# List of geochronologic names

This is a list of official and unofficial names for time spans in the geologic timescale and units of chronostratigraphy. Since many of the smallest subdivisions of the geologic timescale were in the past defined on regional lithostratigraphic units, there are many alternative names that overlap. The body concerned with standardizing the names of geochronologic units is the International Commission on Stratigraphy (ICS). In 2008 however, even though the Phanerozoic eon is almost completely divided into internationally recognizable units, local subdivisions are often still preferred over the international ones.

## List

* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z
| Name (English) | base/start (Ma) | top/end (Ma) | status | subdivision of | usage | named after | author, year |
| Aalenian | 175.6 ± 2.0 | 171.6 ± 3.0 | age | Jurassic | ICS | Aalen (Germany) | Mayer-Eymar, 1864 |
| Abereiddian | 471.8 ± 1.6 | 464 | age | Ordovician | regional | Abereiddy (Wales) | Fortey et al., 1995 |
| Actonian | 454 | 453 | age | Ordovician | regional | Acton Scott (England) | Bancroft, 1929 |
| Adelaidean | 1,300 | 542 | age | Proterozoic | Australia | Adelaide | |
| Aegean | 245 ± 1.5 | 244 | age | Triassic | Europe | Aegean Sea | Tozer, 1967 |
| Aeronian | 439.0 ± 1.8 | 436.0 ± 1.9 | age | Silurian | ICS | Cwm-coed-aeron (Wales) | Cocks et al., 1971 |
| Aftonian | 0.6 | 0.48 | age | Pleistocene | North America | | Chamberlin, 1895 |
| Agenian | 23 | 20.4 | ELMMZ | Miocene | Europe | Agen (France) | Alberdi & Aguirre, 1977 |
| Aimchanian | | 1100 | age | Proterozoic | Siberia | | |
| Aksayan | 493 | 491.5 | age | Cambrian | Russia, Kazakhstan | | Ergaliev, 1980 |
| Alaunian | 216 | 211 | sub-age | Triassic | Europe | | |
| Albertan | | | epoch | Cambrian | North America | | Dawson, 1895 |
| Albian | 112.0 ± 1.0 | 99.6 ± 0.9 | age | Cretaceous | ICS | Albia, Latin name of the river Aube (France) | d'Orbigny, 1842 |
| Alding(i)an | 36 | 30 | age | Eocene | Australia | | |
| Algonkian | | 543 | age | Proterozoic | international | Algonquian native peoples of Canada | Powell, 1890 |
| Allerød | 13,350 BP | 12,700 BP | chronozone | Weichselian | Northern Europe | Allerød (Denmark) | Haltz & Milthers, 1901 |
| Alportian | 324.5 | 318.1 ± 1.3 | age | Carboniferous | regional | Alport (England) | Ramsbotton, 1979 |
| Altonian | 19.0 | 15.9 | age | Miocene | New Zealand | Alton Burn, Southland Region | Frye & Wilmann, 1960 |
| Amazonian | ~1,800 | present | Martian epoch | Martian epoch | Mars | Amazonis Planitia | Greeley & Spudis, 1981 |
| Amgan | 513.0 ± 2.0 | 502 | age | Cambrian | Russia, Kazakhstan | | Guarari, 1955 |
| Amstelian | 2.588 | 2.40 | super-age | Pleistocene | Netherlands | river Amstel | Harmer, 1896 |
| Anglian | 0.465 | 0.418 | age | Pleistocene | Great Britain | East Anglia | |
| Animikean | 2,225 | 1,400 | age | Proterozoic | North America (obsolete) | | Hunt, 1873 |
| Anisian | 245.0 ± 1.5 | 237.0 ± 2.0 | age | Triassic | ICS | Anisus, Latin name for the river Enns (Austria) | Mojsisovics, 1869 |
| Antian | ~2.12 | ~2.0 | age | Pleistocene | Great Britain | River Ant (England) | West, 1962 |
| Antwerpian | ± 21 | ± 12 | age | Miocene | Belgium (obsolete) | Antwerp | Gogels, 1879 |
| Aphebian | 2500 | 1600 | age | Proterozoic | North America | | Stockwell, 1964 |
| Aptian | 125.0 ± 1.0 | 112.0 ± 1.0 | age | Cretaceous | ICS | Apt (France) | d'Orbigny, 1840 |
| Aquatraversian | 2.588 | 2.4 | age | Pleistocene | Italy | | |
| Aquilan | 85.2 | 82.2 | NALMA | Cretaceous | North America | | Russell, 1975 |
| Aquitanian | 23.03 | 20.43 | age | Miocene | ICS | Aquitaine | Mayer-Eymar, 1857 |
| Archean | 4,000 | 2,500 | eon | | ICS | | Dana, 1876 |
| Arenig(-ian) | | | epoch | Ordovician | Europe | Arenig Fawr (Wales) | Sedgwick, 1847; Fearnsides 1905 |
| Arikareean | 30.8 | 20.6 | super-age | Oligo-Miocene | North America | | Wood "et al.", 1941 |
| Arnold | 43.0 | 34.3 | epoch | Paleogene | New Zealand | Arnold River | Kingma, 1962 |
| Arnsbergian | 326 | 325 | sub-age | Carboniferous | regional | | Hudson & Cotton, 1943 |
| Arowhanan | 95.2 | 92.1 | age | Cretaceous | New Zealand | Arowhana | Wellman, 1959 |
| Arshantan | 52.1 | 46.2 | ALMA | Eocene | Asia | | Romer, 1966 |
| Artinskian | 284.4 ± 0.7 | 275.6 ± 0.7 | age | Permian | ICS | Arti (Russia) | Karpinsky, 1874 |
| Arundian | 341 | 339 | age | Carboniferous | regional | from Hobbyhorse Bay, Castlemartin, Pembrokeshire, Wales (arundo is Latin for hobbyhorse) | Ramsbotton, 1974 |
| Asbian | 337.5 | 333 | age | Carboniferous | regional | Little Asby Scar, Cumbria, England | Ramsbotton, 1979 |
| Ashbyan | | | age | Ordovician | North America | | |
| Ashgill(-ian) | | | epoch | Ordovician | Europe | Ash Gill near Coniston, Cumbria | Marr, 1905 |
| Asselian | 299.0 ± 0.8 | 294.6 ± 0.8 | age | Permian | ICS | river Assel (Kazakhstan) | Ruzhenchev, 1954 |
| Astaracian | 15 | 11.1 | ELMMZ | Miocene | Europe | The Astarac (France) | Alberdi & Aguirre, 1977 |
| Asturian | | 305 | age | Carboniferous | Europe | Asturias | Stille, 1920 |
| Atdabanian | 530 | 524 | age | Cambrian | Russia, Kazakhstan | | Pelman, 1977 |
| Atlantic | 5,660 BP | 9,220 BP | chronozone | Holocene | Northern Europe | the Atlantic Ocean | Blytt, 1876 |
| Atokan | | | age | Carboniferous | North America | | Spivey & Roberts, 1946 |
| Aurelucian | 460.9 | 457 | age | Ordovician | Europe | | |
| Austinian | | | age | Cretaceous | south and east of the US | Austin, Texas | Murray, 1961 |
| Autunian | ~300 | ~275 | age | Carboniferous-Permian | Europe | Autun (France) | Munier-Chalmas & Lapparent, 1893 |
| Avernian | 29.2 | 23.03 | ELMMZ | Oligocene | Europe | | |
| Awamoan | 20.0 | 17.5 | age | Miocene | New Zealand | | Thompson, 1916 |
| Ayusokkanian | 501.0 ± 2.0 | 494.5 | age | Cambrian | Russia, Kazakhstan | | Geyer & Shergold, 2000 |
| Azoic see Archean | | | | | | | |
| Badenian | 16.3 | 12.8 | age | Miocene | Paratethys | Baden (Austria) | Papp & Cicha, 1968 |
| Baikalian | 850 | 650 | age | Proterozoic | Siberia | Lake Baikal | Pavloski, 1948 |
| Bairnsdalian | 15.0 | 10.5 | age | Miocene | Australia | | |
| Baishaean | 433 | 429 | age | Silurian | China | | Lu et al., 1974 |
| Bajocian | 171.6 ± 3.0 | 167.7 ± 3.5 | age | Jurassic | ICS | Bayeux (France) | d'Orbigny,1844 |
| Balcombian | 15.5 | 15.0 | age | Miocene | Australia | | Hall & Pritchard, 1902 |
| Baotan | 460.9 | 454.5 | age | Ordovician | China | | |
| Barremian | 130.0 ± 1.5 | 125.0 ± 1.0 | age | Cretaceous | ICS | Barrême (France) | Coquand, 1873 |
| Barruelian | | | age | Carboniferous | Europe | | George & Wagner, 1972 |
| Barstovian | 16.3 | 13.6 | age | Miocene | North America | | Wood "et al.", 1941 |
| Bartonian | 37.2 ± 0.1 | 40.4 ± 0.2 | age | Eocene | ICS | Barton-on-Sea (South England) | Mayer-Eymar, 1857 |
| Bashkirian | 318.1 ± 1.3 | 311.7 ± 1.1 | age | Carboniferous | ICS | Bashkortostan | Semikhatova, 1934 |
| Basin Groups 1-9 | 4,150 | 3,850 | subperiod | Prenectarium | Moon (unofficial) | groups of impact basins | |
| Batesfordian | 16.5 | 15.5 | age | Miocene | Australia | | Chapman & Singleton, 1923 |
| Bathonian | 167.7 ± 3.5 | 164.7 ± 4.0 | age | Jurassic | ICS | Bath (England) | D´Orbigny, 1852 |
| Batyrbayan | 491.5 | 488.3 | age | Cambrian | Russia, Kazakhstan | | Apollonov & Chugaeva, 1983 |
| Bavel Interglacial | 1.03 | 0.96 | age | Pleistocene | Netherlands | Bavel | Zagwijn & De Jong, 1964 |
| Bavelian | 1.03 | 0.85 | super-age | Pleistocene | Netherlands | Bavel | Zawijn & De Jong, 1964 |
| Baventian | ~2.0 | ~1.87 | age | Pleistocene | Great Britain | Easton Bavents (England) | West, 1961 |
| Bedoulian | 129.97 | 125.0 | sub-age | Cretaceous | regional | | Toucas, 1873 |
| Beestonian | 1.77 | ~0.8 | age | Pleistocene | Great Britain | Beeston, Norfolk (England) | West & Wilson, 1966 |
| Belvédère Interglacial | 0.338 | 0.324 | age | Pleistocene | Netherlands | quarry "Belvédère" (Maastricht) | |
| Bendigonian | 473.5 | 471.8 | age | Ordovician | Australia | Bendigo, Victoria | Benson & Keble, 1935 |
| Berriasian | 145.5 ± 4.0 | 140.2 ± 3.0 | age | Cretaceous | ICS | Berrias (France) | Coquand, 1871 |
