Hf isotopes in detrital zircon grains of the Sierra Albarrana Domain (SW Iberian Massif): Eburnean v. Archean basement signatures

Abstract

This study presents Lu–Hf data on detrital zircon grains from the Lower Paleozoic metasedimentary successions of the Sierra Albarrana Domain (SW Iberian Massif). We provide new information about their origin, record of continental crustal evolution and geological affinity. Previous detrital zircon U–Pb data in this terrane reveal two main age populations, with age peaks at c. 595 Ma and c. 1.90 Ga. The Ediacaran events are interpreted to represent a magmatic arc with input of juvenile magmas intruding into the Eburnean basement of Gondwana, and probably mixing with it. The different evolutionary stages of the arc were probably linked to the Cadomian Orogeny during Neoproterozoic–earliest Cambrian times. The Paleoproterozoic zircon population corresponds to the Eburnean Orogeny. The magmas derived from an Eburnean depleted mantle partly intruded an older basement, leading to an incipient mixing process. εHf isotopic compositions indicate a possible affinity with the Central Iberian Zone, suggesting a common geological setting during Ediacaran–Cambrian times but different settings during the Paleoproterozoic.