Archean, highly unradiogenic lead in shallow cratonic mantle

Jun-Bo Zhanga,b, Yong-Sheng Liua,*, Mihai N. Duceac,d, Rong Xua

a State Key Laboratory of Geological Processes and Mineral Resources, School of Earth Sciences, China University

of Geosciences, Wuhan 430074, China

b Institute of Geophysics and Geomatics, China University of Geosciences, Wuhan 430074, China,

c Department of Geosciences, University of Arizona, Tucson, AZ 85721, USA

d Faculty of Geology and Geophysics, University of Bucharest, 010041 Bucharest, Romania

*Corresponding author. State Key Laboratory of Geological Processes and Mineral Resources, China University of

Geosciences, Wuhan 430074, China. Tel: 86-27-67883003; Fax: 86-27-67885096.

Email address: yshliu@hotmail.com (Y.-S. Liu)

Supplementary Online Materials

This PDF file includes:

Analytic methods Figures DR1 to DR2Tables DR1 to DR5

Supporting References

GSA Data Repository 2020172

1. Analytic methods

1.1. Zircon U–Pb dating

Zircon grains were separated using standard density and magnetic separation techniques.

Representative grains were mounted in an epoxy resin disc and polished. Their internal structures

were examined using cathodoluminescence (CL) at the State Key Laboratory of Geological

Processes and Mineral Resources, China University of Geosciences in Wuhan (GPMR-CUG).

U–Pb isotopic analyses were carried out by LA-ICP-MS at GPMR-CUG. Laser sampling was

performed with a spot size of 32 μm using a GeoLas 2005. An Agilent 7500a ICP-MS instrument

was used to acquire ion-signal intensities using Helium as a carrier gas. Argon was used as the

make-up gas and mixed with the carrier gas via a T-connector before entering the ICP. Detailed

operating conditions for the laser ablation system and the ICP-MS instrument and data reduction

are described by Liu et al. (2010). Off-line selection and integration of background and analyte

signals, and time-drift correction and quantitative calibration for trace element contents and U-Pb

dating were performed by ICPMSDataCal (Liu et al., 2010). Zircons from the Jinan gabbro are

euhedral in morphology (up to 150 μm in length) and show clear oscillatory zoning in

cathodoluminescence images (Fig. DR1). The 206Pb/238U ages of twenty-two zircon grains

analyzed by LA-ICP-MS cluster in the range of 124–129 Ma with a weighted mean of 127.3 ± 0.7

Ma (Fig. DR1 and Table DR1), indicating crystallization age of the Jian gabbro.

1.2. In situ analyses of sulfur isotope in sulfide

In situ analyses of sulfur isotope in sulfide were carried out using a 257 nm Yb femtosecond

(fs) laser ablation system (NWR-FemtoUC, USA) coupled to a Neptune Plus multiple collector

inductively coupled plasma mass spectrometer (MC-ICP-MS, Thermo Fisher Scientific, Germany)

at GPMR-CUG. The Neptune Plus is a double-focusing MC-ICP-MS with a movable

multi-collector array of Faraday cups which permitted the simultaneous detection of 32S, 33S and

34S signals collected in the L3, center and H3 Faraday cups, respectively. The detailed

instrumental and data acquisition parameters of the lasers and the MC-ICP-MS are listed in the

previous study (Fu et al., 2017).

The final sulfur isotope ratios (34S/32S) were calculated by correcting for instrumental mass

bias using linear interpolation between the biases calculated from four neighboring standard

analyses. All results are expressed in ‰ using delta notation as follows: δ34SV-CDT (‰) =

(34S/32S)sample/(34S/32S)V-CDT − 1] × 1000, where (34S/32S)sample is the measured 34S/32S of the sample

and (34S/32S)V-CDT is defined as (34S/32S)V-CDT = 0.044163 [V-CDT represents the Vienna Canon

Diablo Troilite (Ding et al., 2001)]. Pyrite PPP-1 reference material (a pyrite single crystal from

the Sukhoi Log deposit, Russia) was used to determine the instrumental mass fractionation (IMF)

and the reference mass instrumental law. The sulfur isotopic values [δ34SV-CDT (‰) = 5.301 ±

0.142 (n = 65, 2σ)] of PPP-1 measured here (see Figure below) are agreement with the reference

values [δ34SV-CDT (‰) = 5.30 ± 0.20 (2σ) (Gilbert et al., 2014)].

