appendix a: analytical methods mineral chemistryappendix a: analytical methods mineral chemistry...

APPENDIX A: ANALYTICAL METHODS

Mineral chemistry

Major element compositions of the minerals were obtained on polished thin sections using a

Cameca SX100 electron microprobe fitted with five spectrometers at the “Service commun

microsonde” (Université de Montpellier). The standard analytical procedure uses an accelerating

voltage of 20 kV, a beam current of 10 nA, a 1 µm spot size, and integrated counting times

ranging from 20 to 30 s. Alkalis were determined first to minimize Na loss during measurements.

Detection limits are ca. 0.2% for major elements. The analytical error is between 1 and 5% for

concentrations higher than 1% and between 5 and 10% for concentrations lower than 1%.

40Ar/39Ar geochronology

Minerals and rocks samples were pretreated and concentrated by standard laboratory

techniques and later selected by handpicking under a binocular microscope from fractions that

ranged in size from (40–60-80-100) mesh at the mineral separation laboratory at Centro de

Geociencias-UNAM, Campus Juriquilla, Querétaro, Qro. Mineral separates were loaded into Al-

foil packets and irradiated together with MAC-83 (24.1 Ma) biotite as a neutron-fluence monitor

at the McMaster Nuclear Reactor (Hamilton, Ontario). 40Ar/39Ar analyses were performed by

standard laser step-heating techniques, described in detail by Clark et al. (1998), at the

Geochronology Research Laboratory of Queen’s University, Kingston, Ontario, Canada. All data

have been corrected for blanks, mass discrimination, and neutron-induced interferences.

Geochemistry

Rock samples were ground first in a steel jaw crusher and then finely powdered in an agate

grinder. Major and compatible trace elements were analyzed by inductively coupled plasma-

atomic emission spectrometry (ICP-AES) at CEREGE (Université Aix-Marseille 3) using a

26

DR2008046

Jobin-Yvon system. Na, K and Rb were determined by flame atomic absorption

spectrophotometry, and Fe2+ by titration. Rare earth elements (REE) and additional trace

elements were obtained for a subset of samples by inductively coupled plasma-mass spectrometry

(ICP-MS) at ALS Chemex laboratory. Analytical errors are 1–3% for major elements and about

3% for trace elements.

Sr (static acquisition) and Nd (dynamic acquisition) isotopic ratios were measured at the

Laboratoire de Géochimie isotopique de l’Université Paul Sabatier de Toulouse on a Finnigan

MAT261 multicollector mass spectrometer using the analytical procedures of Lapierre et al.

(1997). Results on La Jolla Nd standard yielded 143Nd/144Nd =0.511850 ± 8 (mean on 39 runs),

corresponding to an external reproducibility of 0.00001. Results on NBS 987 Sr standard yielded

87Sr/86Sr =0.710250 (mean on 200 runs). The within-run precision (2σ absolute) for 87Sr/86Sr

was 0.000008-0.000015 and 0.000007-0.000011 for 143Nd/144Nd. For lead separation, powdered

samples were weighed to obtain approximately 100 to 200 ng of lead. The chemical separation of

Pb was carried out following the procedure modified from Manhès et al. (1980). Total Pb blanks

are less than 65 pg, for a 100 mg sample. Lead isotope analyses were made on a VG model

Plasma 54 multicollector-inductively coupled plasma-mass spectrometer (MC-ICP-MS) at the

Ecole Normale Supérieure de Lyon. Lead isotope compositions were measured using the Tl

normalization method described by White et al. (2000). For Pb isotope analysis, samples were

bracketed between NIST 981 standards and calculated with respect to the value reported for this

standard by Todt et al. (1996). This technique yields internal precision of ca. 50 ppm (2σ) and an

external reproducibility of ca. 150 ppm (2σ) for 206Pb/204Pb ratios determined on 20 NIST

standards.

