There and Back Again: Recycling of the Appalachian Signature in DZ U-Pb Records of Phanerozoic North America

Abstract Continental-scale recycling of detrital zircon (DZ) grains and associated sediment across North American is not well understood. We trace a through line following the DZ proxy for detritus originally sourced from Grenville Appalachian orogens. This paper lays out an antecedent framework one greatest sedimentation episodes Phanerozoic: initial dispersal Appalachian- Grenville-age to western passive margin Laurentia subsequent paleodrainage reorganization remobilization back east. The U-Pb signature Appalachian-Ouachita orogenic system dominated by (ca. 1250–950 Ma) 500–275 age groups dominates Phanerozoic record America. study juxtaposes Pennsylvanian modern data America demonstrates persistent signature, including recycled Western Lower deposits proximal orogen are 50%–75% grains, representing key component in primary signature. It remains unclear how signal was propagated west, but clearly present late Paleozoic thus potential throughout Mesozoic Cenozoic Eras. Triassic samples document transcontinental fluvial systems that reached Laurentian margin, Jurassic-Cretaceous indicate drainage reversal due rise Cordillera. A exists these western-sourced, eastward-flowing systems—a phenomenon continues present: frequently composed >40% DZ. However, none interpreted be or terranes, suggesting linking two dominate much this day.