Intriguing discussion about age of beach shells.

I was collecting at Ft. Macon, NC when I saw some very large Pecten
fragments that I didn't recognize. (I estimate at least 6 inches in
height). The orange coloration was quite fresh. Pretty startling to find.

Someone from NC Shell Club told me that this is probably Chesapecten and
speculated that valves are being eroded out of nearby sediments because of
dredging in the adjacent channel in order to supply so-called "beach
renourishment."

David Kirsh
Durham, NC



>Linda,
>
>Don't forget the possibility that fossil Chesapecten can be washed out of
>old strata. At many localities along the eastern and southern U.S., ancient
>deposits are eroded from cliffs or even below water, releasing fossil
>shells that sometimes look like they were alive a few days ago.
>
>According to Michal Kowalewski (Virginia Tech, Blacksburg), radiocarbon
>dating shows that beach shells are commonly one to several thousand years
>old, having been buried and reworked many times. Fragile shells do not last
>as long as more robust shells. It is sobering to realize that
>dead-collected material may represent thousands of years of shifting fauna,
>all averaged over time -- incidentally underscoring the need to collect
>live as well as dead shells for environmental studies.
>
>Andrew K. Rindsberg
>Geological Survey of Alabama