A comparison of geochronological methods commonly applied to kimberlites and related rocks: Three case studies from Finland
Hayden Dalton, Andrea Giuliani, David Phillips, Janet Hergt, Roland Maas, Erin Matchan, Jon Woodhead, Hugh O'Brien
CHEMICAL GEOLOGY | ELSEVIER | Published : 2020
Despite their economic and scientific significance, the tectonic drivers that lead to the genesis of kimberlites and related rocks remain enigmatic. The presence of any spatio-temporal relationship(s) between the rift, drift and collision history of continents and the emplacement of kimberlites can only be elucidated with accurate geochronological constraints. In this study, we evaluated the three most common radiogenic dating methods used to determine the emplacement ages of kimberlites and related rocks - Rb-Sr phlogopite, U-Pb perovskite and 40Ar/39Ar phlogopite. We selected minimally altered samples from the Kaavi-Kuopio kimberlites, ultramafic lamprophyres and kimberlites from Kuusamo, ..View full abstract
Awarded by Society of Economic Geology Student Research Grant
Awarded by Swiss National Science Foundation (SNSF)
This work was supported by an Australian Research Training Program PhD Scholarship, Society of Economic Geology Student Research Grant (SRG 18-43) and Geological Society of Australia Victoria Division student award to HD, and a Swiss National Science Foundation (SNSF) Ambizione fellowship (n. PZ00P2_180126/1) to AG. We would like to thank the Geological Survey of Finland (GTK) for providing access to their drill-core storage facility and making this project possible. We thank Graham Hutchinson for his analytical help during SEM sessions, Matthew Felgate and Abaz Alimanovic for mineral separation guidance, Alan Greig for support during LA-ICP-MS analyses, Stan Szczepanski for his expertise in the AuScope-supported 40Ar/39Ar dating laboratory and Ashlea Wainwright and Serene Paul for assistance with column chemistry procedures. HD is also grateful for assistance with IsoplotR provided by Pieter Vermeesch. We are thankful for a positive and constructive review from an anonymous reviewer and the comments and efficient editorial handling of Balz Kamber. This is publication 61 from the Kimberlites and Diamonds Research Group at the University of Melbourne (http://kimberlitesdiamonds.org/).