Which rock type is associated with a high-energy environment (such as a very turbulent mountain stream) ?

Conglomerate rock

Explanation:

This is a type of sediment rock that has a coarse-grained texture. It is made up of small pieces of gravel-sized clasts, such as pebbles and cobbles. The mechanism of conglomerate rock formation is by consolidation and lithification.

Conglomerates are found in a variety of sedimentary environments such as, Deepwater marine, Shallow marine, Fluvial, Alluvial, and Glacial environments.