The timing and petrogenesis of the Creighton Pluton, Ontario: An example of felsic magmatism associated with Matachewan Igneous Events

The Creighton Pluton is located in the southern Superior Province of Ontario and intrudes the lowermost volcanic strata of the Paleoproterozoic Huronian Supergroup. The granitoid pluton is actually composed of two temporally separate intrusions (dated at 2415 ± 5 Ma and 2376.3 ± 2.3 Ma), each of which has distinctive mineralogy, chemistry and isotopic signatures. Overall, the intrusions have &egr;_Nd values of −2 and similar rare-earth element pattern (LREE enrichment, negative Eu, flat HREE). These characteristics conform to other plutonic and volcanic rocks in the region. I propose that the Creighton Pluton was derived by partial melting of two sources, a mafic granulitic crust that formed by the underplating of Matachewan Igneous Events related mafic magmas and older pre-existing lower crust.