| Biber Glacial | ~2.5 | 2.35 | age | Pleistocene | Alps | river Biber (Germany) | Schaefer, 1953 |
| Biber-Donau | | | age | Pleistocene | Alps | | |
| Blancan | 4.9 | 1.8 | age | Plio-Pleistocene | North America | | Wood "et al", 1941 |
| Black River(-an) | | | age | Ordovician) | North America | | Vanuxem, 1842 |
| Bolderian | <21 | >16 | age | Miocene | Belgium (obsolete) | Bolderberg | Dumont, 1850 |
| Bolindian | 450 | 443.7 | age | Ordovician | Australia | | Webby, 1976 |
| Bølling | 13,730 BP | 13,480 BP | chronozone | Weichselian | Northern Europe | Bølling Sø (Denmark) | Iversen, 1942 |
| Bolsovian | | | age | Carboniferous | Europe | Bolsover (England) | Jongsmans, 1928 |
| Boomerangian | 504 | 501 | age | Cambrian | Australia | | Öpik, 1979 |
| Boreal | 10,640 BP | 9,220 BP | chronozone | Holocene | Northern Europe | boreal zone in ecology | Blytt, 1876 |
| Bortonian | 43.0 | 37.0 | age | Eocene | New Zealand | Bortons | Hornibrook, 1961 |
| Botomian | 524 | 518.5 | age | Cambrian | Russia, Kazakhstan | | Repina, 1964 |
| Bramertonian | ~2.12 | ~2.0 | age | Pleistocene | Great Britain | Bramerton Pits (England) | Funnell, Norton, West and Mayhew, 1979 |
| Bridgerian | 50.3 | 46.2 | age | Eocene | North America | | Wood et al., 1941 |
| Brigantian | 336 | 326.4 ± 1.6 | age | Carboniferous | North America, Europe | Brigantes (Celtic tribe) | Ramsbotton, 1979 |
| Brioverian | ~680 | ~600 | age | Neoproterozoic | Armorican Massif, France | | Barrois, 1899 |
| Brüggenian | 2.588 | 2.4 | chronozone | Pleistocene | Northwest Europe | | |
| Brunssumian | 5.3 | 3.6 | chronozone | Pliocene | Northwest Europe | Brunssum (The Netherlands) | Zagwijn, 1960 |
| Bulitian | 55.8 | 53 | age | Eocene | California | | Mallory, 1959 |
| Bumbanian | 55.7 | 52.1 | ALMA | Eocene | Asia | | Russell & Zhai, 1987 |
| Buntsandstein | 251.0 ± 0.4 | 246.6 | epoch/subperiod | Triassic | Europe | German: bunte Sandstein = coloured sandstone | Von Alberti, 1834 |
| Burdigalian | 20.43 | 15.97 | age | Miocene | ICS | Latin: Burdigala = Bordeaux (France) | Depéret, 1892 |
| Burrellian | 457 | 455 | age | Ordovician | Europe | Glenburrell (England) | Fortey "et al.", 1995 |
| Burzyan | 1,400 | 1,375 | age | Proterozoic | Russia | | Kefler, 1952 |
| Caerfai | 542 ± 0.2 | 513 ± 2 | age | Cambrian | Europe (obsolete) | Caerfai Bay (Wales) | Cowie "et al.", 1972 |
| Calabrian | 1.806 | 0.781 | age | Pleistocene | Southern Europe | Calabria | Gignoux, 1913 |
| Callovian | 164.7 ± 4.0 | 161.2 ± 4.0 | age | Jurassic | ICS | Kellaways (England) | d'Orbigny, 1849 |
| Calymmian | 1,600 | 1,400 | period | Proterozoic | ICS | | Plumb, 1991 |
| Cambrian | 542.0 ± 1.0 | 488.3 ± 1.7 | period | Paleozoic | ICS | Cambria (Latin for Wales) | Sedgwick, 1835 |
| Campanian | 83.5 ± 0.7 | 70.6 ± 0.6 | age | Cretaceous | ICS | Champagne (France) | Coquand, 1857 |
| Canadian | | | epoch | Ordovician | North America | | |
| Cantabrian | 305 | | age | Carboniferous | Europe | | Wagner, 1965 |
| Capitanian | 265.8 ± 0.7 | 260.4 ± 0.7 | age | Permian | ICS | Capitan Reef (Texas, US) | Richardson, 1904 |
| Caradocian | 460.9 | 449.5 | epoch | Ordovician | Europe | Caradoc (Welsh king) | Murchison, 1839 |
| Carboniferous | 359.2 ± 2.5 | 299.0 ± 0.8 | period | Paleozoic | ICS | carbon | Conybeare & Phillips, 1822 |
| Carixian | 189.6 ± 1.5 | | sub-age | Jurassic | regional | | Lang, 1913 |
| Carnian | 228.0 ± 2.0 | 216.5 ± 2.0 | age | Triassic | ICS | Carnic Alps (Austria) | Mojsisovics, 1869 |
| Carpentarian | 1,800 | 1,300 | age | Proterozoic | Australia | Gulf of Carpentaria | Dunn et al., 1966 |
| Casamajoran | 54 | 48 | age | Eocene | South America | | Pascual, 1965 |
| Cassian | 1.1 | 0.8 | age | Pleistocene | Italy | | Mayer-Eymar, 1888 |
| Cassinian | 473 | 471.8 | sub-age | Ordovician | North America | | Flower, 1957 |
| Castlecliffian | 1.63 | 0.34 | age | Pleistocene | New Zealand | Castlecliff | Thompson, 1916 |
| Castlemanian | 471 | 470 | age | Ordovician | Australia | Castlemaine | Strachan, 1972 |
| Cautleyan | 447.5 | 446.5 | age | Ordovician | Europe | Cautley Spout (England) | Marr, 1914 |
| Cayugan | 421.3 ± 2.6 | 416.0 ± 2.8 | age | Silurian | North America | | Clark & Schuchert, 1898 |
| Cenomanian | 99.6 ± 0.9 | 93.5 ± 0.8 | age | Cretaceous | ICS | Latin: Cenomanium = Le Mans (France) | d'Orbigny, 1847 |
| Cenozoic | 65.5 ± 0.3 | present | era | Phanerozoic | ICS | new life | Phillips, 1847 |
| Cernaysian | 55.9 | 55.0 | ELMMZ | Paleocene | Europe | | Lemoine, 1880 |
| Chadian | 345.3 ± 2.1 | 341 | age | Carboniferous | regional | St Chad, Chatburn, Lancashire | Ramsbotton, 1979 |
| Chadronian | 38.0 | 33.9 | age | Eocene | North America | | Wood "et al.", 1941 |
| Chamovnicheskian | 306 | 305 | age | Carboniferous | Russia | | |
| Champlanian | | | epoch | Ordovician | North America | | Emmons, 1842 |
| Changhsingian | 253.8 ±0.7 | 251.0 ± 0.4 | age | Permian | ICS | Changxing (China) | Sheng, 1963 |
| Changlangpuan | 523 | 518 | age | Cambrian | China | | |
| Changshanian | 496.8 | 492.5 | age | Cambrian | China | | Walcott, 1913 |
| Chapadmalalan | 4.0 | 3.0 | age | Pliocene | South America | | Kraglievich, 1930 |
| Chasicoan | 10.0 | 9.0 | age | Miocene | South America | | Cabrera & Kraglievich, 1928 |
| Chatauquan | 370 | 359.2 ± 2.5 | age | Devonian | South America | | Clark & Schuchert 1898 |
| Chattian | 28.4 ± 0.1 | 23.03 | age | Oligocene | ICS | Chatti (ancient Germanic tribe) | Fuchs, 1894 |
| Chautauquan | | | age | Devonian | North America | | |
| Chazyan | | | age | Ordovician | North America | | Kay, 1958 |
| Cheltenhamian | 5.0 | 4.3 | age | Pliocene | Australia | | Mayer-eymar, 1881 |
| Cheneyan | 455 | 452 | age | Ordovician | Europe | | |
| Cheremshankian | 314.5 | 313.4 | age | Carboniferous | Russia | | Aisenverg, 1979 |
| Chesterian | 333 | 318.1 | age | Carboniferous | North America | | Worthen, 1860 |
| Chewtonian | 473 | 471 | age | Ordovician | Australia | | Harris & Thomas, 1938 |
| Chokierian | 325 | 324.5 | sub-age | Carboniferous | regional | Chokier, Belgium | Hodson (1957) |
| Cincinnatian | 451 | 443.7 ± 1.5 | epoch | Ordovician | North America | Cincinnati | Meek & Worthen, 1865 |
| Cisuralian | 299.0 ± 0.8 | 270.6 ± 0.7 | epoch | Permian | ICS | | Waterhouse, 1982 |
| Clansayesian | 115.0 | 112.0 | sub-age | Cretaceous | | | Breistroffer, 1947 |
| Clarendonian | 13.6 | 10.3 | age | Miocene | North America | | Wood "et al.", 1941 |
| Clarkforkian | 56.8 | 55.4 | age | Paleo-Eocene | North America | | Granger, 1914 |
| Clifdenian | 15.9 | 15.1 | age | Miocene | New Zealand | Clifden | Fleming, 1959 |
| Colhuehuapian | 21.0 | 17.5 | age | Miocene | South America | | Flynn " et al.", 1995 |
| Colloncuran | 15.5 | 13.8 | age | Miocene | South America | | Groeber, 1929 |
| Coniacian | 89.3 ± 1.0 | 85.8 ± 0.7 | age | Cretaceous | ICS | Cognac (France) | Coquand, 1857 |
| Copernican | 1,100 | present | period | | Moon | Copernicus | |
| Costonian | 460.9 | 459 | age | Ordovician | regional | | Bancroft, 1933 |
| Couvinian | 397.5 ± 2.7 | 391.8 ± 2.7 | age | Devonian | Belgium (obsolete) | Couvin | d'Omalius d'Halloy, 1862 |
| Cressagian | 488.3 ± 1.7 | 486 | age | Ordovician | Europe | | |
| Cretaceous | 145.5 ± 4.0 | 65.5 ± 0.3 | period | Mesozoic | ICS | Crete; Latin creta=chalk | d'Omalius d'Halloy, 1822 |
| Croixan | | | epoch | Cambrian | North America | | |
| Cromerian | 0.85 | 0.465 | super-age/age | Pleistocene | Netherlands, Great Britain | Cromer (England) | Reid, 1882 |
| Cryogenian | 850 | 635.5 ± 1.2 | period | Proterozoic | ICS | frozen beginning | Plumb, 1991 |
| Cryptic | 4,567 | 4,150 | epoch | Prenectarian | Moon (unofficial) | hidden | |
| Dacian | 5.332 ± 0.005 | 3.600 ± 0.005 | age | Pliocene | Paratethys | Dacia (Roman province) | Teisseyre, 1907 |
| Dalanian (Dalaun) | 313 | 310 | age | Carboniferous | China | | |
| Danian | 65.5 ± 0.3 | 61.7 ± 0.2 | age | Paleocene | ICS | Denmark | Desor, 1847 |
| Dannevirke | 65.0 | 43.0 | epoch | Paleogene | New Zealand | Dannevirke | Kingma, 1962 |
| Dapingian | 471.8 ± 1.6 | 468.1 ± 1.6 | age | Ordovician | ICS | Daping (China) | Huang & Zhu, 1948 |
| Darriwilian | 468.1 ± 1.6 | 460.9 ± 1.6 | age | Ordovician | ICS | Darriwil (Australia) | Hall, 1899 |
