1999 GEOLOGIC TIME SCALE CENOZOIC MESOZOIC PALEOZOIC PRECAMBRIAN MAGNETIC MAGNETIC POLARITY POLARITY AGE BDY.

AGE . PICKS AGE . PICKS UNCERT. AGE PICKS . .

N N PERIOD EPOCH AGE PERIOD EPOCH AGE EON ERA . PERIOD EPOCH AGE . AGES M M T T O O (m.y.)

O (Ma) O (Ma) (Ma) S S R R (Ma) I (Ma) I (Ma) (Ma) N N H H H H (Ma) A A C C HOLOCENE 65 .2 1 C1 QUATER- 0.01 C30 NARY PLEISTOCENE CALABRIAN 30 248 543 1.8 31 MAASTRICHTIAN TATARIAN 2 C2 70 C31 L 252 L 71.3 1 N UFIMIAN-KAZANIAN 2A PIACENZIAN 256 C2A PLIOCENE 32 C32 KUNGURIAN 3.6 A 260 260 I 3 E ZANCLEAN 33 CAMPANIAN LATE 5 C3 5.3 ARTINSKIAN 750 C33 M 3A MESSINIAN 80 LATE C3A 269 7.1 83.5 1 R E S SANTONIAN SAKMARIAN

4 85.8 1 E C4 900 CONIACIAN 280 282 4A 89.0 P L TORTONIAN U 1 C4A 90 ASSELIAN 10 5 TURONIAN 1000 C5 E 93.5 4 290 E

11.2 N O . A N S GZELIAN

CENOMANIAN I N S 296 C N U

E 99.0 5A 1 I SERRAVALLIAN 34 C34 A KASIMOVIAN E 300 MIDDLE C5A 100 E V 303 L O C

G M Y L 14.8 MOSCOVIAN . O

5B S 1250 W

15 C R

O 311 C5B ALBIAN N O I LANGHIAN N

5C Z E

C5C 16.4 E BASHKIRIAN 110 A E M P . 5D EARLY 112 2 320 F I C5D N 323 O T 5E N C5E BURDIGALIAN N SERPUKHOVIAN N

A 327

APTIAN I

6 1500 R P

20 C6 E E O 20.5 120 M0 P 6A 121 3 I VISEAN S B M1 E E

N 1600

C6A S

340 I AQUITANIAN M3 R BARREMIAN 342 R A 6B S T C6B M5 I 127 3 S I 6C C6C 23.8 A TOURNAISIAN M M 130 C HAUTERIVIAN

M10 1750 O C 7 E 132 4 25 C7 O 7A M12 354

C7A N C Y 8 CHATTIAN M14 VALANGINIAN R C8 L 360 L FAMENNIAN E M16 O 137 4 9 C9 R 364 P

140 E C FRASNIAN EARLY 10 BERRIASIAN A C10 28.5 N 370

M18 N I O 144 5 2000 30 11 C11 M20 A GIVETIAN I T 12 G

I TITHONIAN E RUPELIAN M22 380 M 380 N

R 150 C12 L 151 6 LATE KIMMERIDGIAN EIFELIAN O E O 154 7 13 33.7 M25 391 V C13 T OXFORDIAN 2250 15 159 7 EMSIAN E C15 C 35 160 M29 400 400

16 C16 L PRIABONIAN I CALLOVIAN

D PRAGHIAN 164 8 37.0 17 C17 S BATHONIAN 412 169 8 LOCKHOVIAN 170 MIDDLE 417 2500 S PRIDOLIAN 2500

18 S N 419 40 C18 BARTONIAN E BAJOCIAN 420 L A

G LUDLOVIAN 176 I 423 N 8

19 A

E WENLOCKIAN R

41.3 A C19 AALENIAN 428 H 180 180 8 U C N

E E

L LATE

20 R

I LLANDOVERIAN Y 2750 E T N

440 S C20 M I TOARCIAN 443 R U 45 E G A LUTETIAN N ASHGILLIAN 190 L 190 8 C L 449 J O A O

21 I P PLIENSBACHIAN N CARADOCIAN C21 O 195 8 D E

I 458 C E 460 I P EARLY 3000 3000 LLANDEILIAN A L 49.0 SINEMURIAN 22 200 A M 464 V 50 C22 R A 202 8 LLANVIRNIAN 470 E 23 HETTANGIAN O C23 P 206 8 MIDDLE H E YPRESIAN D 24 RHAETIAN ARENIGIAN 210 210 8 480 R E 3250 C24 C 54.8 485 C O TREMADOCIAN 55 490

I NORIAN R 25 E LATE SUNWAPTAN* C25 THANETIAN * D 495 3400 N 220 STEPTOEAN* A S 221 9 500 26 N 500

E 57.9 MARJUMAN* 3500

CARNIAN A C 506

C L S C26 9 I DELAMARAN* 60 227 512 O SELANDIAN EARLY 230 R DYERAN*

27 61.0 A MIDDLE LADINIAN B 516 E

B MONTEZUMAN* C27 I 234 9 520

L 520

28 M

A 3750 C28 E DANIAN ANISIAN R P 240 A A 3800? 29 242 9 65 C29 65.0 C T OLENEKIAN EARLY 245 9 30 C30 INDUAN 248 10 540 543

© 1999, The Geological Society of America. Product code CTS004. Compilers: A. R. Palmer, John Geissman *International ages have not been established. These are regional (Laurentian) only. Boundary Picks were based on dating techniques and fossil records as of 1999. Paleomagnetic attributions have errors, Please ignore the paleomagnetic scale. Sources for nomenclature and ages: Primarily from Gradstein, F., and Ogg, J., 1996, Episodes, v. 19, nos. 1 & 2; Gradstein, F., et al., 1995, SEPM Special Pub. 54, p. 95–128; Berggren, W. A., et al., 1995, SEPM Special Pub. 54, p. 129–212; Cambrian and basal Ordovician ages GEOLOGICAL SOCIETY adapted from Landing, E., 1998, Canadian Journal of Earth Sciences, v. 35, p. 329–338; and Davidek, K., et al., 1998, Geological Magazine, OF AMERICA v. 135, p. 305–309. Cambrian age names from Palmer, A. R., 1998, Canadian Journal of Earth Sciences, v. 35, p. 323–328.