bioclast

noun

bio·​clast ˈbī-(ˌ)o-ˌklast 

plural bioclasts

geology

: a fragment of biological origin (such as a shell fragment or fossil) occurring in sedimentary rock

You can have fabrics full of bioclasts—fragments of organic origin, such as bits of plants or clamshells—and you can classify the kinds of mineral grains, their size and distribution.

—Karen Chin, quoted in Discover, June 1996

Word History

First Known Use

1963, in the meaning defined above

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