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Glite Dictionary
trap rock

trap rock

5.7
A hard dark rock formed by volcanoes that people use to build roads and buildings
  • noun
  • /træp rɑk/
  • Specialized
translation icon : roca trampa
  • Many roads are built with trap rock due to its durability.

Examples

  • The construction company used trap rock as a durable material for the new roadbed.

  • Geologists studied the layers of trap rock to learn about the area's volcanic history.

  • Large plateaus of trap rock can be found in regions shaped by ancient volcanic activity.

  • The contractor ordered more trap rock for the project.

  • The construction company used trap rock as a durable material for the new roadbed.

  • Many roads are built with trap rock due to its durability.

  • Geologists studied the layers of trap rock to learn about the area's volcanic history.

Synonyms

rock
vstrap rock
∞ 1.0

Hard natural stone that you find on the ground or underground

is the dark fine grained igneous type often used for roads
igneous rock
vstrap rock
  • Specialized
1 4.1

A hard, solid material that forms when hot, melted rock cools

is a darker fine grained variety often used in construction
gabbro
vstrap rock
  • Specialized
1 9.9

A dark, hard rock made underground when hot liquid rock cools slowly with large crystals

is fine grained and used in construction rather than coarse forms
diabase
vstrap rock
  • Specialized
9.5

A hard dark rock used to make roads and buildings

is fine grained and commonly used for road building

Surface Forms

trap rock singular
trap rocks plural

Morphology

trap + rock

This is a specialized geological term: the element 'trap' does not mean a catching device here but is a historical/technical label for certain basaltic rocks, so its meaning is not predictable from the common word 'trap' plus 'rock'. A B1 learner who knows 'trap' as a device and 'rock' as stone would not be able to derive that it refers to dark igneous rock types, so the expression is opaque.

Etymology

The name trap rock comes from an old word meaning 'stair'. Long lava flows left step-like hills called trap, and the dark, hard rock from those steps was used for roads and building, so trap rock now means that kind of dark building rock.