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INTERNATIONAL STRATIGRAPHIC CHART ICS International Commission on Ma Ma Ma Ma Era Era Era Age Age Age Age Eon Eon Age Eon Age Eon Stage Stage GSSP GSSP GSSA GSSP GSSP Series Epoch Series Epoch Period Period Period Period System System System Erathem Erathem Erathem Eonothem Eonothem 145.5 ±4.0 Eonothem 359.2 ±2.5 542 0.0118 150.8 ±4.0 Upper 374.5 ±2.6 Neo- ~630 Upper Upper 0.126 155.6 385.3 ±2.6 850 Middle 0.781 161.2 ±4.0 Middle 391.8 ±2.7 1000 Lower * 1.806 164.7 ±4.0 397.5 ±2.7 Meso- 1200 proterozoic 2.588 Middle 167.7 ±3.5 407.0 ±2.8 1400 Lower 3.600 171.6 ±3.0 411.2 ±2.8 1600 5.332 175.6 ±2.0 416.0 ±2.8 Proterozoic 1800 Pridoli Paleo- 7.246 183.0 ±1.5 418.7 ±2.7 2050 proterozoic 11.608 Lower 189.6 ±1.5 Ludlow 421.3 ±2.6 2300 13.82 196.5 ±1.0 422.9 ±2.5 2500

Neogene 15.97 199.6 ±0.6 Wenlock 426.2 ±2.4 M e s o z i c 20.43 203.6 ±1.5 428.2 ±2.3 2800 Upper r e c a m b i n P 23.03 216.5 ±2.0 436.0 ±1.9 C e n o z i c Llandovery 28.4 ±0.1 228.7 439.0 ±1.8 3200 33.9 ±0.1 Middle 237.0 ±2.0 443.7 ±1.5 37.2 ±0.1 245.9 445.6 ±1.5 3600 Upper 40.4 ±0.2 Lower 249.7 ±0.7 455.8 ±1.6 Lower limit is not defined 48.6 ±0.2 251.0 ±0.4 460.9 ±1.6

Ypresian a l e o z i c P 55.8 ±0.2 468.1 ±1.6 P h a n e r o z i c P h a n e r o z i c P 253.8 ±0.7 h a n e r o z i c P Middle Subdivisions of the global are 58.7 ±0.2 260.4 ±0.7 471.8 ±1.6 formally defined by their lower boundary. Each unit of the (~542 Ma to ) and the 61.1 265.8 ±0.7 Lower 478.6 ±1.7 base of Ediacaran are defined by a basal Global Standard Section and Point (GSSP ), whereas 65.5 ±0.3 268.0 ±0.7 488.3 ±1.7 Stage 10 units are formally subdivided by 70.6 ±0.6 270.6 ±0.7 ~ 492.0 * absolute age (Global Standard Stratigraphic Age, Stage 9 GSSA). Details of each GSSP are posted on the 83.5 ±0.7 275.6 ±0.7 ~ 496.0 * ICS website (www.stratigraphy.org). International chronostratigraphic units, rank, Upper 85.8 ±0.7 284.4 ±0.7 501.0 ±2.0 names and formal status are approved by the 88.6 294.6 ±0.8 ~ 503.0 * International Commission on Stratigraphy (ICS) Series 3 and ratified by the International Union of Geological 93.5 ±0.8 299.0 ±0.8 ~ 506.5 * Sciences (IUGS). Stage 5 99.6 ±0.9 Upper 303.9 ±0.9 ~ 510.0 * Numerical ages of the unit boundaries in the P a l e o z i c P Stage 4 Phanerozoic are subject to revision. Some stages 112.0 ±1.0 306.5 ±1.0 Series 2 ~ 517.0 * within the Ordovician and Cambrian will be formally

Aptian Penn- Middle Moscovian Stage 3 named upon international agreement on their GSSP 125.0 ±1.0 sylvanian 311.7 ±1.1 ~ 521.0 * M e s o z i c limits. Most sub-Series boundaries (e.g., Middle Lower Stage 2 Lower 130.0 ±1.5 318.1 ±1.3 ~ 534.6 * and Upper ) are not formally defined. Colors are according to the Commission for the Upper 542.0 ±1.0 133.9 326.4 ±1.6 Geological Map of the World (www.cgmw.org). Middle Visean This chart was drafted by Gabi Ogg. Intra Cambrian unit ages The listed numerical ages are from 'A Geologic 140.2 ±3.0 345.3 ±2.1 Missis- sippian with * are informal, and awaiting ratified definitions. Lower Scale 2004', by F.M. Gradstein, J.G. Ogg, 145.5 ±4.0 359.2 ±2.5 Copyright © 2007 International Commission on Stratigraphy A.G. Smith, et al. (2004; Cambridge University Press). * The status of the Quaternary is not yet decided. Its base may be assigned as the base of the Gelasian and extend the base of the Pleistocene to 2.6 Ma.