Geology and Age of the Late Archean Keivy Alkaline Province, Northeastern Baltic Shield

The Keivy alkaline province, Kola Peninsula, consists of six peralkaline granite bodies, alkaline syenogranite dikes, and two nepheline syenite intrusions emplaced between the tonalite‐trondhjemite‐granodiorite basement and the supracrustal Keivy terrane. U‐Pb zircon ages for the Keivy alkaline province range from 2613 to 2682 Ma and, for the spatially associated gabbro‐anorthosite complexes, from 2659 to 2668 Ma. The Keivy alkaline granitoids are geochemically different from other Late Archean alkaline rocks inferred to have been emplaced in subduction zone settings. The Keivy alkaline province may represent the earliest example of magmatism associated with continental rifting and the involvement of a mantle plume with oceanic island basalt–like characteristics.