1.3. Bulk major and trace element analyses

Whole-rock samples were crushed in a corundum jaw crusher (to 60 mesh). Approximately

60 g was powdered in an agate ring mill to less than 200 mesh. The major elements were

determined by using a Rigaku RIX 2100 X-ray fluorescence spectrometer (XRF) at the State Key

Laboratory of Continental Dynamics, Northwest University in Xi'an, China. Analyses of reference

materials and duplicate analyses suggest that the analytical precision and accuracy are better than

5% (Rudnick et al., 2004; Gao et al., 2008).

Trace elements were analyzed with an Agilent 7500a inductively coupled plasma mass

spectrometry (ICP-MS) at the GPMR-CUG. Sample powder (200 mesh, ~50 mg each) was

weighed into a Teflon bomb and moistened with a few drops of Milli-Q ultrapure water. Then, 1.5

ml of HNO3 and 1.5 ml of HF were added to the Teflon bomb, which was sealed in a steel jacket

and heated in an oven at 190 °C for 48 h to completely dissolve the sample. After opening the

bomb and evaporating the solution on a hotplate at ~115 °C to dryness, 1 ml of HNO3 was added

to the Teflon bomb and evaporated to a second round of dryness. The resultant salt was

re-dissolved by adding ~3 ml of 30% HNO3, resealed in a steel jacket and heated in an oven at

190 °C for 12–24 h. The final solution was diluted to ~100 g with a mixture of 2% HNO3 for

ICP-MS analysis. Analyses of international rock standards (AGV-2, BHVO-2 and BCR-2)

4.9

5.1

5.3

5.5

5.7

5.9

Pyrite PPP-1 reference material (n = 65)Ave. value = 5.301 ± 0.142 (this study)Ref. value = 5.30 ± 0.20

δ34 S

V-C

DT

(‰)

indicate that the precision and accuracy are better than 5% for most elements and ~10% for some

transitional elements (Zhang et al., 2017).

1.4. Sr–Nd-Pb isotope analyses

The Sr-Nd-Pb isotope ratios were determined by using a Finnigan Triton thermal ionization

mass spectrometer (TIMS) at the GPMR-CUG. For Rb–Sr and Sm–Nd isotope analyses, sample

powders (200 mesh, ~50 mg each) were digested in Teflon bombs by using mixed agents of

double distilled HNO3 (1 ml) and HF (1 ml) acids at 190 °C for 48 h. After the samples were

completely dissolved, the solutions were dried on a hotplate at 115 °C to remove the HF. The

sample residues were re-dissolved in 1–2 ml of 6 N HCl and then dried down again. Finally, the

samples were dissolved in 1 ml of 2.5 N HCl and then centrifuged to remove any remaining

undissolved material.

The elements Nd and Sr were separated and purified in a clean laboratory by successively

using ion exchange columns of a Dowex AG50WX12 cation resin and Eichrom Ln-Spec resin.

The isotopic ratios of 143Nd/144Nd and 87Sr/86Sr were normalized to 146Nd/144Nd = 0.721900 and

88Sr/86Sr = 8.375209, respectively. Analyses of the reference materials BCR-2 (143Nd/144Nd =

0.512640 ± 3) and NBS-607 (87Sr/86Sr = 1.200 393 ± 10) demonstrate the analytical precision and

accuracy to better than 0.01‰. Measurements of the La Jolla and NBS987 standards provide

average values of 0.511847 ± 3 (n = 25) and 0.710254 ± 8 (n = 22) for the 143Nd/144Nd and

87Sr/86Sr ratios, respectively.

