Table 1. 

SHRIMP U–Pb single-crystal analysis of zircons and monazites from Archaean rocks of the Nuuk region

SpotSite typeU (ppm)Th (ppm)Th/UCommon 206Pb%238U/206Pb ratio207Pb/206Pb ratio207Pb/206Pb ratio% conc.
Kapisilik terrane
G87/223 diatexite, head of Kapisillit fjord (64°27.35′N, 50°13.50′W)* (only reanalysis after obtaining CL images)
17.1c,osc,p70580.820.711.736 ± 0.0550.2195 ± 0.00282977 ± 2199
18.1c,osc,p1511360.900.611.751 ± 0.0570.2194 ± 0.00152977 ± 1198
2.2c,osc,p1111481.330.391.909 ± 0.0540.2135 ± 0.00192932 ± 1593
19.1c,osc,p120960.800.201.779 ± 0.0490.2187 ± 0.00162972 ± 1297
20.1c,osc,p1592421.530.371.938 ± 0.0560.2119 ± 0.00232920 ± 1792
21.1c,osc,p77941.220.341.702 ± 0.0600.2326 ± 0.00683070 ± 4897
23.1c,osc,p931341.440.161.810 ± 0.0670.2240 ± 0.00203010 ± 1494
22.1c,osc,p2733501.290.301.803 ± 0.0490.2197 ± 0.00122978 ± 996
20.2r,hd,p944670.070.032.030 ± 0.0490.1727 ± 0.00072584 ± 6100
7.2r,hd,p1052420.040.042.165 ± 0.0530.1709 ± 0.00072566 ± 695
23.2c,osc,p8123050.380.141.877 ± 0.0450.2183 ± 0.00092969 ± 793
17.2r,hd,p822780.090.072.008 ± 0.0500.1750 ± 0.00052606 ± 5100
5.2r,hd,p11391400.120.082.090 ± 0.0510.1730 ± 0.00042587 ± 497
GGU200892 siliceous volcanosedimentary rock, Ivisârtoq supracrustal belt (64°27.35′N, 50°13.50′W)*
1.1e,osc,fr1619312.050.701.638 ± 0.0730.2304 ± 0.00473055 ± 33101
2.1e,osc,fr1318413.910.941.748 ± 0.1560.2320 ± 0.00693066 ± 4895
3.1m/c,osc,ov1111210.071.231.703 ± 0.0920.2290 ± 0.00753045 ± 5498
4.1e,osc,p,fr99410.390.561.632 ± 0.0930.2368 ± 0.00713099 ± 49100
5.1m/c,osc,ov1316412.250.921.651 ± 0.0670.2356 ± 0.00513090 ± 3599
6.1m,osc,fr1313810.411.401.735 ± 0.0880.2302 ± 0.00693053 ± 4996
7.1e,osc,ov,fr171267.200.331.656 ± 0.0710.2313 ± 0.00453061 ± 31100
8.1m,osc,ov161408.870.471.650 ± 0.0920.2304 ± 0.00483055 ± 34100
9.1m,osc,ov,fr1515410.511.341.687 ± 0.0850.2297 ± 0.00753050 ± 5498
10.1m/c,osc,ov151368.940.731.706 ± 0.0980.2328 ± 0.00433072 ± 3097
11.1e,osc,p/eq11625.850.531.681 ± 0.0760.2361 ± 0.00753094 ± 5297
12.1e,osc,p,fr211748.390.471.672 ± 0.0860.2348 ± 0.00463085 ± 3298
13.1e,osc,p,fr1517711.520.871.601 ± 0.0800.2257 ± 0.00753022 ± 54104
14.1e,osc,p,fr411453.520.301.675 ± 0.0580.2322 ± 0.00333068 ± 2398
15.1e,osc,p,fr3049616.270.381.661 ± 0.0710.2354 ± 0.00433089 ± 2998
16.1e,osc,p,fr1415111.021.071.682 ± 0.1040.2310 ± 0.00513059 ± 3698
