Journal Article

Australian Heritage for the North Lhasa Terrane

Zhou, Jian‐Bo, Shen, Di, Palin, Richard M., Liu, Jin, Yu, Chang‐Sheng, Zhang, Sheng‐Shuo, Wan, Bin, Danzeng, Quewang, Wang, Ming

2025

Overview

The Precambrian history of the Lhasa terrane, southern Tibet is intensely debated, which hinders global plate tectonic reconstructions throughout the Proterozoic. Previous research on Precambrian basement has suggested that the Lhasa terrane originated from India or Africa, although the paucity of exposed pre‐Neoproterozoic rocks in the North Lhasa terrane (NL) has led to significant uncertainty. We document newly identified Neoarchean granites and Mesoproterozoic Guomangtso Suite from the NL. These pre‐Neoproterozoic rocks reveal a 2.62 Ga anorogenic rifting event and a 1.30–1.10 Ga transition from subduction to back‐arc extension, related to the 2.7–2.6 Ga rifting of the Pilbara Craton and the Proterozoic assembly between the North and West Australian Cratons, respectively. However, these tectono‐magmatic events have no equivalents in the South Lhasa terrane (SL). These observations suggest that the NL originated from Western Australia, and the NL and SL may have distinct origins. Plain Language Summary Constraining the origin and evolution of continental fragments plays a crucial role in validating the patterns in the growth of successive supercontinents. However, tracking the evolving paleogeographic position of these fragments, especially for those of Precambrian age without paleolongitude constraints, has proven difficult. We redefine the pre‐Neoproterozoic evolution of the Lhasa terrane, southern Tibet based on newly discovered Neoarchean and Mesoproterozoic rocks, which contain missing information about the pre‐Neoproterozoic evolution of the North Lhasa terrane (NL). We reveal the Neoarchean–Mesoproterozoic evolution of the NL and its affinity with Western Australia, which is clearly distinct from the Indian affinities of the South Lhasa terrane (SL) from the Paleoproterozoic to Mesoproterozoic. These findings suggest that the Lhasa terrane did not originate as a unified entity from India during the pre‐Neoproterozoic, as previously thought, but rather that the NL originated from Western Australia, with the NL and SL having distinct origins. Our study therefore shows for the first time key evidence identifying the origin of the NL before the Neoproterozoic. Key Points Newly identified 2.62 Ga granites in the North Lhasa terrane show affinity with the Pilbara Craton, Western Australia The 1.30–1.10 Ga Guomangtso Suite identified in North Lhasa documents the Proterozoic assembly of North and West Australian Cratons The North Lhasa terrane was connected with Western Australia before separating during the Neoproterozoic

• Publisher: John Wiley & Sons, Inc,Wiley
• Subject: Affinity / Basements & cellars / Cratons / Evolution / Fragments / Geochemistry / Geology / Lhasa terrane / Metamorphism / Neoarchean and Mesoproterozoic magmatism / Origins / Pilbara craton / Plate tectonics / Precambrian / pre‐Neoproterozoic evolution / Rare earth elements / Rifting / Rock / Rocks / Sediments / Subduction / Subduction (geology)