Table 1.

(a) Model Th/U ratio calculated from radiogenic ²⁰⁸Pb/²⁰⁶Pb ratio and ²⁰⁷Pb/²³⁵U age.

Compositional Parameters				Radiogenic Isotope Ratios							Isotopic Ages
An. no	$\frac{\mathbf{Th}}{\mathbf{U}}$	Pbc (pg)	$\frac{{\mathbf{Pb}}^{\mathbf{⁎}}}{\mathbf{Pbc}}$	$\frac{{}^{\mathbf{207}}\mathbf{P}\mathbf{b}}{{}^{\mathbf{206}}\mathbf{P}\mathbf{b}}$	% err	$\frac{{}^{\mathbf{207}}\mathbf{P}\mathbf{b}}{{}^{\mathbf{235}}\mathbf{U}}$	% err	$\frac{{}^{\mathbf{206}}\mathbf{P}\mathbf{b}}{{}^{\mathbf{238}}\mathbf{U}}$	% err	corr. coef.	$\frac{{}^{\mathbf{207}}\mathbf{P}\mathbf{b}}{{}^{\mathbf{206}}\mathbf{P}\mathbf{b}}$	- ±	$\frac{{}^{\mathbf{207}}\mathbf{P}\mathbf{b}}{{}^{\mathbf{235}}\mathbf{U}}$	- ±	$\frac{{}^{\mathbf{206}}\mathbf{P}\mathbf{b}}{{}^{\mathbf{238}}\mathbf{U}}$	-±
	(a)	(b)	(b)	(c)	(d)	(c)	(d)	(c)	(d)		(e)	(d)	(e)	(d)	(e)	(d)
Lk1 (BH 14-2012)
1	0.89	1.7	6.1	0.0482	2.8	0.0639	3.0	0.009608	0.98	0.374	110	67	62.6	1.9	61.64	0.60
2	0.69	0.6	17.2	0.04778	1.0	0.0633	1.1	0.009609	0.25	0.436	88	24	62.32	0.65	61.65	0.15
3	0.55	1.1	6.9	0.0483	2.5	0.0641	2.6	0.009637	0.41	0.304	113	59	63.1	1.6	61.83	0.25
4	1.10	0.7	6.2	0.0488	3.2	0.0648	3.3	0.009620	0.45	0.327	140	75	63.7	2.1	61.72	0.27
5	0.69	0.8	23.5	0.04735	0.6	0.0628	0.6	0.009615	0.20	0.469	67	13	61.82	0.38	61.69	0.12
Dz2 (BH 12-2004)
1	n.m	0.7	0.3	0.0531	16.7	0.075	18	0.01028	1.06	0.806	332	379	74	12	65.93	0.69
2	0.72	1.5	0.6	0.051	24.0	0.065	25	0.00924	1.30	0.828	228	554	64	15	59.30	0.76
3	0.87	0.7	2.2	0.0432	7.61	0.0549	7.9	0.009225	0.47	0.707	−159	189	54.3	4.2	59.20	0.28
4	0.56	0.5	1.6	0.0465	10.5	0.059	11	0.009264	0.65	0.767	20	252	58.6	6.3	59.45	0.38
5	0.82	1.0	0.8	0.0436	18.5	0.056	19	0.009276	0.86	0.816	−135	457	55	10	59.52	0.51
Bk1 (BH 5-2006)
1	0.73	1.4	17.3	0.04780	1.0	0.0632	1.0	0.0095913	0.085	0.235	88	23	62.21	0.59	61.617	0.055
2	0.71	1.0	19.0	0.04763	0.9	0.06289	0.9	0.0095814	0.083	0.240	80	21	61.93	0.55	61.555	0.053
3	0.76	0.8	25.3	0.04757	0.7	0.06284	0.7	0.0095859	0.072	0.217	77	16	61.88	0.41	61.581	0.048
SvN (Svea mine; Am1)
1	0.73	1.0	3.6	0.0481	4.6	0.0635	4.7	0.009595	0.35	0.237	104	109	62.6	2.8	61.56	0.21
2	0.70	0.9	11.2	0.04788	1.5	0.0633	1.5	0.009602	0.12	0.242	92	35	62.30	0.92	61.605	0.072
3	0.80	0.8	11.8	0.04760	1.4	0.0629	1.5	0.009598	0.12	0.256	78	34	61.92	0.88	61.575	0.073
4	0.71	1.1	7.3	0.04798	2.3	0.0635	2.3	0.009616	0.18	0.235	97	54	62.5	1.4	61.69	0.11
5	0.70	0.7	9.7	0.04765	1.7	0.0629	1.8	0.009595	0.14	0.236	81	41	62.0	1.1	61.559	0.085

(b) Pb* and Pbc represent radiogenic and common Pb, respectively. n.m.: Not measured (c) Corrected for fractionation, spike, and common Pb; all common Pb was assumed to be procedural blank. (d) Errors are 2σ, propagated using published algorithms⁵¹. (e) Calculations are based on published decay constants⁵⁴. ²⁰⁶Pb/²³⁸U and ²⁰⁷Pb/²⁰⁶Pb ages corrected for initial disequilibrium in ²³⁰Th/²³⁸U using Th/U [magma] = 3.