This is the word geologists use for loose pieces of minerals and rock. the particles are transported by wind, water, or ice, and/or the force of gravity and eventually deposited.

Sediments
Sediments are solid materials that were broken down by the process of erosion, weather and transported by the water, wind or glaciers and then deposited in a new location. Sediment can consist of minerals and rocks and can be as small as a grain of sand or as large as a boulder.

The internal energy of the system we can term it as total potential energy and kinetic energy. energy flows out of the surrounding from the system then we can say that the internal energy of the final state is lower than its initials. the sign of  δesystem is negative.δesystem = efinal - einitial=-ve  efinal  ∠einitial.