Continuity in geochemistry and time of the Tertiary Bergell intrusion (Central Alps)

Gianola, Omar; Schmidt, Max W.; von Quadt, Albrecht; Peytcheva, Irena; Luraschi, Pietro; Reusser, Eric

doi:10.1007/s00015-014-0174-8

Swiss Journal of Geosciences

Table 4 U–Pb ID-TIMS zircon isotope data for samples from the Bergell intrusion and the Como molasse

From: Continuity in geochemistry and time of the Tertiary Bergell intrusion (Central Alps)

Sample^a	Rock type	Wt. (mg)^b	Compositional parameters							\(\frac{{^{ 20 8} {\text{Pb}}}}{{^{ 20 6} {\text{Pb}}}}\) ^g
			U (ppm)^c	\(\frac{\text{Th}}{\text{U}}\) ^d	Pb (ppm)^c	\(\frac{{{\text{Pb}}*}}{\text{Pbc}}\) ^e	Pb* (pg)^e	Pbc (pg)^e	\(\frac{{^{ 20 6} {\text{Pb}}}}{{^{ 20 4} {\text{Pb}}}}\) ^f
VRU28-1	Tonalite transition zone	0.015	1253	0.416	6.6	23.6	92.1	3.91	1497	0.133
VRU28-2	Tonalite transition zone	0.005	1088	0.438	9.1	1.4	28.6	19.87	108	0.141
VRU28-3	Tonalite transition zone	0.007	1793	0.336	19.1	18.6	132.2	7.12	1202	0.113
VRU28-7	Tonalite transition zone	0.007	883	0.426	4.8	10.8	28.8	2.66	697	0.137
VRU28-8	Tonalite transition zone	0.006	1215	0.304	6.4	9.9	34.6	3.51	656	0.098
VRU28-9	Tonalite transition zone	0.006	1692	0.184	7.9	17.8	46.6	2.61	1212	0.060
VRU28-10	Tonalite transition zone	0.024	497	0.415	2.6	19.4	60.0	3.09	1238	0.134
VRU28-11	Tonalite transition zone	0.006	2380	0.379	12.2	18.0	71.7	3.98	1160	0.122
VRU28-12	Tonalite transition zone	0.006	1228	0.450	6.4	18.7	37.1	1.99	1179	0.145
VRU30-1	Tonalite transition zone	0.012	1374	0.302	6.6	61.3	79.8	1.30	3975	0.097
VRU30-2	Tonalite transition zone	0.010	1774	0.301	8.6	62.3	83.0	1.33	4040	0.097
VRU30-3	Tonalite transition zone	0.011	1015	0.291	4.9	57.1	51.1	0.89	3709	0.094
VRU30-4	Tonalite transition zone	0.004	2135	0.2962	10.4	34.4	44.7	1.15	2289	0.095
VRU30-5	Tonalite transition zone	0.005	1372	0.371	7.0	20.3	30.1	1.49	1302	0.119
VRU30-6	Tonalite transition zone	0.004	1073	0.285	5.7	8.8	20.8	2.37	589	0.092
VRU29-1	Granodiorite transition zone	0.008	1132	0.255	36.3	121.3	294.9	2.43	7922	0.083
VRU29-2	Granodiorite transition zone	0.007	1978	0.317	9.8	34.7	61.8	1.78	2252	0.102
VRU29-3	Granodiorite transition zone	0.012	1742	0.266	8.6	17.9	93.6	5.23	1189	0.086
VRU29-4	Granodiorite transition zone	0.010	1830	0.364	22.7	0.7	91.3	133.8	62.1	0.117
VRU29-5	Granodiorite transition zone	0.004	878	0.284	4.4	14.3	17.6	1.23	945	0.091
VRU29-6	Granodiorite transition zone	0.010	2072	0.305	9.0	15.4	87.0	5.64	1016	0.098
VRU29-8	Granodiorite transition zone	0.007	1561	0.298	7.6	35.2	50.8	1.4	2293	0.096

