Large, coarse, angular rock fragments associated with lava flow that are ejected during explosive volcanic eruptions. Although they may appear to resemble sedimentary conglomerates, agglomerates are igneous rocks that consist almost wholly of angular or rounded lava fragments of varying size and shape. Some geologists sort agglomerates into bombs, blocks, and breccia. Bombs are ejected in a molten state, becoming rounded upon solidification, and blocks are erupted as solid fragments. Upon accumulation and solidification of the angular fragments (also known as pyroclastics), they form agglomerates.
This entry comes from Encyclopædia Britannica Concise.
For the full entry on agglomerate, visit Britannica.com.
Seen & Heard
What made you look up agglomerate? Please tell us what you were reading, watching or discussing that led you here.