Rb-Sr age determinations on shales associated with the Varanger Ice Age

• Published in: Geological Magazine
• Main Author: Pringle, I. R.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1972
• Subjects: Northern Norway; Varanger; Varangerfjord; Varangerfjord*
• Online Access: http://dx.doi.org/10.1017/s0016756800042734; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0016756800042734

Summary Rb–Sr whole-rock isochron ages from shale horizons in the Late Pre-Cambrian tillite succession in Varangerfjord, Northern Norway, are presented. Although data from the Stappogiedde Formation, which overlies the tillite horizons, give a Caledonian, metamorphic age of 530±50 m.y., ages obtained from shales occurring between and below the tillites are believed to represent the approximate times of deposition of the sediments. An age of 810±90 m.y. for the Tanafjord Group enables this group to be correlated with the Upper Torridonian and the age of 668±23 m.y. for the Nyborg Formation, which is taken as the age of the Varanger Ice Age, allows a tentative correlation to be made with the Egan and Marinoan Glaciation in Australia.