| Datangian | 345 | 333 | age | Carboniferous | China | | Ding, 1931 |
| Datsonian | 488.3 ± 1.7 | 485 | age | Ordovician | Australia | | Jones et al., 1971 |
| Dawanian | 472 | 471.8 | age | Ordovician | North America | | Xiang "et al.", 1980 |
| Deerparkian | | | age | Devonian | North America | | Cooper et al., 1942 |
| Delamaran | 512 | 504 | age | Cambrian | North America | Palmer, 1998 |
| Delmontian | 7.5 | 2.9 | age | Plio-Miocene | California | | Kleinpell, 1938 |
| Demingian | 478.6 | 475 | sub-age | Ordovician | North America | | Flower, 1957 |
| Derryan | 311.7 ± 1.1 | 308 | age | Carboniferous | North America | | Thmpson, 1942 |
| Deseadan | 29.0 | 21.0 | age | Oligo-Miocene | South America | | Flynn & Wisher, 1995 |
| Desmoinesian | | | age | Carboniferous | North America | | Keyes, 1893 |
| Deurnian | | | age | Miocene | Belgium (obsolete) | Deurne | de Heinzelin (1955) |
| Devensian | 0.116 | 0.0115 | age | Pleistocene | Great Britain | Devenses, Celtic tribe by the Deva (England and Wales) | Godwin, 1956 |
| Devonian | 416.0 ± 2.8 | 359.2 ± 2.5 | period | Paleozoic | ICS | Devon (England) | Murchison & Sedgwick, 1839 |
| Dewuan | 333 | 318.1 ± 1.3 | age | Carboniferous | China | | Yang "et al.", 1962 |
| Dinantian | 359.2 ± 2.5 | 326.4 ± 1.6 | epoch/sub-period | Carboniferous | Northern Europe | Dinant | Munier-Chalmas & Lapparent, 1893 |
| Dittonian | 418 | | age | Devonian | Wales and England (obsolete) | Ditton Priors, Shropshire, England | King, 1921 |
| Divisaderan | 42 | 36 | age | Eocene | South America | | Pascual, 1983 |
| Dogger | 175.6 ± 2.0 | 161.2 ± 4.0 | epoch | Jurassic | Northern Europe | dogger=ironrich sediment type | Naumann, 1854 |
| Dolgellian | 492.5 | 488.3 ± 1.7 | age | Cambrian | regional | Dolgellau, Wales | Harland et al., 1989 |
| Domerian | | 183.0 ± 1.5 | sub-age | Jurassic | regional | | Bonarelli, 1894 |
| Donau Glacial | 1.7 | 1.35 | age | Pleistocene | Alps | river Danube | Eberl, 1930 |
| Donau-Günz | | >2.35 | age | Pleistocene | Alps | | |
| Dorogomilovskian | 305 | 303.9 ± 0.9 | age | Carboniferous | regional | | Ivanov, 1926 |
| Drenthian | 0.238 | 0.17 | chronozone | Pleistocene | Northwest Europe | Drenthe | Van Der Vlerk & Florschutz, 1950 |
| Dresbachian | 501 | 496.8 | age | Cambrian | North America | | Howell, 1944 |
| Drumian | 506.5 | 503 | age | Cambrian | ICS | Drum Mountains (Utah, US) | Peng & Robinson, 2000 |
| Duchesnean | 42.0 | 38.0 | age | Eocene | North America | | Wood "et al"., 1941 |
| Duckmantian | | | age | Carboniferous | Europe | Duckmanton Railway Cutting, England | Jongmans, 1928 |
| Duntroonian | 27.3 | 25.2 | age | Oligocene | New Zealand | Duntroon | Fleming, 1959 |
| Dyeran | 524.5 | 512 | age | Cambrian | North America | | Palmer, 1998 |
| Eaglefordian | | | age | Cretaceous | Gulf and Atlantic coast of the US | Eagle Ford, Dallas, Texas | Murray, 1961 |
| Early Imbrian | 3850 | 3800 | period | | Moon | Mare Imbrium | |
| Eastonian | 456 | 450 | age | Ordovician | Australia | | Packham, 1968 |
| Eburonian | 1.80 | 1.45 | super-age | Pleistocene | Netherlands | Eburones, Germanic tribe | Zagwijn, 1963 |
| Ectasian | 1,400 | 1,200 | period | Proterozoic | ICS | | Plumb, 1991 |
| Edenian | | | age | Ordovician | North America | | Twenhofel, 1954 |
| Ediacaran | 635.5 ± 1.2 | 542.0 ± 1.0 | period | Proterozoic | ICS | Ediacara Hills (Australia) | Cloud, 1972 |
| Edmontonian | 80.8 | 70.7 | NALMA | Cretaceous | North America | | Russel, 1975 |
| Eemian | 0.130 | 0.116 | age | Pleistocene | Northern Europe | river Eem (Netherlands) | Harting, 1875 |
| Eifelian | 397.5 ± 2.7 | 391.8 ± 2.7 | age | Devonian | ICS | the Eifel (Germany) | Beyrich, 1837 |
| Egerian | 25.8 | 20.3 | age | Oligo-Miocene | Paratethys | Eger (Hungary) | Báldi & Seneš, 1968 |
| Eggenburgian | 20.8 | 18.3 | age | Miocene | Paratethys | Eggenburg (Austria) | Steininger & Seneš, 1968 |
| Eildonian | 433 | 428.2 ± 2.3 | age | Silurian | Australia | | Thomas, 1947 |
| Elsterian | 0.465 | 0.418 | age | Pleistocene | Northern Europe | river Weißen Elster (Germany) | Keilhack, 1911 |
| Elvirian | 326 | 324.5 | age | Carboniferous | regional | | |
| Emilian | 1.5 | 0.781 | sub-age | Pleistocene | Italy | | Ruggeri & Selli, 1948 |
| Emscherian | 89.5 | 83.5 | age | Cretaceous | Germany | | Munier-Chalmas & Lapparent, 1893 |
| Emsian | 407.0 ± 2.8 | 397.5 ± 2.7 | age | Devonian | ICS | Bad Ems (Germany) | de Dorlodot, 1900 |
| Ensenadan | 1.2 | 0.8 | age | Pleistocene | South America | | Ameghino, 1889 |
| Eoarchean | none | 3.600 | era | | ICS | | Plumb, 1991 |
| Eocene | 55.8 ± 0.2 | 33.9 ± 0.1 | epoch | Paleogene | ICS | earliest recent | Lyell, 1847 |
| Eratosthenian | 3,200 | 1,100 | period | | Moon | Eratosthenes | |
| Ergilian | 35.1 | 33.8 | ALMA | Oligo-Eocene | Asia | | Russell & Zhai, 1987 |
| Erian | 391.8 ± 2.7 | 388 | age | Devonian | North America | | Dawson, 1871 |
| Famennian | 374.5 ± 2.6 | 359.2 ± 2.5 | age | Devonian | ICS | the Famenne (Belgium) | Dumont, 1855 |
| Fassanian | 237 ± 2.0 | 233 | sub-age | Triassic | Europe | | Mojsisovics, 1895 |
| Fengshanian | 492.5 | 488.3 ± 1.7 | age | Cambrian | China | | Lu, 1962 |
| Fennian | 473 | 471.8 | age | Ordovician | Europe | | Fortey & Owens, 1987 |
| Festiniogian | 496.8 | 492.5 | age | Cambrian | regional | (anglicised spelling of) Ffestiniog, Wales | Harland et al., 1990 |
| Flaminian | 0.5 | 0.3 | age | Pleistocene | Italy | | |
| Flandrian | 0.01 | present | age | Holocene | Western Europe (obsolete) | Flanders | Rutot & Van den Broeck, 1885 |
| Floian | 478.6 ± 1.7 | 471.8 ± 1.6 | age | Ordovician | ICS | Flo (Sweden) | Gradstein "et al", 2004 |
| Florian | 508 | 504 | age | Cambrian | Australia | | |
| Fortunian | 542.0 ± 1.0 | 528 | age | Cambrian | ICS | Fortune Head (Canada) | Brassier "et al.", 1994 |
| Franconian | 496.8 | 492.5 | age | Cambrian | North America | | Lapparent, 1893 |
| Frasnian | 385.3 ± 2.6 | 374.5 ± 2.6 | age | Devonian | ICS | Frasne (Belgium) | d'Omalius d'Halloy, 1862 |
| Friasian | 16.3 | 15.5 | age | Miocene | South America | | Kraglievich, 1930 |
| Fujian | 11.1 | 9.5 | age | Miocene | Japan | | Ikebe, 1977 |
| Fupingan | 3,100 | 2,600 | age | Archaean | China | | |
| Furongian | 501.0 ± 2.0 | 488.3 ± 1.7 | epoch | Cambrian | ICS | Furong (China) | Cowie & Bassett, 1989 |
| Gallic | 130.0 ± 1.5 | 89.3 ± 1.0 | epoch | Cretaceous | obsolete | | Smith, 1815 |
| Gargasian | 121.0 | 115.0 | sub-age | Cretaceous | regional | | Kilian, 1887 |
| Gashatan | 56.9 | 55.7 | ALMA | Paleo-Eocene | Asia | | Romer, 1966 |
| Gaultian | | | sub-age [Gault] | Cretaceous | regional | | Smith, 1817 |
| Gedinian | 416.0 ± 2.8 | 411.2 ± 2.8 | age | Devonian | Belgium (obsolete) | Gedinne | Dumont, 1848 |
| Geiseltalian | 48.5 | 42.7 | ELMMZ | Eocene | Europe | | Franzel & Haubold, 1986 |
| Gelasian | 2.588 | 1.806 | age | Pleistocene | ICS | Gela (Italy) | Rio et al., 1998 |
| Geringian | 30.8 | 26.3 | age | Oligocene | North America | | Schultz & Falkenbach, 1968 |
| Gisbornian | 460.9 | 456 | age | Ordovician | Australia | | Thomas, 1960 |
| Givetian | 391.8 ± 2.7 | 385.3 ± 2.6 | age | Devonian | ICS | Givet (France) | d'Omalius d'Halloy, 1839 |
| Gleedonian | 425.4 | 422.9 ± 2.5 | age | Silurian | regional | | Bassett "et al.", 1975 |
| Gorstian | 422.9 ± 2.5 | 421.3 ± 2.6 | age | Silurian | ICS | Gorsty (farm at Ludlow, England) | Holland et al., 1980 |
| Gramian | 10.3 | 8.5 | age | Miocene | Northern Germany | | Hinsch, 1952 |
| Grauvian | 50.8 | 48.5 | ELMMZ | Eocene | Europe | | Savage & Russell, 1977 |
| Greenlandian | 0.0117 | 0.0082 | age | Holocene | ICS | North Greenland Ice Core Project | |
| Guadalupian | 270.6 ± 0.7 | 260.4 ± 0.7 | epoch | Permian | ICS | Guadalupe Mountains (Texas, US) | Girty, 1908 |
| Guandian | 425.5 | 422 | age | Silurian | China | | Ting & Wang, 1937 |
| Gulf(-ian) | | | epoch | Cretaceous | south and east of the US | the Mexican Gulf | Cobban & Reeside, 1952 |
| Günz Glacial | 2.35 | | age | Pleistocene | Alps | river Günz (Germany) | Penck & Bruckner, 1909 |
| Günz-Mindel | | | age | Pleistocene | Alps | | |
| Gushanian | 596.8 | 501 | age | Cambrian | China | | Kobayashi, 1935 |
