Jökull - 01.12.1992, Side 45

TABLE 2. Whole-rock radiometric dates on basalt samples from profiles TN and TL, Langidalur valley.
Niðurstöður kalíum-argon aldursgreininga.
Lab. Lava K Rad. 40 Ar 1 OORad.40 Ar Calc. age Av. age
no. no. wt. % 10-12mol/g Total 40 Ar Ma ± 1 s.d. Ma ± 1 s.d.
77-593 TN83 0.4338,0.4314 5.399 37.2 7.18+0.10
5.275 37.1 7.02±0.08 7.1110.11
77-591 TN63 0.2864,0.2863 3.740 44.6 7.51±0.10
3.659 37.2 7.35±0.09 7.4310.11
77-588 TN49 0.4435,0.4446 5.646 43.5 7.32±0.10
5.549 41.9 7.19±0.08 7.2610.09
77-598 TL27 0.4828,0.4829 6.942 39.4 8.27±0.10
6.887 39.0 8.21 ±0.10 8.2410.10
77-597 TL25 0.4436,0.4429 6.468 32.5 8.3910.12
6.385 31.9 8.2910.11 8.3410.11
77-596 TL20 0.2927,0.2918 4.027 26.8 7.9310.12
4.091 26.3 8.0510.11 7.9910.08
Constants: > te + Ae/ = 0.581 x 10-10jr = 4.962 x 10- •%->, *°K/K = 1.167 X \0~4mol/mol
acknowledgements
Kristján Sæmundsson, Jóhann Helgason, and
Agúst Guðmundsson did much of the initial mapping
°f profiles TL, TM and TN in 1976-77. Further strati-
graphic mapping was performed by Haukur Jóhann-
esson and Ágúst Guðmundsson in 1985. We thank
Bjami Kristinsson, Kjartan Ólafsson, Hafliði Hafliða-
son, Kristján Leósson and many others for assistance
úuring field work and paleomagnetic measurements.
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