stable

Name	Notation	Description	Types	Status
Present	0		era boundary , Concept , geochronologic boundary	stable
Base of Precambrian	1001		era boundary , Concept , geochronologic boundary	stable
Base of Archean	1007		era boundary , Concept , geochronologic boundary	stable
Base of Paleoarchean	1009		era boundary , Concept , geochronologic boundary	stable
Base of Mesoarchean	1010		Concept , era boundary , geochronologic boundary	stable
Base of Neoarchean	1011		era boundary , geochronologic boundary , Concept	stable
Base of Proterozoic	1012		geochronologic boundary , Concept , era boundary	stable
Base of Rhyacian	1015		geochronologic boundary , Concept , era boundary	stable
Base of Orosirian	1016		era boundary , Concept , geochronologic boundary	stable
Base of Statherian	1017		Concept , geochronologic boundary , era boundary	stable
Base of Mesoproterozoic	1018		geochronologic boundary , era boundary , Concept	stable
Base of Ectasian	1020		geochronologic boundary , era boundary , Concept	stable
Base of Stenian	1021		Concept , geochronologic boundary , era boundary	stable
Base of Neoproterozoic	1022		Concept , era boundary , geochronologic boundary	stable
Base of Cryogenian	1024		era boundary , Concept , geochronologic boundary	stable
Base of Ediacaran	1025		era boundary , Concept , geochronologic boundary	stable
Base of Upper Edicaran	1027		Concept , geochronologic boundary , era boundary	stable
Base of Phanerozoic	1028		geochronologic boundary , Concept , era boundary	stable
Base of Tommotian	1033		geochronologic boundary , era boundary , Concept	stable
Base of Lenian	1035		geochronologic boundary , era boundary , Concept	stable
Base of Amgaian	1037		era boundary , Concept , geochronologic boundary	stable
Base of Mayaian	1038		era boundary , geochronologic boundary , Concept	stable
Base of Jiangshanian	1041		geochronologic boundary , Concept , era boundary	stable
Base of Stage10	1042		geochronologic boundary , era boundary , Concept	stable
Base of Ordovician	1043		Concept , geochronologic boundary , era boundary	stable
Base of Middle Ordovician	1047		Concept , geochronologic boundary , era boundary	stable
Base of Llanvirn	1048		Concept , geochronologic boundary , era boundary	stable
Base of Llandeilo	1049		geochronologic boundary , Concept , era boundary	stable
Base of Upper Ordovician	1050		era boundary , geochronologic boundary , Concept	stable
Base of Ashgill	1054		geochronologic boundary , era boundary , Concept	stable
Base of Lower Ashgill	1055		Concept , geochronologic boundary , era boundary	stable
Base of Silurian	1057		geochronologic boundary , Concept , era boundary	stable
Base of Aeronian	1060		era boundary , geochronologic boundary , Concept	stable
Base of Telychian	1061		era boundary , Concept , geochronologic boundary	stable
Base of Wenlock	1062		era boundary , Concept , geochronologic boundary	stable
Base of Homerian	1064		era boundary , geochronologic boundary , Concept	stable
Base of Ludlow	1065		era boundary , Concept , geochronologic boundary	stable
Base of Ludfordian	1067		Concept , geochronologic boundary , era boundary	stable
Base of Pridoli	1068		era boundary , Concept , geochronologic boundary	stable
Base of Devonian	1070		era boundary , Concept , geochronologic boundary	stable
Base of Upper Lochkovian	1074		era boundary , Concept , geochronologic boundary	stable
Base of Pragian	1075		era boundary , Concept , geochronologic boundary	stable
Base of Upper Pragian	1077		era boundary , Concept , geochronologic boundary	stable
Base of Emsian	1078		era boundary , geochronologic boundary , Concept	stable
Base of Upper Emsian	1080		era boundary , geochronologic boundary , Concept	stable
Base of Middle Devonian	1081		geochronologic boundary , Concept , era boundary	stable
Base of Upper Eifelian	1084		era boundary , Concept , geochronologic boundary	stable
Base of Givetian	1085		geochronologic boundary , Concept , era boundary	stable
Base of Upper Givetian	1087		geochronologic boundary , Concept , era boundary	stable
Base of Upper Devonian	1088		Concept , geochronologic boundary , era boundary	stable
Base of Upper Frasnian	1091		era boundary , Concept , geochronologic boundary	stable
Base of Famennian	1092		geochronologic boundary , Concept , era boundary	stable
Base of Upper Famennian	1094		geochronologic boundary , Concept , era boundary	stable
Base of Carboniferous	1095		Concept , geochronologic boundary , era boundary	stable
Base of Upper Tournaisian	1099		geochronologic boundary , Concept , era boundary	stable
Base of Upper Visean	1102		era boundary , geochronologic boundary , Concept	stable
Base of Namurian C	1107		era boundary , geochronologic boundary , Concept	stable
Base of Westphalian	1108		Concept , era boundary , geochronologic boundary	stable
Base of Westphalian A	1109		era boundary , geochronologic boundary , Concept	stable
Base of Westphalian B	1110		era boundary , geochronologic boundary , Concept	stable
Base of Westphalian D	1112		era boundary , Concept , geochronologic boundary	stable