27

DR2008046

AOR-712: 91-30 Plg 40/60J Value: 0.002356Can/Pos: 192/8Run date: 2004/05/26

± 0.000006Mass: 33.0 mgPrinted: 2006/04/28

Approx. 0.33% KVolume 39K: 0.66 x 1E-10 cm3 NTP % CaIntegrated Age: 23.93 ± 7.44 Ma

Initial 40/36: 298.91 ± 58.70 (MSWD = 1.03, isochron between -0.41 and 3.83)ERRMSWDCorrelation Age: 19.87 ± 2.45 Ma (100.0% of 39Ar, steps marked by >)

ERRMod. err. Plateau Age: 20.07 ± 2.17 Ma ( 47.1% of 39Ar, steps marked by <)

36Ar/40Ar 39Ar/40Ar r Ca/K %40Atm %39Ar 40Ar*/39K AgePower

0.003385±0.000135 0.001401±0.000331 0.949 144.799 100.02 16.37 -0.140±8.225 -0.60±34.97 5.00 0.003267 0.000079 0.003673 0.000193 0.856 89.264 96.53 36.57 9.423 2.880 39.61 11.98 7.00 0.001566 0.000197 0.113177 0.001650 0.024 26.919 46.10 47.06 4.748 0.517 20.07 2.17< 8.00

40Ar 39Ar 38Ar 37Ar 36Ar Blank 40Ar Atmos 40/36Power

73.327±0.087 0.112±0.004 0.052±0.003 4.270±0.026 0.259±0.003 0.084 286.103 5.00 63.786 0.066 0.247 0.004 0.050 0.002 5.997 0.032 0.219 0.002 0.062 286.103 7.00 2.802 0.016 0.317 0.004 0.019 0.001 2.362 0.014 0.007 0.001 0.069 286.103< 8.00

Measured volumes are x 1E-10 cm3 NTP. All errors are 2 x standard error. Intrim13 28-Mar-02

DR2008046

AOR-712: 91-30 Plg 40/60


0.00

0.05

0.10

0.15

0.20

0.25

39Ar/40Ar

0.000 0.001 0.002 0.003 0.004

36Ar/40Ar

-40

-20

0

20

40

60

Age (Ma)

0.0 1.0

Fraction 39Ar

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

Cumulative Volume 39Ar

0

0

0

0

0

0

0

0

Volume 39Ar / mW

0 2 4 6 8 10 12

Power (W)

0.001

0.01

0.1

1

10

100

Ca/K Cl/K %40 Atmos

0.0 1.0

Fraction 39Ar

DR2008046

AOR-R713: JR98-21 Plg 40/60J Value: 0.002357Can/Pos: 192/9Run date: 2004/05/26

± 0.000006Mass: 66.0 mgPrinted: 2005/06/08

Approx. 0.65% KVolume 39K: 2.60 x 1E-10 cm3 NTP 14.39% CaIntegrated Age: 16.03 ± 0.70 Ma

Initial 40/36: Linear regression has positive slope.ERRMSWDCorrelation Age:



0.002895±0.000070 0.049051±0.000652 0.183 13.130 85.40 23.00 2.951±0.429 12.50±1.81 3.00 0.002623 0.000089 0.067770 0.000763 0.048 29.816 77.33 17.42 3.322 0.378 14.07 1.60 5.00 0.002369 0.000108 0.082775 0.000881 0.028 28.296 69.82 16.88 3.625 0.379 15.35 1.60 7.00 0.002327 0.000050 0.069544 0.000354 0.064 22.244 68.61 42.70 4.493 0.205 19.00 0.86< 7.50


12.234±0.090 0.606±0.007 0.091±0.002 2.244±0.015 0.039±0.001 0.075 286.103 3.00 6.704 0.020 0.461 0.005 0.051 0.002 3.834 0.021 0.021 0.001 0.077 286.103 5.00 5.337 0.013 0.446 0.004 0.033 0.001 3.525 0.019 0.016 0.001 0.076 286.103 7.00 15.942 0.023 1.123 0.005 0.062 0.002 7.025 0.036 0.043 0.001 0.067 286.103< 7.50


DR2008046

AOR-R713: JR98-21 Plg 40/60


0.04

0.05

0.06

0.07

0.08

0.09

39Ar/40Ar

0.000 0.001 0.002 0.003 0.004

36Ar/40Ar

10

12

14

16

18

20

Age (Ma)

0.0 1.0

Fraction 39Ar

0

0.5

1

1.5

2

2.5

3


0

1

1

2

2

3

Volume 39Ar / mW

0 2 4 6 8 10 12

Power (W)

0.001

0.01

0.1

1

10

100

Ca/K Cl/K %40 Atmos

0.0 1.0

Fraction 39Ar

DR2008046

AOR-R711: JR97-23 Plg 40/60J Value: 0.002355Can/Pos: 192/7Run date: 2004/05/26

± 0.000006Mass: 33.0 mgPrinted: 2005/06/08


Initial 40/36: 299.26 ± 421.00 (MSWD = 1.69, isochron between -0.41 and 3.83)ERRMSWDCorrelation Age: 9.89 ± 9.32 Ma ( 43.3% of 39Ar, steps marked by >)


