function getGeologicTime( years_ago ) { var time_period = {}; switch( true ) { case years_ago <= 65: time_period.era = 'Cenozoic'; switch( true ) { case years_ago >= 0 && years_ago <=2: time_period.period = 'Quaternary'; switch( true ) { case years_ago == 0: time_period.epoch = 'Holocene'; time_period.age = 'Holocene'; break; case years_ago == 1: time_period.epoch = 'Pleistocene'; time_period.age = 'Calabrian'; break; case years_ago == 2: time_period.epoch = 'Pleistocene'; time_period.age = 'Gelasian'; break; } break; case years_ago >= 3 && years_ago <= 23: time_period.period = 'Neogene'; switch ( true ) { case years_ago == 3: time_period.epoch = 'Pliocene'; time_period.age = 'Placenzian'; break; case years_ago >= 4 && years_ago <= 5: time_period.epoch = 'Pliocene'; time_period.age = 'Zanclean'; break; case years_ago >= 6 && years_ago <= 23: time_period.epoch = 'Miocene'; switch ( true ) { case years_ago >= 6 && years_ago <= 7: time_period.age = 'Messinian'; break; case years_ago >= 8 && years_ago <= 11: time_period.age = 'Tortonian'; break; case years_ago >= 12 && years_ago <= 13: time_period.age = 'Serravallian'; break; case years_ago >= 14 && years_ago <= 16: time_period.age = 'Langhian'; break; case years_ago >= 17 && years_ago <= 20: time_period.age = 'Burdialian'; break; case years_ago >= 21 && years_ago <= 23: time_period.age = 'Aquitanian'; break; } break; } break; case years_ago >= 24 && years_ago <= 65: time_period.period = 'Paleogene'; switch( true ) { case years_ago >= 24 && years_ago <= 28: time_period.epoch = 'Oligocene'; time_period.age = 'Chattian'; break; case years_ago >= 29 && years_ago <= 33: time_period.epoch = 'Oligocene'; time_period.age = 'Rupelian'; break; case years_ago >= 34 && years_ago <= 55: time_period.epoch = 'Eocene'; switch (true ) { case years_ago >= 34 && years_ago <= 37: time_period.age = 'Priabonian'; break; case years_ago >= 38 && years_ago <= 40: time_period.age = 'Bartonian'; break; case years_ago >= 41 && years_ago <= 48: time_period.age = 'Lutetian'; break; case years_ago >= 49 && years_ago <= 55: time_period.age = 'Ypresian'; break; } break; case years_ago >= 56 && years_ago <= 65: time_period.epoch = 'Paleocene'; switch (true ) { case years_ago >= 56 && years_ago <= 58: time_period.age = 'Thanetian'; break; case years_ago >= 59 && years_ago <= 61: time_period.age = 'Selandian'; break; case years_ago >= 62 && years_ago <= 65: time_period.age = 'Danian'; break; } break; } break; } break; case years_ago >= 66 && years_ago <= 251: time_period.era = 'Mesozoic'; switch( true ) { case years_ago >= 66 && years_ago <= 145: time_period.period = 'Cretaceous'; switch( true ) { case years_ago >= 66 && years_ago <= 99: time_period.epoch = 'Late'; switch ( true ) { case years_ago >= 66 && years_ago <= 70: time_period.age = 'Maastrichtian'; break; case years_ago >= 71 && years_ago <= 83: time_period.age = 'Campanian'; break; case years_ago >= 84 && years_ago <= 85: time_period.age = 'Santonian'; break; case years_ago >= 86 && years_ago <= 89: time_period.age = 'Coniacian'; break; case years_ago >= 90 && years_ago <= 93: time_period.age = 'Turonian'; break; case years_ago >= 94 && years_ago <= 99: time_period.age = 'Cenomanian'; break; } break; case years_ago >= 100 && years_ago <= 145: time_period.epoch = 'Early'; switch ( true ) { case years_ago >= 100 && years_ago <= 112: time_period.age = 'Albian'; break; case years_ago >= 113 && years_ago <= 125: time_period.age = 'Aptian'; break; case years_ago >= 126 && years_ago <= 130: time_period.age = 'Barremian'; break; case years_ago >= 131 && years_ago <= 135: time_period.age = 'Hauterivian'; break; case years_ago >= 136 && years_ago <= 140: time_period.age = 'Valanginian'; break; case years_ago >= 141 && years_ago <= 145: time_period.age = 'Berriasian'; break; } break; } break; case years_ago >= 146 && years_ago <= 201: time_period.period = 'Jurassic'; switch ( true ) { case years_ago >= 146 && years_ago <= 151: time_period.epoch = 'Late'; time_period.age = 'Tithonian'; break; case years_ago >= 152 && years_ago <= 156: time_period.epoch = 'Late'; time_period.age = 'Kimmeridgian'; break; case years_ago >= 157 && years_ago <= 161: time_period.epoch = 'Late'; time_period.age = 'Oxfordian'; break; case years_ago >= 162 && years_ago <= 176: time_period.epoch = 'Middle'; switch ( true ) { case years_ago >= 162 && years_ago <= 165: time_period.age = 'Messinian'; break; case years_ago >= 166 && years_ago <= 168: time_period.age = 'Tortonian'; break; case years_ago >= 169 && years_ago <= 172: time_period.age = 'Serravallian'; break; case years_ago >= 173 && years_ago <= 176: time_period.age = 'Langhian'; break; } break; case years_ago >= 177 && years_ago <= 201: time_period.epoch = 'Early'; switch ( true ) { case years_ago >= 177 && years_ago <= 183: time_period.age = 'Toarcian'; break; case years_ago >= 184 && years_ago <= 190: time_period.age = 'Pliensbachian'; break; case years_ago >= 191 && years_ago <= 197: time_period.age = 'Sinemurian'; break; case years_ago >= 198 && years_ago <= 201: time_period.age = 'Hettangian'; break; } break; } break; case years_ago >= 202 && years_ago <= 251: time_period.period = 'Triassic'; switch( true ) { case years_ago >= 202 && years_ago <= 204: time_period.epoch = 'Late'; time_period.age = 'Rhaetian'; break; case years_ago >= 205 && years_ago <= 228: time_period.epoch = 'Late'; time_period.age = 'Norian'; break; case years_ago >= 229 && years_ago <= 235: time_period.epoch = 'Late'; time_period.age = 'Carnian'; break; case years_ago >= 236 && years_ago <= 241: time_period.epoch = 'Middle'; time_period.age = 'Ladinian'; break; case years_ago >= 242 && years_ago <= 245: time_period.epoch = 'Middle'; time_period.age = 'Anisian'; break; case years_ago >= 246 && years_ago <= 250: time_period.epoch = 'Early'; time_period.age = 'Oleneian'; break; case years_ago == 251: time_period.epoch = 'Early'; time_period.age = 'Induan'; break; } break; } break; case years_ago >= 252 && years_ago <= 542: time_period.era = 'Paleozoic'; switch( true ) { case years_ago >= 252 && years_ago <= 299: time_period.period = 'Permian'; switch( true ) { case years_ago >= 252 && years_ago <= 260: time_period.epoch = 'Late'; switch ( true ) { case years_ago >= 252 && years_ago <= 254: time_period.age = 'Changhsingian'; break; case years_ago >= 255 && years_ago <= 260: time_period.age = 'Wuchiapingian'; break; } break; case years_ago >= 261 && years_ago <= 271: time_period.epoch = 'Middle'; switch ( true ) { case years_ago >= 261 && years_ago <= 266: time_period.age = 'Capitanian'; break; case years_ago >= 267 && years_ago <= 268: time_period.age = 'Wordian'; break; case years_ago >= 269 && years_ago <= 271: time_period.age = 'Roadian'; break; } break; case years_ago >= 272 && years_ago <= 299: time_period.epoch = 'Early'; switch ( true ) { case years_ago >= 272 && years_ago <= 276: time_period.age = 'Kungurian'; break; case years_ago >= 277 && years_ago <= 284: time_period.age = 'Artinskian'; break; case years_ago >= 285 && years_ago <= 297: time_period.age = 'Sakmarian'; break; case years_ago >= 298 && years_ago <= 299: time_period.age = 'Asselian'; break; } break; } break; case years_ago >= 300 && years_ago <= 359: