Eruption age of the Sverrefjellet volcano, Spitsbergen Island, Norway

• Published in: Polar Research
• Main Author: Allan H. Treiman
• Format: Article in Journal/Newspaper
• Language: English
• Published: Norwegian Polar Institute 2012
• Subjects: Svalbard; Spitsbergen; basalt; Knipovich Ridge; Ar–Ar; Environmental sciences; GE1-350; Oceanography; GC1-1581; Svalbard Archipelago; Norway; Sverrefjellet; Polar Research
• Online Access: https://doi.org/10.3402/polar.v31i0.17320; https://doaj.org/article/06de31fc436d49448e97274ebde19f1b

Sverrefjellet is a Pleistocene-age basaltic volcanic construct on north-western Spitsbergen Island (Svalbard Archipelago, Norway). Published ages for the Sverrefjellet eruption range between 6000 years and ca. 1 million years before present. The age of eruption is dated here as 1.05&#x00B1;0.07 (1&#x03C3;) My, consistent with Ar&#x2013;Ar isochron and plateau ages of several analysed samples. Radiogenic Ar represents a small proportion of the released Ar, <15% in nearly all samples. Non-radiogenic Ar components include air, excess 40Ar (seen as inverse isochron intercept values &#x003E;40Ar/36Ar&#x200A;=&#x200A;295.5), low-temperature alterations (Ar release at low temperature, with high Cl/K), carbonates and zeolites (Ar release at intermediate temperature) and xenolithic material (Ar release at high temperature, high Ca/K). The effects of the largely non-radiogenic argon sources are also seen in the total-gas Ar&#x2013;Ar &#x201C;ages&#x201D;, which range from 1.3 to 10.3 My, significantly larger than the inferred eruption age. It is likely that total-gas Ar&#x2013;Ar &#x201C;ages&#x201D; and whole-rock K&#x2013;Ar &#x201C;ages&#x201D; of similar basalts also exceed their true eruption ages.To access the supplementary material to this article please see Supplementary files under Article Tools online.