Latest Cretaceous and Earliest Tertiary Stratigraphy of New Jersey Coastal Plain

Abstract

Biostratigraphic and lithostratigraphic analyses of surface and subsurface sediment samples from latest Cretaceous and earliest Tertiary formations of the New Jersey Coastal Plain have resulted in a new interpretation of the stratigraphy of this sequence. Five formations are recognized and one of these, the New Egypt Formation, is newly described. The Navesink, Tinton, Hornerstown, and New Egypt Formations lithologically are characterized by a great abundance of the mineral glauconite, which occurs principally as sand-size grains. In contrast, the Redbank Formation is a quartz sand. Two new members of the Redbank Formation are recognized, a lower Sandy Hook Member and an upper Shrewsbury Member. Four planktonic foraminiferal assemblage zones are established in this stratigraphic sequence. The Navesink Formation is of late Early or Middle Maestrichtian age and contains the Globotruncana fornicata--Globotruncana tricarinata Assemblage Zone. The Late Maestrichtian Redbank Formation contains the Globotruncana contusa--Hedbergella monmouthensis Assemblage Zone. The Globorotalia compressa--Globigerinoides daubjergensis (Early Paleocene or Danian) and the Globorotalia angulata (Late Paleocene to Early Eocene) Assemblage Zones are present in the Hornerstown Formation. The occurrence of all of these zones in the New Egypt Formation demonstrates the facies relationship which exists between this formation and the other formations considered in this paper. A single cycle of glauconite deposition occurred throughout latest Cretaceous and earliest Tertiary time. The cycle was interrupted locally by influx of the Redbank quartz clastics but adjacent to the site of quartz sand deposition glauconite accumulated continuously. Paleoecological data indicate deposition of this sequence in shallow mid-neritic depths of water. There is no convincing evidence of a Cretaceous-Tertiary unconformity, but in contrast most of the evidence suggests continuous deposition from Cretaceous into Tertiary time. The New Egypt Formation is interpreted as a seaward facies of the more varied nearer-shore facies represented by the Navesink, Redbank, Tinton, and Hornerstown Formations.