Definition

Noun: A large, rounded rock that has been transported from its original location by the force and flow of a river and deposited elsewhere.

Usage

The term "river boulder" specifically describes a boulder whose current position and often smoothed, rounded shape are direct results of fluvial processes. It is used in geological and geographical contexts. - Geologists studied the river boulder to determine the ancient river's path. - The hiking trail was blocked by a massive river boulder deposited during the last flood.

Advanced Usage

• As an indicator: In geology, a river boulder can serve as an indicator of past river flow strength, distance of transport, and erosion history.
  • The composition of the river boulder was foreign to the local bedrock, proving it had traveled a great distance.

Variants and Related Words

• Boulder: A general term for a large rock fragment.
• Glacial erratic: A boulder transported and deposited by a glacier, which is a related but distinct geological feature from a river boulder.

Synonyms

• Fluvial boulder (a more technical synonym)
• Stream-transported boulder

Different Meanings

The term "river boulder" does not have significantly different meanings. Its meaning is consistently tied to its geological origin and mode of transport. It is not used idiomatically.

Phrasal Verbs

Not applicable. "River boulder" is a compound noun and does not form phrasal verbs.

Idioms

There are no common idioms using the term "river boulder."

Noun

1. a boulder that has been carried by a river to a place remote from its place of origin