Isotopic mapping of the Allochthon Boundary Thrust in the Grenville Province of Ontario, Canada

Nd isotope analyses of orthogneissic rocks were conducted in the vicinity of the Allochthon Boundary Thrust (ABT) in the Central Gneiss Belt of Ontario, Canada. Gneisses from the parautochthonous belt have relatively homogeneous Nd isotope signatures with an average TDM model age of 1.91Ga, consistent with an origin as an accreted Paleoproterozoic arc terrane (Barilia). Orthogneissic rocks from the overlying allochthonous belt have a wider …