Phanerozoic cratonization by plume welding

Abstract

Deformation-resistant cratons comprise >60% of the continental landmass on Earth. Because they were formed mostly in the Archean to Mesoproterozoic, it remains unclear if cratonization was a process unique to early Earth. We address this question by presenting an integrated geological-geophysical data set from the Tarim region of central Asia. This data set shows that the Tarim region was a deformable domain from the Proterozoic to early Paleozoic, but deformation ceased after the emplacement of a Permian plume despite the fact that deformation continued to the north and south due to the closure of the Paleo-Asian and Tethyan Oceans. We interpret this spatiotemporal correlation to indicate plume-driven welding of the earlier deformable continents and the formation of Tarim’s stable cratonic lithosphere. Our work highlights the Phanerozoic plume-driven cratonization process and implies that mantle plumes may have significantly contributed to the development of cratons on early Earth.

Limited Northward Expansion of the Tibetan Plateau in the Late Cenozoic: Insights From the Cherchen Fault in the Southeastern Tarim Basin

“…The linear relationship's intercept yields the potential underlying detachment depth of ∼25 km (Gonzalez‐Mieres & Suppe, 2006). This calculated depth supports that the Cherchen fault involved the basement (Xu et al., 2023), implying that deformation migrated from the northern edge of the Tibetan Plateau to the Tarim Basin (Laborde et al., 2019). The computed fault trajectory (black dash line in Figure 7a) steepens upward near the surface (∼77°), which is consistent with our interpretation that the Cherchen fault is a high‐angle fault (see Figure S3in Supporting Information S1 for more fault trajectory calculation details).…”

Lower Crustal Rheology Controls Strain Partitioning and Mode of Intracontinental Deformation

“…Furthermore, our high‐resolution 3D inverted magnetic intensity model shows a crustal‐scale conical structure that penetrates to ∼50‐km‐depth (Figures 3, 7, and 9) beneath the radial magnetic lineaments in the western Tarim Basin that correspond plume‐modified crust (X. Xu et al., 2021, 2023). Our inversion does not artificially introduce any structure in advance, so this conical feature directly reflects the distribution of magnetic bodies (X. Xu et al., 2023). We interpret that the regions of southeast and northeast Tarim Basin that do not exhibit such magnetic anomalies were thus less impacted by the Permian plume event.…”

“…We interpret that this feature is a relic of Permian plume magmatism based on its spatial location beneath the Permian volcanic fields and our refined magnetic imaging of the radiating dike geometry of the plume head (Figures 3, 7, and 10) (X. Xu et al, 2021Xu et al, , 2023. Based on its strong magnetic character and interpreted mafic composition, this feature would have been relatively strong, and therefore it may have efficiently focused stress along its boundaries to drive focused strain (e.g., Calignano et al, 2015;Campbell, 1978).…”

“… (a) Three‐dimensional (3D) magnetization intensity model for Tarim Basin and its surrounding regions, based on the regularization inversion with 130 × 74 × 50 grid cells and 10 × 10 × 1 km resolution (X. Xu et al., 2023). 3D horizontal slice model at crustal depth of 28‐km is presented here, as well as the vertical slice at northward distance of 120 km.…”

“…Based on the spatial correspondence of long-wavelength magnetic signals inferred to represent a mafic lower crust and the location of the impinged Permian mantle plume in western Tarim Basin (Figures 2a and 6), we infer that much of the dense (Deng et al, 2017) mafic lower crust in the Tarim Basin was generated due to plume-related intrusions and underplating (X. Xu et al, 2021Xu et al, , 2023. Furthermore, our high-resolution 3D inverted magnetic intensity model shows a crustal-scale conical structure that penetrates to ∼50-km-depth (Figures 3, 7, and 9) beneath the radial magnetic lineaments in the western Tarim Basin that correspond plume-modified crust (X.…”