Northeastern Section (45th Annual) and Southeastern Section (59th Annual) Joint Meeting (13-16 March 2010)

Paper No. 26
Presentation Time: 8:00 AM-12:05 PM

CALCITE-GRAPHITE THERMOMETRY OF MARBLES IN THE SHARBOT LAKE DOMAIN (GRENVILLE PROVINCE, ONTARIO)


HALFHIDE, Trevor M. and PECK, William H., Department of Geology, Colgate University, Hamilton, NY 13346, wpeck@colgate.edu

Carbon isotope analysis was done on graphite and calcite from marbles in the Sharbot Lake domain of Ontario to quantify metamorphic temperatures of a package of Mesoproterozoic supracrustal rocks. Sampling was concentrated in the Carleton Place quadrangle where isograds have been mapped in marbles by Goodwin-Bell (CJES 2008). Preliminary data from ten samples have carbon isotope fractions between calcite and graphite averaging 3.30±0.46‰, consistent with high-temperature metamorphism. The samples analyzed to-date are from high-grade marbles with coarse graphite, and work is underway on separating minerals from low-grade marbles with fine-grained graphite. In the vicinity of the Wolf Grove structure (Carleton Place quadrangle) calcite-graphite temperatures average 767±85°C (n=6). In the southern Sharbot Lake domain samples average 782±85°C (n=4). Future work will concentrate on lower-grade marbles near the Lavant Gabbro and correlating calcite-graphite temperatures with mapped isograds.