noun
geology
The scientific study of the Earth's physical structure, history, and processes.
彼は大学で地質学を専攻している。
He is majoring in geology at university.
地質学の知識は資源探査に役立つ。
Knowledge of geology is useful for resource exploration.
地球科学 (earth science) is a broader term encompassing geology, oceanography, meteorology, etc. 地質学 is a core subfield.
Compound of 地質 (chishitsu, 'geological features') + 学 (gaku, 'study'). The term is a direct translation of the Western concept of geology.