Sample^a	Rock type	Radiogenic isotope ratios							\(\frac{{^{207} {\text{Pb}}}}{{^{206} {\text{Pb}}}}\) ⁱ	Isotopic ages
Sample^a	Rock type	\(\frac{{^{ 20 7} {\text{Pb}}}}{{^{ 20 6} {\text{Pb}}}}\) ^g	% err^h	\(\frac{{^{ 20 7} {\text{Pb}}}}{{^{ 235} {\text{U}}}}\) ^g	% err^h	\(\frac{{^{206} {\text{Pb}}}}{{^{238} {\text{U}}}}\) ^g	% err^h	Corr. coef.	\(\frac{{^{207} {\text{Pb}}}}{{^{206} {\text{Pb}}}}\) ⁱ	±^h	\(\frac{{^{207} {\text{Pb}}}}{{^{235} {\text{U}}}}\) ⁱ	±^h	\(\frac{{^{206} {\text{Pb}}}}{{^{238} {\text{U}}}}\) ⁱ	±^h
VRU28-1	Tonalite transition zone	0.046546	0.208	0.031942	0.260	0.004977	0.109	0.636	26.00	4.98	31.93	0.08	32.00	0.03
VRU28-2	Tonalite transition zone	0.046500	1.151	0.031189	1.177	0.004865	0.338	0.220	23.65	27.58	31.18	0.36	31.28	0.11
VRU28-3	Tonalite transition zone	0.049867	0.128	0.069480	0.185	0.010105	0.075	0.853	188.82	2.97	68.21	0.12	64.81	0.05
VRU28-7	Tonalite transition zone	0.046687	0.413	0.031335	0.453	0.004868	0.117	0.461	33.25	9.88	31.33	0.14	31.30	0.04
VRU28-8	Tonalite transition zone	0.046698	0.323	0.031130	0.365	0.004835	0.091	0.561	33.82	7.72	31.13	0.11	31.09	0.03
VRU28-9	Tonalite transition zone	0.046891	0.250	0.030306	0.345	0.004688	0.206	0.695	43.68	5.97	30.32	0.10	30.15	0.06
VRU28-10	Tonalite transition zone	0.046675	0.190	0.031443	0.198	0.004886	0.059	0.294	32.61	4.54	31.43	0.06	31.42	0.02
VRU28-11	Tonalite transition zone	0.046689	0.211	0.031230	0.257	0.004851	0.091	0.632	33.33	5.05	31.23	0.08	31.20	0.03
VRU28-12	Tonalite transition zone	0.046670	0.277	0.031239	0.316	0.004855	0.080	0.579	32.39	6.64	31.23	0.10	31.22	0.02
VRU30-1	Tonalite transition zone	0.046634	0.028	0.031224	0.067	0.004856	0.061	0.909	30.52	0.67	31.22	0.02	31.23	0.02
VRU30-2	Tonalite transition zone	0.046627	0.134	0.031322	0.178	0.004872	0.123	0.657	30.16	3.22	31.32	0.05	31.33	0.04
VRU30-3	Tonalite transition zone	0.046622	0.098	0.031203	0.247	0.004854	0.204	0.922	29.90	2.35	31.20	0.08	31.22	0.06
VRU30-4	Tonalite transition zone	0.046643	0.129	0.031252	0.208	0.004860	0.123	0.815	30.97	3.10	31.25	0.06	31.25	0.04
VRU30-5	Tonalite transition zone	0.046641	0.199	0.031357	0.261	0.004876	0.112	0.706	30.90	4.76	31.35	0.08	31.36	0.03
VRU30-6	Tonalite transition zone	0.046625	0.277	0.031179	0.333	0.004850	0.103	0.659	30.08	6.62	31.17	0.10	31.19	0.03
VRU29-1	Granodiorite transition zone	0.051827	0.072	0.232652	0.219	0.032558	0.187	0.950	277.78	1.65	212.39	0.42	206.5	0.38
VRU29-2	Granodiorite transition zone	0.046643	0.111	0.031375	0.226	0.004879	0.167	0.884	30.98	2.65	31.37	0.07	31.37	0.05
VRU29-3	Granodiorite transition zone	0.046641	0.152	0.030949	0.227	0.004813	0.122	0.783	30.89	3.64	30.95	0.07	30.95	0.04
VRU29-4	Granodiorite transition zone	0.046655	3.289	0.032469	3.381	0.005047	0.713	0.232	31.58	78.71	32.44	1.08	32.46	0.23
VRU29-5	Granodiorite transition zone	0.046620	0.281	0.030646	0.340	0.004768	0.118	0.630	29.80	6.73	30.65	0.10	30.66	0.04
VRU29-6	Granodiorite transition zone	0.046574	0.156	0.026673	0.215	0.004154	0.088	0.785	27.43	3.74	26.73	0.06	26.72	0.02
VRU29-8	Granodiorite transition zone	0.046698	0.185	0.031004	0.225	0.004815	0.087	0.610	33.79	4.43	31.00	0.07	30.97	0.03

