GSA GEOLOGIC TIME SCALE v. 5.0 C5A 5B C5B 5C C5C 5D C5D 20 5E C5E 6 C6 SERRAVALLIAN 15.97 12 13 18 19 C18 20 C20 45 21 50 C21 22 C22 23 130 140 150 RUPELIAN 37.8 170 BARTONIAN 41.2 LUTETIAN 180 190 47.8 YPRESIAN 60 27 C27 28 C28 65 29 C29 30 C30 PALEOCENE C26 ~113 320 APTIAN EARLY BARREMIAN HAUTERIVIAN ~125 340 ~129.4 ~132.9 ~139.8 HIST CHRON. TITHONIAN M22 LATE MIDDLE KIMMERIDGIAN OXFORDIAN CALLOVIAN BATHONIAN BAJOCIAN AALENIAN ~152.1 380 ~157.3 ~163.5 ~166.1 ~168.3 ~170.3 ~174.1 400 420 440 ~190.8 SINEMURIAN HETTANGIAN ~199.3 ~201.3 460 220 THANETIAN 59.2 230 SELANDIAN 61.6 240 DANIAN 66.0 250 ~208.5 480 LATE 500 CARNIAN ANISIAN EARLY OLENEKIAN INDUAN EARLY BASHKIRIAN LATE SERPUKHOVIAN MIDDLE VISEAN EARLY TOURNAISIAN LATE ~237 520 ~242 247.2 251.2 251.90 EON MIDDLE 259.1 265.1 268.8 272.95 ~283.5 1250 315.2 323.2 1500 330.9 346.7 NEOPROTEROZOIC 750 1000 290.1 295.0 298.9 303.7 307.0 1750 358.9 ~372.2 GIVETIAN EIFELIAN ERA ~382.7 ~387.7 ~393.3 2000 PRIDOLI LUDLOW WENLOCK LLANDOVERY LATE MIDDLE EARLY Epoch 3 Epoch 2 TERRENEUVIAN LUDFORDIAN GORSTIAN HOMERIAN SHEINWOODIAN TELYCHIAN AERONIAN RHUDDANIAN HIRNANTIAN KATIAN SANDBIAN DARRIWILIAN DAPINGIAN FLOIAN TREMADOCIAN AGE 10 JIANGSHANIAN PAIBIAN GUZHANGIAN DRUMIAN AGE 5 AGE 4 AGE 3 AGE 2 ~407.6 ~410.8 ~419.2 ~423.0 ~425.6 ~427.4 ~430.5 ~433.4 ~438.5 ~440.8 ~443.8 ~445.2 ~453.0 ~458.4 ~467.3 ~470.0 635 720 1000 1200 MESOPROTEROZOIC ECTASIAN 1400 CALYMMIAN 1600 STATHERIAN 1800 OROSIRIAN PALEOPROTEROZOIC 2050 RHYACIAN 2300 SIDERIAN 2500 2500 NEOARCHEAN 2750 2800 3000 3250 3500 MESOARCHEAN 3200 PALEOARCHEAN 3600 3750 EOARCHEAN ~521 ~529 FORTUNIAN 540 541 TONIAN 2250 ~477.7 ~485.4 ~489.5 ~494 ~497 ~500.5 ~504.5 ~509 ~514 CRYOGENIAN BDY. AGES (Ma) STENIAN EMSIAN PRAGIAN PERIOD EDIACARAN FRASNIAN FURONGIAN ~227 MIDDLE MOSCOVIAN AGE (Ma) 251.90 254.14 FAMENNIAN NORIAN LADINIAN SAKMARIAN ASSELIAN GZHELIAN KASIMOVIAN LOCHKOVIAN ~182.7 PLIENSBACHIAN LATE PICKS (Ma) ARTINSKIAN MIDDLE EARLY TOARCIAN EARLY Cisuralian 360 ~145.0 200 210 56.0 C25 300 RHAETIAN C24 25 280 93.9 100.5 BERRIASIAN 160 PRIABONIAN 83.6 86.3 89.8 ALBIAN VALANGINIAN M25 33.9 C23 26 CENOMANIAN M12 M14 M16 M18 M20 M29 24 55 M0r M1 M3 M5 TURONIAN M10 27.82 C17 C19 120 CHATTIAN C13 15 C15 16 C16 17 40 C12 EOCENE 35 C11 PALEOGENE 30 OLIGOCENE TERTIARY 10 C10 11 110 BURDIGALIAN 23.03 7 C7 7A C7A 8 C8 34 C34 LANGHIAN 6C C6C C9 100 AQUITANIAN 6B C6B 9 13.82 20.44 6A C6A 25 90 11.63 SANTONIAN CONIACIAN PERMIAN TORTONIAN LATE Guadalupian CHANGHSINGIAN