indurated clay

8.1

Soil made of clay that becomes hard from drying, heat, or chemicals

noun
/ˈɪndjʊreɪtɪd kleɪ/

Specialized

: arcilla indurada

The foundation was difficult to dig due to a thick layer of indurated clay.

Examples

Geologists often find indurated clay at the base of ancient riverbeds.
The indurated clay was difficult to excavate.
After centuries of pressure, the soft soil turned into indurated clay.
Many ancient structures are built with indurated clays.
Geologists often find indurated clay at the base of ancient riverbeds.
The foundation was difficult to dig due to a thick layer of indurated clay.
After centuries of pressure, the soft soil turned into indurated clay.

Synonyms

claystone

vsindurated clay

Specialized

8.7

A hard rock made of tiny bits of clay pressed together

is broader, meaning clay hardened by drying, heat, or chemical action

Antonyms

unhardened

Specialized

6.3

Not fully solid after making, like metal or mortar

How Hard

indurated clay

Specialized

8.1

potter's clay

4.2

clay

171 1.0

Plasticine

1 4.2

Surface Forms

indurated clay singular

indurated clays plural

Morphology

indurate + clay

The phrase is directly compositional: 'indurated' means 'hardened' (past participle of 'indurate') and 'clay' is the material, so the meaning 'hardened clay' is directly derivable from the constituents. This adjectival past-participle + noun pattern is a common, cross-linguistic construction, so a B1 learner who knows both words should understand the MWE.

Etymology

Indurated clay shows a simple image: soft clay that is made hard by drying, heat, or pressure so it is indurated or 'hardened'. That's why the phrase means 'clay that has become hard'.