11.77 ± 2.91 Ma ( 43.3% of 39Ar, steps marked by {)


0.003192±0.000081 0.020762±0.000364 0.160 26.281 94.25 20.24 2.739±1.099 11.60±4.64{ 3.00> 0.002495 0.000285 0.085454 0.001378 0.019 35.440 73.53 14.45 3.075 0.980 13.02 4.13{ 5.00> 0.002017 0.000920 0.170050 0.003891 0.008 28.044 59.30 8.56 2.376 1.600 10.07 6.76{ 6.00> 0.002097 0.000107 0.077867 0.000726 0.030 26.098 61.81 56.74 4.886 0.404 20.64 1.70< 7.00


8.844±0.057 0.188±0.003 0.019±0.001 1.378±0.009 0.031±0.001 0.069 286.103{ 3.00> 1.590 0.007 0.136 0.002 0.005 0.001 1.321 0.008 0.006 0.000 0.070 286.103{ 5.00> 0.533 0.004 0.082 0.002 0.003 0.001 0.621 0.005 0.002 0.000 0.078 286.103{ 6.00> 6.656 0.017 0.523 0.005 0.015 0.001 3.831 0.021 0.017 0.001 0.086 286.103< 7.00


DR2008046

AOR-R711: JR97-23 Plg 40/60


0.00

0.20

0.40

0.60

0.80

1.00

39Ar/40Ar

0.000 0.001 0.002 0.003 0.004

36Ar/40Ar

0

5

10

15

20

25

Age (Ma)

0.0 1.0

Fraction 39Ar

0

0.2

0.4

0.6

0.8

1


0

0

0

0

0

1

1

Volume 39Ar / mW

0 2 4 6 8 10 12

Power (W)

0.001

0.01

0.1

1

10

100

Ca/K Cl/K %40 Atmos

0.0 1.0

Fraction 39Ar

DR2008046

AOR-L705: JR98-20 Plg 40/60J Value: 0.002366Can/Pos: 192/10Run date: 2004/05/26

± 0.000018Mass: 55.0 mgPrinted: 2004/07/12


Initial 40/36: 267.26 ± 210.12 (MSWD = 1.18, isochron between 0.00 and 3.00)2.745MSWDCorrelation Age: 14.93 ± 6.67 Ma ( 66.5% of 39Ar, steps marked by >)

2.04Mod. err. Plateau Age: 13.53 ± 1.24 Ma ( 54.1% of 39Ar, steps marked by <)


0.003240±0.000068 0.034522±0.000431 0.125 5.433 95.64 25.45 1.235±0.588 5.27±2.50 3.00> 0.002776 0.000101 0.075522 0.000821 0.049 15.674 81.84 20.41 2.379 0.388 10.13 1.65 5.00> 0.002455 0.000195 0.097016 0.001216 0.029 22.996 72.31 13.07 2.832 0.588 12.05 2.49< 6.50> 0.002546 0.000337 0.095571 0.001651 0.174 35.000 75.01 7.52 2.592 0.864 11.03 3.67< 7.00> 0.002746 0.000078 0.054631 0.000464 0.134 30.531 81.01 33.54 3.452 0.361 14.68 1.53< 7.20


13.272±0.073 0.462±0.005 0.077±0.002 0.710±0.007 0.045±0.001 0.059 289.649 3.00> 4.889 0.018 0.373 0.004 0.040 0.001 1.636 0.015 0.016 0.000 0.058 289.649 5.00> 2.466 0.010 0.241 0.003 0.020 0.001 1.532 0.014 0.008 0.000 0.062 289.649< 6.50> 1.456 0.006 0.139 0.002 0.011 0.001 1.335 0.047 0.006 0.000 0.059 289.649< 7.00> 10.976 0.020 0.608 0.005 0.058 0.002 5.196 0.046 0.035 0.001 0.070 289.649< 7.20


DR2008046

AOR-L705: JR98-20 Plg 40/60


0.00

0.10

0.20

0.30

0.40

0.50

39Ar/40Ar

0.000 0.001 0.002 0.003 0.004

36Ar/40Ar

0

5

10

15

20

25

Age (Ma)

0.0 1.0

Fraction 39Ar

0

0.5

1

1.5

2


0

1

1

2

2

3

3

4

Volume 39Ar / mW

0 2 4 6 8 10 12

Power (W)

