liassic

The paleontologist carefully brushes sediment from a liassic ammonite fossil.

Definition

Adjective
- Geological period: Relating to the Lias, the earliest part of the Jurassic System (approximately 201–174 million years ago), characterized by marine sedimentary rocks, especially limestones and shales.
- The term "Liassic" is often used to describe rock formations, fossils, or geological features from this time.

Usage Examples

• (Rock layers from the early Jurassic period.)
• (Fossils from the Lias epoch.)
• (Geological layers from the early Jurassic.)

Advanced Usage

• "Liassic series": A stratigraphic term for the sequence of rock layers deposited during the Lias epoch.
  • Geologists study the Liassic series to understand early Jurassic environments. (A specific set of rock layers from that time.)
• "Liassic fauna": The animal life characteristic of the Lias period.
  • The Liassic fauna includes many species of bivalves and brachiopods. (Animals that lived during the early Jurassic.)

Variants and Related Words

• Lias (noun): The name of the geological unit itself, referring to the rock layers.
  • The Lias is exposed in many parts of western Europe. (The specific rock formation.)
• Liassically (adverb): In a manner relating to the Lias period.
  • The fossils were liassically preserved in fine-grained sediment. (Preserved in a way typical of the Lias.)

Synonyms

• Early Jurassic: The broader geological period encompassing the Lias.
• Jurassic (lower): A synonym for the earliest part of the Jurassic.

Related Idioms