English Dictionary

dropstone

noun

(geology) An isolated fragment of rock found within a sedimentary rock (that had fallen, rather than being carried along).

The dropstone fell from the sky and landed in the middle of the field.

意味（1）

(geology) An isolated fragment of rock found within a sedimentary rock (that had fallen, rather than being carried along).

意味（2）

(glaciology) An isolated rock that is geologically distinct from the surroundings, indicating that it was carried from a distant area and then dropped in place (by a melting glacier); an erratic.