The Eoarchaean foundation of the North Atlantic Craton

• Main Authors: Penelope J. Lancaster, Craig D. Storey, Chris J. Hawkesworth
• Format: Dataset
• Language: unknown
• Published: 2016
• Subjects: Geology; model ages; Detrital zircons; 1700 Ma; Archaean North Atlantic Craton; Hf model ages; supracrustal material; 3200 Ma; Eoarchaean crust; 1070 Ma; Tarbet Supracrustals record; paper reviews; Northern Region basement; crustal evolution; Rubha Ruadh granite; North Atlantic Craton; 3350 Ma; units records Hf model ages; 1410 Ma; Palaeoproterozoic Rubha Ruadh granite; Eoarchaean foundation; Cambrian basal sediments; Archaean Tarbet supracrustal unit; Similar distributions; model age; NW Scotland; Greenland; North Atlantic
• Online Access: https://doi.org/10.6084/m9.figshare.3453806.v1; https://figshare.com/articles/The_Eoarchaean_foundation_of_the_North_Atlantic_Craton/3453806

The Archaean North Atlantic Craton underpins much of North America, Greenland and northern Europe, and incorporates the Earth's oldest extant continental crust. This paper reviews the current understanding of the region's crustal evolution, and considers our ability to investigate interrelationships between different fragments of the North Atlantic Craton. Detrital zircons from Mesoproterozoic to Cambrian basal sediments in NW Scotland have been re-examined in light of new data from the Archaean Tarbet supracrustal unit and the Palaeoproterozoic Rubha Ruadh granite. Hf model ages are recorded from 4160 to 1410 Ma, peaking at c. 3350 Ma, and are associated with U–Pb crystallization ages from 3670 to 1070 Ma, peaking at c. 2700 and 1700 Ma. The Rubha Ruadh granite is consistent with partial melting of Northern Region basement without contamination by juvenile magmas or supracrustal material, while the Tarbet Supracrustals record a minimum model age of c. 3200 Ma. Each of these units records Hf model ages that imply remelting of Eoarchaean (4000–3600 Ma) crust. Similar distributions of crystallization and model ages have been identified around the North Atlantic Craton, suggesting that Eoarchaean crust was once extensive in the region and constitutes the foundation of both Scotland and the North Atlantic Craton.