For Pb isotope determination, ~50 mg sample powders were weighed into the Teflon cup and

dissolved in concentrated HNO3 and HF at 190 °C for 48 h. Pb was separated and purified by ion

exchange columns of Dowex AG50WX12 cation resin with diluted HBr as eluant. Pb standard

NBS 981 was used to determine isotopic fractionation, and the measured isotopic ratios of samples

were corrected with a value of 0.11% per atomic mass unit. Ten analyses on NBS 981 during the

course of this study yielded 206Pb/204Pb = 16.9376 ± 0.0015 (2σ), 207Pb/204Pb = 15.4939 ± 0.0014

(2σ), and 208Pb/204Pb = 36.7219 ± 0.0033 (2σ).

List of geochemical datasets showed in Figure 4C–D

Carbonate (Bolhar et al., 2015)

Shale (Pollack et al., 2009)

Banded iron Formation(Frei and Polat, 2007; Frei et al., 2008; Døssing et al., 2009)

Marble Bar Chert (Li et al., 2013)

Sulfide in sedimentary rock (Døssing et al., 2009)

Modern global subducting sediments (GLOSS) (Plank and Langmuir, 1998)

OIB from GEOROC (http://georoc.mpch-mainz.gwdg.de/georoc)

Uranium contents of black shales (Partin et al., 2013; Wille et al., 2013)

Earth’s atmospheric oxygen content (Campbell and Allen, 2008)

50 mm0.0186

0.0190

0.0194

0.0198

0.0202

0.0206

0.0210

0.11 0.12 0.13 0.14 0.15 0.16 0.17

120

132

207 235Pb/ U2

06

23

8P

b/

U

206 238Weighted mean Pb/ U127.3 ± 0.7 Ma (n = 22)

MSWD = 1.3

Jinan

Figure DR1. Concordia plots for LA-ICP-MS zircon geochronology of Jinan gabbro (MJN0606). Insets show CL images of representative grains analysed.

A B

C D

10μm 10μm

olivine plagioclase

500μm500μm

E F

chalcopyrite

pyrite

silicate melt

pyrite pyrite

50μm50μm

Figure DR2. A-B: Photomicrographs of thin sections of Jinan gabbros (A for MJN0607; B for JN0613) under cross-polarized light. They are mainly composed of coarse-grained plagioclase, hypersthene, augite, olivine and magnetite. C-E: Reflected-light photomicrographs of sulfide (pyrite ± chalcopyrite) inclusions in Jinan gabbros. F: Reflected-light photomicrograph of coexisting sulfide and silicate melt inclusions in olivine, showing two separate, immiscible phases.

Table DR1. U–Pb ages of zircons for the Early Cretaceous Jinan gabbros.

Analysis

number

Th

(ppm)

