. Author manuscript; available in PMC: 2018 Dec 1.

Published in final edited form as: Nature. 2018 May 30;558(7709):288–291. doi: 10.1038/s41586-018-0163-6

Extended Data Table 1.

³He data.

Sample	start cm	stop cm	³He pcc/g	⁴He ncc/g	Absolute ³He/⁴He	Fraction ³He ET	Maximum ³He -Based Model Age (kyr)
KT39	39	40	0.0068	13.6	5.04E-07	0.96	6.0
KT48	48	49	0.0055	35.4	1.56E-07	0.87	4.9
KT59	59	60	0.0064	23.1	2.78E-07	0.92	4.0
KT68	68	69	0.0042	31.6	1.33E-07	0.84	2.9
KT79	79	80	0.0036	18.3	1.99E-07	0.9	1.9
KT89	89	90	0.0105	34.7	3.04E-07	0.93	0.9
KT99	99	100	0.0045	64.3	6.99E-08	0.70	0.1
KT106.5	107	108	0.0109	327	3.32E-08	0.37	0.0