A coarse-grained sedimentary rock composed of rounded fragments which may vary in size from pebbles to boulders.
This sedimentary rock is composed largely of pebbles or other rounded particles whose diameter is larger than 2 mm. Essentially a cemented gravel, conglomerates are formed along beaches, as glacial drift, and in river deposits. Conglomerates formed of angular shaped pebbles are called breccias.
Block of conglomerate from the quarry of Bellevue, with a dinosaur bone in it.