17.1e,osc,p,fr1617110.580.781.651 ± 0.0820.2346 ± 0.00473083 ± 3399
18.1e,osc,p,fr161449.190.451.625 ± 0.0720.2437 ± 0.00413144 ± 2798
19.1m,osc,ov2156327.180.351.645 ± 0.0580.2320 ± 0.00343066 ± 23100
20.1e,osc,p1323718.420.421.592 ± 0.0670.2262 ± 0.00563026 ± 40104
21.1e,osc,p8708.300.731.718 ± 0.1020.2369 ± 0.00683100 ± 4795
22.1e,osc,p8546.890.581.677 ± 0.0850.2416 ± 0.01443131 ± 9896
23.1e,osc,p,fr1925513.410.471.683 ± 0.0770.2335 ± 0.00663076 ± 4698
GGU200499 granite/granodiorite, Central Ivisârtoq Dome structure (64°45.5′N, 49°39.0′W)*
1.1e,osc,p373950.250.301.944 ± 0.1030.2106 ± 0.00382910 ± 2992
2.1e,osc,p1752780.040.361.694 ± 0.0500.1811 ± 0.00162663 ± 15112
3.1e,osc,p13931770.131.591.956 ± 0.0550.1980 ± 0.00102809 ± 895
4.1e,osc,p45923670.081.691.518 ± 0.0730.1835 ± 0.00282685 ± 25122
5.1m/c,osc,p166670.400.731.655 ± 0.1130.2180 ± 0.00432966 ± 32103
6.1m/c,osc,p,fr3271150.350.081.741 ± 0.0800.2187 ± 0.00332971 ± 2498
7.1m,osc,p,fr166580.350.091.627 ± 0.0480.2173 ± 0.00142961 ± 10104
8.1e,osc,p3801720.450.181.728 ± 0.0610.2179 ± 0.00302965 ± 2399
9.1e,osc,p2691670.620.051.760 ± 0.0700.2176 ± 0.00122963 ± 998
10.1m,osc,lp13213380.265.191.800 ± 0.0470.1974 ± 0.00372805 ± 31102
10.2m,osc,lp12145450.451.241.905 ± 0.1500.2136 ± 0.00282933 ± 2293
10.3m,osc,lp12095900.497.271.704 ± 0.0620.2114 ± 0.00732917 ± 57102
10.4e,osc,lp9053570.398.401.795 ± 0.0980.2019 ± 0.02292841 ± 198101
11.1e,osc,p,fr19042080.112.351.758 ± 0.0550.2001 ± 0.00372827 ± 30103
11.2m,osc,p,fr286780.27<0.011.536 ± 0.0660.2179 ± 0.00312965 ± 23109
G91/92 homogeneous granitoid, Ujarassuit Nunaat (64°45.5′N, 49°39.0′W)*
1.1e,osc,p67390.570.131.744 ± 0.0410.2304 ± 0.00183055 ± 1396
2.1e,osc,ov72540.750.091.678 ± 0.0510.2307 ± 0.00293057 ± 2099
3.1e,osc,p155980.630.041.660 ± 0.0480.2328 ± 0.00213072 ± 1599
4.1e,osc,stubby81470.580.081.645 ± 0.0360.2321 ± 0.00143066 ± 10100
5.1e,osc,stubby109630.580.121.666 ± 0.0470.2307 ± 0.00253057 ± 1899
6.1e,osc,p177900.510.061.607 ± 0.0430.2367 ± 0.00453098 ± 30101
7.2e,osc,p93800.850.081.660 ± 0.0390.2360 ± 0.00173093 ± 1198
8.2e,osc,ov74480.650.141.825 ± 0.0500.2325 ± 0.00243069 ± 1792
9.1e,osc,p,fr1241190.960.081.758 ± 0.0350.2328 ± 0.00143071 ± 1095
10.1m,osc,p104670.640.141.840 ± 0.0510.2278 ± 0.00203037 ± 1492
G93/88 banded gneiss (reconnaissance), Ujarassuit Nunaat (64°53.0′N, 50°03.5′W)*
1.1c,osc,p2711380.510.061.705 ± 0.0520.2285 ± 0.00093041 ± 798
