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

More documents

Recommendations

Info

03VOI-0422-1 Trachytic lava, Timiskaming assemblage, Gauthier Township (NAD83, Zone 17 UTM 587842E, 5332221N; #31 on Figure 2 and Table 1) Sample 03VOI-0422-1 was collected from a distinct unit of feldspar-phyric trachytic lava from the volcanic-dominated section of the Timiskaming assemblage in central Gauthier Township. A modest amount of zircon was recovered from this sample, dominated morphologically by small, short (2-3:1), generally cylindrical and often sharply terminated prisms. For the most part, zircons were colourless to brown and free of cracks and inclusions, but distinct cores were visible in some grains and were avoided where possible. Analytical data for two abraded single grains and one fraction comprising two small grains are 0.3 to 3.2% discordant and yield overlapping 207 Pb/ 206 Pb ages between 2668.3 and 2670.1 Ma (Table A1). The strongly collinear nature of the data enable a regression line to be fit through the origin that provides an upper intercept age of 2669.6±1.4 Ma (71% probability of fit; MSWD = 0.34; Figure 7C). Two other fractions, consisting of a single, colourless stubby prism (A2) and two small short brown prisms (A4) are only slightly discordant (0.6%), but have distinctly higher 207 Pb/ 206 Pb ratios than the previous fractions. Their corresponding ages, at 2694 and 2676 Ma, respectively, suggest minor amounts of inheritance— possibly from Porcupine and even earliest Timiskaming sources—although the ages should be regarded as strictly minimum estimates. The 2669.6±1.4 Ma age for the early Timiskaming assemblage alkaline volcanic rock from Gauthier Township is younger than any previous depositional estimate based on the youngest measured detrital zircons from the Timiskaming Group in the Timmins, Kirkland Lake or Larder Lake areas (Corfu, Jackson and Sutcliffe 1991; Ayer et al. 2003). However, this age is in accord with maximum age estimates of Timiskaming assemblage sandstone and conglomerate deposition from the uppermost Three Nations formation (
Based on this relatively small sampling of detrital zircons, the young age of the bulk of the detritus,
Page 1:
ISBN 0-7794-8652-8 THESE TERMS GOVE
Page 5:
ONTARIO GEOLOGICAL SURVEY Open File
Page 9:
Contents Abstract .................
Page 13:
Appendix 1. Thermal Ionization Mass
Page 17:
Miscellaneous Release—Data 155 Di
Page 21:
The Timmins area and Kirkland Lake-
Page 25:
Overview of Results from the Greens
Page 28 and 29:
3. The geophysical subproject funct
Page 30 and 31:
The following Preliminary Maps have
Page 32 and 33:
Samples with zircons analyzed by SH
Page 34 and 35:
Figure 4. U/Pb concordia plots of T
Page 36 and 37:
Figure 6. U/Pb concordia plot of TI
Page 38 and 39:
Targeting of several of these overg
Page 40 and 41:
Figure 10. U/Pb SHRIMP results from
Page 42 and 43:
In northwest Cleaver Township, a fe
Page 44 and 45:
SHRIMP U/Pb dating was carried out
Page 46 and 47:
Stratigraphic Framework In this sec
Page 48 and 49:
PACAUD ASSEMBLAGE The 2750 to 2735
Page 50 and 51:
The iron formation and chert brecci
Page 52 and 53:
(thickness) of banded iron-poor iro
Page 54 and 55:
clast conglomerates at the top of t
Page 56 and 57:
BLAKE RIVER ASSEMBLAGE Lower Part T
Page 58 and 59:
The Krist formation consists of cal
Page 60 and 61:
Timmins Area In the Timmins area, t
Page 62 and 63:
Kirkland Lake-Larder Lake Area Hyde
Page 64 and 65:
Intrusion Framework The plutonic ro
Page 66 and 67:
The youngest dated synvolcanic mafi
Page 68 and 69:
Albitite dikes are crosscut by gold
Page 70 and 71:
Worming Geophysical Data Treatment
Page 72 and 73:
In Timmins, the first generation of
Page 74 and 75:
Figure 20. Geological sketch map of
Page 76 and 77:
from Halfmoon Lake, only 2 km to th
Page 78 and 79:
The Blake River Group is divided in
Page 80 and 81:
Figure 22. Geological map of Munro
Page 82 and 83:
Mine stratigraphic succession, have
Page 84 and 85:
Figure 24. Geological map of Currie
Page 86 and 87:
Table 5. Simplified classification
Page 88 and 89:
mesocumulate). The Stoughton-Roquem
Page 90 and 91:
Shaw Dome Area GEOLOGICAL SETTING T
Page 92 and 93:
66 Figure 26. A generalized map of
Page 94 and 95:
1999) in their REE patterns and oth
Page 96 and 97:
plumbing system geometrically stabl
Page 98 and 99:
GOLD MINERALIZATION Production comm
Page 100 and 101:
The Narrows Break mineralized zone,
Page 102 and 103: Table 7. Diagnostic mineral assembl
Page 104 and 105: anomaly and the Dome Mine (Figures
Page 106 and 107: Recommendations • Further testing
Page 108 and 109: of the inversion product. (Recent a
Page 110 and 111: the evidence for pre-Pacaud strata
Page 112 and 113: plutonism suggests the onset of reg
Page 114 and 115: Watkinson and Comba 1989; Gibson an
Page 116 and 117: The Kirkland Lake giant gold deposi
Page 118 and 119: The Timmins and Kirkland Lake-Larde
Page 120 and 121: References Ames, D.E., Bleeker, W.,
Page 122 and 123: Bleeker, W., Parrish, R.R. and Sage
Page 124 and 125: Galley, A.G., Pilote, P. and Davis,
Page 126 and 127: Heather, K.B., Percival, J.A., Mose
Page 128 and 129: Lesher, C.M., 1989. Komatiite-assoc
Page 130 and 131: Péloquin, A.S., Verpaelst, P., and
Page 132 and 133: Stern, R.A. 1997. The GSC sensitive
Page 134 and 135: 108 This page left blank intentiona
Page 136 and 137: THERMAL IONIZATION MASS SPECTROMETR
Page 138 and 139: 04BHA-0462 Granophyre, Kamiskotia G
Page 140 and 141: contrastingly have been dated near
Page 142 and 143: The revised age of 2672.8±1.1 Ma f
Page 144 and 145: fraction (A1a) also overlaps concor
Page 146 and 147: 04JAA-0010 Albitite dike cutting Ti
Page 148 and 149: Therefore, on geochronological grou
Page 150 and 151: Three individual grains were analyz
Page 154 and 155: 03SJP-115-1 Monzonite, Clifford sto
Page 156 and 157: the original Corfu (1993) age, only
Page 158 and 159: Table A1. U/Pb isotopic data for zi
Page 160 and 161: 206 Sample Analysis Description Wei
Page 162 and 163: Appendix 2 Sensitive High-Resolutio
Page 164 and 165: Table A2. Ion microprobe (SHRIMP II
Page 166 and 167: Table A2. continued Struct. U Th Pb
Page 168 and 169: Table A2. continued 204 U Th Pb* Pb
Page 170 and 171: Table A2. continued 204 U Th Pb* Pb
Page 172: Metric Conversion Table Conversion
Page 175 and 176: Chart A. Magnetic and Gravity Three
show all

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

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?