Table 1 Summary of samples localities and LA-ICP-MS ages

Pre-Carboniferous intrusions/Surselva group

 Russein diorite

R3

2711.559/1175.807

Val Russein, Rhine valley

348.2 ± 1.2/5.5 Ma

 Alp Crap Ner tonalite

CR2

2713.202/1177.546

E of Val Russein

339.8 ± 2.1/8.6 Ma

Group A/Rötifirn group

 Curtin monzonite

CM1

2714.046/1180.850

Disentis

327.6 ± 1.6/3.8 Ma

 Pardatschas granite

PG1

2707.143/1174.703

Truaisch above Disentis

329.9 ± 1.9/5.2 Ma

Group B/Fruttstock group

 Düssi diorite

KAW3210

Bottom of Brunni valley, upper Maderaner valley

307.1 ± 1.6/5.3 Ma

 Aplitic granite

AG1

2662.200/1162.210

Grueben glacier, Hasli valley

307.4 ± 2.0/4.4 Ma

 Munt Dado granite

MD1

2712.247/1176.083

Val Russein

 ~ 308.8 Ma

 Bugnei granodiorite

BG1

2703.345/1171.362

Above Bugnei, Sedrun

 ~ 311 Ma

Group C/Haslital group

 Grimsel granodiorite

KAW2213A

2669.000/1157.500

Above Grimsel lake

297.2 ± 1.0/4.3 Ma

 Reuss granodiorite

KAW2519

2687.660/1167.830

Schöllenen gorge, Reuss valley

298.1 ± 1.1/4.8 Ma

 Southwestern Aar granite

SW1

2669.609/1156.976

South of Grimsel pass

 ~ 296 Ma

 Garwiidi diorite

GD1

2668.366/1166.355

Ofenhorn, Hasli valley

295.6 ± 2.0/7.9 Ma

 Aplitic granite (marginal facies of Grimsel granodiorite)

AR1

2668.949/1157.361

North of Grimsel pass

299.2 ± 1.4/6.8 Ma

 Rossbodenstock diorite

RD2

2698.070/1175.383

Etzli valley, Rossbodenstock

298.6 ± 1.0/3.6 Ma

 Telltistock granite

T1

2671.835/1170.486

Trift glacier

301.2 ± 1.5/5.0 Ma

Samples not assigned to one of the above groups

 Bristenstock syenite

BS1

2694.385/1178.280

Bristenstock

 ~ 304 Ma (?)

 Strem granite

SG1

2702.959/1175.236

Piz Gendusas, Val Segnas

no age