Base of Stephanian A	1114		era boundary , geochronologic boundary , Concept	stable
Base of Stephanian B	1115		era boundary , Concept , geochronologic boundary	stable
Base of Permian	1117		Concept , geochronologic boundary , era boundary	stable
Base of Mesozoic	1124		Concept , geochronologic boundary , era boundary	stable
Base of Olenekian	1128		era boundary , Concept , geochronologic boundary	stable
Base of Upper Olenekian	1130		Concept , geochronologic boundary , era boundary	stable
Base of Middle Triassic	1131		geochronologic boundary , Concept , era boundary	stable
Base of Upper Anisian	1134		era boundary , geochronologic boundary , Concept	stable
Base of Ladinian	1135		Concept , era boundary , geochronologic boundary	stable
Base of Upper Ladinian	1137		Concept , era boundary , geochronologic boundary	stable
Base of Upper Triassic	1138		Concept , geochronologic boundary , era boundary	stable
Base of Upper Carnian	1141		era boundary , geochronologic boundary , Concept	stable
Base of Norian	1142		Concept , geochronologic boundary , era boundary	stable
Base of Upper Norian	1144		geochronologic boundary , era boundary , Concept	stable
Base of Rhaetian	1145		era boundary , Concept , geochronologic boundary	stable
Base of Upper Rhaetian	1147		era boundary , geochronologic boundary , Concept	stable
Base of Jurassic	1148		geochronologic boundary , Concept , era boundary	stable
Base of Middle Hettangian	1152		era boundary , Concept , geochronologic boundary	stable
Base of Upper Hettangian	1153		era boundary , Concept , geochronologic boundary	stable
Base of Sinemurian	1154		Concept , era boundary , geochronologic boundary	stable
Base of Upper Sinemurian	1156		geochronologic boundary , era boundary , Concept	stable
Base of Pliensbachian	1157		Concept , era boundary , geochronologic boundary	stable
Base of Upper Pliensbachian	1159		Concept , era boundary , geochronologic boundary	stable
Base of Toarcian	1160		era boundary , Concept , geochronologic boundary	stable
Base of Middle Toarcian	1162		era boundary , Concept , geochronologic boundary	stable
Base of Upper Toarcian	1163		Concept , era boundary , geochronologic boundary	stable
Base of Middle Aalenian	1167		geochronologic boundary , Concept , era boundary	stable
Base of Upper Aalenian	1168		era boundary , Concept , geochronologic boundary	stable
Base of Bajocian	1169		geochronologic boundary , Concept , era boundary	stable
Base of Upper Bajocian	1171		Concept , geochronologic boundary , era boundary	stable
Base of Bathonian	1172		era boundary , geochronologic boundary , Concept	stable
Base of Middle Bathonian	1174		era boundary , geochronologic boundary , Concept	stable
Base of Upper Bathonian	1175		Concept , geochronologic boundary , era boundary	stable
Base of Callovian	1176		geochronologic boundary , Concept , era boundary	stable
Base of Middle Callovian	1178		Concept , era boundary , geochronologic boundary	stable
Base of Upper Callovian	1179		era boundary , geochronologic boundary , Concept	stable
Base of Middle Oxfordian	1183		era boundary , Concept , geochronologic boundary	stable
Base of Upper Oxfordian	1184		era boundary , geochronologic boundary , Concept	stable
Base of Kimmeridgian	1185		era boundary , Concept , geochronologic boundary	stable
Base of Upper Kimmeridgian	1187		era boundary , Concept , geochronologic boundary	stable
Base of Tithonian	1188		geochronologic boundary , Concept , era boundary	stable
Base of Middle Tithonian	1190		Concept , geochronologic boundary , era boundary	stable
Base of Upper Tithonian	1191		era boundary , geochronologic boundary , Concept	stable
Base of Cretaceous	1192		Concept , geochronologic boundary , era boundary	stable
Base of Middle Berriasian	1197		Concept , geochronologic boundary , era boundary	stable
Base of Upper Berriasian	1198		geochronologic boundary , era boundary , Concept	stable
Base of Valanginian	1199		geochronologic boundary , era boundary , Concept	stable
Base of Upper Valanginian	1201		Concept , geochronologic boundary , era boundary	stable
Base of Hauterivian	1202		Concept , geochronologic boundary , era boundary	stable
Base of Upper Hauterivian	1204		era boundary , Concept , geochronologic boundary	stable
Base of Barremian	1205		geochronologic boundary , Concept , era boundary	stable
Base of Upper Barremian	1207		Concept , geochronologic boundary , era boundary	stable
Base of Aptian	1208		geochronologic boundary , Concept , era boundary	stable
Base of Upper Aptian	1211		Concept , geochronologic boundary , era boundary	stable
Base of Albian	1212		geochronologic boundary , Concept , era boundary	stable
Base of Middle Albian	1214		geochronologic boundary , Concept , era boundary	stable
Base of Upper Albian	1215		Concept , geochronologic boundary , era boundary	stable
Base of Upper Cretaceous	1216		Concept , era boundary , geochronologic boundary	stable
Base of Middle Cenomanian	1219		geochronologic boundary , Concept , era boundary	stable
Base of Upper Cenomanian	1220		geochronologic boundary , Concept , era boundary	stable