U

(ppm) Th/U

Isotopic ratio Apparent age (Ma) Concordance

207Pb/206Pb±σ 206Pb/238U±σ 207Pb/235U±σ 208Pb/232Th±σ 206Pb/238U±σ

MJN0606

JUL06E07 193 213 0.91 0.04964 0.00154 0.01946 0.00021 0.1332 0.00402 0.00593 0.00008 124.2 1.35 0.99

JUL06E06 272 384 0.71 0.04949 0.00146 0.01953 0.00022 0.1333 0.00383 0.00599 0.00009 124.7 1.36 0.99

JUL06E08 202 250 0.81 0.04915 0.00161 0.01956 0.00022 0.13258 0.00424 0.00642 0.0001 124.9 1.41 0.99

JUL06E13 89 124 0.72 0.04984 0.0024 0.01965 0.00026 0.13507 0.00639 0.00605 0.00013 125.5 1.61 0.99

JUL06E22 229 223 1.03 0.04931 0.00152 0.01967 0.00022 0.13374 0.00403 0.00641 0.00008 125.6 1.37 0.99

JUL06E15 303 300 1.01 0.04832 0.00131 0.01971 0.00021 0.13134 0.00346 0.00608 0.00007 125.8 1.32 1.00

JUL06E21 73 111 0.66 0.05081 0.00365 0.01972 0.00035 0.13816 0.00971 0.00612 0.00021 125.9 2.19 0.98

JUL06E30 499 472 1.06 0.04826 0.0011 0.01986 0.00021 0.1322 0.00293 0.00622 0.00007 126.8 1.3 1.00

JUL06E10 644 628 1.03 0.04935 0.00117 0.01992 0.00021 0.13561 0.00313 0.00627 0.00007 127.2 1.31 0.99

JUL06E17 383 478 0.80 0.04905 0.00105 0.01992 0.0002 0.13476 0.00279 0.00624 0.00007 127.2 1.28 1.00

JUL06E25 342 466 0.73 0.04831 0.00109 0.01996 0.0002 0.13299 0.00292 0.00628 0.00008 127.4 1.29 1.00

JUL06E28 241 261 0.92 0.04875 0.00138 0.01997 0.00022 0.13423 0.00371 0.0063 0.00008 127.4 1.37 1.00

JUL06E34 321 456 0.70 0.04777 0.00106 0.02 0.00021 0.13174 0.00284 0.00655 0.00008 127.7 1.3 1.01

JUL06E24 323 464 0.70 0.04738 0.00113 0.02008 0.00021 0.13121 0.00306 0.00631 0.00008 128.2 1.32 1.01

JUL06E33 278 295 0.94 0.05000 0.0013 0.02009 0.00021 0.13848 0.0035 0.00628 0.00008 128.2 1.36 0.99

JUL06E31 541 558 0.97 0.04852 0.00098 0.0201 0.0002 0.13448 0.00262 0.00626 0.00007 128.3 1.29 1.00

JUL06E16 191 213 0.90 0.05034 0.00166 0.02013 0.00023 0.13976 0.00451 0.00593 0.00009 128.5 1.45 0.98

JUL06E14 303 301 1.01 0.04777 0.0013 0.02018 0.00021 0.13299 0.00353 0.00615 0.00008 128.8 1.36 1.01

JUL06E29 674 626 1.08 0.04759 0.00095 0.0202 0.0002 0.13256 0.00257 0.00636 0.00007 128.9 1.29 1.01

JUL06E09 910 832 1.09 0.04916 0.00084 0.02021 0.0002 0.13704 0.00225 0.00618 0.00006 129 1.25 0.99

JUL06E32 113 183 0.62 0.04708 0.0019 0.02025 0.00024 0.13145 0.0052 0.00675 0.00012 129.2 1.53 1.02

JUL06E23 1847 1373 1.34 0.04964 0.00079 0.02027 0.0002 0.13879 0.00213 0.00638 0.00006 129.4 1.25 0.99

Table DR2. Geochemical compositions for the Early Cretaceous Jinan gabbros.

