The University of British Columbia

This project is a P-T-t-d study of multiply deformed, Paleoproterozoic metamorphic rocks of the Southern Wopmay Orogen, NWT. The orogen, which comprises four main tectonic elements that were amalgamated between 1.92-1.84 Ga has been subject to numerous large scale tectonic and geophysical studies, including Lithoprobe’s well known SNORCLE project. Recent transects, using magnetotelluric data, have crossed the Archean/Proterozoic boundary and suggest the Proterozoic Bear Structural Province shallowly overlies the Archean Slave craton. Previous structural studies have suggested this geometry developed via fold and thrust style continental deformation, with large antiform-synform pairs developing in the supracrustal rocks. In this model, domes of Archean gneiss within the Proterozoic sequence represent windows through a basal thrust. However, recent mapping has identified unconformable stratigraphic contacts of overlying Proterozoic sediments on the Archean rocks, suggesting that deformation of the Proterozoic sequence also involved Archean crust. Field relationships also show that the Proterozoic metasedimentary rocks have multiple fabrics, varying from more shallow fabrics around the Archean domes, to more steeply dipping fabrics to the East, adjacent to the Slave Craton. This suggests orogenic deformation involved significant lateral contraction of the Proterozoic crust and underlying Archean lithosphere. The overall goal of this proposed research is to unravel the nature of the deformation and metamorphism of the Proterozoic supracrustal sequence and the Archean gneiss domes, and to assess the constraints this places on the process by which the underlying Archean lithosphere must have deformed. The field work component of this study is cornerstone to understanding orogenic processes on all scales. In the first season, mapping was undertaken along an 8 km traverse across stratigraphy at Brownwater Lake to assess mesoscopic and macroscopic geometries, and to look for kinematic indicators. Mapping of metamorphic assemblages also took place at Grant Lake, 40km to the northwest, to understand isograd patterns and relationships in relation to macroscopic structure. This academic year I have completed microstructural analysis of spatially oriented thin sections to look at matrix and porphyroblast textures and mineral paragenesis, to help decipher kinematic and metamorphic history. This will facilitate the P-T modeling of equilibrium mineral assemblages using internally consistent thermodynamic datasets. In-situ dating of U-Th bearing monazite and xenotime and the dating of cross-cutting relationships in the field will provide important time constraints, enabling the P-T-d analysis of rocks to be placed in a real-time framework; and ultimately contributing to a clearer understanding of lithospheric scale deformation paths in Proterozoic crust on Archean lithosphere. In the next field season I will complete parallel traverses, crossing the Archean/Proterozoic contact, through similarly deformed rocks to verify isograd and deformational consistency northward, and to further define the limits of metamorphism and deformation. A structural/metamorphic map, multiple cross-sections showing large-scale features, and a clear understanding of the constraints on the P-T-t-d evolutionary history will aid in more accurate interpretations and will provide essential information about the orogenic evolution of the Proterozoic and Archean lithosphere.

Smar, L., Hickey, K., and Jackson, V. (2010) Investigations into the P-T-t-d history of Paleoproterozoic rocks of the Coronation Supergroup, Southern Wopmay Orogen. Student talk given at: Northwest Territories Geoscience Forum 2010; November 16-18 2010; Yellowknife, NT.

Smar, L., Hickey, K., and Jackson, V. (2010) Initial investigations into the P-T-t-d history of Paleoproterozoic supracrustal rocks at Grant and Brownwater lakes, southern Wopmay Orogen, NWT. Poster session presented at: Association for Mineral Exploration British Columbia, Mineral Exploration Roundup 2010; January 18-20 2010; Vancouver, BC.

Smar, L., Hickey, K., and Jackson, V. (2010) Initial investigations into the P-T-t-d history of Paleoproterozoic supracrustal rocks at Grant and Brownwater lakes, southern Wopmay Orogen, NWT. Poster session presented at: Yellowknife Geoscience Forum 2009; November 17-19 2009; Yellowknife, NT.

