Ar-40/Ar-39 geochronology reveals rapid change from plume-assisted to stress-dependent volcanism in the Newer Volcanic Province, SE Australia
KF Oostingh, F Jourdan, EL Matchan, D Phillips
Geochemistry Geophysics Geosystems | American Geophysical Union | Published : 2017
Here we present 40Ar/39Ar ages of volcanic features in the Cenozoic intraplate Newer Volcanic Province in southeast Australia. The <5 Ma volcanic products in the Newer Volcanic Province can be subdivided into tholeiitic, valley‐filling Newer Plains basalts, and alkaline scoria cones, lava shields, and maars of the Newer Cones series. Plateau ages range from 3.76 ± 0.01 to 4.32 ± 0.03 Ma (2σ; all sources of uncertainties included) for the Newer Plains series, with production rates of volcanism decreasing post 4 Ma. We suggest that magmatism is related to the complex interplay of magma upwelling due to edge‐driven convection and the Cosgrove track mantle plume located in the northeast of the p..View full abstract
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Awarded by Australian Research Council Discovery grant
David Taylor of the Geological Survey Victoria is thanked for his assistance in the field. Adam Frew, Zdenka Martelli, and Celia Mayers of WAAIF are thanked for their assistance during sample preparation. Julie Boyce (Monash University) as well as Nicholas Le Corvec (Lunar and Planetary Institute) are thanked for discussion. Benjamin Cohen (UQ) is thanked for sharing his geochronology database. Darren Mark (SUERC) and Anthony Koppers (OSU) are thanked for their reviews, which have significantly improved the quality of this publication. Janne Blichert-Toft is thanked for editorial handling. The support of TiGER and the department Applied Geology at Curtin University of Technology is gratefully acknowledged. This research was funded by Australian Research Council Discovery grant DP130100517. Full step-heating data can be found in the supporting information data set table, whereas K/Ca ratio diagrams and thin section photos can be found in supporting information Figures S1 (Newer Plains) and S2 (Newer Cones).