Editorial for Special Issue “Tectonic Evolution of the Tethys Ocean in the Qinghai–Tibet Plateau”

1. Introduction

The Tethys Ocean, a geodynamically pivotal transcontinental oceanic system sandwiched between the Laurasian and Gondwanan supercontinents, underwent successive evolutionary phases (Proto-Tethys, Palaeo-Tethys, Neo-Tethys) sculpted by continental drift, convergence, and breakup. Its demise imprinted profound tectonic signatures across the 15,000 km extensive Tethyan tectonic realm, with the Qinghai–Tibet Plateau emerging as a “natural laboratory” archiving a near-complete geochronological record of this epic geodynamic journey. Acclaimed as a premier global hotspot for Earth system science and a strategic repository of mineral and hydrocarbon resources, the Plateau affords important perspectives on continental assembly–disassembly, oceanic opening–closure, and deep Earth geodynamics. Tackling long-standing debates surrounding Tethyan subdivision, geodynamic driving mechanisms, and resource–genetic links, this Special Issue (affiliated with the section “Mineral Geochemistry and Geochronology”) brings together ten original contributions spanning the full spectrum of Tethyan evolutionary stages and diverse tectonic settings, pushing the frontiers of our understanding of this iconic geological system.

2. Tethyan Subduction-Driven Magmatism and Tectonic Transition

Six contributions focus on magmatic responses and tectonic transformations across the Neo-Tethyan, Palaeo-Tethyan, and Meso-Tethyan stages. Yang et al. (Contribution 1) documented the first A1-type granite in central Lhasa’s Meibaqieqin region (130 Ma), linking its crust–mantle mixed sources to lithospheric extension driven by northward Neo-Tethyan subduction. Hui et al. (Contribution 2) dated the East Kunlun Xingshugou A2-type monzogranite to 247.1 Ma, attributing its formation to the high-temperature partial melting of juvenile crust under extensional conditions triggered by Palaeo-Tethyan slab rollback. He et al. (Contribution 3) investigated Early–Middle Devonian volcanic rocks and granites in the Southern Beishan Orogenic Belt, revealing a tectonic transition from advancing to retreating subduction and constraining ocean–continent transformation in the southern Central Asian Orogenic Belt. Sahoo et al. (Contribution 4) studied amphibole-rich cumulates in the NE Himalayan Mayudia Ophiolite Complex, identifying an island arc root formed by fractional crystallization of super-hydrous magma (10.56–13.61 wt.% H₂O) from sub-arc mantle wedge melting, which constrains late Cretaceous–early Tertiary Neo-Tethyan closure processes. Xia et al. (Contribution 5) documented magma mixing in the North Qilian Menyuan Granodioritic Pluton (ca. 456 Ma), showing that interactions between mantle-derived mafic magma and ancient lower crustal felsic melts in an active continental arc triggered by Proto-Tethyan subduction. Bai et al. (Contribution 6) studied Early Silurian Shandan adakites in the North Qilian Orogen, constraining the 446–440 Ma collision between the Alxa and Qilian blocks and highlighting post-collisional crustal thickening and crust–mantle interactions. These studies collectively capture the diverse magmatic and tectonic dynamics across multiple Tethyan evolutionary stages.

3. Proto-Tethyan and Meso-Tethyan Closure-Related Magmatism

Three contributions address magmatic processes linked to Proto-Tethyan orogeny and Meso-Tethyan closure. Mo et al. (Contribution 7) reported ca. 118.3–120.5 Ma old rhyolites in the Tengchong Terrane, linking their calc–alkaline affinity and crust–mantle mixed sources to Meso-Tethyan subduction, slab rollback, and closure-related Burma-Tengchong terrane collision. Zhang et al. (Contribution 8) analyzed S-type granites from central Tibet’s Guomang-Co area, identifying Paleoproterozoic metasedimentary sources and a syn-collisional setting and linking them to Early Paleozoic Andean-type orogeny and southward Proto-Tethyan subduction. Shan et al. (Contribution 9) focused on mafic intrusions in the eastern Himalayan Cuona area, dating diabase porphyrite to 135 Ma and identifying OIB-type geochemical signatures. Their εNd(t) and εHf(t) data link the intrusions to enriched mantle sources influenced by the Kerguelen mantle plume, providing critical constraints on Early Cretaceous East Gondwana rifting and mantle plume activity.

4. Neo-Tethyan Pre-Collisional Magmatism and India–Asia Collision Prelude

Wang et al. (Contribution 10) identified Mazin rhyolite porphyries (58.8–56.1 Ma) as the northernmost extension of the Linzizong volcanic suite, attributing their formation to juvenile lower crust remelting triggered by Neo-Tethyan slab rollback at the onset of the India–Asia collision. This study fills an important gap in understanding the magmatic response to early collisional tectonics in the Tibetan Plateau, bridging Neo-Tethyan closure and continental collision.

This Special Issue brings together research from leading teams worldwide, covering all major Tethyan stages and integrating diverse analytical techniques. The contributions advance key debates on subduction dynamics, crust–mantle interactions, and continental rifting/collision, while providing practical implications for resource exploration. We anticipate these findings will inspire further research into Tethyan evolution and deepen our understanding of Earth’s dynamic history.