Base of Turonian	1221		geochronologic boundary , era boundary , Concept	stable
Base of Middle Turonian	1223		Concept , geochronologic boundary , era boundary	stable
Base of Upper Turonian	1224		geochronologic boundary , era boundary , Concept	stable
Base of Coniacian	1226		geochronologic boundary , era boundary , Concept	stable
Base of Middle Coniacian	1228		geochronologic boundary , era boundary , Concept	stable
Base of Upper Coniacian	1229		era boundary , Concept , geochronologic boundary	stable
Base of Santonian	1230		geochronologic boundary , Concept , era boundary	stable
Base of Middle Santonian	1232		geochronologic boundary , Concept , era boundary	stable
Base of Upper Santonian	1233		geochronologic boundary , Concept , era boundary	stable
Base of Campanian	1234		Concept , geochronologic boundary , era boundary	stable
Base of Middle Campanian	1236		geochronologic boundary , Concept , era boundary	stable
Base of Upper Campanian	1237		Concept , era boundary , geochronologic boundary	stable
Base of Maastrichtian	1238		geochronologic boundary , Concept , era boundary	stable
Base of Upper Maastrichtian	1240		era boundary , Concept , geochronologic boundary	stable
Base of Cenozoic	1241		era boundary , geochronologic boundary , Concept	stable
Base of Selandian	1247		Concept , era boundary , geochronologic boundary	stable
Base of Thanetian	1248		era boundary , geochronologic boundary , Concept	stable
Base of Eocene	1249		era boundary , geochronologic boundary , Concept	stable
Base of Upper Ypresian	1253		Concept , era boundary , geochronologic boundary	stable
Base of Lutetian	1255		Concept , era boundary , geochronologic boundary	stable
Base of Middle Lutetian	1257		Concept , era boundary , geochronologic boundary	stable
Base of Upper Lutetian	1258		era boundary , Concept , geochronologic boundary	stable
Base of Bartonian	1259		geochronologic boundary , Concept , era boundary	stable
Base of Upper Bartonian	1261		geochronologic boundary , era boundary , Concept	stable
Base of Priabonian	1263		geochronologic boundary , Concept , era boundary	stable
Base of Oligocene	1264		geochronologic boundary , era boundary , Concept	stable
Base of Chattian	1268		era boundary , geochronologic boundary , Concept	stable
Base of Neogene	1269		era boundary , Concept , geochronologic boundary	stable
Base of Upper Aquitanian	1274		geochronologic boundary , era boundary , Concept	stable
Base of Burdigalian	1275		era boundary , geochronologic boundary , Concept	stable
Base of Upper Burdigalian	1277		era boundary , Concept , geochronologic boundary	stable
Base of Langhian	1279		era boundary , geochronologic boundary , Concept	stable
Base of Serravallian	1280		geochronologic boundary , Concept , era boundary	stable
Base of Tortonian	1282		Concept , era boundary , geochronologic boundary	stable
Base of Messinian	1283		era boundary , geochronologic boundary , Concept	stable
Base of Pliocene	1284		Concept , era boundary , geochronologic boundary	stable
Base of Piacenzian	1288		geochronologic boundary , era boundary , Concept	stable
Base of Quaternary	1289		era boundary , geochronologic boundary , Concept	stable
Base of Praetiglian	1292		geochronologic boundary , Concept , era boundary	stable
Base of Tiglian	1293		Concept , geochronologic boundary , era boundary	stable
Base of Eburonian	1294		Concept , era boundary , geochronologic boundary	stable
Base of Waalian	1295		Concept , era boundary , geochronologic boundary	stable
Base of Menapian	1296		Concept , era boundary , geochronologic boundary	stable
Base of Bavelian	1297		era boundary , geochronologic boundary , Concept	stable
Base of Cromerian	1298		era boundary , Concept , geochronologic boundary	stable
Base of Middle Pleistocene	1299		geochronologic boundary , Concept , era boundary	stable
Base of Cromerian I	1301		era boundary , Concept , geochronologic boundary	stable
Base of Glacial a	1302		era boundary , geochronologic boundary , Concept	stable
Base of Cromeriann II	1303		era boundary , Concept , geochronologic boundary	stable
Base of Glacial b	1304		era boundary , Concept , geochronologic boundary	stable
Base of Cromerian III	1305		geochronologic boundary , Concept , era boundary	stable
Base of Glacial c	1306		era boundary , Concept , geochronologic boundary	stable
Base of Cromerian IV	1307		era boundary , geochronologic boundary , Concept	stable
Base of Elsterian	1308		era boundary , Concept , geochronologic boundary	stable
Base of Holsteinian	1309		era boundary , geochronologic boundary , Concept	stable
Base of Saalian	1310		Concept , geochronologic boundary , era boundary	stable
Base of Fuhne	1311		geochronologic boundary , era boundary , Concept	stable
Base of Wacken/Dömnitz	1312		geochronologic boundary , Concept , era boundary	stable
Base of Drenthe	1313		era boundary , Concept , geochronologic boundary	stable
Base of Saale/Warthe	1314		geochronologic boundary , Concept , era boundary	stable
Base of Warthe	1315		era boundary , Concept , geochronologic boundary	stable
Base of Upper/Late Pleistocene	1316		geochronologic boundary , era boundary , Concept	stable