0.001

0.01

0.1

1

10

100

Ca/K Cl/K %40 Atmos

0.0 1.0

Fraction 39Ar

DR2008046

AOR-R714: JR99-83 Hb 40/60J Value: 0.002358Can/Pos: 192/11Run date: 2004/05/26

± 0.000006Mass: 123.0 mgPrinted: 2005/06/08


Initial 40/36: 294.87 ± 90.93 (MSWD = 0.77, isochron between 0.37 and 2.26)0.051MSWDCorrelation Age: 12.02 ± 2.48 Ma (100.0% of 39Ar, steps marked by >)



0.003040±0.000129 0.039463±0.000704 0.082 2.893 89.70 9.77 2.583±0.972 10.95±4.11 2.50 0.002955 0.000108 0.055553 0.000771 0.083 3.012 87.17 19.05 2.284 0.578 9.69 2.45 5.00 0.003276 0.000070 0.013375 0.000231 0.026 4.689 96.75 7.27 2.399 1.562 10.18 6.61 5.10 0.003038 0.000077 0.036060 0.000375 0.103 26.609 89.66 18.61 2.841 0.611 12.05 2.58< 6.00 0.003077 0.000096 0.030498 0.000480 0.060 31.090 90.82 9.87 2.982 0.889 12.64 3.76< 7.00

0.002617 0.000114 0.080753 0.000785 0.035 35.326 77.07 28.96 2.817 0.407 11.94 1.72< 7.50 0.002875 0.000253 0.055734 0.000977 0.024 29.497 84.75 6.46 2.710 1.336 11.49 5.65< 8.00


4.842±0.037 0.193±0.003 0.038±0.002 0.157±0.003 0.016±0.001 0.074 286.103 2.50 6.692 0.042 0.373 0.005 0.072 0.002 0.316 0.004 0.021 0.001 0.084 286.103 5.00 10.521 0.022 0.144 0.002 0.037 0.002 0.189 0.002 0.037 0.001 0.074 286.103 5.10 9.924 0.035 0.364 0.003 0.171 0.003 2.702 0.016 0.033 0.001 0.076 286.103< 6.00 6.241 0.014 0.194 0.003 0.091 0.002 1.672 0.010 0.022 0.001 0.074 286.103< 7.00

6.917 0.014 0.565 0.005 0.277 0.004 5.560 0.030 0.023 0.001 0.086 286.103< 7.50 2.277 0.011 0.129 0.002 0.056 0.001 1.034 0.007 0.008 0.001 0.066 286.103< 8.00


DR2008046

AOR-R714: JR99-83 Hb 40/60


0.00

0.10

0.20

0.30

0.40

0.50

39Ar/40Ar

0.000 0.001 0.002 0.003 0.004

36Ar/40Ar

2

4

6

8

10

12

14

16

18

Age (Ma)

0.0 1.0

Fraction 39Ar

0

0.5

1

1.5

2


0

0

0

1

1

1

1

1

2

Volume 39Ar / mW

0 2 4 6 8 10 12

Power (W)

0.001

0.01

0.1

1

10

100

Ca/K Cl/K %40 Atmos

0.0 1.0

Fraction 39Ar

DR2008046

AOR-R726: PO3-27 Obs 40/60J Value: 0.002342Can/Pos: 192/1Run date: 2004/05/27

± 0.000008Mass: 123.0 mgPrinted: 2005/06/08


Initial 40/36: 288.85 ± 73.44 (MSWD = 0.61, isochron between -0.41 and 3.83)1.076MSWDCorrelation Age: 14.16 ± 1.82 Ma ( 20.2% of 39Ar, steps marked by >)



0.003088±0.000043 0.031837±0.000190 0.023 0.112 91.15 2.69 2.754±0.416 11.60±1.74 1.00> 0.002551 0.000031 0.079253 0.000343 0.061 0.068 75.18 7.41 3.109 0.123 13.09 0.52 2.00> 0.002006 0.000025 0.125036 0.000487 0.055 0.054 59.01 10.11 3.260 0.065 13.72 0.27 3.00> 0.001961 0.000025 0.124154 0.000433 0.048 0.051 57.68 11.68 3.391 0.065 14.27 0.27 4.00 0.001618 0.000026 0.149527 0.000496 0.041 0.044 47.54 9.72 3.494 0.056 14.70 0.23 5.00

