Table 1.

U-Pb and astrochronological ages compared

Boundary or unit	Newark igneous*	Newark–Hartford*	Pucara Basin	Bristol Channel† Pucara‡/Newark§
Hettangian–Sinemurian boundary	—	199.70 ± 0.02	199.46 ± 0.17	199.61/199.66
Hook Mountain Basalt	200.916 ± 0.064	200.93 ± 0.02	—	—
Preakness Basalt	201.274 ± 0.032	201.28 ± 0.02	—	—
Rhaetian–Hettangian boundary	—	201.42 ± 0.022	201.36 ± 0.14‡	201.32/201.37
Orange Mountain Basalt	201.520 ± 0.034	201.52 ± 0.02	—	—
End-Triassic extinction	201.564 ± 0.015	201.56 ± 0.02	201.51 ± 0.15	201.51/201.56

^*See ref. 2 for ages. Details in Table S2.

^†See refs. 19 and 31 for ages. Details in Table S2.

^‡See refs. 12 and 17 for ages. Details in Table S2.

^§See ref. 15 for ages. Details in Table S2.