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Table Ig12-Hf
Lu, Yb and Hf LA-MC-ICPMS data of zircon crystals from sample GCH-18
176
Yb
a
176
Lu
a
178
Hf
180
Hf Sig
Hf
b 176
Hf
176
Hf
d
ı
c
T
DM
e
age
f
ı U-Pb
g
Lu-Hf
h
177
Hf
177
Hf
177
Hf
177
Hf
(V)
177
Hf
177
Hf
(t)
İ+I (Ga) (Ma) (Ma) conc seq
A454_40_seq2 0.0368 34 0
.00124 10 1.46712
1.88663 20 0.282332 18 0.282321 -5.3 0.6 1.45 499 7 99 1
A457_40_seq2 0.0404 33 0
.00130 8 1.46716
1.88664 20 0.282333 17 0.282321 -5.0 0.6 1.44 513 7 100 1
A461_40_seq2 0.0414 34 0
.00128 8 1.46718
1.88660 17 0.282317 22 0.282305 -5.7 0.8 1.48 503 7 101 1
A465_40_seq2 0.0358 30 0
.00113 7 1.46713
1.88672 19 0.282328 21 0.282318 -5.4 0.7 1.45 500 7 99 1
A467_40_seq2 0.0364 30 0
.00112 7 1.46714
1.88668 18 0.282318 16 0.282307 -5.6 0.6 1.47 508 7 98 1
A468_40_seq2 0.0381 31 0
.00118 7 1.46718
1.88670 17 0.282345 16 0.282333 -4.5 0.6 1.42 513 7 98 1
A471_40_seq2 0.0473 48 0
.00151 15 1.46715
1.88673 20 0.282322 20 0.282308 -5.7 0.7 1.47 501 8 99 1
A479_40_seq2 0.0509 64 0
.00168 18 1.46712
1.88663 19 0.282332 21 0.282316 -5.5 0.7 1.46 495 7 100 1
A488_40_seq2 0.0340 31 0
.00110 8 1.46718
1.88689 18 0.282357 17 0.282346 -4.5 0.6 1.40 495 6 98 1
A489_40_seq2 0.0458 39 0
.00146 10 1.46716
1.88676 20 0.282338 20 0.282324 -5.0 0.7 1.44 508 7 101 1
A493_40_seq2 0.0524 90 0
.00150 23 1.46718
1.88661 19 0.282326 21 0.282312 -5.8 0.7 1.47 492 7 100 1
A503_40_seq2 0.0676 80 0
.00221 25 1.46710 1
.88626 18 0.282299 22 0.282278 -6.5 0.8 1.53 515 7 100 1
A512_26_seq2 0.0356 31 0
.00119 9 1.46706
1.88617 11 0.282279 29 0.282267 -6.9 1.0 1.55 511 7 98 1
A517_40_seq2 0.0144 12 0.00048 3 1.46720 1.88688 12 0.281003 22 0.280982 -10.2 0.8 3.25 2365 30 83 1
A518_40_seq2 0.0164 14 0.00046 3 1.46710 1.88650 12 0.281996 47 0.281986 -2.4 1.7 1.83 1151 62 101 1
Grain
ı
ı
±2ı
c
İ+I
(t)
d
Quoted uncertainties (absolute) relate to the last quoted figure. The effect of the inter-element fractionation on Lu/Hf was estimated to be about 6 % or less
based on analyses of the GJ-ϭ ĂŶĚ WůĞƐŽǀŝēĞ njŝƌĐŽŶ͘ ĐĐƵƌĂĐLJ ĂŶĚ ƌĞƉƌŽĚƵĐŝďŝůŝƚLJ ǁĂƐ ĐŚĞĐŬĞĚ ďLJ ƌĞƉĞĂƚĞĚ ĂŶĂůLJƐĞƐ ŽĨ ƌĞĨĞƌĞŶĐĞ njircon GJ-ϭ ĂŶĚ WůĞƐŽǀŝēĞ
(data given as mean with 2 standard deviation uncertainties).
(a)
176
Yb/
177
Hf = (
176
Yb/
173
Yb)
true
x (
173
Yb/
177
Hf)
meas
x (M
173(Yb)
/M
177(Hf)
)
ɴ;,ĨͿ
͕ ɴ;,ĨͿ с ůŶ;;
179
Hf/
177
Hf
true
)/(
179
Hf/
177
Hf
measured
)) / ln(M
179(Hf)
/M
177(Hf)
), M = mass of
respective isotopes. The
176
Lu/
177
Hf was calculated in a similar way using
175
Lu/
177
,Ĩ ĂŶĚ ɴ;zďͿ͘
(b)
Mean Hf signal in volts.
(c)
Uncertainties are quadratic additions of the within-run precision and the daily reproducibility of the 40ppb-JMC475 solution. Uncertainties for the JMC475
quoted at 2SD (2 standard deviation).
(d)
Initial
176
Hf/
177
,Ĩ ĂŶĚ ɸ,Ĩ ĐĂůĐƵůĂƚĞĚ ƵƐŝŶŐ ƚŚĞ ĂƉƉĂƌĞŶƚ h-Pb age determined by LA-ICP-MSdating (see column f), and the CHUR parameters:
176
Lu/
177
Hf =
0.0336, and
176
Hf/
177
Hf = 0.282785 (Bouvier et al. 2008).
(e)
Two stage model age in Ga using measured
176
Lu/
177
Lu of each spot (first stage = age of zircon), a value of 0.0113 for the average continental crust (second
stage, values compiled from Rudnick and Gao (2003), and depleted mantle
176
Lu/
177
Lu = 0.0379, and
176
Hf/
177
Hf = 0.283164.
(f)
Apparent U-Pb age determined by LA-ICP-MS.
(g)
U-Pb age concordance (%).
(h)
Sequence in which Lu-Hf analyses were performed. Standard analyses for each sequence are showed on Table 12.
332