0.001791 0.000027 0.130374 0.000430 0.032 0.048 52.69 14.65 3.613 0.064 15.20 0.27< 6.00 0.001584 0.000026 0.147356 0.000519 0.035 0.045 46.56 9.66 3.612 0.056 15.20 0.23< 7.00 0.001602 0.000028 0.146377 0.000481 0.028 0.056 47.09 8.07 3.601 0.060 15.15 0.25< 7.20 0.001755 0.000025 0.131270 0.000517 0.069 0.057 51.60 26.03 3.671 0.062 15.45 0.26< 7.50


48.895±0.066 1.569±0.009 0.279±0.004 0.050±0.002 0.157±0.002 0.076 286.103 1.00> 54.204 0.096 4.318 0.017 0.712 0.006 0.083 0.002 0.144 0.002 0.068 286.103 2.00> 46.951 0.076 5.890 0.021 0.969 0.007 0.089 0.002 0.098 0.001 0.062 286.103 3.00> 54.650 0.080 6.810 0.021 1.140 0.008 0.096 0.002 0.111 0.001 0.063 286.103 4.00 37.785 0.055 5.663 0.017 0.959 0.006 0.071 0.002 0.064 0.001 0.065 286.103 5.00

65.244 0.080 8.536 0.026 1.448 0.010 0.115 0.002 0.121 0.002 0.064 286.103< 6.00 38.117 0.054 5.631 0.018 0.963 0.006 0.071 0.002 0.063 0.001 0.064 286.103< 7.00 32.061 0.040 4.704 0.014 0.809 0.006 0.074 0.002 0.054 0.001 0.069 286.103< 7.20 115.127 0.226 15.167 0.051 2.647 0.019 0.243 0.005 0.210 0.003 0.085 286.103< 7.50


DR2008046

AOR-R726: PO3-27 Obs 40/60


0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

39Ar/40Ar

0.000 0.001 0.002 0.003 0.004

36Ar/40Ar

0

2

4

6

8

10

12

14

16

18

20

Age (Ma)

0.0 1.0

Fraction 39Ar

0

10

20

30

40

50

60


0

10

20

30

40

50

60

Volume 39Ar / mW

0 2 4 6 8 10 12

Power (W)

0.001

0.01

0.1

1

10

100

Ca/K Cl/K %40 Atmos

0.0 1.0

Fraction 39Ar

DR2008046

AOR-R715: JR98-23 Wr 40/60J Value: 0.002359Can/Pos: 192/12Run date: 2004/05/26

± 0.000006Mass: 77.0 mgPrinted: 2005/06/08


ERRERRMSWDERR



0.003127±0.000044 0.028981±0.000325 0.211 1.015 92.33 9.32 2.617±0.464 11.10±1.96 2.00 0.000738 0.000018 0.232931 0.001647 0.150 0.239 21.65 90.68 3.357 0.036 14.23 0.15< 7.00


64.744±0.370 1.891±0.018 0.155±0.004 0.544±0.008 0.210±0.003 0.084 286.103 2.00 78.844 0.392 18.368 0.090 0.334 0.006 1.246 0.013 0.061 0.001 0.084 286.103< 7.00


DR2008046

AOR-R715: JR98-23 Wr 40/60


0.00

0.05

0.10

0.15

0.20

0.25

0.30

39Ar/40Ar

0.000 0.001 0.002 0.003 0.004

36Ar/40Ar

9

10

11

12

13

14

15

Age (Ma)

0.0 1.0

Fraction 39Ar

0

5

10

15

20

25


1

1

2

2

3

3

4

4

Volume 39Ar / mW

0 2 4 6 8 10 12

Power (W)

0.001

0.01

0.1

1

10

100

Ca/K Cl/K %40 Atmos

0.0 1.0

Fraction 39Ar

DR2008046

AOR-R727: PO3-22-OBS Obs 40/60J Value: 0.002348Can/Pos: 192/5Run date: 2004/05/28

± 0.000008Mass: 56.0 mgPrinted: 2005/06/08


Initial 40/36: 291.26 ±2394.39 (MSWD = 0.07, isochron between 0.00 and 3.00)ERRMSWDCorrelation Age: 13.27 ± 71.03 Ma ( 51.2% of 39Ar, steps marked by >)




0.003075±0.000040 0.033695±0.000245 0.103 0.073 90.75 4.80 2.717±0.366 11.47±1.54{ 2.00> 0.002932 0.000036 0.045994 0.000237 0.027 0.054 86.49 13.56 2.912 0.241 12.29 1.02{ 4.00> 0.002956 0.000035 0.044257 0.000213 0.011 0.053 87.20 17.84 2.867 0.248 12.10 1.04{ 6.00> 0.002974 0.000034 0.042605 0.000185 0.022 0.055 87.73 14.96 2.854 0.248 12.05 1.04{ 7.00> 0.002903 0.000027 0.042149 0.000179 0.024 0.057 85.64 48.85 3.381 0.206 14.27 0.87< 7.50


