Dating authigenic K-feldspar is difficult, but a new study at Wisconsin’s Reef Au-Cu deposit used in situ 40Ar/39Ar dating on micro-vein K-spar to identify a 499.7 ± 0.8 Ma Paleozoic fault-fluid event—offering new clues to midcontinent tectonics.
Read more: geosociety.co/feldspar