2.1c,osc,p2891350.47<0.011.640 ± 0.0470.2285 ± 0.00093042 ± 6101
3.1e,osc,p1851230.670.061.610 ± 0.0460.2332 ± 0.00123074 ± 8101
4.1m,osc,p155480.310.021.581 ± 0.0660.2313 ± 0.00293061 ± 20103
5.1e,osc/hd,p39073060.080.011.965 ± 0.0540.1629 ± 0.00052486 ± 5107
6.1r,hd,p30821370.040.011.930 ± 0.0610.1822 ± 0.00112673 ± 10101
7.1e,osc/h,lp36051860.05<0.011.842 ± 0.0610.1771 ± 0.00072626 ± 6106
8.1e,h,p25111400.060.011.994 ± 0.1160.1830 ± 0.00032681 ± 398
9.1e,h,p23071150.05<0.011.780 ± 0.0560.1814 ± 0.00062666 ± 5108
G03/71 banded gneiss, southern Ivisaartoq (64°43.759′N, 49°47.382′W)*
1.1e,osc,p2771300.470.701.767 ± 0.0710.2079 ± 0.00232889 ± 18100
2.1e,osc,p2461280.520.111.755 ± 0.0620.2186 ± 0.00122970 ± 998
3.1m,osc,p103760.740.101.647 ± 0.0620.2202 ± 0.00362982 ± 27103
4.1e,osc,lp7881630.210.141.833 ± 0.0530.2116 ± 0.00332918 ± 2696
5.1e,osc,p7032840.400.131.690 ± 0.0430.2163 ± 0.00132953 ± 10102
6.1e,osc/hd,p14223790.270.021.610 ± 0.0390.2182 ± 0.00092968 ± 7105
6.2m,osc,p2521990.793.401.678 ± 0.0530.2171 ± 0.00862959 ± 65102
7.1e,osc,p62411081.782.351.726 ± 0.0530.2178 ± 0.00232965 ± 1799
8.1e,osc,p5133610.705.291.715 ± 0.0430.2131 ± 0.00652929 ± 50101
9.1e,osc,p245410250.420.021.727 ± 0.0670.2074 ± 0.00592885 ± 47102
10.1e,osc,p2351400.600.201.710 ± 0.0550.2153 ± 0.00212946 ± 16101
11.1m,osc,p,fr3033331.109.112.197 ± 0.1340.2223 ± 0.00992997 ± 7481
12.1m,osc,p,fr5192990.580.491.557 ± 0.0680.2111 ± 0.00162914 ± 12110
13.1?c,osc,p,fr1491801.210.841.847 ± 0.0740.2247 ± 0.00373015 ± 2793
Isukasia terrane; structurally below Kapisilik terrane
G91/80 tonalitic gneiss, eastern Ujaragssuit Nunaat (64°55.5′N, 49°59′W)*
1.1c,osc/rex,p5614940.880.041.367 ± 0.0640.3507 ± 0.00153710 ± 795
1.2r,hd,p1933440.020.041.839 ± 0.0820.2226 ± 0.00193000 ± 1393
1.3r,hd, p1516240.020.051.836 ± 0.0690.2192 ± 0.00032975 ± 294
2.1e,osc/rex,p8403330.403.661.340 ± 0.0620.3489 ± 0.00243702 ± 1197
3.1e,osc/rex,p16248940.550.151.396 ± 0.0580.3388 ± 0.00113657 ± 595
4.1e,osc/rex,p,fr10762560.240.111.314 ± 0.0610.3487 ± 0.00153701 ± 699
5.1r,hd,p816200.020.251.718 ± 0.1030.2212 ± 0.00272989 ± 2099
6.1m,osc/h,p,fr147530.360.101.205 ± 0.0520.3732 ± 0.00343804 ± 14102
7.1m,osc/h,p,fr149590.390.101.213 ± 0.0560.3734 ± 0.00263805 ± 11102
7.2r,hd, p51070.010.471.568 ± 0.1600.2188 ± 0.00082972 ± 6107
7.3r,hd, p39740.010.171.637 ± 0.1310.2240 ± 0.00103010 ± 7102
