Stratigraphic Evidence of Salt Marsh Erosion Along North Shore of Delaware Bay Associated With Sever Storms.

Detailed stratigraphy documented from over 50 hand-driven cores obtained from the Back Creek marsh near Sea Breeze, south New Jersey shows that this marsh along the north shore of Delaware Bay experienced significant erosion several times during the past few thousand years. Eroded marsh deposits were replaced by a regressive sequence of tidal mud, low marsh peat and high marsh peat. Tidal mud units that filled eroded accommodation space vary in thickness from 1 m to 3 m. Given the overall horizontal facies boundaries within the regressive sequences, which suggest rapid post-erosion infilling and marsh recovery, we hypothesize that the observed erosion of marsh deposits was related to the passage of hurricanes. We recognize four erosion surfaces, the deepest three of which are overlain by complete regressive sequences. The fourth regressive sequence is incomplete, suggesting that the system is still recovering from recent storm erosion. Pending radiometric dates, we estimate, on the basis of depth and a published relative sea-level curve for Delaware Bay, that the deepest two erosion surfaces date to approximately 800-700 cal BP and 600-400 cal BP. The third storm-erosion event is estimated to have occurred less than a century ago. Similar depths of erosion surfaces and distinct shape of eroded spaces indicate that the erosion could have happened under storm-surge conditions.