Chapter 14: Clastic Coastlines Flashcards
Why do berms form on beaches?
It marks the barrier of the foreshore and the backshore. The foreshore is where the weak backwash can reach, but can’t reach the backshore except during storm surge conditions
How does longshore drift develops
Wind driven waves acting obliquely to the shoreline, creating a shore-parallel current
What is a strand plain-how does it form?
Sandy coastlines where an extensive area of beach deposits lie directly adjacent to the coastal plain . It is composed of sediments deposited on both its foreshore and backshore.
What is Mesotidal conditions?
an exchange of water between lagoon and sea resulting in more inlets forming, breaking up the barrier into islands
What is Macrotidal Coasts
Coasts that have high tidal ranges do not develop barrier systems because the ebb and flood tidal currents are a stronger control on distribution of sediments than wave action
How to tell the difference of macro vs mesotidal
Macro can be identified by mudflats from flooding, meso by flood-tidal deltas and subaqueous dunes
What is an estuary
A river system that feeds a lagoon
Wave Dominated estuary
developed in a small area with small tidal reange and strong wave energy
Tidal Dominated estuary
Tidal current energy exceeds wave energy at estuary mouth.
Difference beween delta and estuary in the rock record
Deltas are progradational sediment bodies that build out into the sea and will coarsen upward. Estuaries are retrogradational, forming as shorelines move landward due to rising sea levels.