Base of Weichselian	1318		geochronologic boundary , era boundary , Concept	stable
Base of Early Weichselian	1319		era boundary , geochronologic boundary , Concept	stable
Base of Middle Weichselian	1320		Concept , geochronologic boundary , era boundary	stable
Base of Lower Pleniglacial	1321		era boundary , Concept , geochronologic boundary	stable
Base of Interpleniglacial	1322		geochronologic boundary , era boundary , Concept	stable
Base of Upper Weichselian	1323		Concept , geochronologic boundary , era boundary	stable
Base of Upper Pleniglacial	1324		geochronologic boundary , era boundary , Concept	stable
Base of Late Glacial	1325		geochronologic boundary , Concept , era boundary	stable
Base of Holocene	1326		geochronologic boundary , era boundary , Concept	stable
Base of Boreal	1328		Concept , geochronologic boundary , era boundary	stable
Base of Atlantic	1329		geochronologic boundary , era boundary , Concept	stable
Base of Subboreal	1330		era boundary , Concept , geochronologic boundary	stable
Base of Subatlantic	1331		geochronologic boundary , Concept , era boundary	stable
Base of Icartian	2002		era boundary , geochronologic boundary , Concept	stable
Base of Paleo-proterozoic	2003		Concept , geochronologic boundary , era boundary	stable
Base of Sturtian	2007		Concept , geochronologic boundary , era boundary	stable
Base of Vendian	2008		geochronologic boundary , era boundary , Concept	stable
Base of Stage2	2014		Concept , geochronologic boundary , era boundary	stable
Base of Series2	2016		geochronologic boundary , era boundary , Concept	stable
Base of Stage4	2018		geochronologic boundary , era boundary , Concept	stable
Base of Miaolingian	2019		Concept , geochronologic boundary , era boundary	stable
Base of Drumian	2021		geochronologic boundary , era boundary , Concept	stable
Base of Guzhangian	2022		era boundary , Concept , geochronologic boundary	stable
Base of Furongian	2025		geochronologic boundary , era boundary , Concept	stable
Base of Floian	2034		geochronologic boundary , era boundary , Concept	stable
Base of Darriwilian	2036		geochronologic boundary , era boundary , Concept	stable
Base of Katian	2038		Concept , geochronologic boundary , era boundary	stable
Base of Hirnantian	2039		geochronologic boundary , era boundary , Concept	stable
Base of Couvinian	2044		geochronologic boundary , Concept , era boundary	stable
Base of Middle Mississippian	2047		Concept , era boundary , geochronologic boundary	stable
Base of Upper Mississippian	2048		Concept , geochronologic boundary , era boundary	stable
Base of Strunian	2052		Concept , era boundary , geochronologic boundary	stable
Base of Ivorian	2053		Concept , era boundary , geochronologic boundary	stable
Base of Livian	2056		era boundary , geochronologic boundary , Concept	stable
Base of Arundian	2057		Concept , geochronologic boundary , era boundary	stable
Base of Holkerian	2058		era boundary , Concept , geochronologic boundary	stable
Base of Asbian	2059		geochronologic boundary , Concept , era boundary	stable
Base of Brigantian	2060		geochronologic boundary , era boundary , Concept	stable
Base of Warnantian	2061		Concept , geochronologic boundary , era boundary	stable
Base of Pennsylvanian	2067		era boundary , Concept , geochronologic boundary	stable
Base of Middle Pennsylvanian	2069		Concept , geochronologic boundary , era boundary	stable
Base of Upper Pennsylvanian	2070		era boundary , Concept , geochronologic boundary	stable
Base of Gzhelian	2074		geochronologic boundary , era boundary , Concept	stable
Base of Sakmarian	2080		era boundary , Concept , geochronologic boundary	stable
Base of Artinskian	2081		Concept , era boundary , geochronologic boundary	stable
Base of Kungurian	2082		era boundary , Concept , geochronologic boundary	stable
Base of Guadalupian	2085		era boundary , geochronologic boundary , Concept	stable
Base of Wordian	2087		era boundary , geochronologic boundary , Concept	stable
Base of Capitanian	2088		era boundary , geochronologic boundary , Concept	stable
Base of Lopingian	2089		Concept , era boundary , geochronologic boundary	stable
Base of Changhsingian	2091		era boundary , Concept , geochronologic boundary	stable
Base of Lotharigian	2117		era boundary , geochronologic boundary , Concept	stable
Base of Domerian	2120		Concept , era boundary , geochronologic boundary	stable
Base of Middle Jurassic	2121		Concept , era boundary , geochronologic boundary	stable
Base of Upper Jurassic	2122		era boundary , Concept , geochronologic boundary	stable
Base of Astartian	2128		Concept , era boundary , geochronologic boundary	stable
Base of Sequanian	2129		era boundary , geochronologic boundary , Concept	stable
Base of Pterocerian	2130		Concept , geochronologic boundary , era boundary	stable
Base of Virgulian	2131		era boundary , Concept , geochronologic boundary	stable
Base of Middle Volgian	2138		Concept , geochronologic boundary , era boundary	stable
Base of Upper Volgian	2139		era boundary , geochronologic boundary , Concept	stable
