Unraveling the Geological Evolution of the Tethyan Himalaya Region: Insights from Zircon Geochronology and Geochemistry

Abstract

Zircon crystals, which form directly from igneous melts, are invaluable for probing the deep crustal basement and provide crucial insights into its composition and evolution. Supercontinent cycles, including the formation and breakup of Columbia, Rodinia, and Gondwana, play a pivotal role in shaping global magmatic and metamorphic records, and deciphering magmatic patterns is critical for unraveling the complex interplay between tectonics and magmatism. This study investigates U-Pb geochronology and trace/rare earth element (REE) compositions of zircons from the Early Cretaceous Tethyan Himalaya Igneous Province, revealing critical insights into Precambrian–Paleozoic magmatic and tectonic evolution. Dominant Paleoproterozoic (2498 Ma, 1912 Ma) and Neoproterozoic (826–762 Ma) zircon populations confirm the existence of the Precambrian basement. Neoproterozoic magmatism shows decoupling between light and heavy REE (LREE/HREE) and europium anomalies (Eu/Eu* = Eu_N/(Sm_N × Gd_N)^1/2) during the 826–762 Ma and 725–702 Ma intervals, indicating that the Rodinia margin evolved from Andean-style subduction to continental collision. Early Paleozoic magmatism correlates with Pan-African orogenesis and subsequent Proto-Tethyan Ocean subduction beneath the Indian Craton. Neo-Tethyan initiation (ca. 273 Ma) is evidenced by 200–300 Ma zircons which exhibit (1) absence of LREE/HREE–Eu/Eu* crustal thickness correlations, and (2) a thermal peak at 273 Ma.

Keywords

captured zircon geochronology / geochemistry / Tethyan Himalaya / Rodinia supercontinent / Pan-African orogeny

RIGHTS & PERMISSIONS

2025 Geological Society of China