Mantle heterogeneity during the formation of the North Atlantic Tertiary Province: Constraints from trace element and Sr^Nd^Os^O isotope systematics of Baffin Island picrites

[1] Sr-Nd-Os-O isotope and major and trace element data from 62 Ma picrites from Baffin Island constrain the composition of mantle sources sampled at the inception of North Atlantic Igneous Province (NAIP) magmatism. We recognize two compositional types. Depleted (N-type) lavas have low 87Sr/86Sri (0.702990–0.703060) and 187Os/188Osi (0.1220–0.1247) and high 143Nd/144Ndi (0.512989–0.512999) and are depleted in incompatible elements relative to primitive mantle. Enriched (E-type) lavas have highe