Base of Portlandian	2140		era boundary , Concept , geochronologic boundary	stable
Base of Lower Portlandian	2141		era boundary , Concept , geochronologic boundary	stable
Base of Upper Portlandian	2142		geochronologic boundary , era boundary , Concept	stable
Base of Purbeckian	2143		Concept , geochronologic boundary , era boundary	stable
Base of Purbecko-wealdian	2144		era boundary , Concept , geochronologic boundary	stable
Base of Gargasian	2151		era boundary , geochronologic boundary , Concept	stable
Base of Clansayesian	2152		Concept , era boundary , geochronologic boundary	stable
Base of Vraconian	2154		Concept , geochronologic boundary , era boundary	stable
Base of Fuvelian	2164		Concept , era boundary , geochronologic boundary	stable
Base of Dano-montian	2169		geochronologic boundary , Concept , era boundary	stable
Base of Montian	2170		geochronologic boundary , era boundary , Concept	stable
Base of Heersian	2171		geochronologic boundary , era boundary , Concept	stable
Base of Cuisian	2174		era boundary , geochronologic boundary , Concept	stable
Base of Ledian	2177		geochronologic boundary , era boundary , Concept	stable
Base of Wemmelian	2178		era boundary , Concept , geochronologic boundary	stable
Base of Assian	2180		Concept , era boundary , geochronologic boundary	stable
Base of Marinesian	2182		Concept , geochronologic boundary , era boundary	stable
Base of Orleanian	2191		geochronologic boundary , Concept , era boundary	stable
Base of Astaracian	2195		Concept , geochronologic boundary , era boundary	stable
Base of Savignean	2196		geochronologic boundary , era boundary , Concept	stable
Base of Redonian	2201		era boundary , Concept , geochronologic boundary	stable
Base of Poederlian	2211		era boundary , geochronologic boundary , Concept	stable
Base of Reuverian B	2214		Concept , era boundary , geochronologic boundary	stable
Base of Reuverian C	2215		era boundary , Concept , geochronologic boundary	stable
Base of Upper Villafranchian	2218		Concept , era boundary , geochronologic boundary	stable
Base of Biber	2220		Concept , geochronologic boundary , era boundary	stable
Base of Biber/Donau Interglacial	2221		geochronologic boundary , Concept , era boundary	stable
Base of Calabrian	2222		Concept , era boundary , geochronologic boundary	stable
Base of Emilian	2224		era boundary , geochronologic boundary , Concept	stable
Base of Sicilian	2225		geochronologic boundary , Concept , era boundary	stable
Base of Donau	2226		era boundary , Concept , geochronologic boundary	stable
Base of Donau/Gunz Interglacial	2227		geochronologic boundary , Concept , era boundary	stable
Base of Gunz	2228		Concept , era boundary , geochronologic boundary	stable
Base of Gunz/Mindel Interglacial	2230		era boundary , Concept , geochronologic boundary	stable
Base of Mindel	2231		geochronologic boundary , Concept , era boundary	stable
Base of Mindel/Riss Interglacial	2232		Concept , geochronologic boundary , era boundary	stable
Base of Riss	2233		geochronologic boundary , Concept , era boundary	stable
Base of Wurm	2237		geochronologic boundary , Concept , era boundary	stable
Base of Würm I	2238		Concept , geochronologic boundary , era boundary	stable
Base of Würm II	2239		era boundary , geochronologic boundary , Concept	stable
Base of Würm III	2240		era boundary , geochronologic boundary , Concept	stable
Base of Würm IV	2241		era boundary , Concept , geochronologic boundary	stable
Base of Oldest Dryas	2242		era boundary , Concept , geochronologic boundary	stable
Base of Bølling	2243		Concept , era boundary , geochronologic boundary	stable
Base of Older Dryas	2244		era boundary , Concept , geochronologic boundary	stable
Base of Allerød	2245		geochronologic boundary , era boundary , Concept	stable
Base of Younger Dryas	2246		Concept , era boundary , geochronologic boundary	stable
Base of Dienerian	3003		Concept , era boundary , geochronologic boundary	stable
Base of Spathian	3005		era boundary , Concept , geochronologic boundary	stable
Base of Middle Anisian	3007		era boundary , Concept , geochronologic boundary	stable
Base of Bithynian	3008		Concept , era boundary , geochronologic boundary	stable
Base of Pelsonian	3009		era boundary , geochronologic boundary , Concept	stable
Base of Illyrian	3010		Concept , geochronologic boundary , era boundary	stable
Base of Longobardian	3012		Concept , era boundary , geochronologic boundary	stable
Base of Tuvalian	3014		era boundary , geochronologic boundary , Concept	stable
Base of Alaunian	3016		era boundary , Concept , geochronologic boundary	stable
Base of Sevatian	3017		Concept , geochronologic boundary , era boundary	stable
Base of Middle Holocene	3020		era boundary , Concept , geochronologic boundary	stable
Base of Upper/Late Holocene	3022		Concept , geochronologic boundary , era boundary	stable
Base of Paniselian	3026		era boundary , Concept , geochronologic boundary	stable
Base of Toyonian	3028		Concept , geochronologic boundary , era boundary	stable
Base of Botomian	3029		Concept , geochronologic boundary , era boundary	stable
