Diachronous Redistribution of Hf and Nd Isotopes at the Crystal Scale—Consequences for the Isotopic Evolution of a Poly-Metamorphic Crustal Terrane

In metamorphic rocks, mineral species react over a range of pressure–temperature conditions that do not necessarily overlap. Mineral equilibration can occur at varied points along the (PT) path, and thus different times. The sole or dominant use zircon isotopic compositions to constrain evolution rocks might then inadvertently skew geological interpretations towards one aspect moment rock’s history. Here, we present in-situ U–Pb/Sm–Nd isotope analyses apatite crystals extracted from two meta-igneous exposed in Saglek Block (North Atlantic craton, Canada), an Archean terrane, with aim examining various signatures events they record. data are combined published U–Pb/Hf/O same hand-specimens. We found offset nearly ca. 1.5 Gyr between U-Pb ages derived oldest cores ages, 200 Ma youngest overgrowths apatite. These differences recorded by mean redistribution Hf isotopes (largely hosted zircon) Nd within these rocks), were synchronous hand-specimen scale (?~0.001 m3). propose diachronous their parent was caused PT growth during metamorphism. findings document latest Block, highlighting role played intra-crustal reworking late-Archean regional event.