U-Pb Zircon Dates from North American and British Avalonia Bracket the Lower–Middle Cambrian Boundary Interval, with Evaluation of the Miaolingian Series as a Global Unit

• Main Authors: Landing, Ed, Schmitz, Mark D., Westrop, Stephen R., Geyer, Gerd
• Format: Text
• Language: unknown
• Published: ScholarWorks 2023
• Subjects: Lower Cambrian; Middle Cambrian; U-Pb dates; Newfoundland; Miaolingian; Earth Sciences; Geophysics and Seismology; Breton Island
• Online Access: https://scholarworks.boisestate.edu/geo_facpubs/794; https://scholarworks.boisestate.edu/context/geo_facpubs/article/1799/viewcontent/Schmitz__Mark__2023__U_Pb_zircon_dates___pub.pdf

High-precision U-Pb zircon ages on SE Newfoundland tuffs now bracket the Avalonian Lower–Middle Cambrian boundary. Upper Lower Cambrian Brigus Formation tuffs yield depositional ages of 507.91 ± 0.07 Ma (Callavia broeggeri Zone) and 507.67 ± 0.08 Ma and 507.21 ± 0.13 Ma (Morocconus-Condylopyge eli A...