Articles | Volume 4, issue 2
Geochronology, 4, 471–500, 2022
Geochronology, 4, 471–500, 2022
Research article
20 Jul 2022
Research article | 20 Jul 2022

Complex 40Ar ∕ 39Ar age spectra from low-grade metamorphic rocks: resolving the input of detrital and metamorphic components in a case study from the Delamerian Orogen

Anthony Reid et al.

Data sets

Complex 40Ar/39Ar age spectra from low metamorphic grade rocks, Delamerian Orogen Anthony Reid and Marnie Forster

Short summary
Dating low-grade metamorphic rocks with the 40Ar / 39Ar method is difficult because samples are fine-grained mixtures between detrital and newly grown metamorphic minerals. We use a careful step-heating schedule and resolve limits within the complex age spectra thus derived to infer the timing of metamorphism and deformation in the Delamerian Orogen (formerly part of eastern Gondwana). Results suggest detrital mineral from up to 1172 Ma and that metamorphic minerals grew at 470–458 Ma.