Definition

Noun 1. Unstratified glacial deposit: A type of soil or sediment directly deposited by a glacier, characterized by its lack of distinct layers (unstratified). It is a heterogeneous mixture of particles of vastly different sizes, including clay, sand, gravel, and boulders.

Usage

This is a technical geological term. It is used to describe a specific type of glacial deposit found in landscapes shaped by past ice sheets. * The landscape was formed from boulder clay left behind after the last ice age. * Excavations for the new road revealed a thick layer of boulder clay. * The poor drainage in this area is due to the impermeable boulder clay beneath the soil.

Advanced Usage

• Synonym: The term till is a more common and precise synonym in geology. "Boulder clay" is often considered a layperson's or older term for glacial till.
  • The geologist identified the material as till, also known as boulder clay.

Variants and Related Words

• Till (n.): The standard geological term for unsorted, unstratified glacial sediment.
• Glacial drift (n.): A broader term for all material (stratified and unstratified) transported and deposited by glaciers.
• Moraine (n.): A distinct landform (a ridge or mound) composed of glacial till.

Synonyms

• Till
• Glacial till

Notes

• "Boulder clay" is a compound noun. The definition provided explains this specific geological term. It is not defining the separate words "boulder" or "clay" in isolation.
• The key characteristics are its unsorted nature (all particle sizes mixed together) and its unstratified nature (no visible layers), which distinguish it from sediments deposited by water.

Noun

1. unstratified soil deposited by a glacier; consists of sand and clay and gravel and boulders mixed together