Lower shoreface

Lower shoreface refers to the portion of the seafloor, and the sedimentary depositional environment, that lies below the everyday wave base. ^[1]

Wave base diagram.

Process

The wave base is the maximum depth at which a water wave's passage causes significant water motion.^[1]

In this portion of the coastal marine environment, only the larger waves produced during storms have the power to agitate the seafloor.

Hummocky cross-stratification sandstone sedimentary structure, Cretaceous era Book Cliffs formation, Utah.

Between storms, finer grained sediments accumulate on the seafloor, but during storms those sediments get suspended and moved around, resulting in a sedimentary structure form described as hummocky cross-stratification.^[1]

See also

• Upper shoreface
• Sedimentary structures

References

1. R. G. Dean and R. A. Dalrymple (1991). Water wave mechanics for engineers and scientists. Advanced Series on Ocean Engineering. Vol. 2. World Scientific, Singapore. ISBN 978-981-02-0420-4.