Improvement of 40Ar/39Ar age determinations for Quaternary basaltic rocks by eliminating the peak suppression effect

• Main Authors: Jeongmin Kim, In-Hwa Cho
• Format: Article
• Language: English
• Published: SpringerOpen 2020-02-01
• Series: Journal of Analytical Science and Technology
• Subjects: 40Ar/39Ar age; Noble gas mass spectrometer; Quaternary; Peak suppression; Getters
• Online Access: http://link.springer.com/article/10.1186/s40543-020-00207-9

Abstract Background The peak suppression effect, which suppresses the argon isotope signal due to the incomplete cleaning of gas from geological samples during measurement, is found in volatile-rich samples using the ARGUS VI noble gas mass spectrometer and its sample preparation system. Such effect hampers getting the precise isotope ratio essential for the 40Ar/39Ar age calculation. Findings The addition of one hot-getter and three room-temperature getters to the sample preparation system can effectively eliminate the peak suppression effect for several milligrams of sample during argon measurement to yield highly plausible 40Ar/39Ar ages of Quaternary volcanic rocks. Conclusions The modified preparation system makes it possible to get highly precise zero-time isotope signals, and thereby a geologically plausible 40Ar/39Ar age, especially for a small amount of volatile-rich samples.