The Eoarchaean foundation of the North Atlantic Craton

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.

北极古陆支撑着北美大部分地区、格陵兰岛和北欧，并包含了地球上现存最古老的陆壳。本文回顾了该区域陆壳演化的当前理解，并探讨了我们研究北极古陆不同碎块之间相互关系的能力。在苏格兰西北部从中元古代至寒武纪基底层沉积物中提取的碎屑锆石，基于新获取的阿卡迪亚塔尔贝特上地壳单元和古元古代鲁哈鲁阿德花岗岩的数据进行了重新审视。 haf 模型年龄记录在 4160 至 1410 Ma 之间，峰值约为 3350 Ma，并与 3670 至 1070 Ma 的 U-Pb 结晶年龄相关联，峰值分别约为 2700 Ma 和 1700 Ma。鲁哈鲁阿德花岗岩与北部地区基底部分熔融一致，未受年轻岩浆或上地壳物质的污染，而塔尔贝特上地壳记录了约 3200 Ma 的最小模型年龄。这些单元均记录了 haf 模型年龄，暗示了早太古代（4000-3600 Ma）陆壳的再熔融。在北极古陆周围已识别出类似的结晶和模型年龄分布，表明早太古代陆壳曾经在该地区广泛分布，并构成了苏格兰和北极古陆的基础。