地質

ちしつ · chishitsu · JLPT N2 · noun

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🪨 地 (earth) + 質 (substance, quality) = the qualities of the earth

地 is earth and 質 is substance or quality, so 地質 means the qualities of the earth. Rock layers, faults and soil traits all fall under this compound.

地 — earth 土 + 也 (phonetic)
地 is a semantic-phonetic compound. The left component 土 means 'earth' or 'soil' and gives the meaning, while 也 on the right hints at the pronunciation. Originally referring to the ground or land, it broadened to mean 'place,' 'region,' and 'territory.'

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