65 Igneous/Metamorphic Petrology and Geochemistry (Posters)

Tuesday, 16 March 2010
8:00 AM - 12:05 PM
International ABCDF

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

Paper number: 65-26
Program: Technical Sessions
Time: 8:00 AM – 12:05 PM

Authors

Abstract

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.