41.900±0.130 1.425±0.009 0.535±0.005 0.031±0.002 0.134±0.002 0.079 286.103{ 2.00> 86.734 0.112 4.017 0.020 1.454 0.011 0.063 0.003 0.264 0.003 0.084 286.103{ 4.00> 118.499 0.094 5.280 0.025 1.903 0.017 0.079 0.003 0.363 0.004 0.074 286.103{ 6.00> 103.209 0.105 4.427 0.018 1.610 0.014 0.069 0.002 0.318 0.003 0.071 286.103{ 7.00> 340.542 0.329 14.451 0.059 5.285 0.039 0.229 0.007 1.021 0.009 0.068 286.103< 7.50


DR2008046

AOR-R727: PO3-22-OBS Obs 40/60


-1.50

-1.00

-0.50

0.00

0.50

1.00

1.50

2.00

2.50

39Ar/40Ar

0.000 0.001 0.002 0.003 0.004

36Ar/40Ar

0

2

4

6

8

10

12

14

16

18

20

Age (Ma)

0.0 1.0

Fraction 39Ar

0

5

10

15

20

25

30


0

5

10

15

20

25

30

Volume 39Ar / mW

0 2 4 6 8 10 12

Power (W)

0.001

0.01

0.1

1

10

100

Ca/K Cl/K %40 Atmos

0.0 1.0

Fraction 39Ar

DR2008046

AOR-R756: PO3-22-OBS-HCL Obs 40/60J Value: 0.002352Can/Pos: 192/6Run date: 2004/05/31

± 0.000006Mass: 44.0 mgPrinted: 2005/06/08


Initial 40/36: Linear regression has positive slope.ERRMSWDCorrelation Age:




0.002958±0.000036 0.044176±0.000222 0.026 0.052 87.26 7.00 2.858±0.252 12.09±1.06{ 2.00 0.002964 0.000036 0.044279 0.000214 0.026 0.055 87.43 19.00 2.813 0.249 11.90 1.05{ 4.00 0.002987 0.000031 0.042597 0.000226 0.033 0.056 88.13 22.56 2.759 0.232 11.67 0.98{ 6.00 0.002976 0.000040 0.040887 0.000211 0.019 0.055 87.80 14.82 2.958 0.298 12.51 1.25{ 7.00 0.002972 0.000032 0.036458 0.000197 0.023 0.055 87.70 36.61 3.348 0.272 14.15 1.15< 7.00


35.314±0.044 1.565±0.008 0.561±0.005 0.023±0.002 0.108±0.001 0.205 286.103{ 2.00 95.253 0.115 4.240 0.020 1.537 0.013 0.061 0.003 0.292 0.003 0.203 286.103{ 4.00 117.510 0.156 5.033 0.026 1.841 0.015 0.074 0.003 0.363 0.004 0.203 286.103{ 6.00 80.477 0.090 3.307 0.017 1.215 0.011 0.048 0.002 0.248 0.003 0.202 286.103{ 7.00 222.541 0.251 8.164 0.043 2.983 0.024 0.116 0.006 0.683 0.007 0.202 286.103< 7.00


DR2008046

AOR-R756: PO3-22-OBS-HCL Obs 40/60


0.04

0.04

0.04

0.04

0.04

0.05

39Ar/40Ar

0.000 0.001 0.002 0.003 0.004

36Ar/40Ar

0

2

4

6

8

10

12

14

16

18

20

Age (Ma)

0.0 1.0

Fraction 39Ar

0

5

10

15

20

25


1

1

2

2

3

3

4

Volume 39Ar / mW

0 2 4 6 8 10 12

Power (W)

0.001

0.01

0.1

1

10

100

Ca/K Cl/K %40 Atmos

0.0 1.0

Fraction 39Ar

DR2008046

AOR-R730: PO2-8 Lag-Obs 40/60J Value: 0.002345Can/Pos: 192/3Run date: 2004/05/28

± 0.000008Mass: 55.0 mgPrinted: 2005/06/08


Initial 40/36: 270.25 ± 138.27 (MSWD = 1.40, isochron between 0.00 and 3.00)0.159MSWDCorrelation Age: 12.16 ± 0.08 Ma ( 95.5% of 39Ar, steps marked by >)