8.1r,hd, p5801070.180.231.319 ± 0.0430.3671 ± 0.00143780 ± 696
9.1r,hd, p718240.030.322.001 ± 0.1030.2074 ± 0.00092886 ± 791
10.1r/rex,hd,p1143160.010.121.747 ± 0.0560.2114 ± 0.00122916 ± 9100
11.1r,hd,p,fr568450.080.672.045 ± 0.1050.2251 ± 0.00153017 ± 1185
12.1r,hd, p915180.020.161.676 ± 0.0520.2217 ± 0.00052993 ± 4101
13.1r,hd, p2020110.010.873.677 ± 0.2030.1874 ± 0.00182719 ± 1657
14.1r,hd, p19006360.330.711.883 ± 0.0560.2831 ± 0.00193380 ± 1081
15.1r,hd, p733260.031.071.830 ± 0.0650.2134 ± 0.00102931 ± 796
G93/54 Itsaq Gneiss Complex paragneiss, Ujarassuit Nunaat (64°58.40′N, 50°09.00′W),† from Nutman et al. (2002)
1.1tw260790.310.261.458 ± 0.0450.3119 ± 0.00273530 ± 13−5
1.2tw422380.090.011.727 ± 0.0480.2416 ± 0.00123131 ± 894
2.1ov1251180.010.062.008 ± 0.0650.1835 ± 0.00122685 ± 1197
2.2ov980110.010.001.942 ± 0.0410.1829 ± 0.00042679 ± 4100
3.1p4753430.720.081.412 ± 0.0400.3291 ± 0.00303613 ± 1495
3.2p4101640.400.011.412 ± 0.0300.3126 ± 0.00113534 ± 598
4.1ov1232100.010.071.745 ± 0.0490.2168 ± 0.00112957 ± 999
4.2ov1247120.010.051.802 ± 0.0390.2092 ± 0.00112900 ± 898
5.1p,f2141160.540.341.357 ± 0.0410.3456 ± 0.00463688 ± 2096
5.2p,f234940.400.051.454 ± 0.0320.3159 ± 0.00273550 ± 1395
5.3p,f211710.340.081.355 ± 0.0370.3228 ± 0.00273583 ± 1399
5.4p,f243540.220.311.344 ± 0.0870.3111 ± 0.00523526 ± 26102
6.1m,anh1931280.670.211.418 ± 0.0420.3278 ± 0.00273607 ± 1395
6.2m,anh2782020.730.061.451 ± 0.0400.3244 ± 0.00123591 ± 694
7.1m,p145920.640.311.285 ± 0.0380.3536 ± 0.00203722 ± 9100
7.2e,p1561210.770.081.274 ± 0.0290.3549 ± 0.00193728 ± 8100
8.1e,p278820.290.151.306 ± 0.0390.3459 ± 0.00393689 ± 1799
8.2e,p2601110.430.011.289 ± 0.0300.3587 ± 0.00133744 ± 699
9.1p2521420.560.031.211 ± 0.0260.3868 ± 0.00083859 ± 3101
9.2p4172270.540.021.289 ± 0.0280.3819 ± 0.00423839 ± 1796
10.1m,p,f2663181.190.181.255 ± 0.0330.3508 ± 0.00133710 ± 6102
10.2m,p,f2241950.870.001.127 ± 0.0620.3508 ± 0.00973711 ± 43110
11.1eq3771130.300.011.565 ± 0.0340.2853 ± 0.00093392 ± 594
12.1e,p85180.010.011.715 ± 0.0350.2149 ± 0.00212943 ± 16101
13.1c,p182670.370.041.437 ± 0.0330.3075 ± 0.00313509 ± 1697
13.2c,p236940.400.011.304 ± 0.0340.3527 ± 0.00173719 ± 799
13.3c,p2961440.490.011.312 ± 0.0530.3530 ± 0.00153720 ± 698
13.4r+c,p11002200.200.241.427 ± 0.0980.2539 ± 0.00363209 ± 23107
14.1p5151080.210.011.539 ± 0.0360.2656 ± 0.00103280 ± 698
