关键词: 北方造山带东段, 微陆块群, 地质年代学, 地球化学, 大陆边缘演化, 超大陆旋回

Abstract: The Eastern Northern orogenic belt, located along the eastern margin of Eurasia, is composed of a series of microcontinents or terrenes, including, from west to east, the Erguna, Xing’an, Songliao, and Jiamusi-Khanka blocks. This belt preserves a complex Phanerozoic evolutionary history of multiple paleo-oceans, such as the Paleo-Asian, Heilongjiang, and Paleo-Pacific Oceans. However, the crustal evolution of these ocontinent microcontinents and their tectonic linkages to global supercontinent cycles remain relatively constrained, representing a key research frontier in modern geology. To address this, we first systematically compile published geochronological data from the Archean to Early Paleozoic to delineate the major evolutionary stages of the microcontinent group within the belt. We then integrate this temporal framework with the geochemical signatures of coeval magmatic records to evaluate the tectonic affinity of these microcontinents with ancient continental blocks throughout the supercontinent cycle since the Archean. Based on this integrated analysis, we propose a revised supercontinent evolutionary model for the microcontinent group. Our results indicate that the microcontinent group records five major geological events from the Archean to Early Paleozoic, which collectively define three distinct tectonic cycles.This history indicates their active involvement in the staged assembly and breakup of the Columbia, Rodinia, and Gondwana supercontinents. Furthermore, the tectonic evolution of the microcontinent group exhibits a persistent continental margin affinity, maintaining a close and dynamic tectonic relationship with the Tarim craton throughout these supercontinent cycles. During the Early Paleozoic, the microcontinent group in the Eastern North orogenic belt rifted from the northeastern margin of Gondwana and subsequently drifted northward to accrete to the southern margin of the Siberia craton. This migration established the fundamental regional tectonic framework that preconditioned the subsequent superimposition and transition of multiple paleo-oceanic systems along the eastern margin of Eurasia.

Key words: Eastern North orogenic belt, microcontinent group, geochronology, geochemistry, continental margin evolution, supercontinent cycle