agglomerate
![agglomerate, Kootznahoo Formation, Southeastern
Alaska](../../images/agglomerate.jpg)
Agglomerate, Kootznahoo Formation, Southeastern Alaska. Credit: USGS.
Agglomerate is a coarse volcanic rock made up of both rounded and angular fragments of lava in a matrix of smaller, often ashy, particles. It thus combines the characteristics of conglomerates and breccias.