Sample MJN0602 MJN0603 MJN0604 MJN0605 MJN0606 MJN0607 MJN0608 MJN0609 MJN0610 MJN0612 MJN0613

Location 36°42.59′N 36°42.60′N 36°42.64′N 36°42.67′N 36°43.61′N

116°57.52′E 116°57.54′E 116°57.51′E 116°57.68′E 117°03.66′E

SiO2 53.47 54.53 53.43 53.56 51.78 48.48 48.45 49.51 55.08 56.35 53.05

TiO2 0.65 0.77 0.74 0.86 0.69 0.61 0.61 0.49 0.69 0.71 0.60

Al2O3 13.09 14.15 13.55 14.26 13.81 11.24 11.23 14.56 15.07 15.57 14.68

TFe2O3 9.69 9.32 9.74 9.14 9.93 12.46 12.90 10.70 8.35 8.12 9.38

MnO 0.16 0.15 0.15 0.13 0.16 0.19 0.19 0.16 0.12 0.13 0.14

MgO 9.57 7.79 9.07 7.65 8.58 13.71 13.33 11.02 7.40 6.68 8.68

CaO 8.97 8.08 8.79 9.28 9.00 11.16 10.82 11.03 7.22 7.28 8.89

Na2O 2.57 2.81 2.63 2.73 2.71 1.48 1.90 1.98 3.38 3.55 2.87

K2O 1.04 1.78 1.28 1.38 0.83 0.23 0.36 0.30 1.67 1.48 1.24

P2O5 0.13 0.17 0.20 0.38 0.17 0.32 0.08 0.12 0.24 0.24 0.18

LOI 0.20 0.28 0.03 0.26 -0.06 -0.32 -0.26 -0.08 0.41 0.03 -0.70

TOTAL 99.54 99.83 99.61 99.63 97.60 99.56 99.61 99.79 99.63 100.14 99.01

Mg# 66.17 62.35 64.85 62.38 63.12 68.55 67.18 67.11 63.71 61.97 64.70

V 184 210 313 233 251 259 282 275 184 193 255.29

Cr 702 466 835 376 646 698 608 756 504 380 616

Ni 132 90.1 161 105 136 151 149 186 165 125 149

Rb 26.7 38.9 40.1 33.4 23.1 3.48 6.18 5.66 34.8 34.8 35.5

Sr 404 445 605 483 619 407 436 765 614 604 720

Y 17.8 19.5 25.7 23.1 22.4 12.2 11.2 12.6 17.5 17.6 21.9

Zr 55.6 64.7 99.3 78.9 69.9 15.9 23.1 21.6 80.8 86.0 88.5

Nb 4.21 4.66 6.13 5.40 4.37 0.60 1.00 0.88 5.09 5.20 4.77

Ba 484 842 866 598 630 173 222 313 812 769 757

La 13.2 16.4 20.2 19.9 18.1 6.06 4.99 6.49 19.0 20.1 17.9

Ce 29.3 34.9 47.2 46.5 40.6 15.2 12.4 15.1 40.7 42.6 40.6

Pr 3.67 4.33 5.46 5.54 4.98 2.13 1.75 2.05 4.75 4.94 4.98

Nd 16.4 19.1 24.6 24.0 21.7 10.4 8.35 9.98 20.0 21.0 21.2

Sm 3.81 4.00 5.29 5.12 4.90 2.65 2.29 2.54 4.04 4.15 4.68

Eu 1.12 1.28 1.59 1.38 1.59 0.84 0.80 1.11 1.25 1.25 1.48

Gd 3.01 3.42 4.52 4.35 4.11 2.32 2.00 2.33 3.23 3.36 3.87

Tb 0.49 0.55 0.70 0.65 0.64 0.36 0.33 0.36 0.48 0.49 0.58

Dy 3.13 3.36 4.34 3.99 4.07 2.21 2.02 2.31 2.98 3.03 3.61

Ho 0.64 0.67 0.88 0.78 0.81 0.44 0.40 0.46 0.60 0.61 0.72

Er 1.67 1.78 2.34 1.95 2.00 1.10 0.98 1.18 1.54 1.54 1.87

Tm 0.23 0.25 0.31 0.26 0.28 0.14 0.13 0.16 0.22 0.22 0.26

Yb 1.64 1.77 2.33 1.86 2.09 1.03 0.95 1.14 1.57 1.56 1.84

Lu 0.22 0.26 0.31 0.24 0.28 0.13 0.13 0.15 0.21 0.22 0.26

Hf 1.54 1.68 2.42 2.06 1.83 0.49 0.68 0.65 1.84 2.03 2.10

Ta 0.23 0.23 0.31 0.28 0.25 0.057 0.073 0.082 0.25 0.28 0.27

Pb 6.25 7.93 9.97 7.96 9.12 1.67 2.15 3.15 5.02 7.24 8.06

Th 1.72 2.35 2.26 2.55 1.89 0.26 0.38 0.33 1.89 2.04 2.05

U 0.51 0.63 0.65 0.73 0.53 0.08 0.12 0.12 0.51 0.57 0.65

Eu/Eu* 1.01 1.05 0.99 0.89 1.08 1.03 1.14 1.39 1.06 1.02 1.05

Fe/Mn 52.63 56.38 57.07 59.83 54.36 58.33 58.31 59.44 57.59 57.97 57.36

Y/Yb 10.85 11.02 11.03 12.42 10.72 11.84 11.79 11.05 11.15 11.28 11.90

Gd/Lu 13.68 13.15 14.58 18.13 14.68 17.85 15.38 15.53 15.38 15.27 14.88

Ba/Rb 18.1 21.6 21.6 17.9 27.3 49.7 35.9 55.3 23.3 22.1 21.3

Ba/Th 281 358 383 235 333 665 584 948 430 377 369

Th/U 3.37 3.73 3.48 3.49 3.57 3.25 3.17 2.75 3.71 3.58 3.15

Table DR3. Sulfur isotopic composition of sulfides in the Jinan gabbros.