15.1m,anh,f89890.010.011.721 ± 0.0390.2189 ± 0.00122972 ± 999
16.1m,p320960.300.261.605 ± 0.0410.2812 ± 0.00113370 ± 693
17.1m,p,f229800.350.011.285 ± 0.0310.3493 ± 0.00263704 ± 12100
18.1c,ov/anh3242740.840.181.385 ± 0.0290.3194 ± 0.00133567 ± 698
18.2r,ov/anh1029200.020.391.972 ± 0.0930.1787 ± 0.00312641 ± 29100
19.1ov/anh903140.020.021.859 ± 0.1800.2159 ± 0.00412950 ± 3194
20.1m,ov1206130.010.011.934 ± 0.0670.1833 ± 0.00042683 ± 4100
21.1ov/anh8572260.260.011.379 ± 0.1270.2728 ± 0.00173322 ± 10106
22.1ov/anh73390.010.001.894 ± 0.0540.2012 ± 0.00252836 ± 2096
23.1rex/e,p/anh2001140.570.041.306 ± 0.1280.3185 ± 0.00363562 ± 17103
24.1m,ov1836250.010.011.873 ± 0.0490.1834 ± 0.00072684 ± 7103
25.1m,ov1574200.010.011.919 ± 0.1110.1848 ± 0.00142696 ± 13100
26.1m,p187500.270.231.634 ± 0.1470.3004 ± 0.00333472 ± 1789
27.1m,p/anh729830.110.021.672 ± 0.0360.2562 ± 0.00093223 ± 694
28.1e,p/tw969180.020.011.859 ± 0.0410.2001 ± 0.00062827 ± 598
G97/58 Itsaq Gneiss Complex felsic schist, Ujarassuit Nunaat (64°58.20′N, 50°13.62′W)*
1.1m,osc,stubby2423330.010.042.404 ± 0.1100.1811 ± 0.00112663 ± 1084
2.1m,h,stubby40930.010.082.050 ± 0.0780.1828 ± 0.00142678 ± 1396
3.1m,osc,p1500200.010.011.997 ± 0.0570.1837 ± 0.00032686 ± 397
G97/04 monazites in 3647 Ma granite sheet, south of Isua (65°00.58′N, 50°12.36′W)
1.115192778418.300.0521.936 ± 0.0420.1811 ± 0.00112663 ± 10101
1.216472560215.540.0571.941 ± 0.0470.1826 ± 0.00082677 ± 7100
2.12185127635.840.0271.913 ± 0.0560.1860 ± 0.00142707 ± 12100
3.11905169448.890.0341.929 ± 0.0610.1821 ± 0.00102672 ± 9101
4.119742119710.740.0461.968 ± 0.0450.1802 ± 0.00112655 ± 10100
5.12085178668.570.0291.904 ± 0.0420.1796 ± 0.00122649 ± 11103
6.11919163218.500.0211.890 ± 0.0410.1819 ± 0.00072670 ± 6103
7.11981137876.960.0241.932 ± 0.0620.1819 ± 0.00062670 ± 5101
8.117209912857.620.1501.895 ± 0.0600.1829 ± 0.00122679 ± 11102
81-0318 fuchsite–quartzite, Isua supracrustal belt;† rims on detrital zircons of Nutman & Collerson (1991)
2.2r,h,p3541<0.010.041.927 ± 0.0630.1863 ± 0.00062710 ± 599
3.2r,h,p3302<0.010.701.946 ± 0.0640.1833 ± 0.00102683 ± 9100
5.1r,h,p3191<0.010.131.984 ± 0.0630.1835 ± 0.00072685 ± 698
Rocks structurally above the Kapisilik terrane
G87/242 gneiss (Ikkattoq), Ujarassuit Paavat (64°47′N, 50°11′W);* igneous zircons (reconnaissance only)
