Hornerstown Formation

Hornerstown Formation
Stratigraphic range: Maastrichtian-Danian
66.5–65.5 Ma
↓
[1]
TypeGeological formation
UnderliesVincentown Formation
OverliesNew Egypt Formation and Tinton Formation
Location
RegionNew Jersey
CountryUSA

The Hornerstown Formation is a Paleogene or latest Mesozoic geologic formation in New Jersey.[2] The age of these deposits have been controversial. While most fossils are of animals types known from the earliest Cenozoic era, several fossils of otherwise exclusively Cretaceous age have been found. These include remains of the shark Squalicorax, several types of non-avian dinosaurs, the teleost fish Enchodus, several species of ammonite, and marine lizards referred to the genus Mosasaurus. Some of these remains show signs of severe abrasion and erosion, however, implying that they are probably re-worked from older deposits. Most of these fossils are restricted to the lowest point in the formation, one rich in fossils and known as the Main Fossiliferous Layer, or MFL. Other explanations for the out-of-place fossils in the MFL is that they represent a time-averaged assemblage that built up and remained unburied during a time of low sediment deposition, or that they were stirred up from deeper in the sediment and deposited together during a tsunami.[3]

  1. ^ Gentry, A.D.; Kiernan, C.R.; Parham, J.F. (2022). "A large non-marine turtle from the Upper Cretaceous of Alabama and a review of North American "Macrobaenids"". The Anatomical Record. doi:10.1002/ar.25054.
  2. ^ Weishampel, et al. (2004). "Dinosaur distribution." Pp. 517-607.
  3. ^ Gallagher, W.B. (2005). "Recent mosasaur discoveries from New Jersey and Delaware, USA: stratigraphy, taphonomy and implications for mosasaur extinction." Netherlands Journal of Geosciences — Geologie en Mijnbouw, 84(3): 241-245. [1] Archived 2012-09-04 at the Wayback Machine