stratum
地層
Archaeological horizon
Bed (geology)
Geological formation
Geologic map
Geologic unit
Lamination (geology)
Law of superposition
/suto3/google.iconstratum
/suto3/Google画像検索.iconstratum
/suto3/Google定義検索.icon stratum
/suto3/wikipedia.iconstratum
/suto3/weblio.icon stratum
/suto3/kotobank.icon stratum
/suto3/jisho.icon stratum