Detrital zircon age signatures of the Mesozoic in the Lusitanian Basin and implications for the evolution of Iberia–Newfoundland conjugate margins

Abstract

New detrital zircon age results from the Lusitanian Basin are integrated with published data for the Mesozoic of west Iberia and eastern Canada (4959 concordant ages). Zircons in new samples are either mainly Devonian‐Permian, Cryogenian‐Ediacaran or reveal a combination of these two age populations, showing secondary to minor Mesoproterozoic‐Archean ages. Statistical tools applied to the compiled age data allow grouping the samples according to age signatures and explain main features of the age spectra. Age signatures are determined by the abundance of zircon: (1) recycled from terranes involved in Pangea amalgamation; (2) associated with Acadian‐Variscan crystalline rocks (~420–310 Ma), which becomes younger from the Laurentian to the Gondwanan sides of the orogen; (3) associated with post‐collisional events (~300–285 Ma) that affected different terranes and were exhumed in major structures controlling basin formation; and (4) resulting from Mesozoic magmatism (~145 Ma) with a stronger imprint in the west Atlantic margin.