RUSSIAN JOURNAL OF EARTH SCIENCES VOL. 3, NO. 1, PAGES 79–82, doi:10.2205/2001ES000053, 2001

New K-Ar Ages for Basalts from Franz Josef Land

M. M. Arakelyantz, and V. A. Lebedev
Institute of Geology of Ore Deposits, Petrography, Mineralogy, and Geochemistry, Russian Academy of Sciences (IGEM RAS), Moscow, Russia

E. E Musatov, and N. M. Stolbov
All-Russian Research Institute of Oceanology, St. Petersburg, Russia

Abstract

[1]  New K-Ar age determinations on basalt samples from three drillholes and outcrops on Franz Josef Land suggest that flood volcanism throughout the archipelago fits in a very narrow age interval (116 5 Ma). For 95% of the samples we studied, age scatter is within analytical uncertainty. New data on basaltic bulk-rock, trace element, and REE compositions point to mantle plume affinity for the Early Cretaceous magmatism on Franz Josef Land, which preceded the onset of seafloor spreading in the Canada Basin.

Received 5 June 2001; published 16 June 2001.

Keywords: Franz Josef Land, flood volcanism, K-Ar dating.

Version of this paper in Russian