Base of Middle Visean	3030		geochronologic boundary , era boundary , Concept	stable
Base of Middle Norian	3032		era boundary , Concept , geochronologic boundary	stable
Base of GS-26	3036		geochronologic boundary , Concept , era boundary	stable
Base of GI-25c	3037		Concept , era boundary , geochronologic boundary	stable
Base of GI-25b	3038		era boundary , Concept , geochronologic boundary	stable
Base of GI-25a	3039		era boundary , geochronologic boundary , Concept	stable
Base of GS-25	3040		geochronologic boundary , Concept , era boundary	stable
Base of GI-24.2	3041		era boundary , Concept , geochronologic boundary	stable
Base of GS-24.2	3042		geochronologic boundary , Concept , era boundary	stable
Base of GI-24.1c	3043		era boundary , Concept , geochronologic boundary	stable
Base of GI-24.1b	3044		geochronologic boundary , era boundary , Concept	stable
Base of GI-24.1a	3045		geochronologic boundary , Concept , era boundary	stable
Base of GS-24.1	3046		geochronologic boundary , era boundary , Concept	stable
Base of GI-23.2	3047		geochronologic boundary , era boundary , Concept	stable
Base of GS-23.2	3048		geochronologic boundary , Concept , era boundary	stable
Base of GI-23.1	3049		era boundary , geochronologic boundary , Concept	stable
Base of GS-23.1	3050		Concept , geochronologic boundary , era boundary	stable
Base of GI-22g	3051		geochronologic boundary , era boundary , Concept	stable
Base of GI-22f	3052		geochronologic boundary , Concept , era boundary	stable
Base of GI-22e	3053		Concept , geochronologic boundary , era boundary	stable
Base of GI-22d	3054		Concept , era boundary , geochronologic boundary	stable
Base of GI-22c	3055		geochronologic boundary , era boundary , Concept	stable
Base of GI-22b	3056		geochronologic boundary , era boundary , Concept	stable
Base of GI-22a	3057		geochronologic boundary , Concept , era boundary	stable
Base of GS-22	3058		geochronologic boundary , era boundary , Concept	stable
Base of GI-21.2	3059		Concept , geochronologic boundary , era boundary	stable
Base of GS-21.2	3060		geochronologic boundary , era boundary , Concept	stable
Base of GI-21.1e	3061		era boundary , Concept , geochronologic boundary	stable
Base of GI-21.1d	3062		era boundary , Concept , geochronologic boundary	stable
Base of GI-21.1c	3063		Concept , geochronologic boundary , era boundary	stable
Base of GI-21.1b	3064		era boundary , Concept , geochronologic boundary	stable
Base of GI-21.1a	3065		geochronologic boundary , Concept , era boundary	stable
Base of GS-21.1	3066		era boundary , Concept , geochronologic boundary	stable
Base of GI-20c	3067		geochronologic boundary , Concept , era boundary	stable
Base of GI-20b	3068		era boundary , Concept , geochronologic boundary	stable
Base of GI-20a	3069		Concept , geochronologic boundary , era boundary	stable
Base of GS-20	3070		era boundary , Concept , geochronologic boundary	stable
Base of GI-19.2	3071		geochronologic boundary , era boundary , Concept	stable
Base of GS-19.2	3072		geochronologic boundary , era boundary , Concept	stable
Base of GI-19.1	3073		Concept , geochronologic boundary , era boundary	stable
Base of GS-19.1	3074		era boundary , Concept , geochronologic boundary	stable
Base of GI-18	3075		era boundary , Concept , geochronologic boundary	stable
Base of GS-18	3076		era boundary , Concept , geochronologic boundary	stable
Base of GI-17.2	3077		era boundary , geochronologic boundary , Concept	stable
Base of GS-17.2	3078		Concept , geochronologic boundary , era boundary	stable
Base of GI-17.1c	3079		era boundary , geochronologic boundary , Concept	stable
Base of GI-17.1b	3080		era boundary , Concept , geochronologic boundary	stable
Base of GI-17.1a	3081		geochronologic boundary , Concept , era boundary	stable
Base of GS-17.1	3082		Concept , geochronologic boundary , era boundary	stable
Base of GI-16.2	3083		geochronologic boundary , Concept , era boundary	stable
Base of GS-16.2	3084		geochronologic boundary , Concept , era boundary	stable
Base of GI-16.1c	3085		geochronologic boundary , era boundary , Concept	stable
Base of GI-16.1b	3086		Concept , geochronologic boundary , era boundary	stable
Base of GI-16.1a	3087		geochronologic boundary , era boundary , Concept	stable
Base of GS-16.1	3088		geochronologic boundary , Concept , era boundary	stable
Base of GI-15.2	3089		era boundary , Concept , geochronologic boundary	stable
Base of GS-15.2	3090		Concept , geochronologic boundary , era boundary	stable
Base of GI-15.1	3091		Concept , geochronologic boundary , era boundary	stable
Base of GS-15.1	3092		Concept , geochronologic boundary , era boundary	stable
Base of GI-14e	3093		era boundary , geochronologic boundary , Concept	stable
Base of GI-14d	3094		Concept , geochronologic boundary , era boundary	stable
Base of GI-14c	3095		geochronologic boundary , Concept , era boundary	stable
Base of GI-14b	3096		geochronologic boundary , Concept , era boundary	stable
Base of GI-14a	3097		Concept , geochronologic boundary , era boundary	stable
