, bluish-grey limestone used in construction and for making cement.

Usage Examples

• Noun:
  • The cliffs along the coast are formed from lias, which dates back to the early Jurassic period. (A geological rock formation.)
  • Quarries in this region extract lias for use in building materials. (A specific type of limestone.)

Advanced Usage

• "Lias clay": a type of clay found within the Lias Group, often used in brickmaking.

  • The lias clay in this area produces high-quality bricks. (Clay from the Lias formation.)

• "Lias limestone": the hard, durable limestone component of the Lias Group.

  • Lias limestone is prized for its resistance to weathering. (A specific stone type.)

Variants and Related Words

• Liassic (adj): relating to the Lias Group or its geological period.
  • The Liassic fossils found here are well-preserved. (Pertaining to the Lias.)

Synonyms

• Lower Jurassic: the geological time period corresponding to the Lias.
• Blue lias: a common name for the bluish-grey limestone of the Lias Group.

Related Idioms