CARBON ISOTOPE THERMOMETRY IN THE CENTRAL METASEDIMENTARY BELT BOUNDARY THRUST ZONE GRENVILLE PROVINCE, ONTARIO

摘要

INTRODUCTION The Mesoproterozoic Grenville Province in Ontario consists of two major belts, the Central Gneiss Belt (CGB) in the west and the Central Metasedimentary Belt (CMB) in the east (Streepey et al. 1997). The CMB is a compilation of domains that range in age from 1.4 -1.16 Ga (Hanmer et al. 2000 and references therein), and have a key role in geologic history of the Laurentian margin. The CGB and CMB are separated in southern Ontario (Fig. 1) by the Central Metasedimentary Belt boundary thrust zone (CMBbtz) (Hanmer et al. 2000). The CMBbtz borders (or includes, in some reconstructions) the westernmost Bancroft Terrane, which borders the Elzevir Ter-rane in the east. The CMBbtz, Bancroft Terrane, and the western Elzevir Terrane were all metamorphosed to the amphibolites facies.