Sample^a	Rock type	Wt. (mg)^b	Compositional parameters							\(\frac{{^{ 20 8} {\text{Pb}}}}{{^{ 20 6} {\text{Pb}}}}\) ^g
Sample^a	Rock type	Wt. (mg)^b	U (ppm)^c	\(\frac{\text{Th}}{\text{U}}\) ^d	Pb (ppm)^c	\(\frac{{{\text{Pb}}*}}{\text{Pbc}}\) ^e	Pb* (pg)^e	Pbc (pg)^e	\(\frac{{^{ 20 6} {\text{Pb}}}}{{^{ 20 4} {\text{Pb}}}}\) ^f
VRU40-1b	Granodiorite transition zone	0.018	2964	0.304	14.4	48.9	247.3	5.1	3187	0.098
VRU40-1	Granodiorite transition zone	0.032	2122	0.302	10.3	46.0	327.5	7.1	2998	0.097
VRU40-2	Granodiorite transition zone	0.018	1507	0.310	7.3	60.3	129.0	2.1	3905	0.100
VRU40-2b	Granodiorite transition zone	0.018	1507	0.318	7.4	103.4	132.2	1.3	6655	0.102
VRU40-3	Granodiorite transition zone	0.006	734	0.465	24.5	9.0	123.6	13.8	565	0.163
VRU40-4	Granodiorite transition zone	0.016	44	0.238	0.3	1.5	3.1	2.1	116	0.081
VRU40-5	Granodiorite transition zone	0.011	3226	0.334	16.8	13.0	167.0	12.9	853	0.107
VRU40-6	Granodiorite transition zone	0.007	1257	0.339	22.9	0.4	44.0	107	45	0.119
VRU40-7	Granodiorite transition zone	0.010	1897	0.344	9.4	33.3	94.0	2.8	2146	0.111
VRU40-8	Granodiorite transition zone	0.009	2145	0.278	10.3	43.2	92.4	2.1	2830	0.090
CMB4-1	Tonalite Como molasse	0.013	221	0.575	1.3	8	12.4	1.84	517	0.185
CMB4-2	Tonalite Como molasse	0.006	214	0.513	1.4	4	5.5	1.63	268	0.165
CMB4-3	Tonalite Como molasse	0.013	224	0.485	1.3	8	12.7	2.02	483	0.156
CMB4-6	Tonalite Como molasse	0.008	461	0.332	2.5	9	15.9	1.94	624	0.107
CMB4-7	Tonalite Como molasse	0.013	287	0.298	1.6	8	16.0	2.22	552	0.096
CMB4-4	Tonalite Como molasse	0.009	482	0.288	2.5	13	17.9	1.57	859	0.093
CMB4-5	Tonalite Como molasse	0.007	368	0.314	2.1	7	10.7	1.82	451	0.101

