MIOCENE SEA LEVEL EVENTS IN THE MARYLAND COASTAL PLAIN AND THE OFFSHORE BALTIMORE CANYON TROUGH
Published:June 09, 1905
R.K. Olsson, A.J. Melillo, B.L. Schreiber, 1905. "MIOCENE SEA LEVEL EVENTS IN THE MARYLAND COASTAL PLAIN AND THE OFFSHORE BALTIMORE CANYON TROUGH", Timing and Depositional History of Eustatic Sequences: Constraints on Seismic Stratigraphy, Charles A. Ross, Drew Haman
Download citation file:
Biofacies analysis of benthic foraminifera and planktonic foraminiferal biostratigraphy in Miocene formations in the Maryland coastal plain subsurface are used to identify depositional sequences and to correlate them with the third-order cycles of Haq and others (1987). Four sequences are identified in the Calvert Formation and correlated with cycles TB 1.5, 2.1, 2.2, and 2.3. The Choptank Formation is upper Miocene (Zone N16) and correlated with cycle TB 3.1. The St. Marys Formation is placed in Zone N16 and in cycle TB 3.2. In downdip coastal wells an upper upper Miocene unit (Zone N17) suggests the presence of the Eastover Formation and cycle TB 3.3.
An unconformity and associated long hiatus which represents three missing sequences separates the Choptank Formation from the Calvert Formation. The missing sequences (TB 2.4, 2.5, and 2.6) occur offshore in the Baltimore Canyon Trough. Their absence in Maryland is probably due to erosion in the coastal plain during a low stand of sea level when submarine canyons formed on the New Jersey slope at the end of the middle Miocene (10.5 Ma).
Paleoslope modeling indicates that relative sea level stood between 15 to 50 m above present sea level during deposition of transgressive deposits in the Maryland coastal plain.