| Guzhangian | 503 | 499 | age | Cambrian | ICS | Guzhang (China) | Peng, 1992 |
| Gzhelian | 303.9 ± 0.9 | 299.0 ± 0.8 | age | Carboniferous | ICS | Gzhel (Russia) | Nikitim, 1890 |
| Hadean | none | 4000 | eon | | ICS | Hades, hell | Cloud, 1972 |
| Hadrynian | 850 | 542 | age | Neoproterozoic | North America | | Fahrig "et al.", 1971 |
| Hallian | ~10.000 | 0 | age | Holocene | California | | |
| Haranoyan | 18.2 | 15.97 | age | Miocene | Japan | | Ikebe, 1977 |
| Harnagian | 459 | 458 | age | Ordovician | regional | | Bancroft, 1929 |
| Harrisonian | 24.8 | 20.6 | age | Oligo-Miocene | North America | | Wilson, 1960 |
| Hastarian | 359.2 ± 2.5 | 348 | age | Carboniferous | regional | | Conil, 1977 |
| Haumurian | 84 | 65.5 | age | Cretaceous | New Zealand | Haumuri Bluff | |
| Hautawan | 3.1 | 2.2 | sub-age | Plio-Pleistocene | New Zealand | | |
| Hauterivian | 136.4 ± 2.0 | 130.0 ± 1.5 | age | Cretaceous | ICS | Hauterive (Switzerland) | Renevier, 1873 |
| Haweran | 0.01 | present | age | Holocene | New Zealand | Hāwera | Thompson, 1917 |
| Headonian | 37.2 | 33.8 | ELMMZ | Oligo-Eocene | Europe | | Bosma, 1974 |
| Helikian | 1,600 | 850 | age | Proterozoic | North America | | Stockwell, 1964 |
| Hemingfordian | 20.6 | 16.3 | age | Miocene | North America | | Wood "et al.", 1941 |
| Hemmoorian | | | age | Miocene | Northern Germany | | Kautsky, 1925 |
| Hemphillian | 10.3 | 4.9 | age | Mio-Pliocene | North America | | Wood "et al.", 1941 |
| Heretaungan | 49.5 | 46.2 | age | Eocene | New Zealand | Heretaunga Plains | Hornibrook & Harrington, 1957 |
| Hesperian | ~3,500 | ~1,800 | Martian epoch | | Mars | Hesperia Planum | |
| Hettangian | 199.6 ± 0.6 | 196.5 ± 1.0 | age | Jurassic | ICS | Hettange-Grande (France) | Renevier, 1864 |
| Hirnantian | 445.6 ± 1.5 | 443.7 ± 1.5 | age | Ordovician | ICS | Cwm Hirnant (Wales) | Bancroft, 1933 |
| Holkerian | 339 | 337.5 | age | Carboniferous | regional | | Ramsbotton, 1979 |
| Holocene | 11,800 BP | present | epoch | Quaternary | ICS | Greek: totally new | Gervais, 1867 |
| Holsteinian | 0.418 | 0.386 | age | Pleistocene | Northern Europe | Holstein (Germany) | Jung, 1957 |
| Homerian | 426.2 ± 2.4 | 422.9 ± 2.5 | age | Silurian | ICS | Homer (England) | Bassett et al., 1975 |
| Honghuayuanian | 478.6 | 472 | age | Ordovician | China | | Yang, 1990 |
| Houldjinian | 37.2 | 33.9 | ALMA | | Asia | | Meng "et al.", 1998 |
| Houthalenian | <21 | >16 | age | Miocene | Belgium (obsolete) | Houthalen | Hirsch, 1952 |
| Hoxnian | 0.418 | 0.386 | age | Pleistocene | Great Britain | Hoxne (Suffolk) | West & Donner, 1956 |
| Hsandgolian | 33.8 | 24.0 | ALMA | Oligocene | Asia | | Meng "et al"., 1998 |
| Huashibanian | 318.1 ± 1.3 | 313 | age | Carboniferous | China | | Jin "et al.", 1962 |
| Huayquerian | 9.0 | 6.8 | age | Miocene | South America | | Pascual & Odreman, 1971 |
| Hutchinsonian | 21 | 20 | age | Miocene | New Zealand | | Fleming, 1959 |
| Huronian | 2,500 | 1,400 | age | Proterozoic | worldwide (obsolete) | | Logan & Murray, 1855 |
| Ibexian | ~505 | 471.8 | age | Cambrian-Ordovician | North America | | Ross, 1951 |
| Icenian | 2.4 | ~2 | age | Pleistocene | Netherlands, England (obsolete) | Iceni, ancient tribe (England) | Harmer, 1900 |
| Idamean | 497 | 494 | age | Cambrian | Australia | | Öpik, 1963 |
| Ilfordian | | | age | Pleistocene | British Isles | Ilford (England) | Bowen, 1978 |
| Illinoian | 0.17 | 0.125 | age | Pleistocene | North America | | Chamberlin, 1896 |
| Illyrian | 240 ± 2.0 | 237 ± 2.0 | sub-age | Triassic | Europe | | Tozer, 1967 |
| Induan | 251.0 ± 0.4 | 249.7 ± 0.7 | age | Triassic | ICS | river Indus | Kiparisova & Popov, 1956 |
| Ionian | 0.781 | 0.126 | age | Pleistocene | Southern Europe | Ionian Sea (between Greece and Italy) | Carianfi, 1995 |
| Ipswichian | 0.130 | 0.116 | age | Pleistocene | Great Britain | Ipswich (England) | West, 1957 |
| Irdinmanhan | 46.2 | 40.4 | ALMA | Eocene | Asia | | Russell & Zhai, 1987 |
| Irvingtonian | 1.8 | | age | Pleistocene | North America | Irvington | Wood "et al.", 1941 |
| Isuan | 3,800 | 3,500 | age | Archaean | Europe | | McGregor, 1968 |
| Itaboraian | 59 | 57 | age | Paleocene | South America | | Paula-coutos, 1946 |
| Ivorean | 348 | 345.3 ± 2.1 | age | Carboniferous | regional | | Conil, 1977 |
| Jacksonian | | | age | Eocene | southern US | | Heilprin, 1882 |
| Janjukian | 30.0 | 27.5 | age | Oligocene | Australia | | Hall & Pritchard, 1902 |
| Jeffersonian | 475 | 473 | sub-age | Ordovician | North America | | Flower, 1979 |
| Jiangshanian | 494 | 489.5 | age | Cambrian | ICS | | |
| Jinningian | 1,750 | 800 | age | Proterozoic | China | | Peng, 2000 |
| Jiusian | | | age | Carboniferous | China | | Jin "et al"., 2000 |
| Johannian | 48 | 35 | age | Eocene | Australia | | Singleton, 1955 |
| Judithian | 82.2 | 80.8 | NALMA | Cretaceous | North America | | Russell, 1975 |
| Julian | 229.6 ± 2.0 | 222.5 | sub-age | Triassic | Europe | | Tozer, 1967 [Mojsisovics, 1895] |
| Jurassic | 199.6 ± 0.6 | 145.5 ± 4.0 | period | Mesozoic | ICS | Jura mountains | Brongniart, 1829 |
| Kaburan | 13.5 | 11.1 | age | Miocene | Japan | | Ikebe, 1977 |
| Kaiatan | 37.0 | 36.0 | age | Eocene | New Zealand | Kaiata | Fleming, 1959 |
| Kalimnan | 4.3 | 3.4 | age | Pliocene | Australia | | Hall & Pritchard, 1902 |
| Kansan | 0.48 | 0.26 | age | Pleistocene | North America | | Geikie, 1894 |
| Kapitean | 6.5 | 5.0 | age | Miocene | New Zealand | Kapitea Creek, West Coast Region | Fleming, 1959 |
| Karatau | 1,100 | 800 | age | Proterozoic | Russia | | |
| Karoo Ice Age | ~360 | ~260 | ice age | Phanerozoic | | Karoo (South Africa) | |
| Karpatian | 17.0 | 16.0 | age | Miocene | Paratethys | the Carpathian Mountains | Cicha et al., 1967 |
| Kashirskian | 309.2 | 308.0 | age | Carboniferous | Russia | | Stepanov, 1962 |
| Kasimovian | 306.5 ± 1.0 | 303.9 ± 0.9 | age | Carboniferous | ICS | Kasimov (Russia) | Theodorovich, 1949 |
| Kasterlian | ~4.7 | ~3.6 | age | Pliocene | Belgium (obsolete) | Kasterlee | Dumont, 1882 |
| Katian | 455.8 ± 1.6 | 445.6 ± 1.5 | age | Ordovician | ICS | Lake Katy (Oklahoma, US) | Bergstrom et al., 2003 |
| Kattendijkian | ~5 | ~3.6 | age | Pliocene | Belgium (obsolete) | Kattendijke | Glibert & de Heinzelin, 1957 |
| Kazanian | | | age | Permian | Russia | | Netxaev, 1915 |
| Kechienjian | 1.9 | 1.5 | age | Pleistocene | Japan | | Ikebe, 1977 |
| Keiloran | 443.7 ± 1.5 | 433 | age | Silurian | Australia | | |
| Kekeamuan | 28.4 | 33.9 | ALMA | | Asia | | Wang, 1981 |
| Keuper | ±230 | 199.6 | epoch | Triassic | Europe | | Von Alberti, 1834 |
| Kimmeridgian | 155.7 ± 4.0 | 150.8 ± 4.0 | age | Jurassic | ICS | Kimmeridge (England) | d'Orbigny, 1852 |
| Kinderhookian | 359.2 ± 2.5 | 348 | age | Carboniferous | North America | | Bizat, 1928 |
| Kinderscoutian | 318.1 ± 1.3 | 317 | age | Carboniferous | regional | Kinder Scout (England) | Bisat (1928) |
| Kirkfield | 458 | 457 | age | Ordovician | regional | | Liddell, 1975 |
| Kiscellian | | 25.8 | age | Oligocene | Paratethys | | Nolf & Brzobohaty, 1994 |
| Klazminskian | 303.9 ± 0.9 | 300.5 | age | Carboniferous | regional | | Ivanova & Khovorova, 1955 |
| Korangan | 117.5 | 108.4 | age | Cretaceous | New Zealand | Koranga | Wellman, 1959 |
| Krevyakinskian | 306.5 | 306 | age | Carboniferous | Russia | | Ivanova & Khovorova, 1955 |
| Kryzhanovan | 1.9 | 1.2 | age | Pleistocene | Eastern Europe | | |
| Kungurian | 275.6 ± 0.7 | 270.6 ± 0.7 | age | Permian | ICS | Kungur (Russia) | Stuckenberg, 1890 |
| Lacian | 217.4 ± 2.0 | 211 | sub-age | | Europe | | Mojsisovics, 1895 |
| Ladinian | 237.0 ± 2.0 | 228.0 ± 2.0 | age | Triassic | ICS | Ladini, people in northern Italy | Bittner, 1892 |
| Lancefieldian | 482 | 475 | age | Ordovician | Australia | | Harris & Keble, 1932 |
| Lancian | 70.7 | 65.5 | NALMA | Cretaceous | North America | | Russell, 1964 |
| Landenian | <60 | >55 | age | Paleocene | Western Europe (obsolete) | Landen (Belgium) | Dumont, 1839 |
| Landon | 34.3 | 21.7 | epoch | Paleo-Neogene | New Zealand | Landon Creek | Kingma, 1962 |
| Langenfeldian | | | age | Miocene | Northern Germany | | |