1.1m,osc,p3933600.910.121.091 ± 0.0220.1967 ± 0.00162799 ± 1497
1.2e,osc,p3293070.930.051.951 ± 0.0810.1964 ± 0.00112797 ± 995
2.1m,osc,p6385100.800.071.984 ± 0.0240.1991 ± 0.00122819 ± 1093
3.1e,osc,p,fr14918940.600.071.982 ± 0.1010.1946 ± 0.00052781 ± 495
4.1e,osc,p2262261.000.171.941 ± 0.0690.1956 ± 0.00112790 ± 1096
5.1m,osc,p3042850.940.011.880 ± 0.0640.1952 ± 0.00062787 ± 599
6.1e,osc,p2492491.000.082.009 ± 0.1090.1969 ± 0.00072801 ± 693
7.1e,osc,p40127280.180.222.274 ± 0.0580.1874 ± 0.00152719 ± 1386
7.2e,osc,p31915280.170.031.837 ± 0.1000.1958 ± 0.00042791 ± 3100
8.1e,osc,p2622530.970.011.882 ± 0.0450.1970 ± 0.00152801 ± 1298
G91/69 gneiss (Ikkattoq), Ujarassuit Paavat (64°47.5′N, 50°11′W);* igneous zircon from host granodiorite
1.1osc,stubby3981410.350.081.770 ± 0.0180.2026 ± 0.00152847 ± 12101
Monazites from host granodiorite
M1.147499744920.50.011.846 ± 0.1130.1863 ± 0.00142710 ± 12.0103
M1.244409101220.50.031.808 ± 0.1040.1857 ± 0.00092704 ± 7.8105
M2.140039863224.60.041.781 ± 0.0550.1866 ± 0.00032713 ± 2.6106
M2.237199367725.20.721.905 ± 0.0570.1895 ± 0.00242738 ± 21.399
M3.132186870621.40.111.937 ± 0.0570.1778 ± 0.00072632 ± 6.1102
M3.235046865919.60.011.933 ± 0.0740.1770 ± 0.00032625 ± 3.1102
Igneous zircon from pegmatite vein
1.1e,osc,stubby1876550.030.561.942 ± 0.0380.1808 ± 0.00082660 ± 8101
2.1e,h,stubby2499580.020.021.893 ± 0.0430.1780 ± 0.00082634 ± 8104
3.1e,h,stubby2503660.030.011.887 ± 0.0830.1851 ± 0.00122699 ± 11102
4.1e,h/osc,stubby42861040.020.111.923 ± 0.0450.1766 ± 0.00072621 ± 6103
5.1e,h,p2303570.020.031.875 ± 0.0200.1811 ± 0.00032663 ± 2104
6.1h,stubby2565570.020.011.948 ± 0.0420.1747 ± 0.00062603 ± 5103
7.1e,h,p2274500.020.011.953 ± 0.0590.1835 ± 0.00072685 ± 699
Monazites in pegmatite vein
M1.140146063415.10.021.916 ± 0.0750.1770 ± 0.00102625 ± 9.2103
M2.128205207018.50.021.964 ± 0.0570.1777 ± 0.00062631 ± 5.5101
M3.131674473714.10.681.971 ± 0.0740.1759 ± 0.00142614 ± 13.7101
M4.131634095412.90.052.713 ± 0.1380.1719 ± 0.00152576 ± 14.479
M1.230634645915.20.031.996 ± 0.1410.1761 ± 0.00122617 ± 11.6100
M1.331024602114.80.021.919 ± 0.1150.1764 ± 0.00052619 ± 4.8103
M3.226543748214.10.142.011 ± 0.0400.1777 ± 0.00052631 ± 5.099
M5.124594316217.60.571.850 ± 0.0430.1773 ± 0.00052628 ± 4.3106
M2.224314485218.50.031.930 ± 0.0820.1773 ± 0.00142628 ± 13.6102
M6.125414080316.10.022.066 ± 0.1360.1757 ± 0.00312613 ± 29.797
