Among the cones in Payún Matrú are the Plio-Pleistocene (5.333 million years ago until 11,700 years ago) Morados Grandes east and the cones around Pihuel volcano northeast of the field, respectively; the Guadalosos, La Mina and Montón de Cerros cones in the northern part of the field; and the Holocene cones in the eastern and western part of the field. Among these the Los Morados, Morado Sur and Volcán Santa María cones in the eastern and northeastern part of the field are uneroded and are probably of recent age. These cones are the source of conspicuous black lava flows in the western part of the field; some lava flows are over long.