| Langhian | 15.97 | 13.65 | age | Miocene | ICS | Serravalle Langhe (Italy) | Pareto, 1864 |
| Langsettian | 314.5 | 313.4 | age | Carboniferous | regional | Langsett (England) | Jongsmans, 1928 |
| Latdorfian | | | age | Oligocene | Germany | | Mayer-Eymar, 1893 |
| Late Imbrian | 3,800 | 3,200 | period | | Moon | Mare Imbrium | |
| Laventan | 13.8 | 12.0 | age | Miocene | South America | | Madden, 1994 |
| Leonardian | | | age | Permian | North America | | Adams et al., 1939 |
| Lias | 199.6 ± 0.6 | 175.6 ± 2.0 | epoch | Jurassic | Northern Europe | unclear | Mantell, 1833 [Smith, 1817] |
| Likhvinian | 0.3 | 0.18 | age | Pleistocene | Eastern Europe | | Krasnenkov & Kazantseva, 1993 |
| Lillburnian | 15.1 | 12.7 | age | Miocene | New Zealand | Lill Burn, Southland Region | Fleming, 1959 |
| Linxiangian | 454.5 | 449 | age | Ordovician | China | | |
| Lishihhuangtuan | 1.2 | 0.1 | age | Pleistocene | China | | |
| Livian | 335 | 331 | age | Carboniferous | Belgium (obsolete) | Lives | Conil, 1977 |
| Llandeilo (Llandeilean) | | | epoch/age | Ordovician | Europe | Llandeilo (Wales) | Murchison, 1835 |
| Llandovery | 443.7 ± 1.5 | 428.2 ± 2.3 | epoch | Silurian | ICS | Llandovery (Wales) | Murchison, 1859 |
| Llanvirn(-ian) | Llanvirn Farm near St Davids, Wales | Hicks (1881) | epoch | Ordovician | Europe | | Hicks, 1875 |
| Lochkovian | 416.0 ± 2.8 | 411.2 ± 2.8 | age | Devonian | ICS | Lochkov (Czech Republic) | Chlupac, 1972 |
| Longfordian | 27.5 | 16.5 | age | Oligo-Miocene | Australia | | Crespin, 1943 |
| Longmaxian | 443.7 ± 1.5 | 438 | age | Silurian | China | | Yin, 1949 |
| Longobardian | 233 | 229.6 ± 2.0 | sub-age | Triassic | Europe | | Mojsisovics, 1895 |
| Longvillian | 457 | 455 | age | Ordovician | regional | Cheney Longville (England) | Bancroft, 1929 |
| Longwangmioan | 518 | 513 | age | Cambrian | China | | Bengston & Jell, 1990 |
| Lopingian | 260.4 ± 0.7 | 251.0 ± 0.4 | epoch | Permian | ICS | Luoping (China) | Huang, 1932 |
| Lotharingian | 193.3 ± 0.7 | 189.6 ± 0.7 | substage | Jurassic | | | Haug, 1910 |
| Ludfordian | 421.3 ± 2.6 | 418.7 ± 2.7 | age | Silurian | ICS | Ludford (England) | Holland et al., 1980 |
| Ludhamian | ~2.52 | ~2.25 | age | Pleistocene | Great Britain | Ludham (England) | Beck et al., 1972 |
| Ludian | | | age | Eocene | western Europe | | de Lapparent, 1893 |
| Ludlovian | 422.9 ± 2.5 | 418.7 ± 2.7 | epoch | Silurian | ICS | Ludlow (England) | Murchison, 1854 |
| Luisian | 15.5 | 13.5 | age | Miocene | California | | Kleinpell, 1938 |
| Lujanian | 0.8 | 0.3 | age | Pleistocene | South America | | Ameghino 1889 |
| Luliangian | 2,350 | 1,750 | age | Proterozoic | China | | |
| Luosuan | 318.1 | ~314 | age | Carboniferous | China | | Jin et al., 1962 |
| Lutetian | 48.6 ± 0.2 | 40.4 ± 0.2 | age | Eocene | ICS | Latin: Lutetia=Paris (France) | de Lapparent, 1883 |
| Maastrichtian | 70.6 ± 0.6 | 65.5 ± 0.3 | age | Cretaceous | ICS | Maastricht (Netherlands) | Dumont, 1849 |
| Maentwrogian | 501 | 496.8 | age | Cambrian | regional | Maentwrog (Wales) | Hicks, 1881 |
| Malanghuangtuan | 0.1 | 0.01 | age | Pleistocene | China | | Liu & Chang, 1964 |
| Malm | 161.2 ± 4.0 | 145.5 ± 4.0 | epoch | Jurassic | Europe | Old English: malm = calcareous soil | Oppel & Quenstedt, 1858 |
| Mangaorapan | 53.0 | 49.5 | age | Eocene | New Zealand | Mangaorapa | Marwick & Fleming, 1959 |
| Mangaotanean | 92.1 | 89.1 | age | Cretaceous | New Zealand | Mangaotane | Wellman, 1959 |
| Mangapanian | 3.00 | 2.40 | age | Plio-Pleistocene | New Zealand | Mangapani | Fleming, 1953 |
| Maozhangian | 513 | 509 | age | Cambrian | China | | |
| Mapingian | 310 | 299.0 ± 0.8 | age | Carboniferous | China | | Ting, 1928 |
| Marahuan | 2.2 | 1.8 | sub-age | Pleistocene | New Zealand | | |
| Marjuman | 504 | 494.5 | age | Cambrian | North America | | Ludvigsen & Westrop, 1985 |
| Marsdenian | 317 | 315.5 | age | Carboniferous | regional | Marsden, West Yorkshire, England | Bisat (1928) |
| Marshbrookian | 455 | 454 | age | Ordovician | regional | Marshbrook (England) | Bancroft, 1929 |
| Mayan | 502 | 501 ± 2.0 | age | Cambrian | Russia, Kazakhstan | | Yarmoulyuk, 1946 |
| Mayanan | 1100 | 850 | age | Proterozoic | Siberia | | Datsenko et al., 1968 |
| Mayoian | 12.0 | 10.0 | age | Miocene | South America | | Villaroel, 1974 |
| Mayvillian | 453 | 447.5 | age | Ordovician | North America | | Foerste, 1905 |
| Medinan | | | age | Silurian | North America | | Clark & Schuchert, 1898 |
| Meghalayan | 0.0042 | 0 | age | Holocene | ICS | Caves of Meghalaya GSSP, India | |
| Meishuchuan | 542 | 532 | age | Cambrian | China | | Qian, 1977 |
| Melbournian | 428.2 ± 2.3 | 416.0 ± 2.8 | age | Silurian | Australia | Melbourne | Gregory, 1902 |
| Melekesskian | 313.4 | 311.7 | age | Carboniferous | Russia | | Aisenverg et al., 1979 |
| Menapian | | 1.03 | super-age | Pleistocene | Netherlands | Menapii, Germanic tribe | Zagweijn, 1957 |
| Meramecian | 340 | 333 | age | Carboniferous | North America | | Ulrich, 1904 |
| Merioneth | 501 ± 2 | 488.3 ± 1.7 | epoch | Cambrian | Europe (obsolete) | Merioneth (Wales) | Cowie et al., 1972 |
| Merksemian | ~2.5 | ~2 | age | Pleistocene | Belgium (obsolete) | Merksem | de Heinzelin, 1958 |
| Mesoarchean | 3,200 | 2,800 | era | Archean | ICS | | Plumb, 1991 |
| Mesoproterozoic | 1,600 | 1,000 | era | ICS | | Hofmann, 1987 |
| Mesozoic | 251.0 ± 0.7 | 65.5 ± 0.3 | era | | ICS | middle life | Philips, 1818 |
| Messinian | 7.246 | 5.332 | age | Miocene | ICS | Messina (Italy) | Mayer-Eymar, 1867 |
| Miaogoalingian | 422 | 418.7 | age | Silurian | China | | |
| Miaolingian | 509 | 497 | Epoch | Cambrian | ICS | | |
| Migneintian | 486 | 478.6 ± 1.7 | age | Ordovician | Europe | | Fortey et al., 1995 |
| Mindel | 0.85 | 0.465 | age | Pleistocene | Alps | river Mindel (Germany) | Penck, 1882 |
| Mindel-Riss | 0.465 | 0.238 | age | Pleistocene | Alps | | |
| Mindyallan | 501 | 497 | age | Cambrian | Australia | | Öpik, 1963 |
| Miocene | 23.03 | 5.332 | epoch | Neogene | ICS | Greek: less recent | Lyell, 1847 |
| Mississippian | 359.2 ± 2.5 | 318.1 ± 1.3 | epoch | Carboniferous | ICS | Mississippi River (US) | Winchell, 1870 |
| Missourian | | | age | Carboniferous | North America | | Keyes, 1873 |
| Mitchellian | 10.5 | 5.0 | age | Plio-Miocene | Australia | | |
| Mohawkian | 462 | 451 | epoch | Ordovician | North America | | Hall, 1842 |
| Mohnian | 13.5 | 7.5 | age | Miocene | California | | Kleinpell, 1938 |
| Mokolian | 2,050 | 900 | age | Proterozoic | South Africa | | |
| Monroecreekian | 26.3 | 24.8 | age | Oligocene | North America | Monroe Creek | Wilson, 1960 |
| Montehermosan | 6.8 | 4.0 | age | Plio-Miocene | South America | [Hermosean; Ameghino, 1889] | Simpson, 1940 |
| Montezuman | 529.5 | 524.5 | age | Cambrian | North America | | Palmer, 1998 |
| Montian | ~65 | ~61 | age | Paleocene | Europe (obsolete) | Mons (Belgium) | Dewalque, 1868 |
| Moridunian | 478.6 ± 1.7 | 475 | age | Ordovician | Europe | Moridunum (Wales) | Fortey & Owens, 1987 |
| Morozovan | 0.8 | 0.5 | age | Pleistocene | Eastern Europe | | |
| Morrowan | | | age | Carboniferous | North America | | Adams & Ulrich, 1904 |
| Moscovian | 311.7 ± 1.1 | 306.5 ± 1.0 | age | Carboniferous | ICS | Moscow (Russia) | Nikitin, 1890 |
| Motuan | 103.3 | 100.2 | age | Cretaceous | New Zealand | Motu River | Wellman, 1959 |
| Muschelkalk | 243 ± 2 | 235 ± 2 | epoch | Triassic | Europe | German: limestone with mussels | Füchsel, 1761 |
| Mustersan | 48 | 42 | age | Eocene | South America | | Kraglievich, 1930 |
| Myachkovskian | 307.2 | 306.5 | age | Carboniferous | Russia | | Stepanov, 1962 |
| Namibian | 900 | 542 | age | Neoproterozoic | South Africa | Namibia | |
| Namurian | 326.4 | 313.0 | age | Carboniferous | Europe | Namur (Belgium) | Purves, 1883 |
| Nanzian | 48 | 35 | age | Eocene | California | | |
| Navarroan | | | age | Cretaceous-Paleocene | south and east of the US | Navarro, Texas | Murray, 1961 |
| Nebraskian | 0.93 | 0.6 | age | Pleistocene | North America (obsolete) | | Shimek, 1909 |
| Nectarian | 3920 | 3850 | period | | Moon | Mare Nectaris | |
| Needian | 0.42 | 0.38 | age | Pleistocene | Netherlands (obsolete) | Neede | Van der Vlerk & Florschutz, 1950 |
