For example:
* Large, angular pebbles indicate a high-energy environment like a mountain stream or a glacier.
* Small, rounded pebbles suggest a gentler environment like a beach or a river with a slower current.
* The composition of the pebbles can tell us what types of rocks were present in the area at the time.
So, by studying conglomerate rocks, geologists can piece together the story of what the Earth was like millions or even billions of years ago!