2 New Publications - Ar/Ar dating of basalts from Australia and the South Atlantic

2 new publications are now availiable online from the Ar Lab Group, both involving dating of basalt....

1. Marshall et al IN PRESS, New 40Ar/39Ar dating of the Antrim Plateau Volcanics, Australia: clarifying an age for the eruptive phase of the Kalkarindji continental flood basalt province

This paper written by Peter Marshall dates basalts from the Cambrian Kalkarindji Large Igneous Province in Australia, the study results in age of 508.0 - 498.3 +/- 5.5 Ma. This age for the flood basalts indicates the plateau volcanics are younger than the intrusive rocks and with ages for eruption not later than 510Ma disassociates the lavas from being a major cause of 510Ma biotic crises which had been suggested previously to be synchronous.

2.  D.A. Jerram, I.R. Sharp, T.H. Torsvik, R. Poulsen, T. Watton,
U. Freitag, A. Halton, S.C. Sherlock, J.A.S. Malley, A. Finley, J. Roberge, R. Swart, P. Fabregas, C.H. Ferreira, V. Machado , Volcanic constraints on the unzipping of Africa from South America: Insights from new geochronological controls along the Angola margin. Tectonophysics (2018), doi:10.1016/j.tecto.2018.07.027

This paper uses Ar/Ar ages, combined with U-Pb and Palaeontology to provide age constraints on the Angolan portion of the African margin withe new ages suggesting 3 main events, (cr.100, 91 and 82-81Ma). Using additional age information from onshore and offshore Angola, a  younging trend during the early stages of rift to drift is recorded in voclanic events, unzipping from North to South.