115-1 Plume welding and cratonization: A recent example of Permian plume activity modifying the Asian lithosphere to control Cenozoic patterns of the Himalayan-Tibetan orogen

Session: Petrology, Volcanology, and Mantle Plumes across the Solar System (Posters)

Presenting Author:

Authors:

Abstract:

Mantle plumes have operated throughout Earth history, and they are found on almost all other terrestrial bodies. However, the impacts of mantle plumes on the lithosphere are contentious. Plumes may thermally erode or otherwise destabilize thick lithospheric roots, or they may grow refractory cratonic keels that resist deformation. Therefore, a better understanding of the impacts of plume activity can inform us on the evolution of the continental lithosphere through time. Here we synthesize geological and geophysical data from craton-like domains (i.e., the Tarim Basin and southeast Tibet) in central Asia, which are interpreted to have been cratonized in the Permian (ca. 300–260 Ma) during plume impingement to resist Cenozoic (ca. 60–0 Ma) deformation in the Himalayan-Tibetan orogen. This includes a lack of Cenozoic deformation of the Tarim basin, as well as slowed Cenozoic exhumation, tracked via low-temperature thermochronology, above the ca. 260 Ma Emeishan plume head in southeast Tibet. Geophysical observations, particularly reprocessed aeromagnetic maps, reveal the crustal influence of these Permian plumes. Knowledge of the geologic history shows that the Permian plumes were the only major geologic event that could have welded Proterozoic suture zones and uniquely strengthened the lithosphere prior to widespread Cenozoic orogeny across central Asia. Together, we interpret that crustal iron enrichment, as observed via magnetic datasets, reflects chemically coupled iron depletion in the mantle lithosphere, to generate craton-like lithosphere in the Permian. We also discuss how high-flux melting associated with mantle plumes uniquely redistribute lithospheric iron, which controls the styles of intra-plate orogeny, such as the Tian Shan pure-shear orogen to the north of the Tarim basin. Regardless of the exact process, these continent-scale observations reveal how plume activity modifies and ultimately strengths the lithosphere. Our interpretations imply that mantle plumes may be instrumental to the development of cratons on early Earth when there was more rigorous and frequent plume activity, which may also be important on other terrestrial bodies.

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-6815

© Copyright 2025 The Geological Society of America (GSA), all rights reserved.