G91/68 diatexite in the Itsaq Gneiss Complex, entrance of Ujarassuit Paavat (extra CL-guided analyses, 2003)*
1.1c,osc,p108410.380.091.249 ± 0.0600.3831 ± 0.00323844 ± 1399
1.2r,h,p111420.380.151.988 ± 0.0800.1836 ± 0.00172686 ± 1698
1.3r,h,p onto edge253420.160.041.886 ± 0.1220.1784 ± 0.00142638 ± 13104
2.1c,osc,fr226280.130.021.414 ± 0.0610.3277 ± 0.00463606 ± 2296
2.2r,h/osc,fr108430.400.152.012 ± 0.0880.1876 ± 0.00172721 ± 1596
2.3r,h/osc,fr122450.370.161.908 ± 0.1250.1807 ± 0.00422659 ± 39102
2.4r,h/osc,fr112430.390.351.918 ± 0.1030.1844 ± 0.00222693 ± 20101
3.1e,h,p2971420.480.121.967 ± 0.0700.1851 ± 0.00162699 ± 1498
3.2e,h,p2811310.470.032.008 ± 0.0970.1828 ± 0.00132679 ± 1297
4.1h.ov2901010.350.131.949 ± 0.0880.1851 ± 0.00242699 ± 2199
5.1h,fr2411660.690.051.543 ± 0.0600.2856 ± 0.00673394 ± 3795
5.2h,fr2131530.720.061.274 ± 0.0580.3337 ± 0.00433634 ± 20103
6.1r,osc/h,p124420.340.081.969 ± 0.0800.1886 ± 0.00202730 ± 1897
7.1r,h,p8342730.330.011.949 ± 0.0800.1841 ± 0.00152690 ± 1499
7.2r,h,p13674980.360.031.968 ± 0.0710.1844 ± 0.00122693 ± 1098
8.1r,h/osc,p113410.361.541.908 ± 0.0830.1836 ± 0.00342685 ± 30101
9.1h,ov203730.360.001.977 ± 0.0960.1850 ± 0.00262698 ± 2398
9.2h,ov200790.390.071.858 ± 0.0650.1851 ± 0.00112699 ± 10103
10.1r,h,p,fr168640.38<0.012.230 ± 0.6960.1862 ± 0.00232709 ± 2088
11.1eh/osc,p384460.120.381.573 ± 0.0600.1840 ± 0.00252689 ± 23118
12.1e,h,p,fr154580.380.071.956 ± 0.1150.1828 ± 0.00362678 ± 3399
13.1r,h,p,fr99450.450.051.970 ± 0.0870.1851 ± 0.00162699 ± 1498
13.2r,h,p,fr96400.410.251.994 ± 0.0940.1858 ± 0.00202705 ± 1897
  • First column: x.y, grain number followed by analysis number on that grain. Analyses in bold used in calculating the dates discussed in the text. Second column: brief summary of grain morphology and structure. Abbreviations: p, prism; stubby, short prism; ov, oval or equant; anh, anhedral; e, edge; m, middle; r, rim; c, core; tw, twinned; fr, fragment. Appearance of analysis site in CL images: rex, recrystallized; osc, euhedral fine-scale zoning; h, homogeneous; hd, dark homogeneous. Common 206Pb% is amount of 206Pb considered common, based on correction using measured 204Pb and using the model Pb of Cumming & Richards (1975) for the likely age of the rock. All analytical errors are quoted at 1σ.

  • * Zircon samples with CL images available.

  • † Samples without CL images.