Sample name Mineral δ34SV-CDT (‰) ±2σ

17JN10-1 pyrite 24.92 0.11

17JN10-2 pyrite 23.87 0.22

17JN10-6 pyrite 25.31 0.31

17JN10-14 pyrite 23.96 0.16

17JN10-19 pyrite 25.34 0.19

TDM

2.31

1.98

2.01

2.06

2.30

2.99

3.84

3.00

2.28

2.25

2.20

Table DR4. Bulk Sr-Nd isotopic compositions for the Early Cretaceous Jinan gabbros. εNd

-8.49

-8.92

-8.46

-9.41

-9.77

-10.01

-10.57

-10.06

-13.77

-14.20

-9.57

Note, Chondrite uniform reservoir (CHUR) values (87Rb/86Sr = 0.0847, 87Sr/86Sr = 0.7045, 147Sm/144Nd = 0.1967, 143Nd/144Nd = 0.512638) are used for the calculation. λRb= 1.42×10-11 year-1; λSm= 6.54×10-12

year-1. Both initial Sr and εNd were obtained by assuming 127 Ma. Ratios of 147Sm/144Nd and 87Rb/86Sr were calculated using Sm, Nd, Rb and Sr concentrations determined by ICP-MS.

(143Nd/144Nd)i

0.512042

0.512020

0.512044

0.511995

0.511976

0.511964

0.511935

0.511961

0.511771

0.511749

0.511987

2σ

2

1

1

1

1

3

1

2

1

2

1

143Nd/144Nd

0.512157

0.512124

0.512150

0.512100

0.512088

0.512090

0.512071

0.512087

0.511871

0.511847

0.512096

147Sm/144Nd

0.1409

0.1269

0.1300

0.1287

0.1363

0.1538

0.1659

0.1536

0.1218

0.1192

0.1335

Nd (ppm)

16.4

19.1

24.6

24.0

21.7

10.4

8.35

9.98

20.0

21.0

21.2

Sm (ppm)

3.81

4.00

5.29

5.12

4.90

2.65

2.29

2.54

4.04

4.15

4.68

(87Sr/86Sr)i

0.705429

0.705457

0.705464

0.705613

0.705489

0.705499

0.705495

0.705465

0.705951

0.706236

0.705572

2σ

2

3

3

3

3

2

2

4

2

3

3

87Sr/86Sr

0.705769

0.705907

0.705804

0.705968

0.705681

0.705543

0.705568

0.705503

0.706242

0.706532

0.705825

87Rb/86Sr

0.1914

0.2532

0.1915

0.1997

0.1079

0.0248

0.0410

0.0214

0.1639

0.1665

0.1425

Sr (ppm)

404

445

605

483

619

407

436

765

614

604

720

Rb (ppm)

26.7

38.9

40.1

33.4

23.1

3.48

6.18

5.66

34.8

34.8

35.5

Sample

MJN0602

MJN0603

MJN0604

MJN0605

MJN0606

MJN0607

MJN0608

MJN0609

MJN0610

MJN0612

MJN0613

Table DR5. Bulk lead isotopic compositions for the Early Cretaceous Jinan gabbros. △8/4

58.6

49.3

58.7

70.4

94.8

107.4

77.3

Note, λU238=1.55125×10–10 year–1; λU235=9.8485×10–10 year–1; λTh232=4.9475×10–10 year–1; △7/4 = ((207Pb/204Pb)i – (207Pb/204Pb)NHRL)×100; △8/4 = ((208Pb/204Pb)i – (208Pb/204Pb)NHRL)×100; (207Pb/204Pb)NHRL= 0.1084×(206Pb/204Pb)i +

13.491; (208Pb/204Pb)NHRL= 1.209×(206Pb/204Pb)i + 15.627. Initial Pb isotopes were obtained by assuming 127 Ma.