WUCHIAPINGIAN CAPITANIAN WORDIAN ROADIAN KUNGURIAN PRECAMBRIAN PROTEROZOIC 15 C5 260 CAMPANIAN PENNSYLVANIAN 5A C4A C33 80 7.246 Lopingian 72.1 33 AGE 66.0 MISSISSIPPIAN 5 MIOCENE 10 NEOGENE 4A C4 5.333 MAASTRICHTIAN 32 C32 CARBONIFEROUS MESSINIAN 3A C3A 4 ZANCLEAN 30 C30 31 C31 AGE PERIOD EPOCH (Ma) DEVONIAN PLIOCENE C3 70 PICKS (Ma) ORDOVICIAN SILURIAN 3 0.012 1.8 2.58 3.600 AGE PALEOZOIC CAMBRIAN 5 CALABRIAN GELASIAN PIACENZIAN PERIOD EPOCH CRETACEOUS 2A C2A AGE (Ma) JURASSIC HOLOCENE QUATERNARY PLEISTOCENE* PICKS (Ma) TRIASSIC C1 C2 AGE RAPID POLARITY CHANGES 1 2 EPOCH ANOM. PERIOD CHRON. HIST. ANOM. AGE (Ma) MAGNETIC POLARITY ARCHEAN MESOZOIC CENOZOIC MAGNETIC POLARITY 541.0 4000 4000 HADEAN Walker, J.D., Geissman, J.W., Bowring, S.A., and Babcock, L.E., compilers, 2018, Geologic Time Scale v. 5.0: Geological Society of America, https://doi.org/10.1130/2018.CTS005R3C. ©2018 The Geological Society of America *The Pleistocene is divided into four ages, but only two are shown here. What is shown as Calabrian is actually three ages—Calabrian from 1.80 to 0.781 Ma, Middle from 0.781 to 0.126 Ma, and Late from 0.126 to 0.0117 Ma. The Cenozoic, Mesozoic, and Paleozoic are the Eras of the Phanerozoic Eon. Names of units and age boundaries usually follow the Gradstein et al. (2012), Cohen et al. (2012) , and Cohen et al. (2013, updated) compilations. Numerical age estimates and picks of boundaries usually follow the Cohen et al. (2013, updated) compilation. The numbered epochs and ages of the Cambrian are provisional. A “~” before a numerical age estimate typically indicates an associated error of ±0.4 to over 1.6 Ma. REFERENCES CITED Cohen, K.M., Finney, S., and Gibbard, P.L., 2012, International Chronostratigraphic Chart: International Commission on Stratigraphy, www.stratigraphy.org (accessed May 2012). (Chart reproduced for the 34th International Geological Congress, Brisbane, Australia, 5–10 August 2012.) Cohen, K.M., Finney, S.C., Gibbard, P.L., and Fan, J.-X., 2013, The ICS International Chronostratigraphic Chart: Episodes v. 36, no. 3, p. 199–204 (updated 2017, v. 2, http://www.stratigraphy.org/index.php/ics-chart-timescale; accessed May 2018). Gradstein, F.M, Ogg, J.G., Schmitz, M.D., et al., 2012, The Geologic Time Scale 2012: Boston, USA, Elsevier, https://doi.org/10.1016/B978-0-444-59425-9.00004-4. Previous versions of the time scale and previously published papers about the time scale and its evolution are posted to http://www.geosociety.org/timescale.