Overview of Results from the Greenstone ... - Geology Ontario

Table A1. continued
206
Sample Analysis Description Weight U Th/U Pb* Pb C Pb/
204 Pb
206 Pb/
238 U ±
207
2σ Pb/
235 U ±
207
2σ Pb/
206 Pb ± 2σ
207 Pb/
206 Pb ± 2σ Disc. Corr.
Fraction no. (# = location on Figure 2 & Table 1) (mg) (ppm) (pg) (pg) Age (Ma) (%) Coeff.
03VOI-0422-1 #31, Trachyte, Timiskaming Group, Gauthier Twp.
A1 MAH4040 1 clr, cls, small, stubby prism 0.0003 107 0.66 16.1 0.4 2359 0.51157 0.00231 12.8293 0.0624 0.18189 0.00030 2670.1 2.8 0.3 0.9401
A2 MAH4041r 1 clr, cls, small, stubby prism 0.0006 74 0.40 27.3 0.8 2114 0.51571 0.00160 13.1224 0.0488 0.18455 0.00031 2694.2 2.8 0.6 0.8938
A3 MAH4042a 1 clr, brn, small, 2:1 prism 0.0003 478 0.53 69.1 2.7 1440 0.50561 0.00135 12.6658 0.0480 0.18169 0.00040 2668.3 3.6 1.4 0.8224
A4 MAH4064a 2 clr, brn, small, 2:1 prism 0.0003 356 0.66 74.8 3.4 1239 0.51170 0.00131 12.8828 0.0499 0.18260 0.00047 2676.6 4.3 0.6 0.7471
A5 MAH4065 2 clr, brn, small, 2:1 prism 0.0003 277 0.69 48.6 0.4 7586 0.49685 0.00134 12.4571 0.0370 0.18184 0.00022 2669.7 2.0 3.2 0.9166
03VOI-570-1 #32, Timiskaming sandstone, Gauthier Twp.
1a MAH4049 1 clr, med-brn, sharp, subeq euh prism 0.0026 169 0.63 267.1 0.4 35802 0.51336 0.00127 12.9593 0.0357 0.18309 0.00017 2681.0 1.5 0.5 0.9440
1b MAH4050 1 clr, med-brn, sharp, subeq euh prism 0.0026 122 0.83 193.6 0.4 23858 0.51235 0.00172 12.9073 0.0410 0.18271 0.00034 2677.7 3.1 0.5 0.8370
2a MAH4051 1 clr, pbr, subrnd, sl. elong, prism 0.0015 97 0.36 84.6 0.5 9801 0.53342 0.00171 14.2115 0.0489 0.19323 0.00019 2769.8 1.7 0.6 0.9567
2b MAH4109 1 clr, pbr, subrnd, sl. elong, prism 0.0007 73 0.47 29.4 0.5 3500 0.51450 0.00199 12.9986 0.0543 0.18324 0.00023 2682.4 2.0 0.3 0.9560
3a MAH4052 1 large clr, brn, sharp frag 0.0041 145 0.83 368.3 0.6 30646 0.51284 0.00146 12.9239 0.0401 0.18277 0.00016 2678.2 1.5 0.4 0.9581
3b MAH4110 1 large clr, brn, sharp frag 0.0049 74 0.71 221.0 1.5 8024 0.51216 0.00107 12.9136 0.0322 0.18287 0.00016 2679.1 1.5 0.6 0.9411
03SJP-115-1 #34, Clifford stock monzogranite, Clifford Twp.
Z1 MAH4010 1 cls-pbr, clr, elong euh prism (>4:1); minor inc 0.0025 141 0.48 207.3 2.2 5337 0.51364 0.00292 13.0176 0.0758 0.18381 0.00023 2687.6 2.1 0.7 0.9770
Z2 MAH4007 1 large, pbr, clr, frag; minor incl, frac 0.0008 147 1.02 74.0 2.1 1796 0.51737 0.00209 13.1081 0.0576 0.18375 0.00043 2687.0 3.9 0.0 0.8507
Z3 MAH4012 1 large, cls, clr, frag; minor incl, frac 0.0014 102 0.51 85.8 1.2 4154 0.51660 0.00230 13.0819 0.0612 0.18366 0.00022 2686.2 2.0 0.1 0.9668
03ASP-130-1 #35, Porphyritic rhyolite, Clifford Twp.
