Geologic Time Scale

  Phanerozoic
(542.0 mya
to present)
  Cenozoic
(65.5 mya
to present)
Quaternary (2.588 mya to present)
Neogene (23.03 to 2.588 mya)
Paleogene (65.5 to 23.03 mya)
  Mesozoic
(251.0 to
65.5 mya)
Cretaceous (145.5 to 65.5 mya)

  • Upper (99.6 to 65.5 mya)
  • Lower (145.5 to 99.6 mya)
Jurassic (199.6 to 145.5 mya)

Triassic (251.0 to 199.6 mya)
  Paleozoic
(542.0 to
251.0 mya)
Permian (299.0 to 251.0 mya)

  • Lopingian (260.4 to 251.0 mya)
  • Guadalupian (270.6 to 260.4 mya)
  • Cisuralian (299.0 to 270.6 mya)
Carboniferous (359.2 to 299.0 mya)

  • Pennsylvanian (318.1 to 299.0 mya)
    • Upper (307.2 to 299.0 mya)
    • Middle (311.7 to 307.2 mya)
    • Lower (318.1 to 311.7 mya)
  • Mississippian (359.2 to 318.1 mya)
    • Upper (328.3 to 318.1 mya)
    • Middle (345.3 to 328.3 mya)
    • Lower (359.2 to 345.3 mya)
Devonian (416.0 to 359.2 mya)

  • Upper (385.3 to 359.2 mya)
  • Middle (397.5 to 385.3 mya)
  • Lower (416.0 to 397.5 mya)
Silurian (443.7 to 416.0 mya)
Ordovician (488.3 to 443.7 mya)

  • Upper (460.9 to 443.7 mya)
  • Middle (471.8 to 460.9 mya)
  • Lower (488.3 to 471.8 mya)
Cambrian (542.0 to 488.3 mya)
  Precambrian
(4600 to
542.0 mya)
  Proterozoic
(2500 to
542.0 mya)
Neoproterozoic (1000 to 542.0 mya)
Mesoproterozoic (1600 to 1000 mya)
Paleoproterozoic (2500 to 1600 mya)
  Archean
(4000 to
2500 mya)
Neoarchean (2800 to 2500 mya)
Mesoarchean (3200 to 2800 mya)
Paleoarchean (3600 to 3200 mya)
Eoarchean (4000 to 3600 mya)

Hadean
(4600 to 4000
mya)