Base of GS-14QS	3098		Concept , geochronologic boundary , era boundary	stable
Base of GI-13c	3099		Concept , geochronologic boundary , era boundary	stable
Base of GI-13b	3100		geochronologic boundary , Concept , era boundary	stable
Base of GI-13a	3101		Concept , era boundary , geochronologic boundary	stable
Base of GS-13	3102		era boundary , geochronologic boundary , Concept	stable
Base of GI-12c	3103		Concept , era boundary , geochronologic boundary	stable
Base of GI-12b	3104		era boundary , Concept , geochronologic boundary	stable
Base of GI-12a	3105		era boundary , geochronologic boundary , Concept	stable
Base of GS-12	3106		era boundary , geochronologic boundary , Concept	stable
Base of GI-11	3107		era boundary , geochronologic boundary , Concept	stable
Base of GS-11	3108		era boundary , Concept , geochronologic boundary	stable
Base of GI-10	3109		era boundary , geochronologic boundary , Concept	stable
Base of GS-10	3110		geochronologic boundary , Concept , era boundary	stable
Base of GI-9	3111		Concept , era boundary , geochronologic boundary	stable
Base of GS-9	3112		era boundary , Concept , geochronologic boundary	stable
Base of GI-8c	3113		geochronologic boundary , era boundary , Concept	stable
Base of GI-8b	3114		geochronologic boundary , Concept , era boundary	stable
Base of GI-8a	3115		Concept , era boundary , geochronologic boundary	stable
Base of GS-8	3116		geochronologic boundary , Concept , era boundary	stable
Base of GI-7c	3117		Concept , era boundary , geochronologic boundary	stable
Base of GI-7b	3118		Concept , era boundary , geochronologic boundary	stable
Base of GI-7a	3119		Concept , era boundary , geochronologic boundary	stable
Base of GS-7	3120		geochronologic boundary , era boundary , Concept	stable
Base of GI-6	3121		geochronologic boundary , Concept , era boundary	stable
Base of GS-6	3122		Concept , era boundary , geochronologic boundary	stable
Base of GI-5.2	3123		geochronologic boundary , Concept , era boundary	stable
Base of GS-5.2	3124		era boundary , Concept , geochronologic boundary	stable
Base of GI-5.1	3125		geochronologic boundary , Concept , era boundary	stable
Base of GS-5.1	3126		geochronologic boundary , Concept , era boundary	stable
Base of GI-4	3127		era boundary , geochronologic boundary , Concept	stable
Base of GS-4	3128		geochronologic boundary , Concept , era boundary	stable
Base of GI-3	3129		geochronologic boundary , Concept , era boundary	stable
Base of GS-3	3130		Concept , era boundary , geochronologic boundary	stable
Base of GI-2.2	3131		era boundary , Concept , geochronologic boundary	stable
Base of GS-2.2	3132		Concept , era boundary , geochronologic boundary	stable
Base of GI-2.1	3133		era boundary , geochronologic boundary , Concept	stable
Base of GS-2.1c	3134		Concept , era boundary , geochronologic boundary	stable
Base of GS-2.1b	3135		era boundary , geochronologic boundary , Concept	stable
Base of GS-2.1a	3136		Concept , era boundary , geochronologic boundary	stable
Base of GI-1e	3137		era boundary , Concept , geochronologic boundary	stable
Base of GI-1d	3138		era boundary , Concept , geochronologic boundary	stable
Base of GI-1c3	3139		era boundary , geochronologic boundary , Concept	stable
Base of GI-1c2	3140		era boundary , geochronologic boundary , Concept	stable
Base of GI-1c1	3141		Concept , geochronologic boundary , era boundary	stable
Base of GI-1b	3142		Concept , era boundary , geochronologic boundary	stable
Base of GI-1a	3143		geochronologic boundary , era boundary , Concept	stable
Base of GS-1	3144		Concept , era boundary , geochronologic boundary	stable
End of Lenian	e1035		era boundary , Concept , geochronologic boundary	stable
End of Amgaian	e1037		Concept , geochronologic boundary , era boundary	stable
End of Mayaian	e1038		era boundary , geochronologic boundary , Concept	stable
End of Arenig	e1046		Concept , era boundary , geochronologic boundary	stable
End of Caradoc	e1051		Concept , geochronologic boundary , era boundary	stable
End of Upper Caradoc	e1053		geochronologic boundary , era boundary , Concept	stable
End of Namurian	e1104		era boundary , geochronologic boundary , Concept	stable
End of Namurian C	e1107		Concept , geochronologic boundary , era boundary	stable
End of Stephanian C	e1116		geochronologic boundary , era boundary , Concept	stable
End of Lower Olenekian	e1129		geochronologic boundary , era boundary , Concept	stable
End of Lower Anisian	e1133		era boundary , Concept , geochronologic boundary	stable
End of Lower Ladinian	e1136		era boundary , geochronologic boundary , Concept	stable
End of Lower Carnian	e1140		era boundary , Concept , geochronologic boundary	stable
End of Lower Norian	e1143		geochronologic boundary , Concept , era boundary	stable
End of Lower Pliensbachian	e1158		geochronologic boundary , era boundary , Concept	stable
End of Middle Toarcian	e1162		geochronologic boundary , Concept , era boundary	stable
End of Middle Berriasian	e1197		era boundary , Concept , geochronologic boundary	stable
End of Upper Lutetian	e1258		geochronologic boundary , Concept , era boundary	stable