Sample^a	Rock type	Radiogenic isotope ratios							\(\frac{{^{207} {\text{Pb}}}}{{^{206} {\text{Pb}}}}\) ⁱ	Isotopic ages
Sample^a	Rock type	\(\frac{{^{ 20 7} {\text{Pb}}}}{{^{ 20 6} {\text{Pb}}}}\) ^g	% err^h	\(\frac{{^{ 20 7} {\text{Pb}}}}{{^{ 235} {\text{U}}}}\) ^g	% err^h	\(\frac{{^{206} {\text{Pb}}}}{{^{238} {\text{U}}}}\) ^g	% err^h	Corr. coef.		±^h	\(\frac{{^{207} {\text{Pb}}}}{{^{235} {\text{U}}}}\) ⁱ	±^h	\(\frac{{^{206} {\text{Pb}}}}{{^{238} {\text{U}}}}\) ⁱ	±^h
VRU40-1b	Granodiorite transition zone	0.046736	0.225	0.031283	0.440	0.004855	0.383	0.858	35.75	5.39	31.28	0.14	31.22	0.12
VRU40-1	Granodiorite transition zone	0.046684	0.233	0.031237	0.443	0.004853	0.383	0.851	33.07	5.58	31.23	0.14	31.21	0.12
VRU40-2	Granodiorite transition zone	0.046599	0.148	0.031062	0.240	0.004834	0.158	0.799	28.72	3.54	31.06	0.07	31.09	0.05
VRU40-2b	Granodiorite transition zone	0.046646	0.085	0.031789	0.238	0.004943	0.204	0.938	31.15	2.03	31.78	0.07	31.78	0.06
VRU40-3	Granodiorite transition zone	0.055348	0.190	0.218956	0.246	0.028691	0.102	0.692	426.32	4.24	201.04	0.45	182.35	0.18
VRU40-4	Granodiorite transition zone	0.049221	1.890	0.031258	2.011	0.004606	0.222	0.583	158.35	44.18	31.25	0.62	29.62	0.07
VRU40-5	Granodiorite transition zone	0.046711	0.171	0.031467	0.265	0.004886	0.162	0.782	34.48	4.10	31.46	0.08	31.42	0.05
VRU40-6	Granodiorite transition zone	0.050988	3.393	0.037137	3.303	0.005283	1.151	0.095	240.28	78.14	37.03	1.20	33.96	0.39
VRU40-7	Granodiorite transition zone	0.046822	0.195	0.031265	0.249	0.004843	0.126	0.638	40.13	4.65	31.26	0.08	31.14	0.04
VRU40-8	Granodiorite transition zone	0.046816	0.150	0.030984	0.203	0.004800	0.101	0.706	39.85	3.59	30.98	0.06	30.87	0.03
CMB4-1	Tonalite Como molasse	0.046671	0.588	0.032145	0.614	0.004995	0.076	0.391	32.45	14.07	32.13	0.19	32.12	0.02
CMB4-2	Tonalite Como molasse	0.046672	1.462	0.032133	1.525	0.004993	0.180	0.399	32.46	34.98	32.11	0.48	32.11	0.06
CMB4-3	Tonalite Como molasse	0.046665	0.655	0.032115	0.679	0.004991	0.104	0.309	32.12	15.67	32.10	0.21	32.10	0.03
CMB4-6	Tonalite Como molasse	0.046665	0.488	0.032019	0.508	0.004976	0.081	0.324	32.14	11.67	32.00	0.16	32.00	0.03
CMB4-7	Tonalite Como molasse	0.046669	0.472	0.032027	0.492	0.004977	0.080	0.334	32.33	11.29	32.01	0.16	32.01	0.03
CMB4-4	Tonalite Como molasse	0.046664	0.502	0.031985	0.518	0.004971	0.088	0.254	32.04	12.02	31.97	0.16	31.97	0.03
CMB4-5	Tonalite Como molasse	0.046663	0.719	0.032011	0.749	0.004975	0.099	0.363	32.02	17.19	31.99	0.24	31.99	0.03

^aLabels for fractions composed of single zircon grains or fragments; all zircons are annealed-leached (after Mattinson 2005)
^bNominal fraction weights measured after chemical abrasion
^cNominal U and total Pb concentrations subject to uncertainty in weighting zircons
^dModel Th/U ratio calculated from radiogenic ²⁰⁸Pb/²⁰⁶Pb ratio, assuming concordance
^ePb* and Pbc represent radiogenic and common Pb, respectively
^fMeasured ratio corrected for spike and fractionation only
^gCorrected for fractionation, spike, and common Pb; the composition of the procedure blank: ²⁰⁶Pb/²⁰⁴Pb = 18.08 ± 0.22 %; ²⁰⁷Pb/²⁰⁴Pb = 15.62 ± 0.28 %; ²⁰⁸Pb/²⁰⁴Pb = 38.0 5 ± 0.59 %, the procedure blank was estimated between 0.5–1.5 ppb; the common Pb correction according Stacey and Kramers (1975) at 31 Ma (all uncertainties 2-sigma). ²⁰⁶Pb/²³⁸U and ²⁰⁷Pb/²⁰⁶Pb ratios corrected for initial disequilibrium in ²³⁰Th/²³⁸U
^hErrors are 2-sigma, propagated using the algorithms of Schmitz and Schoene (2007) and Crowley et al. (2007)
ⁱCalculations are based on the decay constants of Jaffey et al. (1971). ²⁰⁶Pb/²³⁸U and ²⁰⁷Pb/²⁰⁶Pb ages corrected for initial disequilibrium in ²³⁰Th/²³⁸U

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