| Nemakit-Daldynian | 542 | 534 | age | Cambrian | Russia, Kazakhstan | | Savitsky, 1962 |
| Neoarchean | 2,800 | 2,500 | era | Archean | ICS | | Plumb, 1991 |
| Neocomian | 145.5 | 125.0/130.0 | epoch | | obsolete | Neocomium, Latin name for Neuchâtel | Thurmann, 1835 |
| Neogene | 23.0 | 2.588 | period | Cenozoic | ICS | | Hoernes, 1856 |
| Neoproterozoic | 1,000 | 542.0 ± 1.0 | era | | ICS | | Hofmann, 1987 |
| Neporatan | 2.5 | 1.7 | age | Pleistocene | Eastern Europe | | Esu, 1980 |
| Neustrian | 55.0 | 50.8 | ELMMZ | Paleo-Eocene | Europe | | Fahlbusch, 1976 |
| Ngaterian | 100.2 | 95.2 | age | Cretaceous | New Zealand | Ngateretere | Wellman, 1959 |
| Niagaran | | | age | Silurian | North America | | Sterry Hunt, 1871 |
| Noachian | none | ~3,500 | Martian epoch | | Mars | Noachis Terra | |
| Noginskian | 300.5 | 299.0 ± 0.8 | age | Carboniferous | Russia | | Ivanova & Khovorova, 1955 |
| Nomentanan | 0.24 | 0.13 | age | Pleistocene | Italy | | |
| Nongshanian | 62.9 | 56.9 | ALMA | Paleocene | Asia | | Ting, 1998 |
| Norian | 216.5 ± 2.0 | 203.6 ± 1.5 | age | Triassic | ICS | Noric Alps (Austria) | Mojsisovics, 1869 |
| Northgrippian | 0.0082 | 0.0042 | age | Holocene | ICS | North Greenland Ice Core Project | |
| Nukumaruan | 3.1 | 1.8 | age | Pleistocene | New Zealand | Nukumaru | Fleming, 1953 |
| Nullaginian | 2,500 | 1,800 | age | Proterozoic | Australia | | Dunn et al., 1966 |
| Ochoan | | | age | Permian | North America | | Adams et al., 1939 |
| Odesan | 1.2 | 0.8 | age | Pleistocene | Eastern Europe | | |
| Okaian | 0.5 | 0.3 | sub-age | Ordovician | North America | | |
| Okehuan | 1.1 | 0.37 | age | Pleistocene | New Zealand | | Fleming, 1962 |
| Older Dryas | 13,480 BP | 13,350 BP | chron | Weichselian | Europe | Dryas octopetala (plant) | |
| Oldest Dryas | 13,860 | 13,780 | chron | Weichselian | Europe | Dryas octopetala (plant) | |
| Olenekian | 249.5 | 245.9 | age | Triassic | ICS | river Olenyok (Siberia) | Kiparisova & Popov, 1956 |
| Oligocene | 33.9 ± 0.1 | 23.03 | epoch | Paleogene | ICS | "not so recent" | Beyrich, 1857 |
| Onnian | 453 | 449 | age | Ordovician | regional | River Onny (England) | Bancroft, 1929 |
| Oostermeer Interglacial | 0.243 | 0.238 | age | Pleistocene | Netherlands | Oostermeer | |
| Opoitian | 5.0 | 3.8 | age | Pliocene | New Zealand | Opoiti | Fleming, 1959 |
| Ordian | 520 | 510 | age | Cambrian | Australia | | Öpik, 1968 |
| Ordovician | 488.3 ± 1.7 | 443.7 ± 1.5 | period | Paleozoic | ICS | Ordovices, Celtic tribe | Lapworth, 1879 |
| Orellan | 33.9 | 33.3 | age | Oligocene | North America | | Prothero & Emry, 1996 |
| Orleanian | 20.4 | 15 | ELMMZ | Miocene | Europe | Orléans (France) | Alberdi & Aguirre, 1977 |
| Orosirian | 2,050 | 1,800 | period | Proterozoic | ICS | | Plumb, 1991 |
| Osagean | | | age | Carboniferous | North America | | Branner, 1888 |
| Otaian | 21.7 | 19.0 | age | Miocene | New Zealand | Otaio | Fleming, 1959 |
| Ottnangian | 18.3 | 17.0 | age | Miocene | Paratethys | Ottnang am Hausruck (Austria) | Papp & Rögl, 1967 |
| Oxfordian | 161.2 ± 4.0 | 155.0 ± 4.0 | age | Jurassic | ICS | Oxford (England) | d'Orbigny, 1849 |
| Paibian | 501.0 ± 2.0 | 496 | age | Cambrian | ICS | Paibi (China) | Peng et al., 2004 |
| Paleoarchean | 3,600 | 3,200 | era | Archean | ICS | | Plumb, 1991 |
| Paleocene | 65.5 ± 0.3 | 55.8 ± 0.2 | epoch | Paleogene | ICS | oldest recent | Schimper, 1847 |
| Paleophytic | ~450 | ~270 | era | | paleobotany | old flora | |
| Paleogene | 65.5 ± 0.3 | 23.0 | period | Cenozoic | ICS | | Hoernes, 1856 |
| Paleoproterozoic | 2,500 | 1,600 | era | | ICS | | Hofmann, 1987 |
| Paleozoic | 542.0 ± 1.0 | 251.0 ± 0.7 | era | | ICS | old life | Sedwick, 1838 |
| Pannonian | 11.608 ± 0.005 | 7.246 ± 0.005 | age | Miocene | Paratethys | Pannonia (Roman province) | Roth von Telegd, 1879 |
| Pareora | 21.7 | 15.9 | epoch | Neogene | New Zealand | Pareora | Kingma, 1957 |
| Pastonian | ~1.87 | 1.77 | age | Pleistocene | Great Britain | Paston, Norfolk (England) | West & Wilson, 1966 |
| Payntonian | 491 | 488.3 ± 1.7 | age | Cambrian | Australia | | Jones, 1971 |
| Peligran | 62.5 | 59 | age | Paleocene | South America | | Bonaparte, 1993 |
| Pendleian | 326.4 ± 1.6 | 326 | age | Carboniferous | regional | Pendle Hill (England) | Hudson & Cotton, 1943 |
| Pennsylvanian | 318.1 ± 1.3 | 299.0 ± 0.8 | epoch | Carboniferous | ICS | Pennsylvania (US) | Williams, 1891 |
| Penutian | 53 | 51 | age | Eocene | California | | Mallory, 1959 |
| Permian | 299.0 ± 0.8 | 251.0 ± 0.4 | period | Paleozoic | ICS | Perm (Russia) | Murchison, 1849 |
| Phanerozoic | 542.0 ± 1.0 | present | eon | | ICS | visible life | Chadwick, 1930 |
| Piacenzian | 3.600 | 2.588 | age | Pliocene | ICS | Piacenza (Italy) | Mayer-Eymar, 1858 |
| Piripauan | 86.5 | 84 | age | Cretaceous | New Zealand | Piripaua | Wellman, 1959 |
| Pleistocene | 2.588 | 0.0117 | epoch | Quaternary | ICS | youngest recent | Lyell, 1833 |
| Pleniglacial | 73,000 BP | 14,500 BP | sub-age | Pleistocene | Northern Europe | | |
| Pliensbachian | 189.6 ± 1.5 | 183.0 ± 1.5 | age | Jurassic | ICS | Pliensbach (Germany) | Oppel, 1858 |
| Pliocene | 5.332 | 2.588 | epoch | Neogene | ICS | newer recent | Lyell, 1847 |
| Podolskian | 308 | 307.2 | age | Carboniferous | Russia | | Ivanov, 1926 |
| Poederlian | ~3.5 | ~2.5 | age | Pliocene | Belgium (obsolete) | Poederlee | Vincent, 1889 |
| Pontian | 7.246 ± 0.005 | 5.332 ± 0.005 | epoch | Miocene | Paratethys | Pontus Euxinus, Latin name for the Black Sea | Le Play, 1842 |
| Pontinian | 0.1 | 0.01 | age | Pleistocene | Italy | | Blanc, 1937 |
| Porangan | 46.2 | 43.0 | age | Eocene | New Zealand | Poranga | Hornibrook, 1961 |
| Portlandian | | | age | Jurassic | British Isles | Isle of Portland (England) | Brongniart, 1829 |
| Potsdamian | 501 ± 2 | 488.3 ± 1.7 | epoch | Cambrian | Germany | | Walcott, 1891 |
| Poundian | 570 | 542 ± 0.3 | age | Cambrian | Australia | | |
| Pragian | 411.2 ± 2.8 | 407.0 ± 2.8 | age | Devonian | ICS | Prague (Czech Republic) | Ziegler, 1979 |
| Preboreal | 11,560 BP | 10,640 BP | chron | | Northern Europe | before the Boreal | |
| Precambrian | none | 542.0 ± 1.0 | none (before: eon) | | worldwide | before the Cambrian | Logan, 1841 |
| Pre-Illinoian | | | age | Pleistocene | North America | before the Illinoian | Leverett, 1929 |
| Preludhamian | ~2.52 | ~2.61 | age | Plio-Pleistocene | Great Britain | before the Ludhamian | Funnell & West, 1977 |
| Prenectarian | 4567 | 3850 | period | | Moon | before the Nectarian | |
| Prepastonian | ~2.0 | ~1.87 | age | Pleistocene | Great Britain | before the Pastonian | West, 1980 |
| Pretiglian | 2.588 | 2.40 | super-age | Pleistocene | Netherlands | before the Tiglian Tegelen (The Netherlands) | Van der Vlerk, 1948 |
| Priabonian | 37.2 ± 0.1 | 33.9 ± 0.1 | age | Eocene | ICS | Priabona (Italy) | Munier-Chalmas & De Lapparent, 1893 |
| Pridoli(an) | 418.7 ± 2.7 | 416.0 ± 2.8 | epoch | Silurian | ICS | Přidoli (Czech Republic) | Prantl & Pribyl, 1948 |
| Proterozoic | 2,500 | 542.0 ± 1.0 | eon | | ICS | | Emmons, 1888 |
| Puercan | 65.5 | 63.3 | age | Paleocene-Cretaceous | North America | | Wood et al., 1941 |
| Purbeckian | | | age | Cretaceous-Jurassic | England (obsolete) | Isle of Purbeck (England) | Brongniart, 1829 |
| Pusgillian | 449 | 447.5 | age | Ordovician | Europe | Pus Gill, Cumbria (England) | Dean, 1959 |
| Putikian | 0.37 | 0.01 | age | Pleistocene | New Zealand | | Fleming, 1953 |
| Quaternary | 2.588 | present | period | Cenozoic | ICS | fourth part | Arduino, 1760 |
| Qungzusian | 532 | 523 | age | Cambrian | China | | |
| Rancholabrean | | | age | Pleistocene | North America | | Wood et al., 1941 |
| Randian | 3,000 | 2,500 | age | Archaean | South Africa | | Kent & Hughes, 1978 |
| Rawtheyan | 446.5 | 445.5 | age | Ordovician | Europe | River Rawthey (England) | Brenchley & Cocks, 1982 |
| Refugian | 35.0 | 33.5 | age | Oligo-Eocene | California | | Schenck & Kleinpell, 1936 |
| Reinbekian | | | age | Miocene | Northern Germany | | Van Couvering, 1977 |
| Relizian | 16.5 | 13.5 | age | Miocene | California | | Kleinpell, 1934 |
| Repettian | 2.9 | 2.2 | age | Plio-Pleistocene | California | | Natalnd, 1952 |
