Strontium-isotope and sequence stratigraphy of the Miocene Kirkwood Formation, southern New Jersey

Sr-isotope stratigraphy is used to correlate the Miocene Kirkwood Formation of the New Jersey Coastal Plain to the Geomagnetic Polarity Time Scale and to ascertain the age of Miocene depositional sequences. Sr-isotope stratigraphy confirms diatom biostratigraphy, which delineates three Kirkwood sequences corresponding to East Coast Diatom Zone (ECDZ) 1, ECDZ 2, and ECDZ 6 of Andrews (1988). Sedimentation rates were as high as 40 m per million years during deposition of the Kirkwood Formation, suggesting possible tectonic influences on depositional history. The timing of lower to middle Miocene sequence boundaries from the New Jersey Coastal Plain compares well with other indicators of sea-level change. -from Authors