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Table 2 U–Pb isotope data on zircons from pre-Variscan basement rocks (LA-ICPMS, Univ. Lausanne)

From: Timing of Palaeozoic magmatism in the Maggia and Sambuco nappes and paleogeographic implications (Central Lepontine Alps)

Spot

Analyse number

207Pb/235U

±1σ

206Pb/238U

±1σ

Rho

207Pb/235U apparent age (Ma)

±2σ

206Pb/238U apparent age (Ma)

±2σ

Pre-Variscan Basement

 DB25

Massari augengneiss

  1

G2

0.5889

410

0.0745

42

0.4008

470.1

52.4

463.1

49.9

  2

G3

0.5983

290

0.0732

27

0.3785

476.2

36.8

455.6

32.2

  3

H2

0.5949

369

0.0766

40

0.4183

474.0

47.0

475.8

47.6

  4

H3

0.5849

272

0.0741

26

0.3766

467.6

34.8

461.0

31.2

  5

H5

0.5996

434

0.0768

44

0.3920

477.0

55.1

476.9

52.2

  6

I1

0.5859

242

0.0734

21

0.3504

468.3

30.9

456.7

25.5

  7

I4

0.5889

552

0.0755

59

0.4176

470.2

70.6

468.9

70.8

  8

I6

0.5754

242

0.0737

21

0.3440

461.5

31.2

458.7

25.6

  9

I7

0.5653

398

0.0724

30

0.2899

455.0

51.6

450.8

35.5

  10

I8

0.5922

89

0.0754

9

0.4149

472.3

11.3

468.4

11.2

 DB38

Sasso Nero augengneiss

  1

H2

0.8528

374

0.0982

34

0.3934

626.2

41.0

603.8

39.8

  2

H3

0.8745

1007

0.0988

92

0.4040

638.0

109.1

607.3

107.8

  3

H13

0.8437

1,188

0.0974

115

0.4189

621.2

130.9

599.3

135.0

  4

H15

0.8253

139

0.0987

13

0.3772

611.0

15.5

606.9

14.7

  5

I10

0.8845

528

0.0964

38

0.3324

643.4

56.9

593.1

45.0

  6

I22

0.8392

300

0.0963

32

0.4652

618.7

33.1

593.0

37.6

 DB61

Sasso Nero augengneiss

  1

J1

0.8612

165

0.1008

11

0.2939

630.8

18.0

619.3

13.3

  2

J1-2

0.6054

213

0.0770

21

0.3866

480.6

27.0

478.3

25.1

  3

J2-2

0.7375

384

0.0875

36

0.4002

560.9

44.9

540.6

43.2

  4

K3

0.5326

1,111

0.0669

67

0.2387

433.5

147.2

417.4

80.5

  5

K4

0.6318

531

0.0737

41

0.3342

497.2

66.0

458.5

49.7

  6

K10

0.5891

90

0.0761

8

0.3291

470.3

11.5

472.9

9.2

  7

K11-2

0.7175

949

0.0846

109

0.4861

549.2

112.2

523.4

129.2

  8

K12

0.5934

486

0.0764

30

0.2398

473.0

61.9

474.4

35.9

  9

K13-2

0.5183

406

0.0661

45

0.4382

424.0

54.3

412.8

54.9

  10

K16

0.5212

496

0.0677

52

0.4018

426.0

66.3

422.1

62.5

  11

K17

0.8719

978

0.1028

92

0.4006

636.6

106.1

630.6

108.0

  12

K17-2

0.7318

442

0.0895

44

0.4094

557.6

51.8

552.8

52.3

  13

K19

0.7109

1,707

0.0853

200

0.4893

545.3

202.6

527.9

238.2

  14

K19-2

0.5067

539

0.0643

61

0.4436

416.2

72.6

402.0

73.5

  15

K23

0.5306

339

0.0695

34

0.3827

432.2

45.0

433.0

41.0

  16

K54

0.8536

788

0.1026

70

0.3688

626.6

86.3

629.4

81.6

  17

L1-2

0.8871

668

0.1063

56

0.3522

644.8

71.9

651.1

65.7

  18

L3

0.6695

1,318

0.0868

63

0.1837

520.4

160.3

536.5

74.4

  19

L4

0.8733

242

0.1047

15

0.2525

637.4

26.2

642.1

17.1

  20

L5

0.6079

417

0.0763

25

0.2363

482.2

52.7

473.8

29.6

  21

L8

0.5982

360

0.0772

26

0.2822

476.1

45.7

479.4

31.4

  22

L10

0.8503

1,060

0.1029

99

0.3869

624.8

116.3

631.2

116.0

  23

L10-2

0.6766

541

0.0839

30

0.2255

524.7

65.6

519.1

36.0

  24

L14

0.6064

461

0.0748

52

0.4579

481.3

58.3

464.8

62.4

  25

L19

0.5102

339

0.0666

31

0.3510

418.6

45.6

415.9

37.6

  26

L23

0.5149

350

0.0663

35

0.3916

421.7

46.9

414.1

42.7

  27

L27

0.8883

980

0.1055

97

0.4191

645.5

105.3

646.4

113.7