End of Lower Bartonian	e1260		Concept , geochronologic boundary , era boundary	stable
End of Bavelian	e1297		geochronologic boundary , era boundary , Concept	stable
End of Holsteinian	e1309		geochronologic boundary , era boundary , Concept	stable
End of Eemian	e1317		geochronologic boundary , era boundary , Concept	stable
End of Early Weichselian	e1319		Concept , geochronologic boundary , era boundary	stable
End of Middle Weichselian	e1320		Concept , geochronologic boundary , era boundary	stable
End of Interpleniglacial	e1322		geochronologic boundary , Concept , era boundary	stable
End of Upper Pleniglacial	e1324		Concept , geochronologic boundary , era boundary	stable
End of Icartian	e2002		Concept , geochronologic boundary , era boundary	stable
End of Paleo-proterozoic	e2003		Concept , geochronologic boundary , era boundary	stable
End of Sturtian	e2007		Concept , geochronologic boundary , era boundary	stable
End of Acadian	e2023		era boundary , geochronologic boundary , Concept	stable
End of Devillian	e2024		era boundary , Concept , geochronologic boundary	stable
End of Skiddavian	e2033		Concept , geochronologic boundary , era boundary	stable
End of Molinacian	e2055		era boundary , Concept , geochronologic boundary	stable
End of Livian	e2056		geochronologic boundary , Concept , era boundary	stable
End of Arundian	e2057		era boundary , Concept , geochronologic boundary	stable
End of Holkerian	e2058		geochronologic boundary , Concept , era boundary	stable
End of Upper Namurian	e2066		Concept , era boundary , geochronologic boundary	stable
End of Carixian	e2119		era boundary , Concept , geochronologic boundary	stable
End of Neuzivian	e2123		Concept , geochronologic boundary , era boundary	stable
End of Villersian	e2124		Concept , era boundary , geochronologic boundary	stable
End of Lusitanian	e2125		geochronologic boundary , era boundary , Concept	stable
End of Sequanian	e2129		geochronologic boundary , era boundary , Concept	stable
End of Pterocerian	e2130		Concept , era boundary , geochronologic boundary	stable
End of Volgian	e2136		geochronologic boundary , era boundary , Concept	stable
End of Upper Volgian	e2139		Concept , geochronologic boundary , era boundary	stable
End of Portlandian	e2140		geochronologic boundary , Concept , era boundary	stable
End of Upper Portlandian	e2142		era boundary , geochronologic boundary , Concept	stable
End of Urgonian (Provence)	e2146		geochronologic boundary , Concept , era boundary	stable
End of Urgonian (Vercors)	e2147		era boundary , Concept , geochronologic boundary	stable
End of Urgonian (Jura)	e2148		geochronologic boundary , era boundary , Concept	stable
End of Bedoulian	e2150		geochronologic boundary , era boundary , Concept	stable
End of Rognacian	e2166		geochronologic boundary , era boundary , Concept	stable
End of Ilerdian	e2175		Concept , era boundary , geochronologic boundary	stable
End of Biarritzian	e2179		era boundary , Concept , geochronologic boundary	stable
End of Assian	e2180		geochronologic boundary , Concept , era boundary	stable
End of Auversian	e2181		geochronologic boundary , era boundary , Concept	stable
End of Lattorfian	e2184		era boundary , geochronologic boundary , Concept	stable
End of Tongrian	e2185		Concept , era boundary , geochronologic boundary	stable
End of Upper Tongrian	e2187		Concept , era boundary , geochronologic boundary	stable
End of Sannoisian	e2189		geochronologic boundary , era boundary , Concept	stable
End of Astaracian	e2195		geochronologic boundary , Concept , era boundary	stable
End of Savignean	e2196		era boundary , geochronologic boundary , Concept	stable
End of Villafranchian	e2216		era boundary , Concept , geochronologic boundary	stable
End of Upper Villafranchian	e2218		geochronologic boundary , Concept , era boundary	stable
End of Biber/Donau Interglacial	e2221		Concept , geochronologic boundary , era boundary	stable
End of Tyrrhenian	e2235		era boundary , geochronologic boundary , Concept	stable
End of Riss/Wurm interglacial	e2236		era boundary , geochronologic boundary , Concept	stable
End of Oldest Dryas	e2242		geochronologic boundary , era boundary , Concept	stable
End of Smithian	e3004		geochronologic boundary , era boundary , Concept	stable
End of Aegean	e3006		era boundary , Concept , geochronologic boundary	stable
End of Middle Anisian	e3007		geochronologic boundary , Concept , era boundary	stable
End of Pelsonian	e3009		geochronologic boundary , Concept , era boundary	stable
End of Fassanian	e3011		geochronologic boundary , Concept , era boundary	stable
End of Julian	e3013		Concept , geochronologic boundary , era boundary	stable
End of Lacian	e3015		geochronologic boundary , Concept , era boundary	stable
End of Alaunian	e3016		Concept , geochronologic boundary , era boundary	stable
End of Toyonian	e3028		Concept , era boundary , geochronologic boundary	stable
End of Botomian	e3029		era boundary , Concept , geochronologic boundary	stable
End of Middle Norian	e3032		Concept , geochronologic boundary , era boundary	stable