Geology and geochronology of McMurdo Volcanic Group rocks in the vicinity of Lake Morning, McMurdo Sound, Antarctica

• Published in: Antarctic Science
• Main Authors: Kyle, Philip R., Muncy, H. Lee
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1989
• Subjects: Antarc*; Antarctic Science; Antarctica; Ice Shelf; McMurdo Sound; Ross Ice Shelf; Ross Sea
• Online Access: http://dx.doi.org/10.1017/s0954102089000520; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102089000520

Trachyandesite lava flows and trachytic dykes exposed at ‘Gandalf Ridge’ and near Lake Morning on the northern slopes of Mount Morning represent the oldest exposed volcanic rocks in the Erebus volcanic province of the McMurdo Volcanic Group. Conventional whole rock K-Ar age determinations show the rocks are mid-Miocene, ranging between 14.6 and 18.7 Ma. North–south trending faults, which parallel the Transantarctic Mountains, cut the dated dykes. The faults are probably part of a broad fault zone which bounds the uplifted Transantarctic Mountains and the down-dropped Ross Sea/Ross Ice Shelf embayment.