Cosmogenic 21 Ne exposure dating of young basaltic lava flows from the Newer Volcanic Province, western Victoria, Australia

Abstract

Cosmogenic 21Ne was utilised to determine exposure ages of young subaerial basaltic lava flows from the Newer Volcanic Province, western Victoria, Australia. The ages (36-53 ka) determined from co-existing cosmogenic 21Ne and 3He in olivines separated from basalts are consistent within analytical uncertainties with ages previously determined by cosmogenic 36Cl exposure dating. This paper illustrates the potential of cosmogenic neon exposure ages in studying the eruption, surface morphology, and erosion history of young volcanic rocks, which are difficult to date using other conventional methods, such as K-Ar or 40Ar/39Ar dating. The present study demonstrates that combined cosmogenic 3He and 21Ne dating, specifically measured cosmogenic 3He/21Ne ratios, on the same samples, is powerful for evaluating the validity of calculated cosmogenic 3He and 21Ne surface exposure ages.