The Nuvvuagittuq Greenstone Belt (NOO-voo-AG-it-tuck) (NGB) is a sequence of metamorphosed mafic to ultramafic volcanic and associated sedimentary rocks (a greenstone belt) located on the eastern shore of Hudson Bay, 40 km southeast of Inukjuak, Quebec. These rocks have undergone extensive metamorphism, and represent some of the oldest rocks on earth. Using uranium-lead dating on zircons, these rocks have been dated to be no younger than 3.7 billion years. More recently, measurements were made using samarium-neodymium dating that suggest a formation age of 4.3 billion years ago.