1.
a sedimentary rock composed mainly of calcium carbonate, usually formed from the accumulated shells and skeletons of marine organisms, and widely used as a building stone and as raw material for cement, glass, and lime; limestone
A common sedimentary rock whose main component is calcium carbonate (CaCO3). Most natural limestone forms on the ocean floor from the gradual accumulation and compression of the shells of corals, foraminifera, and other marine organisms. When exposed to slightly acidic groundwater over long periods, limestone dissolves to form distinctive landscapes full of caves, sinkholes, and underground rivers (カルスト{地形}). Japan has several famous limestone areas, including 秋吉台 in Yamaguchi and 平尾台 in Fukuoka. Economically, limestone is the raw material for cement and lime and is one of the few mineral resources Japan produces in surplus.
この山は石灰岩でできている。
This mountain is made of limestone.
石灰岩はセメントの原料になる。
Limestone is used as a raw material for cement.
石灰岩が雨水に溶けて鍾乳洞ができる。
Limestone dissolves in rainwater, forming limestone caves.
石灰岩は、大昔の海に住んでいた生物の殻や骨が積み重なってできた岩石だ。
Limestone is a rock formed from the accumulated shells and bones of creatures that lived in ancient seas.
Composed of 石灰 (lime, calcium oxide / calcium hydroxide) + 岩 (rock). Literally 'lime rock,' referring to the fact that limestone is the raw material from which lime is produced when heated.
COMMON COLLOCATIONS:
- 石灰岩の地層: a limestone stratum / bed
- 石灰岩の洞窟: a limestone cave
- 石灰岩質: limestone-based, calcareous
- 石灰岩を採掘する: to quarry limestone
- 石灰岩地帯: a limestone zone / region
RELATED TERMS:
- 石灰: lime — the processed form (calcium oxide or calcium hydroxide) obtained by heating limestone.
- 大理石: marble — limestone that has been recrystallized by heat and pressure (metamorphosed); used for sculpture and decorative stone.
- 鍾乳洞: limestone cave, stalactite cave — formed by the dissolution of 石灰岩.
- 鍾乳石: stalactite — the hanging mineral formation found in limestone caves.
- カルスト地形: karst topography — the distinctive landscape of sinkholes, caves, and rock towers produced when limestone is eroded by slightly acidic water.
- 炭酸カルシウム: calcium carbonate — the main chemical component of limestone.
SIMILAR WORDS (ROCK TYPES):
- 花崗岩: granite — an igneous rock; unrelated in formation.
- 砂岩: sandstone — another sedimentary rock, but formed from sand rather than calcium carbonate.
- 玄武岩: basalt — an igneous rock formed from volcanic lava.
ECONOMIC NOTE:
Limestone is one of the very few mineral resources Japan produces in abundance. It is quarried in large quantities for cement, steelmaking, and agricultural lime, and famous limestone areas such as 秋吉台 and 平尾台 are also popular tourist destinations.