| Reuverian | 3.5 | 2.558 | chronozone | Pliocene | Northwest Europe | Reuver (The Netherlands) | Bifnot, 1972 |
| Rhaetian | 203.6 ± 1.5 | 199.6 ± 0.6 | age | Triassic | ICS | Rhaetian Alps (Switzerland, Austria, Italy) | Gümbel, 1862 |
| Rhuddanian | 443.7 ± 1.5 | 439.0 ± 1.8 | age | Silurian | ICS | Cwm-Rhuddian (Wales) | Cocks et al., 1971 |
| Rhyacian | 2,300 | 2,050 | period | Proterozoic | ICS | | Cowie 6 Basset, 1989 |
| Richmondian | 449 | 445.6 ± 1.5 | age | Ordovician | North America | | Winchell & Ulrich 1897 |
| Riochican | 57 | 54 | age | Eo-Paleocene | South America | | Simpson, 1940 |
| Riphean | 1,650 | 650 | age | Proterozoic | worldwide (obsolete) | | Shatsky, 1945 |
| Riss Glacial | 0.238 | 0.128 | age | Pleistocene | Alps | river Riß (Germany) | |
| Riss-Würm Interglacial | 0.128 | 0.116 | age | Pleistocene | Alps | | Penck, 1882 [Penck & Burckner, 1909] |
| Roadian | 270.6 ± 0.7 | 268.0 ± 0.7 | age | Permian | ICS | | Furnish, 1968 |
| Robiacian | 42.7 | 37.2 | ELMMZ | Miocene | Europe | | Savage & Russell, 1983 |
| Romanian | 3.6 | 1.8 | age | Plio-Pleistocene | Paratethys | | Krejci-Graf, 1932 |
| Rotliegend(-es) | 299 | 270.6 | sub-period | Permian | unofficial | German for "Red foot wall". | A traditional copper mining term in the Mansfelder Land for the red oreless sandstone below the Kupferschiefer. |
| Runangan | 36.0 | 34.3 | age | Eo-Oligocene | New Zealand | Runanga | Finlay et al., 1945 |
| Rupelian | 33.9 ± 0.1 | 28.4 ± 0.1 | age | Oligocene | ICS | river Rupel (Belgium) | Dumont, 1850 |
| Ruscinian | 4.9 | 3.5 | ELMMZ | Pliocene | Europe | Ruscino, Latin for the Roussillon (France) | Kretzoi, 1962 |
| Saalian | 0.238 | 0.128 | age | Pleistocene | Northern Europe | river Saale (Germany) | Stille, 1920 |
| Sakian | 494.5 | 493 | age | Cambrian | Russia, Kazakhstan | | Ergaliev, 1980 |
| Sakmarian | 294.6 ± 0.8 | 284.4 ± 0.7 | age | Permian | ICS | river Sakmara (Russia) | Karpinski, 1874 |
| Sandbian | 460.9 ± 1.6 | 455.8 ± 1.6 | age | Ordovician | ICS | Sandby, Sweden | Begstrom et al., 2003 |
| Sangamonian | 0.125 | 0.075 | age | Pleistocene | North America | | Leverett, 1898 |
| Santacrucian | 17.5 | 16.3 | age | Miocene | South America | | Ameghino, 1889 |
| Santomian | 1.81 | 1.5 | sub-age | Pleistocene | Italy | | |
| Santonian | 85.8 ± 0.7 | 83.5 ± 0.7 | age | Cretaceous | ICS | Saintes (France) | Coquand, 1873 |
| Sarmatian | 12.7 | 11.6 | age | Miocene | Paratethys | Sarmatians (ancient people) | Suess, 1866 |
| Saxonian | ~290 | ~258 | age | Permian | Europe (obsolete) | Saxony | Munier-Chalmas & Lapparent, 1893 |
| Saucesian | 22.0 | 16.5 | age | Miocene | California | | Kleinpell, 1938 |
| Scaldisian | ~4 | ~2.5 | age | Pliocene | Belgium (obsolete) | Scaldus, Latin name for the river Scheldt | Dumont, 1850 |
| Scythian | 251 ± 0.2 | 245 ± 1.5 | Epoch | Early Triassic | Europe | Scythia | Arthaber, 1895 |
| Selandian | 61.7 ± 0.2 | 58.7 ± 0.2 | age | Paleocene | ICS | Seeland (Denmark) | Rosenkrantz, 1924 |
| Senecan | 388 | 370 | age | Devonian | North America | | Clarke & Schuchert, 1898 |
| Senonian | 89.3 | 65.5 | epoch | Cretaceous | unofficial | Sens (France) | d'Orbigny, 1842 |
| Serpukhovian | 326.4 ± 1.6 | 318.1 ± 1.3 | age | Carboniferous | ICS | Serpukhov (Russia) | Nikitin, 1890 |
| Serravallian | 13.65 | 11.608 | age | Miocene | ICS | Serravalle Scrivia (Italy) | Pareto, 1864 |
| Sevatian | 206 | 202.3 ± 1.5 | sub-age | Triassic | Europe | | Mojsisovics, 1895 |
| Shanghuan | 65.5 | 62.9 | ALMA | Paleocene | Asia | | Ting & Li, 1983 |
| Shangsian | | 318.1 | age | Carboniferous | China | | Ting, 1931 |
| Shaodongian | 359.2 ± 2.5 | 349.5 | age | Carboniferous | China | | Hou, 1962 |
| Sharamurunian | 40.4 | 37.2 | ALMA | Eocene | Asia | | Russell & Zhai, 1987 |
| Sheinwoodian | 428.2 ± 2.3 | 426.2 ± 2.4 | age | Silurian | ICS | Sheinwood (England) | Basset et al., 1975 |
| Shermanian | 457 | 454 | age | Ordovician | regional | | Kay, 1937 |
| Shinulanian | 438 | 433 | age | Silurian | China | | Ting, 1930 |
| Sicilian | 0.781 | 0.260 | sub-age | Pleistocene | Italy | Sicily | Doderlein, 1872 |
| Siderian | 2,500 | 2,300 | period | Proterozoic | ICS | | Plumb, 1991 |
| Silesian | 326.4 | 299.0 | subperiod | Carboniferous | Europe | Silesia | Leckwijck, 1960 |
| Siegenian | | | age | Devonian | North America, Europe | | Kayser, 1885 |
| Silurian | 443.7 ± 1.5 | 416.0 ± 2.8 | period | Paleozoic | ICS | Silures, Celtic tribe | Murchison, 1835 |
| Sinemurian | 196.5 ± 1.0 | 189.6 ± 1.5 | age | Jurassic | ICS | Semur-en-Auxois (France) | d'Orbigny, 1842 |
| Sinian | 800 | 542 | age | Neoproterozoic | China | | Willis et al., 1907 |
| Soudleyan | 458 | 457 | age | Ordovician | regional | Soudley (England) | Bancroft, 1929 |
| Southland | 15.9 | 10.9 | epoch | Neogene | New Zealand | Southland Region | Kingma, 1965 |
| Springerian | | | age | Carboniferous | North America | | |
| St. David's | 513 ± 2 | 501 ± 2 | epoch | Cambrian | Europe (obsolete) | St Davids (Wales) | Cowie et al., 1972 |
| Stampian | | | age | Oligocene | western Europe | Étampes (France) | d'Orbigny, 1852 |
| Statherian | 1,800 | 1,600 | period | Proterozoic | ICS | | Plumb, 1991 |
| Stenian | 1,200 | 1,000 | period | Proterozoic | ICS | | Cowie & Basset, 1989 |
| Stephanian | 303.9 | 299.0 | age | Carboniferous | Europe | Saint-Étienne (France) | Mayer-Eymar, 1878 |
| Steptoan | 494.5 | 493 | age | Cambrian | North America | | Ludvigsen & westrop, 1985 |
| Streffordian | 452 | 449 | age | Ordovician | Europe | Strefford (England) | Williams et al., 1972 |
| Sturtian | ~730 | | age | Neoproterozoic | worldwide, unofficial | | Gregory, 1927 |
| Subatlantic | 2400 BP | 0 | chron | Holocene | Northern Europe | | Sernander, 1889 |
| Subboreal | 5660 BP | 2400 BP | chron | Holocene | Northern Europe | | Sernander, 1889 |
| Suchian | 3.0 | 1.9 | age | Plio-Pleistocene | Japan | | Ikebe, 1977 |
| Suevian | 33.8 | 29.2 | ELMMZ | Oligocene | Europe | | Tobien, 1980 |
| Sunwaptan | 493 | 491 | age | Cambrian | North America | | Ludvigsen & Westrop, 1985 |
| Susterian | 8.5 | 5.3 | chronozone | Miocene | Northwest Europe | Susteren (The Netherlands) | Van Der Hammenn et al., 1971 |
| Swazian | 4,000 | 3,000 | age | Archaean | South Africa | | Kent & Hughes, 1978 |
| Syltian | | | age | Miocene | Northern Germany | | Staesche, 1930 |
| Tabenbulakian | 24.0 | 23.03 | ALMA | Oligocene | Asia | | Meng & McKenna, 1998 |
| Tangbagouan | 359.2 | | age | Carboniferous | China | | Jin et al., 2000 |
| Taranaki | 10.9 | 5.28 | epoch | Neogene | New Zealand | Taranaki Region | Kingma, 1962 |
| Tarantian | 0.15 | 0.0115 | age | Pleistocene | Southern Europe | Tarento (Italy) | Castradori & Cita, 1995 |
| Tatarian | | | age | Permian | Russia | Tatarstan | Nikitin, 1887 |
| Taxandrian | 1.80 | 0.418 | super-age | Pleistocene | Netherlands (obsolete) | | Van Der Vlerk & Florschutz, 1950 |
| Tayloran | | | age | Cretaceous | south and west of the US | Taylor, Texas | Murray, 1961 |
| Telychian | 436.0 ± 1.9 | 428.2 ± 2.3 | age | Silurian | ICS | Pen-lan-Telych (Wales) | Cocks et al. 1973 |
| Templetonian | 510 | 508 | age | Cambrian | Australia | | Whitehouse, 1936 |
| Teratan | 89.1 | 86.5 | age | Cretaceous | New Zealand | Te Rata, Gisborne Region | Wellman, 1959 |
| Terreneuvian | 542.0 ± 1.0 | 521 | epoch | Cambrian | ICS | Terre-Neuve, French name for Newfoundland | Narbonne, 1987 |
| Tertiary | 65.5 ± 0.3 | 2.588 | sub-era | Cenozoic | worldwide | third part | Arduino, 1760 |
| Teurian | 65.0 | 55.5 | age | Paleocene | New Zealand | Te Uri | Hornibrook & Harrington, 1957 |
| Thanetian | 58.7 ± 0.2 | 55.8 ± 0.2 | age | Paleocene | ICS | Isle of Thanet (England) | Renevier, 1874 |
| Thuringian | 285 | 251 | age | Permian) | Europe (obsolete) | Thuringia (Germany) | Renevier, 1874 |
| Thurnian | ~2.25 | ~2.12 | age | Pleistocene | Great Britain | River Thurne (England} | West, 1961 |
| Tiffanian | 60.2 | 56.8 | age | Paleocene | North America | | Granger, 1917 |
| Tiglian | 2.40 | 1.80 | super-age | Pleistocene | Netherlands | Tegelen (The Netherlands) | Dubois, 1905 |
| Tinguirirican | 36 | 29 | age | Oligo-Eocene | South America | | Flynn & Wyss, 2004 |