0.001163±0.000186 0.223592±0.001908 0.013 0.131 34.06 2.44 2.939±0.247 12.39±1.04 2.00> 0.002659 0.000354 0.329829 0.036347 0.693 0.206 77.68 4.51 0.653 0.371 2.76 1.57 4.00 0.000116 0.000046 0.335288 0.001448 -0.014 0.135 3.29 13.91 2.883 0.042 12.16 0.18< 6.00> 0.000081 0.000044 0.339895 0.001054 0.001 0.134 2.25 13.39 2.875 0.039 12.12 0.16< 7.00> 0.000016 0.000014 0.345195 0.001087 0.001 0.141 0.34 65.75 2.887 0.015 12.17 0.06< 7.50>


3.079±0.013 0.677±0.005 0.125±0.002 0.027±0.001 0.005±0.001 0.073 286.103 2.00> 3.841 0.376 1.246 0.054 0.241 0.011 0.073 0.004 0.012 0.001 0.069 286.103 4.00 11.521 0.030 3.847 0.012 0.687 0.005 0.148 0.002 0.006 0.001 0.065 286.103< 6.00> 10.955 0.018 3.701 0.009 0.657 0.005 0.140 0.002 0.004 0.000 0.075 286.103< 7.00> 52.685 0.083 18.124 0.048 3.206 0.016 0.705 0.007 0.004 0.001 0.079 286.103< 7.50>


DR2008046

AOR-R730: PO2-8 Lag-Obs 40/60


0.00

0.10

0.20

0.30

0.40

39Ar/40Ar

0.000 0.001 0.002 0.003 0.004

36Ar/40Ar

0

2

4

6

8

10

12

14

16

18

20

Age (Ma)

0.0 1.0

Fraction 39Ar

0

5

10

15

20

25

30


0

10

20

30

40

Volume 39Ar / mW

0 2 4 6 8 10 12

Power (W)

0.001

0.01

0.1

1

10

100

Ca/K Cl/K %40 Atmos

0.0 1.0

Fraction 39Ar

DR2008046

AOR-R743: PO2-8-HCL-OBS Lag-Obs 40/60J Value: 0.002346Can/Pos: 192/4Run date: 2004/05/29

± 0.000008Mass: 37.0 mgPrinted: 2005/06/08


Initial 40/36: 235.36 ± 109.34 (MSWD = 4.45, isochron between 0.18 and 2.63)1.445MSWDCorrelation Age: 12.30 ± 0.38 Ma (100.0% of 39Ar, steps marked by >)



0.001262±0.000189 0.212197±0.003748 0.036 0.129 36.97 2.94 2.959±0.270 12.48±1.14 2.00 0.000283 0.000089 0.320209 0.002547 -0.039 0.134 8.18 9.21 2.865 0.084 12.09 0.36< 4.00 0.000117 0.000058 0.333600 0.002040 -0.060 0.136 3.30 12.77 2.898 0.053 12.22 0.22< 6.00 0.000066 0.000062 0.337641 0.002210 -0.052 0.135 1.80 13.11 2.908 0.057 12.27 0.24< 7.00 0.000346 0.000022 0.315049 0.001884 0.066 0.145 10.02 61.97 2.853 0.028 12.04 0.12< 7.00


2.715±0.035 0.546±0.004 0.101±0.002 0.020±0.001 0.005±0.000 0.169 286.103 2.00 5.462 0.032 1.701 0.006 0.304 0.003 0.062 0.001 0.003 0.000 0.155 286.103< 4.00 7.209 0.029 2.355 0.008 0.420 0.004 0.086 0.001 0.002 0.000 0.148 286.103< 6.00 7.304 0.032 2.418 0.010 0.431 0.004 0.088 0.002 0.002 0.000 0.139 286.103< 7.00 36.404 0.188 11.413 0.032 2.026 0.012 0.444 0.005 0.014 0.001 0.134 286.103< 7.00


DR2008046

AOR-R743: PO2-8-HCL-OBS Lag-Obs 40/60


0.00

0.10

0.20

0.30

0.40

39Ar/40Ar

0.000 0.001 0.002 0.003 0.004

36Ar/40Ar

0

2

4

6

8

10

12

14

16

18

20

Age (Ma)

0.0 1.0

Fraction 39Ar

0

5

10

15

20


0

1

1

2

2

3

Volume 39Ar / mW

0 2 4 6 8 10 12

Power (W)