△7/4

-7.4

-14.8

-9.5

-3.9

-6.3

-4.2

-0.9

(208Pb/204Pb)i

36.5170

36.2247

36.3830

36.4818

36.2528

36.2770

36.6947

(207Pb/204Pb)i

15.2376

15.1460

15.2042

15.2592

15.1924

15.2047

15.3021

(206Pb/204Pb)i

16.7943

16.6290

16.6823

16.6675

16.2761

16.1923

16.7863

232Th/204Pb

17.1665

20.1010

11.4197

6.7345

24.1456

18.0800

16.6648

235U/204Pb

0.0356

0.0401

0.0246

0.0177

0.0457

0.0355

0.0372

238U/204Pb

4.9089

5.5312

3.3878

2.4344

6.3043

4.8939

5.1280

206Pb/204Pb

16.8904

16.7373

16.7486

16.7152

16.3995

16.2881

16.8867

207Pb/204Pb

15.2423

15.1513

15.2074

15.2615

15.1984

15.2093

15.307

208Pb/204Pb

36.6235

36.3494

36.4538

36.5236

36.4026

36.3892

36.7981

U (ppm)

0.51

0.73

0.12

0.12

0.51

0.57

0.65

Th (ppm)

1.72

2.55

0.38

0.33

1.89

2.04

2.05

Pb (ppm)

6.25

7.96

2.15

3.15

5.02

7.24

8.06

Sample

MJN0602

MJN0605

MJN0608

MJN0609

MJN0610

MJN0612

MJN0613

SUPPORTING REFERENCES CITED

Bolhar, R., Hofmann, A., Siahi, M., Feng, Y.-x., and Delvigne, C., 2015, A trace element and Pb isotopic

investigation into the provenance and deposition of stromatolitic carbonates, ironstones and associated shales

of the ∼3.0Ga Pongola Supergroup, Kaapvaal Craton: Geochimica et Cosmochimica Acta, v. 158, p. 57-78,

doi: 10.1016/j.gca.2015.02.026.

Campbell, I.H., and Allen, C.M., 2008, Formation of supercontinents linked to increases in atmospheric oxygen:

Nature Geoscience, v. 1, p. 554-558, doi: 10.1038/ngeo259.

Døssing, L.N., Frei, R., Stendal, H., and Mapeo, R.B.M., 2009, Characterization of enriched lithospheric mantle

components in ∼2.7Ga Banded Iron Formations: An example from the Tati Greenstone Belt, Northeastern

Botswana: Precambrian Research, v. 172, p. 334-356, doi: 10.1016/j.precamres.2009.06.004.

Ding, T.P., Valkiers, S., Kipphardt, H., De Bièvre, P., Taylor, P.D.P., Gonfiantini, R., and Krouse, R., 2001,

Calibrated sulfur isotope abundance ratios of three IAEA sulfur isotope reference materials and V-CDT with a

reassessment of the atomic weight of sulfur: Geochimica et Cosmochimica Acta, v. 65, p. 2433-2437, doi:

10.1016/S0016-7037(01)00611-1.

Frei, R., Dahl, P.S., Duke, E.F., Frei, K.M., Hansen, T.R., Frandsson, M.M., and Jensen, L.A., 2008, Trace element

and isotopic characterization of Neoarchean and Paleoproterozoic iron formations in the Black Hills (South

Dakota, USA): Assessment of chemical change during 2.9–1.9Ga deposition bracketing the 2.4–2.2Ga first

rise of atmospheric oxygen: Precambrian Research, v. 162, p. 441-474, doi: 10.1016/j.precamres.2007.10.005.

Frei, R., and Polat, A., 2007, Source heterogeneity for the major components of 3.7 Ga Banded Iron Formations

(Isua Greenstone Belt, Western Greenland): Tracing the nature of interacting water masses in BIF formation:

Earth and Planetary Science Letters, v. 253, p. 266-281, doi: 10.1016/j.epsl.2006.10.033.

Fu, J.L., Hu, Z.C., Li, J.W., Yang, L., Zhang, W., Liu, Y.S., Li, Q.L., Zong, K.Q., and Hu, S.H., 2017, Accurate

determination of sulfur isotopes (δ33S and δ34S) in sulfides and elemental sulfur by femtosecond laser ablation

MC-ICP-MS with non-matrix matched calibration: Journal of Analytical Atomic Spectrometry, v. 32, p.