| Tithonian | 150.8 ± 4.0 | 145.5 ± 4.0 | age | Jurassic | ICS | Tithon (Greek mythology) | Oppel, 1865 |
| Tiupampan | 64.5 | 62.5 | age | Paleocene | South America | Tiupampa | Marshall & de Muizon, 1988 |
| Toarcian | 183.0 ± 1.5 | 175.6 ± 2.0 | age | Jurassic | ICS | Thouars (France) | d'Orbigny, 1849 |
| Toyonian | 518.5 | 513.0 ± 2.0 | age | Cambrian | Russia, Kazakhstan | | Hill, 1964 |
| Tommotian | 534 | 530 | age | Cambrian | Russia, Kazakhstan | | Rozanov et al., 1966 |
| Tongaporutuan | 10.9 | 6.5 | age | Miocene | New Zealand | Tongaporutu, Taranaki Region | Fleming, 1959 |
| Tongrian | | | age | Oligocene | western Europe | | Dumont, 1839 |
| Tonian | 1,000 | 850 | period | Proterozoic | ICS | | Cowie & Bassler, 1989 |
| Torrejonian | 63.3 | 60.2 | age | Paleocene | North America | | wood et al., 1941 |
| Tortonian | 11.608 | 7.246 | age | Miocene | ICS | Tortona (Italy) | Mayer-Eymar, 1858 |
| Totomian | 3.6 | 3.0 | age | Pliocene | Japan | | Ikebe, 1977 |
| Tournaisian | 359.2 ± 2.5 | 345.3 ± 2.1 | age | Carboniferous | ICS | Tournai (Belgium) | Dumont, 1832 |
| Tozawan | 15.97 | 13.5 | age | Miocene | Japan | | Ikebe, 1977 |
| Treenean | 0.15 | 0.17 | chronozone | Pleistocene | Northwest Europe | | |
| Tremadoc(-ian) | 488.3 ± 1.7 | 478.6 ± 1.7 | epoch | Ordovician | ICS | Tremadoc Bay (Wales) | Sedgwick, 1846 |
| Trempealeauan | 492.5 | 488.3 ± 1.7 | age | Cambrian | North America | | |
| Trentonian | | | age | Carboniferous | North America | | |
| Triassic | 251.0 ± 0.4 | 199.6 ± 0.6 | period | Mesozoic | ICS | threefold | Von Alberti, 1834 |
| Tubantian | 0.116 | 0.0115 | age | Pleistocene | Netherlands (obsolete) | | Van der Vlerk & Florschütz, 1950 |
| Turolian | 8.7 | 4.9 | ELMMZ | Mio-Pliocene | Europe | Turolium, Latin for Teruel (Spain) | Crusafont, 1965 |
| Turonian | 93.5 ± 0.8 | 89.3 ± 1.0 | age | Cretaceous | ICS | Tours (France) | d'Orbigny, 1842 |
| Tuvalian | 222.5 | 217.4 ± 2.0 | sub-age | Triassic | Europe | | Mojsisovics, 1895 |
| Tyrrhenian | 0.26 | 0.01143 | sub-age | Pleistocene | Italy | Tyrrhenian Sea | Issel, 1914 |
| Ufimian | 268 | 270,6 | age | Permian | obsolete | | Netxaev, 1915 |
| Uintan | 46.2 | 42.0 | age | Eocene | North America | | Wood et al., 1941 |
| Ulangochuian | 37.2 | 35.1 | ALMA | Eocene | Asia | | Li & Ting, 1983 |
| Ulatisian | 51 | 48 | age | Eocene | California | | Mallory, 1959 |
| Ulsterian | | | age | Devonian | North America | | Clarke & Schuchert, 1898 |
| Undillian | 506 | 504 | age | Cambrian | Australia | | Opik, 1979 |
| Uquian | 3.0 | 1.2 | age | Plio-Pleistocene | South America | Uquia (Argentina) | Castellanos, 1923 |
| Urutawan | 108.4 | 103.3 | age | Cretaceous | New Zealand | Urutawa Hill | Wellman, 1959 |
| Vaalian | 2,500 | 2,050 | age | Proterozoic | South Africa | | Kent & Hugh, 1978 |
| Valanginian | 140.2 ± 3.0 | 136.4 ± 2.0 | age | Cretaceous | ICS | Valangin (Switzerland) | Desor, 1853 |
| Vallesian | 11.1 | 8.7 | ELMMZ | Miocene | Europe | The Vallès (Spain) | Crusafont, 1950 |
| Vendian | ~610 | 542.0 ± 1.0 | sub-era | Proterozoic | worldwide (obsolete) | | Murchison, 1835 |
| Venturian | 2.2 | 1.9 | age | Pleistocene | California | | Natland, 1953 |
| Vereiskian | 311.7 ± 1.1 | 309.2 | age | Carboniferous | Russia | | |
| Vierlandian | | | age | Miocene | Northern Germany | | |
| Vicksburgian | | | age | Oligocene | southern US | | Heilprin, 1882 |
| Villafranchian | 3.5 | 1.1 | ELMMZ | Plio-Pleistocene | Europe | | Pareto, 1865 |
| Virgilian | | | age | Carboniferous | North America | | Moore, 1932 |
| Visean | 345.3 ± 2.1 | 326.4 ± 1.6 | age | Carboniferous | ICS | Visé (Belgium) | Dumont, 1832 |
| Vraconian | | | sub-age | Cretaceous | regional | | Renevier, 1867 |
| Waalian | 1.45 | 1.20 | super-age | Pleistocene | Netherlands | river Waal | Zagwijn, 1960 |
| Waiauan | 12.7 | 10.9 | age | Miocene | New Zealand | Waiau River, Southland Region | Fleming, 1959 |
| Waipawan | 55.5 | 53.0 | age | Eocene | New Zealand | Waipawa | Hornibrook & Harrington, 1957 |
| Waipipian | 3.60 | 3.00 | age | Pliocene | New Zealand | Waipipi | Fleming, 1953 |
| Waitakian | 25.2 | 21.7 | age | Oligo-Miocene | New Zealand | Waitaki River | Fleming, 1959 |
| Waitotaran | 3.8 | 3.1 | sub-age | Pliocene | New Zealand | Waitōtara River | Fleming, 1953 |
| Waltonian | | ~2.52 | age | Pliocene | Great Britain | Walton-on-the-Naze | Harmer,1900 |
| Wanganui | 5.28 | present | epoch | Neogene-Quaternary | New Zealand | Whanganui | Kingma, 1962 |
| Wangerripian | | | age | Paleo-Eocene | Australia | | Singleton, 1953 |
| Warendian | 485 | 478.6 | age | Ordovician | Australia | | Jones et al., 1971 |
| Warthian | 0.15 | 0.13 | chronozone | Pleistocene | Northwest Europe | | |
| Wasatchian | 55.4 | 50.3 | age | Eocene | North America | | McGrew & Roehler, 1960 |
| Waucoban | | | epoch | Cambrian | North America | | Walcott, 1912 |
| Weichselian | 0.116 | 0.0115 | age | | Northern Europe | Weichsel, German name for the river Vistula (Poland) | Keilhack, 1926 |
| Wenlock(-ian) | 428.2 ± 2.3 | 422.9 ± 2.5 | epoch | Silurian | ICS | Much Wenlock (England) | Murchison, 1833 |
| Werrikooian | 1.00 | 1.806 | age | Pleistocene | Australia | | Hall & Pritchard, 1902 |
| Westphalian | 313.0 | 303.9 | age | Carboniferous | Europe | Westphalia (Germany) | de Lapparent & Munier-Chalmas, 1892 |
| Whaingaroan | 34.3 | 27.3 | age | Oligocene | New Zealand | Whaingaroa, Waikato Region | Finlay & Marwick, 1947 |
| Wheelerian | 1.9 | 0.01143 | age | Pleistocene | California | | Natland, 1953 |
| Whiterockian | 471.8 ± 1.6 | 462 | age | Ordovician | North America | | Cooper, 1956 |
| Whitlandian | 475 | 473.5 | age | Ordovician | Europe | Whitland (Wales) | Owens & Fortey, 1987 |
| Whitneyan | 33.3 | 30.8 | age | Oligocene | North America | | Wood, 1937 |
| Whitwellian | 426.2 ± 2.4 | 425.4 | age | Silurian | regional | Whitwell Coppice (England) | Bassett et al., 1975 |
| Wisconsinan | 0.075 | 0.01 | age | Pleistocene | North America | | Geikie, 1894 |
| Wolfcampian | | | age | Permian | North America | | Udden, 1917 |
| Wolstonian | 0.238 | 0.128 | age | Pleistocene | Great Britain | Wolston (England) | West & Donner, 1956 |
| Woodbinian | | | age | Cretaceous | Gulf and Atlantic coast of the US | | Murray, 1961 |
| Wordian | 268.0 ± 0.7 | 265.8 ± 0.7 | age | Permian | ICS | | Udden, 1916 |
| Wuchenghuangtuan | 2.4 | 1.2 | age | Pleistocene | China | | |
| Wuchiapingian | 260.4 ± 0.7 | 253.8 ± 0.7 | age | Permian | ICS | | Kaimera & Nakazawa, 1973 [Sheng, 1962] |
| Wuliuan | 509 | 504.5 | age | Cambrian | ICS | | |
| Würm Glacial | 0.116 | 0.0115 | age | Pleistocene | Alps | river Würm (Germany) | Penck & Bruckner, 1909 |
| Wutaian | 2,600 | 2,350 | age | Archaean-Proterozoic | China | | Zhang, 1951 |
| Xiaodushanian | | 299 | age | Carboniferous | China | | zhou et al., 1987 |
| Xiushanian | 429 | 425.5 | age | Silurian | China | | Ge, 1980 |
| Yanguan | 349.5 | 345 | age | Carboniferous | China | | |
| Yarmouthian | 0.26 | 0.17 | age | Pleistocene | North America | Aegean Sea | Leverett, 1898 |
| Yatalan | 3.4 | 2.0 | age | Plio-Pleistocene | Australia | | Ludbrook, 1963 |
| Yeadonian | 315.5 | 314.5 | age | Carboniferous | regional | Yeadon (England) | Hudson, 1945 |
| Younger Dryas | 12,700 BP | 11,560 BP | chron | Weichselian | Northern Europe | Dryas octopetala (plant) | |
| Ypeenian | 470 | 468.1 | age | Ordovician | Australia | | |
| Ypresian | 55.8 ± 0.2 | 48.6 ± 0.2 | age | Eocene | ICS | Ypres, French name for Ieper (Ieper) in Belgium | Dumont, 1849 |
| Ynezian | 61.5 | 55.8 | age | Paleocene | California | | Mallory, 1959 |
| Yuian | 9.5 | 3.6 | age | Plio-Miocene | Japan | | Ikebe, 1977 |
| Yurmatian | 1,375 | 1,100 | age | Proterozoic | Russia | | Keller, 1952 |
| Yuzanjian | 1.5 | 0.75 | age | Pleistocene | Japan | | Ikebe, 1977 |
| Zanclean | 5.332 | 3.60 | age | Pliocene | ICS | Zancla, old name for Messina (Italy) | Sequenza, 1868 |
| Zechstein | ±270 | ±250 | sub-period | Permian | Europe (unofficial) | | Lehmann, 1756 |
| Zemorrian | 33.5 | 22.0 | age | Oligo-Miocene | California | | Kleinpell, 1938 |
| Zhungxian | 505 | 501 | age | Cambrian | China | | |
| Zuzhungian | 509 | 503 | age | Cambrian | China | | |