The Virtual Rock Kit -

Rock 12: Alluvium

Alluvium is loose material deposited within the floodplain of a river or stream.  Alluvium can range from boulder- to clay-sized particles.  As the rocks of the Eno River area continue to erode, they are broken down into boulders-, cobbles-, sand-, silt- and clay-sized sediment. During flood events, as the water level rise, sand, silt and clay particles are transported over the river banks and are deposited within the floodplain.  The sand, silt and clay deposits present in the river bed of the Eno are slowly making a long journey toward the Atlantic Ocean.  Alluvium is the youngest geologic unit within the Eno River area.  Someday the sand, silt and clay material that compose the alluvium will be deposited at the mouth of the Neuse River near the coast and if buried deep enough and long enough will become sandstone, siltstone and mudstone. 

Alluvium - silt and sand sized material



alluvium sample

Please remember that rock and mineral collecting is STRICTLY PROHIBITTED on protected land!




Want to learn more about the geology of the Eno River area?

You may be interested in A Geologic Adventure Along the Eno River - A richly illustrated publication from the North Carolina Geological Survey.