Mount Morning

Mount Morning is a glaciated, undissected, alkalic shield volcano in the Erebus volcanic province SE of the south end of the Royal Society Range. An elongated 4.9 x 4.1 km caldera lies at the summit, and numerous lava domes and cinder cones formed on fissures on the N, NE, and SE flanks. The latest volcanism associated with growth of the phonolitic central volcano was Potassium-Argon dated at about 1.2 to 1 million years, and late-Pleistocene to zero-age Argon-Argon dates were obtained for some of the volumetrically dominant basanitic fissure vents. More than 50 morphologically youthful vents occur on the flanks.