Were South India, the North China Craton, and the Korean Peninsula contiguous in a Neoarchaean supercontinent? New geochemical and isotopic constraints

Abstract

The composition and configuration of possible Archaean supercontinents remain unresolved. Kenorland, a Neoarchaean supercontinent containing the Southern Granulite Terrane (SGT) in South India, the eastern block of the North China Craton (E-NCC), and the north-central Korean Peninsula, was probably assembled at ca. 2.5 Ga. A detailed comparison of meta-granitoid samples from the Madras Block (SGT), the Yishui Terrane (Shandong Peninsula, E-NCC), and Daeijak Island (NW-Gyeonggi Massif, Korean Peninsula) demonstrates their close similarities in geological setting, age, petrochemistry, isotopic composition and metamorphic history. They were all formed at 2.6–2.5 Ga and metamorphosed at a high grade soon after ca. 2.5 Ga. All are LREE-enriched and HREE-depleted, have low 87Sr/86Sri (0.70201–0.70375) and similar near-chondritic ƐNd(T) (+1.2 to −1.9). These factors, and their close match of geological features, suggest that the three terranes were once contiguous as part of a Neoarchaean supercontinent. Show more