0.001

0.01

0.1

1

10

100

Ca/K Cl/K %40 Atmos

0.0 1.0

Fraction 39Ar

DR2008046

AOR-R716: PO2-8 Wr 40/60J Value: 0.002360Can/Pos: 192/13Run date: 2004/05/26

± 0.000006Mass: 34.0 mgPrinted: 2005/06/08


Initial 40/36: 333.27 ±1991.22 (MSWD = 5.01, isochron between -0.41 and 3.83)1.809MSWDCorrelation Age: 11.93 ± 1.72 Ma ( 24.1% of 39Ar, steps marked by >)



0.000912±0.000124 0.245235±0.002296 0.025 0.221 26.67 4.00 2.982±0.153 12.65±0.65 1.50> 0.000415 0.000164 0.328900 0.004872 0.027 0.205 12.04 5.68 2.671 0.154 11.33 0.65 2.50> 0.000067 0.000068 0.347869 0.001738 0.001 0.146 1.84 14.45 2.821 0.059 11.97 0.25< 4.00> 0.000010 0.000022 0.348963 0.001103 -0.001 0.139 0.19 24.09 2.860 0.021 12.14 0.09< 6.00 0.000037 0.000012 0.349013 0.001695 0.006 0.151 0.96 51.78 2.837 0.017 12.04 0.07< 7.00


3.297±0.018 0.792±0.006 0.142±0.002 0.050±0.002 0.004±0.000 0.085 286.103 1.50> 3.477 0.043 1.121 0.008 0.200 0.003 0.065 0.002 0.003 0.001 0.074 286.103 2.50> 8.277 0.021 2.849 0.012 0.506 0.005 0.118 0.002 0.002 0.001 0.078 286.103< 4.00> 13.689 0.018 4.745 0.013 0.843 0.006 0.187 0.002 0.001 0.000 0.066 286.103< 6.00 29.337 0.093 10.195 0.037 1.796 0.012 0.437 0.004 0.002 0.000 0.063 286.103< 7.00


DR2008046

AOR-R716: PO2-8 Wr 40/60


0.00

0.10

0.20

0.30

0.40

0.50

39Ar/40Ar

0.000 0.001 0.002 0.003 0.004

36Ar/40Ar

0

2

4

6

8

10

12

14

16

18

20

Age (Ma)

0.0 1.0

Fraction 39Ar

0

5

10

15

20


0

2

4

6

8

10

12

Volume 39Ar / mW

0 2 4 6 8 10 12

Power (W)

0.001

0.01

0.1

1

10

100

Ca/K Cl/K %40 Atmos

0.0 1.0

Fraction 39Ar

DR2008046

REFERENCES: Clark, A.H., Archibald, D.A., Lee, A.W., Farrar, E., and Hodgson, C.J., 1998, Laser

Probe 40Ar/39Ar agers of early- and late-stage alteration assemblages, Rosario porphyry copper–molybdenum deposit, Collahuasi District, I Region, Chili: Economic Geology and the Bulletin of the Society of Economic Geologists, v. 93, p. 326–337.

Lapierre, H., Dupuis, V., Mercier de Lepinay, B., Tardy, M., Ruiz, J., Maury, R.C.,

Hernandez, J., and Loubet, M., 1997, Is the Lower Duarte igneous complex (Hispaniola) a remnant of the Caribbean plume-generated oceanic plateau?: The Journal of Geology, v. 105, p. 111–120.

Manhès, G., Allègre, C.J., Dupré, B., and Hamelin, B., 1980, Lead isotope study of basic-

ultrabasic layered complex: Speculations about the ages of the Earth and primitive mantle characteristics: Earth and Planetary Science Letters, v. 47, p. 370–382, doi: 10.1016/0012-821X(80)90024-2.

Todt, W., Cliff, R.A., Hanser, A., and Hoffmann, A.W., 1996, Evaluation of a

202Pb/205Pb double spike for high-precision lead isotope analysis, in Basu, A., and Hart, S., eds., Earth processes: Reading the isotopic code: American Geophysical Union, Geophysical Monograph, v. 95, p. 429–437.

White, M.W., Albarède, F., and Telouk, F., 2000, High-precision analysis of Pb isotopic

ratios by multi-collector ICP-MS: Chemical Geology, v. 167, p. 257–270, doi: 10.1016/S0009-2541(99)00182-5.

DR2008046

appendix a: analytical methods mineral chemistryappendix a: analytical methods mineral chemistry...

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