time_period.period = 'Carboniferous'; switch ( true ) { case years_ago >= 300 && years_ago <= 318: time_period.epoch = 'Pennsylvanian'; switch ( true ) { case years_ago >= 300 && years_ago <= 304: time_period.age = 'Gzelian'; break; case years_ago >= 305 && years_ago <= 306: time_period.age = 'Kasimovian'; break; case years_ago >= 307 && years_ago <= 312: time_period.age = 'Moscovian'; break; case years_ago >= 313 && years_ago <= 318: time_period.age = 'Bashkirian'; break; } break; case years_ago >= 319 && years_ago <= 359: time_period.epoch = 'Mississippian'; switch ( true ) { case years_ago >= 319 && years_ago <= 326: time_period.age = 'Serpukhovian'; break; case years_ago >= 327 && years_ago <= 345: time_period.age = 'Visean'; break; case years_ago >= 346 && years_ago <= 359: time_period.age = 'Tournaisian'; break; } break; } break; case years_ago >= 360 && years_ago <= 416: time_period.period = 'Devonian'; switch( true ) { case years_ago >= 360 && years_ago <= 374: time_period.epoch = 'Late'; time_period.age = 'Famennian'; break; case years_ago >= 375 && years_ago <= 385: time_period.epoch = 'Late'; time_period.age = 'Frasnian'; break; case years_ago >= 386 && years_ago <= 392: time_period.epoch = 'Middle'; time_period.age = 'Givetian'; break; case years_ago >= 393 && years_ago <= 398: time_period.epoch = 'Middle'; time_period.age = 'Eifelian'; break; case years_ago >= 399 && years_ago <= 407: time_period.epoch = 'Early'; time_period.age = 'Emsian'; break; case years_ago >= 408 && years_ago <= 411: time_period.epoch = 'Early'; time_period.age = 'Praghian'; break; case years_ago >= 412 && years_ago <= 416: time_period.epoch = 'Early'; time_period.age = 'Lockhovian'; break; } break; case years_ago >= 417 && years_ago <= 444: time_period.period = 'Silurian'; switch ( true ) { case years_ago >= 417 && years_ago <= 419: time_period.epoch = 'Late'; time_period.age = 'Pridolian'; break; case years_ago >= 420 && years_ago <= 421: time_period.epoch = 'Late'; time_period.age = 'Ludfordian'; break; case years_ago >= 422 && years_ago <= 423: time_period.epoch = 'Middle'; time_period.age = 'Gorstian'; break; case years_ago >= 424 && years_ago <= 426: time_period.epoch = 'Middle'; time_period.age = 'Homerian'; break; case years_ago >= 427 && years_ago <= 428: time_period.epoch = 'Early'; time_period.age = 'Sheinwoodian'; break; case years_ago >= 429 && years_ago <= 436: time_period.epoch = 'Early'; time_period.age = 'Telychian'; break; case years_ago >= 437 && years_ago <= 439: time_period.epoch = 'Early'; time_period.age = 'Aeronian'; break; case years_ago >= 440 && years_ago <= 444: time_period.epoch = 'Early'; time_period.age = 'Rhuddanian'; break; } break; case years_ago >= 445 && years_ago <= 488: time_period.period = 'Ordovician'; switch( true ) { case years_ago >= 445 && years_ago <= 446: time_period.epoch = 'Late'; time_period.age = 'Hirnantian'; break; case years_ago >= 447 && years_ago <= 455: time_period.epoch = 'Late'; time_period.age = 'Katian'; break; case years_ago >= 456 && years_ago <= 461: time_period.epoch = 'Late'; time_period.age = 'Sandbian'; break; case years_ago >= 462 && years_ago <= 468: time_period.epoch = 'Middle'; time_period.age = 'Darriwilian'; break; case years_ago >= 469 && years_ago <= 472: time_period.epoch = 'Middle'; time_period.age = 'Dapingian'; break; case years_ago >= 473 && years_ago <= 479: time_period.epoch = 'Early'; time_period.age = 'Floian'; break; case years_ago >= 480 && years_ago <= 488: time_period.epoch = 'Early'; time_period.age = 'Tremadocian'; break; } break; case years_ago >= 489 && years_ago <= 542: time_period.period = 'Cambrian'; switch( true ) { case years_ago >= 489 && years_ago <= 492: time_period.epoch = 'Furongian'; time_period.age = 'Stage 10'; break; case years_ago >= 493 && years_ago <= 496: time_period.epoch = 'Furongian'; time_period.age = 'Stage 9'; break; case years_ago >= 497 && years_ago <= 501: time_period.epoch = 'Furongian'; time_period.age = 'Paibian'; break; case years_ago >= 502 && years_ago <= 503: time_period.epoch = 'Series 3'; time_period.age = 'Guzhangian'; break; case years_ago >= 504 && years_ago <= 507: time_period.epoch = 'Series 3'; time_period.age = 'Drumian'; break; case years_ago >= 508 && years_ago <= 510: time_period.epoch = 'Series 3'; time_period.age = 'Stage 5'; break; case years_ago >= 511 && years_ago <= 517: time_period.epoch = 'Series 2'; time_period.age = 'Stage 4'; break; case years_ago >= 518 && years_ago <= 521: time_period.epoch = 'Series 2'; time_period.age = 'Stage 3'; break; case years_ago >= 522 && years_ago <= 535: time_period.epoch = 'Terreneuvian'; time_period.age = 'Stage 2'; break; case years_ago >= 536 && years_ago <= 542: time_period.epoch = 'Terreneuvian'; time_period.age = 'Fortunian'; break; } break; } break; } return time_period; } /* Era -> Period -> Epoch -> Age ============================= - Cenozoic - Quaternary - Holocene 0 - Pleistocene - Calabrian 1 - Gelasian 2 - Neogene - Pliocene - Placenzian 3 - Zanclean 4-5 - Miocene - Messinian 6-7 - Tortonian 8-11 - Serravallian 12-13 - Langhian 14-16 - Burdialian 17-20 - Aquitanian 21-23 - Paleogene - Oligocene - Chattian 24-28 - Rupelian 29-33 - Eocene - Priabonian 34-37 - Bartonian 38-40 - Lutetian 41-48 - Ypresian 49-55 - Paleocene - Thanetian 56-58 - Selandian 59-61 - Danian 62-65 - Mesozoic - Cretaceous - Late - Maastrichtian 66-70 - Campanian 71-83 - Santonian 84-85 - Coniacian 86-89 - Turonian 90-93 - Cenomanian 94-99 - Early - Albian 100-112 - Aptian 113-125 - Barremian 126-130 - Hauterivian 131-135 - Valanginian 136-140 - Berriasian 141-145 - Jurassic - Late - Tithonian 146-151 - Kimmeridgian 152-156 - Oxfordian 157-161 - Middle - Callovian 162-165 - Bathonian 166-168 - Bajocian 169-172 - Aalenian 173-176 - Early - Toarcian 177-183 - Pliensbachian 184-190 - Sinemurian 191-197 - Hettangian 198-201 - Triassic - Late - Rhaetian 202-204 - Norian 205-228 - Carnian 229-235 - Middle - Ladinian 236-241 - Anisian 242-245 - Early - Oleneian 246-250 - Induan 251 - Paleozoic - Permian - Late - Changhsingian 252-254 - Wuchiapingian 255-260 - Middle - Capitanian 261-266 - Wordian 267-268 - Roadian 269-271 - Early - Kungurian 272-276 - Artinskian 277-284 - Sakmarian 285-297 - Asselian 298-299 - Carboniferous - Pennsylvanian - Gzelian 300-304 - Kasimovian 305-306 - Moscovian 307-312 - Bashkirian 313-318 - Mississippian - Serpukhovian 319-326 - Visean 327-345 - Tournaisian 346-359 - Devonian - Late - Famennian 360-374 - Frasnian 375-385 - Middle - Givetian 386-392 - Eifelian 393-398 - Early - Emsian 399-407 - Praghian 408-411 - Lockhovian 412-416 - Silurian - Late - Pridolian 417-419 - Ludfordian 420-421 - Gorstian 422-423 - Middle - Homerian 424-426 - Sheinwoodian 426-428 - Early - Telychian 429-436 - Aeronian 437-439 - Rhuddanian 440-444 - Ordovician - Late - Hirnantian 445-446 - Katian 447-455 - Sandbian 456-461 - Middle - Darriwilian 462-468 - Dapingian 469-472 - Early - Floian 473-479 - Tremadocian 480-488 - Cambrian - Furongian - Stage 10 489-492 - Stage 9 493-496 - Paibian 497-501 - Series 3 - Guzhangian 502-503 - Drumian 504-507 - Stage 5 508-510 - Series 2 - Stage 4 511-517 - Stage 3 518-521 - Terreneuvian - Stage 2 522-535 - Fortunian 536-542 */