A1a MAH4022 1 clr, pbr, short, stubby euh prism 0.0016 244 0.49 225.9 7.3 1756 0.51867 0.00112 13.2145 0.0422 0.18478 0.00033 2696.3 2.9 0.1 0.8515
A1b MAH4023c 1 clr, pbr, short, stubby euh prism 0.0010 239 0.45 146.1 6.3 1348 0.51746 0.00111 13.1732 0.0472 0.18463 0.00040 2694.9 3.6 0.3 0.8231
A1d MAH4058 3 clr, pbr, short, stubby euh prism 0.0024 124 0.53 177.5 0.4 27790 0.51810 0.00115 13.2031 0.0338 0.18482 0.00016 2696.6 1.5 0.2 0.9407
A2a MAH4024 1 clr, pbr, short, stubby euh prism 0.0012 252 0.56 177.8 2.6 3901 0.51036 0.00127 12.8882 0.0374 0.18315 0.00022 2681.6 2.0 1.1 0.9103
03ASP-0179-1 #36, Massive rhyolite, Ben Nevis Twp.
A1 MAH4053b 3 small, pyell, sharp subeq prisms 0.0007 102 0.46 39.9 0.4 6519 0.51917 0.00168 13.2323 0.0464 0.18485 0.00019 2696.9 1.7 0.1 0.9588
A2 MAH4054 6 v.small, pyell, shrp, subeq prisms 0.0007 298 0.58 119.0 1.1 6132 0.49406 0.00121 12.5774 0.0349 0.18464 0.00020 2694.9 1.8 4.8 0.9216
A3 MAH4055c 6 v.small, pyell, shrp, subeq prisms 0.0007 126 0.55 52.0 0.6 4734 0.51234 0.00130 13.0484 0.0385 0.18471 0.00019 2695.7 1.7 1.3 0.9394
C89-7
#38, Pegmatitic gabbro, Ghost Range sill, Lamplugh Twp. (Corfu, 1993)
Bd-1 MAH5025 3 small, thin, br blade frags, frosted; HF etched 0.0010 313 0.07 168.2 5.1 2057 0.51761 0.00157 13.3232 0.0492 0.18668 0.00030 2713.1 2.6 1.1 0.9053
Bd-2 MAH5026 3 small, thin, br blade frags, frosted; HF etched 0.0010 209 0.06 112.2 0.8 8777 0.51825 0.00101 13.3358 0.0318 0.18663 0.00016 2712.7 1.4 0.9 0.9391
04JAA-0002 #39 Leucogabbro, Centre Hill complex, north-central Munro Twp.
Z2 MAH4068 1 clr, cls square skeletal flange 0.0004 119 1.73 33.7 0.5 3365 0.51971 0.00180 13.3245 0.0505 0.18595 0.00024 2706.6 2.1 0.4 0.9418
Z3 MAH5001a 1 clr, cls euh, skeletal 0.0008 287 1.26 149.6 5.9 1246 0.51897 0.00134 13.3073 0.0595 0.18597 0.00056 2706.9 5.0 0.5 0.7613
Bd-1 MAH4069a 1 unabr, frosted? 0.0001 135 0.14 10.2 0.9 688 0.51421 0.00306 13.1697 0.1035 0.18575 0.00075 2704.9 6.7 1.4 0.8626
Bd-3 MAH5002 1 unabr, large blade frag 0.0009 288 0.18 148.3 2.0 4409 0.51648 0.00116 13.2446 0.0358 0.18599 0.00020 2707.0 1.8 1.0 0.9221
Notes:
All analyzed fractions represent least magnetic, air-abraded single zircon grains, free of inclusions, cores or cracks, unless otherwise noted.
Abbreviations: clr - clear; cls - colourless; pyell - pale yellow; brn - brown; pbr - pale brown; eq - equant; subeq - subequant; elong - elongate; euh - euhedral; prism - prismatic; frag - fragment; frac. - fracture(s); subrnd - subrounded
Pb* is total amount (in picograms) of radiogenic Pb.
Pb C is total measured common Pb (in picograms) assuming the isotopic composition of laboratory blank: 206/204 - 18.221; 207/204 - 15.612; 208/204 - 39.360 (errors of 2%).
Pb/U atomic ratios are corrected for spike, fractionation, blank, and, where necessary, initial common Pb; 206 Pb/ 204 Pb is corrected for spike and fractionation.
Th/U is model value calculated from radiogenic 208Pb/206Pb ratio and 207Pb/206Pb age assuming concordance.
Disc. (%) - per cent discordance for the given 207Pb/206Pb age.
Uranium decay constants are from Jaffey et al. (1971).
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