CLAM CALAMITY - A RECENT SUPRATIDAL STORM-DEPOSIT AS AN ANALOG FOR FOSSIL SHELL BEDS

A winter storm struck the South Jersey shore near Atlantic City, New Jersey in 1992, excavating a population (10(8) individuals) of the burrowing infaunal surf-clam, Spisula solidissima, and depositing them above the high tide fine. Nearly all individuals survived transport during the storm. Small clams at the base of the storm deposit reburrowed, larger individuals and small ones above the base of the deposit did not. The overburden of conspecifics most likely prevented them from attaining the requisite vertical burrowing orientation, or an under-lying pavement of conspecifics blocked burrowing. Clams accumulated in piles or ''dunes'' standing as high as one meter on, the beach and two meters in. the lee of breakwaters and extending laterally <20 meters. Such accumulations might appear in the fossil record and as yet be unrecognized. Larger shells were often. distinctively chipped at the anterior and posterior ends, probably as a result of collision with other shells during transport.