New Jersey can be divided into four physiographic provinces or regions with similar sequences of rock types, geologic structures and common geologic history. The four provinces in New Jersey are the Valley and Ridge, the Highlands, the Piedmont and the Coastal Plain.

The Valley and Ridge province is in the northwestern section of New Jersey and is characterized by long, parallel ridges and valleys formed by folded and faulted limestone's, shale's and sandstones or early to middle Paleozoic age. This region contains rocks from the Ordovician, Silurian and Devonian periods.

The Highlands province consists of metamorphic rocks of Precambrian time and lie to the east of the Valley and Ridge province. The granites and gneiss's are resistant to erosion and create a hilly upland with deep, step-sided valleys carved by streams.

The Piedmont province lies to the east of the Highlands and is characterized by gently rolling hills. The rocks are of Late Triassic and Early Jurassic period. As sediments eroded from adjacent uplands and were deposited along rivers and lakes within the basin, they became compacted and cemented to form conglomerate, sandstone, siltstone and shale.

The Coastal Plain province overlaps the Piedmont to the southeast and lies in a relatively flat terrain that consists of unconsolidated sedimentary formations, such as sands, clays and marls. The rocks of this region are Cretaceous, Paleogene and Neogene in age.

The four regions of New Jersey span millions of years representing many different geologic periods. Fossils can be found from most of these periods in New Jersey. The periods are represented on the geologic map of New Jersey. Follow the links to each of these periods to see the range of fossils from that time.

  • Neogene: The Neogene Period began about 24 million years ago and it continues up to the present time. The name “Neogene” is a new name for part of the old Tertiary Period and includes the old Quaternary Period. It is represented by the light gray band along the Jersey Shore and Delaware Bay.
  • Paleogene: The Paleogene Period marks the beginning of the Cenozoic Era. It began 65 million years ago and lasted until 24 million  years ago and is represented by the yellow and beige bands covering most of the southern  half of the state.
  • Cretaceous: 65-144 million years ago represented by the olive green band running from Monmouth County south west in a band along the Delaware River to the south west corner of the state. Cretaceous New Jersey Species
  • Jurassic: 144-205 million years ago represented by the light green areas intermixed in the Triassic band.
  • Triassic: 205-250 million years ago represented by the green running from the north east corner of the state bordering New York in a south westerly direction until it contacts the Delaware River.
  • Permian: 250-295 million years ago. There are no rocks of this age preserved in New Jersey.
  • Carboniferous: 295 - 354 million years ago. There are no rocks of this age preserved in New Jersey.
  • Devonian: 354 - 409 million years ago represented by the light blue area in the extreme north west corner of the state.
  • Silurian: 409 - 439 million years ago represented by the light purple band to the west of the Ordovician rocks.
  • Ordovician: 439 - 500 million years ago represented by bluish purple area to the west of the Precambrian rocks.
  • Cambrian: 500 - 540 million years ago. There are no surface rocks from the Cambrian in New Jersey, but there are fossils from this era.
  • Precambrian: Older than 540 million years ago represented by the light orange bands in the north west portion of the state.