2341-2351, doi: 10.1039/C7JA00282C.

Gao, S., Rudnick, R., Xu, W.L., Yuan, H.L., Liu, Y.S., Walker, R.J., Puchtel, I.S., Liu, X.M., Huang, H., Wang,

X.R., and Yang, J., 2008, Recycling deep cratonic lithosphere and generation of intraplate magmatism in the

North China Craton: Earth and Planetary Science Letters, v. 270, p. 41-53, doi: 10.1016/j.epsl.2008.03.008.

Gilbert, S.E., Danyushevsky, L.V., Rodemann, T., Shimizu, N., Gurenko, A., Meffre, S., Thomas, H., Large, R.R.,

and Death, D., 2014, Optimisation of laser parameters for the analysis of sulphur isotopes in sulphide minerals

by laser ablation ICP-MS: Journal of Analytical Atomic Spectrometry v. 29, p. 1042-1051, doi:

10.1039/c4ja00011k.

Li, W.Q., Czaja, A.D., Van Kranendonk, M.J., Beard, B.L., Roden, E.E., and Johnson, C.M., 2013, An anoxic,

Fe(II)-rich, U-poor ocean 3.46 billion years ago: Geochimica et Cosmochimica Acta, v. 120, p. 65-79, doi:

10.1016/j.gca.2013.06.033.

Liu, Y.S., Gao, S., Hu, Z.C., Gao, C.G., Zong, K.Q., and Wang, D.B., 2010, Continental and oceanic crust

recycling-induced melt-peridotite interactions in the Trans-North China Orogen: U-Pb dating, Hf Isotopes and

trace elements in zircons from mantle xenoliths: Journal of Petrology, v. 51, p. 537-571, doi:

10.1093/petrology/egp082.

Partin, C.A., Bekker, A., Planavsky, N.J., Scott, C.T., Gill, B.C., Li, C., Podkovyrov, V., Maslov, A., Konhauser,

K.O., Lalonde, S.V., Love, G.D., Poulton, S.W., and Lyons, T.W., 2013, Large-scale fluctuations in

Precambrian atmospheric and oceanic oxygen levels from the record of U in shales: Earth and Planetary

Science Letters, v. 369–370, p. 284-293, doi: 10.1016/j.epsl.2013.03.031.

Plank, T., and Langmuir, C.H., 1998, The chemical composition of subducting sediment and its consequences for

the crust and mantle: Chemical Geology, v. 145, p. 325-394, doi: 10.1016/S0009-2541(97)00150-2.

Pollack, G.D., Krogstad, E.J., and Bekker, A., 2009, U–Th–Pb–REE systematics of organic-rich shales from the ca.

2.15 Ga Sengoma Argillite Formation, Botswana: Evidence for oxidative continental weathering during the

Great Oxidation Event: Chemical Geology, v. 260, p. 172-185, doi: 10.1016/j.chemgeo.2008.10.038.

Rudnick, R.L., Gao, S., Ling, W.L., Liu, Y.S., and McDonough, W.F., 2004, Petrology and geochemistry of spinel

peridotite xenoliths from Hannuoba and Qixia, North China craton: Lithos, v. 77, p. 609-637, doi:

10.1016/j.lithos.2004.03.033.

Wille, M., Nebel, O., Van Kranendonk, M.J., Schoenberg, R., Kleinhanns, I.C., and Ellwood, M.J., 2013, Mo–Cr

isotope evidence for a reducing Archean atmosphere in 3.46–2.76Ga black shales from the Pilbara, Western

Australia: Chemical Geology, v. 340, p. 68-76, doi: 10.1016/j.chemgeo.2012.12.018.

Zhang, J.B., Liu, Y.S., Ling, W.L., and Gao, S., 2017, Pressure-dependent compatibility of iron in garnet: Insights

into the origin of ferropicritic melt: Geochimica et Cosmochimica Acta, v. 197, p. 356-377, doi:

10.1016/j.gca.2016.10.047.