Small Mantle Fragments from the Renard Kimberlites, Quebec: Powerful Recorders of Mantle Lithosphere Formation and Modification Beneath the Eastern Superior

The origin and evolution of diamondiferous lithospheric mantle sampled by the Neoproterozoic Renard kimberlites (eastern Superior Province, Quebec) is constrained based on mantle-derived microxenoliths and xenocrysts.The dataset illustrates the wealth of knowledge that can be gleaned from small samples (1·2 mg^2·2 g) through an integration of multiple, mainly single mineral based approaches. Our samples document the presence of an 200 km thick lithosphere with a ‘cold ’ (38 mW m2 surface heat flow) model geotherm at the time of kimberlite emplacement (c. 632 Ma), resulting in a large diamond window from 130 to 200 km (42^60 kbar). On the basis of the mantle xenolith and xenocryst record and excluding megacrysts, the lithospheric mantle beneath Renard was dominated by peridotite (91%), composed of lherzolite (72 % of samples), harzburgite (24%) and wehrlite (5%), with minor eclogitic (3%) and websteritic (6%) portions. Com