GEOLOGY DISCUSSION R M Easton Ontario Geological Survey

GEOLOGY DISCUSSION R. M. Easton Ontario Geological Survey Precambrian Geoscience Section Geoneutrino Conference, Sudbury, September 17 -19, 2008

~500 km radius ~300 km radius Ontario Geological Survey Precambrian Geoscience Section Geoneutrino Conference, Sudbury, September 17 -19, 2008

Elliot Lake mines extracted 350 million tonnes of ore with an average grade of 765 ppm U, roughly equal Th (0. 09% U 3 O 8 or 1. 8 lbs/ton or 136, 000 tonnes of uranium metal) Pele Mtn. Pecors Lake prospect 2008 estimate 30 million tonnes at 425 ppm U Chalk River ~290 km Darlington ~340 km Ontario Geological Survey Precambrian Geoscience Section Bruce Pickering~330 km ~260 km Geoneutrino Conference, Sudbury, September 17 -19, 2008

DATA SETS CURRENTLY AVAILABLE RELEVANT TO ESTIMATING HPE IN THE CRUST IN THE SUDBURY AREA 1. Determine crustal thickness, estimates of lower, middle, upper crust thickness, depth to Moho – Seismic reflection and refraction data on land in Great Lakes, for Superior and Grenville Provinces, under Southern Province east of Sudbury (Wanapitei magnetic anomaly) (GLIMPCE, COCRUST, LITHOPROBE) Ontario Geological Survey Precambrian Geoscience Section Geoneutrino Conference, Sudbury, September 17 -19, 2008

Inferred crustal levels Sudbury region Ontario Geological Survey Precambrian Geoscience Section Geoneutrino Conference, Sudbury, September 17 -19, 2008

Cross-section through the Sudbury region Ontario Geological Survey Precambrian Geoscience Section Geoneutrino Conference, Sudbury, September 17 -19, 2008

2. Ground gravity data good for Sudbury and parts of Abitibi, gravity models for Sudbury, Killarney, various parts of the Grenville Province 3. Actual heat flow measurements and HPE determinations – Data of Jean-Claude Mareschal and co-workers 4. Regional geology well known, with one exception (crust beneath Manitoulin Island northern Lake Huron) Ontario Geological Survey Precambrian Geoscience Section Geoneutrino Conference, Sudbury, September 17 -19, 2008

KNOWN UNKNOWNS Midcontinent Rift axis Superior Grenville unknown Ontario Geological Survey Precambrian Geoscience Section Paleozoic atop Grenville Geoneutrino Conference, Sudbury, September 17 -19, 2008 KMB

5. Upper crustal compositional data – – Whole-rock geochemical data (modern, high-quality data for Abitibi, Sudbury structure, more limited highquality data for parts of Huronian, Grenville, Killarney) Airborne gamma-ray surveys (both low and highresolution over land) Ground gamma-ray data in some areas in the Huronian (assay mode K, U, Th) collected in conjunction with a more limited whole-rock geochemistry data set OGS Meridian 80 surface water and sediment geochemical data along 80 W from Lake Erie to James Bay Ontario Geological Survey Precambrian Geoscience Section Geoneutrino Conference, Sudbury, September 17 -19, 2008

Examples of K, U, Th data for Sudbury area rocks Unit K U Th method Pecors (mudstone) FELSIC 3. 1 2. 73 7. 3 5. 9 13. 8 Scintillometer XRF-F/ICP-MS Lower Matinenda Upper Matinenda Mc. Kim Ramsey Lake Espanola (FELSIC) 4. 5 3. 3 2. 7 1. 6 0. 1 8. 5 1. 9 4. 3 5. 9 1. 2 38. 3 9. 9 13. 2 14. 4 5. 9 Scintillometer, n=15 Scintillometer, n=10 Birch Lake granite 2651 Ma FELSIC 4. 5 4. 4 5. 2 6. 8 9. 9 6. 1 29. 1 88. 8 34. 7 Scintillometer, n=13 highest scint XRF-F/ICP-MS Nipissing gabbro MAFIC 1. 01 1. 66 2. 1 2. 6 6. 9 7. 6 (P) XRF-F/ICP-MS (M) XRF-F/ICP-MS 0. 1 0. 5 Huronian volcanics are similar (Espanola) East Bull Lake suite 0. 4 MAFIC Ontario Geological Survey Precambrian Geoscience Section Geoneutrino Conference, Sudbury, September 17 -19, 2008

Ontario Geological Survey Precambrian Geoscience Section Geoneutrino Conference, Sudbury, September 17 -19, 2008

6. Paleozoic data – OPG Bruce Nuclear diamond drill program collecting core through the Paleozoic from surface to Grenville basement beneath the Bruce site, core is accessible to OGS if we needed to collect K, U, Th data on main Paleozoic units – OPG making 3 -D crustal model of Paleozoic for much of southwestern Ontario as part of their nuclear waste management program – Paleozoic stratigraphy well-known – Map of Grenville basement exists based on examining all basement-penetrating exploration holes Ontario Geological Survey Precambrian Geoscience Section Geoneutrino Conference, Sudbury, September 17 -19, 2008

Extensional Events (± plume) Event Age (Ma) Intrusions/Mineralization EBLI suite 2480 -2445 layered intrusions, dikes NA + Europe Nipissing ~2220 PGE-Cu-Ni, contact style, reef? sills, contact style, skarn Ni-Cu-PGE, 5 -element veins, Cu veins Sudbury impact Sudbury swarm MCR 1850 Ni-Cu-PGE (not plume but mantle input/reworking of existing deposits? ) ~1250 layered intrusions, dikes Fe-Ti oxides, Cu? , potential unknown Grenville 1140 -1080 layered intrusions, sills, contact style, Ontario Geological Survey Precambrian Geoscience Section reef Ni-Cu-PGE dikes only, Cu? , potential unknown ~590 Geoneutrino Conference, Sudbury, September 17 -19, 2008