archaean
/ɑ:'ki:ən/
Học thuậtThân thiện
Definition
- Adjective:
- Relating to the earliest known rocks formed during the Precambrian Eon: "Archaean" describes geological features, rocks, or the eon itself that belongs to the earlier of the two divisions of the Precambrian time, spanning from about 4 billion to 2.5 billion years ago.
Usage Examples
- Adjective:
- The Archaean crust is composed primarily of igneous and metamorphic rocks.
- Scientists study Archaean formations to understand the early conditions on Earth.
Advanced Usage
- "Archaean Eon": The formal name for the geological time period.
- The atmosphere during the Archaean Eon was very different from today's.
- "Archaean rocks": Rocks formed during this eon.
- These Archaean rocks contain some of the earliest evidence of life.
Variants and Related Words
- Archean: An alternative spelling, especially in American English.
- The Archean basement underlies much of the continent.
- Archaean-age (compound adjective): Of or pertaining to the Archaean Eon.
- Archaean-age greenstone belts are important for mineral exploration.
Synonyms
- Early Precambrian: A broader, less specific term for the early part of the Precambrian supereon.
- Primordial: Suggesting the earliest ages of the Earth (more poetic/general).
Related Phrases
- Archaean geology: The study of the Earth's crust from the Archaean Eon.
- He specializes in Archaean geology.
- Archaean-Proterozoic boundary: The transition point between the Archaean and the later Proterozoic Eon.
- The Archaean-Proterozoic boundary is marked by significant changes in rock composition.
Adjective
- of or relating to the earliest known rocks formed during the Precambrian Eon