Buse, S., Smar, L., Stott, G.M. and McIlraith, S.J. (2009) Precambrian geology of the Winisk Lake area; Ontario Geological Survey, Preliminary Map P.3607, scale 1:100 000.

Buse, S., Moss, T., Smar, L. and Henderson, A. 2008. Precambrian geology of the Hewitt Lake area, North Spirit Lake greenstone belt, northwestern Ontario; Ontario Geological Society, Preliminary Map P.3604, scale 1:20,000.

Smar, L. (2008) Geological History and Structural Analysis of folding in the North Spirit Greenstone Belt, Hewitt Lake, Ontario. Thesis (B.Sc.) Carleton University.

Buse, S., Moss, T., Smar, L. and Henderson, A. 2007. Geology of the Hewitt Lake and Mattson Lake area, northwestern Ontario: new insights into the structure, metamorphism and mineralization of the North Spirit Lake greenstone belt; in Summary of Field Work and Other Activities 2007, Ontario Geological Survey, Open File Report 6213, p.35-1 to 35-8.

Buse, S. and Smar, L. 2007. Geology of the Winisk Lake area, northwestern Ontario: a fresh look at a granitoid and gneissic terrane; in Summary of Field Work and Other Activities 2007, Ontario Geological Survey, Open File Report 6213, p.34-1 to 34-6.

University of British Columbia, Earth and Ocean Sciences, Vancouver, Fall 2009 to Present

M.Sc. student and Teaching Assistant: I have taught one weekly lab section each semester since starting at UBC, in 2nd and 3rd year petrology and 1st year introduction to geology. My thesis aims to define a pressure-temperature-time-deformation path for the multiply deformed Paleoproterozoic rocks of the Coronation Supergroup in the Southern Wopmay Orogen, NWT.

Northwest Territories Geoscience Office, Yellowknife, Summer 2009 to Present

Senior Geological Mapper: My thesis area is part of a larger mapping initiative with the NTGO - a three year, multi-phase project aiming to re-map the Southern Wopmay Orogen. Over two summers I have contributed to the map, led my own field crew and attended conferences where I've presented my project data in the form of posters and talks.

Geological Survey of Canada, Ottawa, Winter & Spring 2009

Support Geologist: Full-time assistant to GSC researchers in both office and labratory settings. I updated databases, reworked geological maps as part of Flin Flon TGI3, and worked in the geochronology lab (zircon separation, picking and mounting).

Crosshair Exploration & Mining, Labrador, Summer 2008

Student Geologist: Mapping and mineral exploration processes within the Central Mineral Belt of Labrador. My responsibilities included the completion of three geological maps at 1:2000 and 1:5000-scale of Paleoproterozoic hydrothermally altered sedimentary units and felsic volcanic rocks, report writing and till/soil sampling (biogeochemical and soil gas hydrocarbon surveys).

Carleton University, Earth Sciences Department, Ottawa, 2008

Teaching Assistant: I lead 3-hour laboratory sessions for a first-year geology course which reviewed basic rocks and minerals, and dealt with various mapping and geodynamic problems.

Ontario Geological Survey, Northern Ontario, Summers 2006 & 2007

Junior mapping assistant & Senior Mapper: Mapping deformation and mineralization, contributing to 1:50,000 scale bedrock maps of Archean Greenstone belts in remote locations in Northern Ontario. I also completed a structural mapping undergraduate thesis within a highly deformed transect of the belt.

University of British Columbia, Dept of Earth and Ocean Sciences

Fall 2009 to Present
M.Sc. Candidate (Geological Sciences), Supervised by Dr. Kenneth Hickey (UBC) and Valerie Jackson (NTGO)

Carleton University, Earth Sciences Dept

2004-2008
B.Sc. Honours, Thesis supervised by Dr. Sharon Carr