  28

L40-2

0.5398

308

0.0693

25

0.3123

438.3

40.7

432.0

29.8

  29

L40-3

0.5178

261

0.0647

18

0.2678

423.7

35.0

404.2

21.2

 DB26

Massari diorite

  1

G1

0.7109

1,565

0.0883

67

0.1718

545.3

185.7

545.5

79.1

  2

G3-2

0.7048

830

0.0857

90

0.4432

541.6

98.9

530.2

106.3

  3

G4

0.7197

145

0.0903

9

0.2562

550.5

17.1

557.3

11.0

  4

G4-2

0.6779

671

0.0823

63

0.3842

525.5

81.2

509.6

74.5

  5

G5

0.7396

843

0.0891

81

0.3995

562.2

98.5

550.0

96.1

  6

G5-2

0.6714

201

0.0847

17

0.3396

521.6

24.4

524.1

20.4

  7

G6

0.7513

715

0.0898

69

0.4024

569.0

82.9

554.1

81.4

  8

G7

0.7302

718

0.0884

67

0.3830

556.7

84.2

546.2

78.9

  9

G8

0.7024

421

0.0861

32

0.3053

540.2

50.2

532.4

37.4

  10

G8-2

0.7093

142

0.0882

9

0.2571

544.3

16.9

545.1

10.8

  11

H2

0.7165

171

0.0880

10

0.2413

548.6

20.2

543.9

12.0

  12

H4

0.6902

447

0.0841

31

0.2842

532.9

53.7

520.6

36.8

  13

H6

0.6859

844

0.0868

84

0.3944

530.3

101.6

536.9

100.0

  14

H7

0.7130

347

0.0864

20

0.2354

546.5

41.1

534.3

23.5

  15

H9

0.7248

127

0.0890

10

0.3094

553.5

15.0

549.6

11.4

  16

H10

0.6981

557

0.0852

45

0.3283

537.7

66.7

527.3

53.1

  17

H17

0.7149

737

0.0863

35

0.1993

547.7

87.3

533.9

42.1

  18

H21

0.6795

365

0.0848

37

0.4031

526.4

44.2

524.5

43.7

  19

H22

0.7336

678

0.0877

37

0.2288

558.7

79.4

542.2

44.0

  20

H24

0.7142

158

0.0871

11

0.2769

547.2

18.8

538.3

12.7

  21

H25

0.7208

644

0.0891

51

0.3232

551.1

76.0

550.0

60.9

  22

H26

0.7129

315

0.0877

28

0.3641

546.4

37.3

541.9

33.4

 DB66

Scheggia diorite

  1

J5

0.6747

273

0.0845

28

0.4084

523.6

33.1

522.9

33.2

  2

J6

0.7131

538

0.0853

43

0.3377

546.6

63.7

527.4

51.6

  3

J7

0.6777

836

0.0859

67

0.3184

525.4

101.2

531.3

80.1

  4

J8

0.6967

320

0.0837

29

0.3753

536.8

38.3

518.2

34.3

  5

J11

0.7335

428

0.0897

35

0.3343

558.6

50.2

554.0

41.5

  6

J12

0.7021

503

0.0841

36

0.2984

540.0

60.0

520.6

42.8

  7

J13

0.6568

586

0.0852

36

0.2368

512.7

71.9

526.9

42.8

  8

J14

0.6768

421

0.0844

36

0.3458

524.9

51.0

522.2

43.2

  9

J27

0.7146

169

0.0880

13

0.3133

547.5

20.0

543.8

15.5

  10

J28

0.7193

383

0.0888

24

0.2561

550.3

45.2

548.6

28.7

  11

J30

0.6842

309

0.0848

23

0.2972

529.3

37.3

524.6

27.1

  12

J31

0.6961

382

0.0840

24

0.2599

536.4

45.7

520.0

28.5

  13

J33

0.6926

498

0.0855

50

0.4060

534.4

59.8

529.0

59.3

  14

J34

0.7176

443

0.0880

28

0.2552

549.2

52.4

543.5

32.9

  15

J47

0.6962

322

0.0840

32

0.4062

536.5

38.6

520.0

37.6

  16

J50

0.6799

341

0.0859

28

0.3226

526.7

41.2

531.4

33.0

  17

K2

0.6811

427

0.0853

41

0.3836

527.4

51.6

527.6

48.7

  18

K9

0.6890

528

0.0863

49

0.3673

532.2

63.4

533.5

57.6

  19

K11

0.7155

344

0.0866

26

0.3118

548.0

40.7

535.4

30.8

  20

K13

0.7078

607

0.0872

60

0.4023

543.4

72.1

539.0

71.3

 DB04

Zött paragneiss

  1

E1

0.6573

650

0.0813

46

0.2839

512.9

39.8

503.9

27.2

  2

E4

0.6065

874

0.0734

59

0.2780

481.3

55.2

456.8

35.3

  3

E4-2

0.6496

1,118

0.0772

49

0.1849

508.2

68.8

479.5

29.4

  4

E7

0.6066

1,008

0.0777

73

0.2820

481.4

63.7

482.3

43.6

  5

E7-2

0.5959

1,928

0.0701

203

0.4468

474.6

122.7

436.5

122.0

  1. Errors refer to last significant digits