Eocene to Miocene biostratigraphy of New Jersey core ACGS #4; implications for regional stratigraphy

Lower Eocene through probable upper Miocene sediments were recovered in a 945-foot core (ACGS #4) taken near Mays Landing, New Jersey. Calcareous nannofossils and planktic foraminifers are common to abundant in most of the lower part of the core. All standard calcareous nannofossil zones from lower Eocene Zone NP 12 through lower Oligocene Zone NP 21 are identified, and the midlatitude Eocene planktic foraminifer zones based on the Turborotalia cerroazulensis lineage are recognized. The Paleogene section of this core is unique for the New Jersey coastal plain because it includes a nearly continuous lower Eocene to lower Oligocene sequence of marine sediments. In contrast, previous analyses of this area indicate that a major unconformity is present between the middle Eocene and the Oligocene.

A time versus depth plot controlled primarily by nannofossil zone boundaries shows that sediment accumulation rates during the early and middle Eocene were in the range of 6 to 15 feet per million years. During the late Eocene, accumulation rates were much higher, perhaps exceeding 70 feet per million years. The only clear hiatus detected in the Paleogene part of ACGS #4 on the basis of microfossils is between the early and (?)late Oligocene. However, hiatuses are suspected at the early-middle Eocene boundary and within the late Eocene. Occurrences of calcareous nannofossils and planktic foraminifers are documented, and a number of key taxa are illustrated.