Three-Dimensional Density Structure of the Pamir Plateau and Adjacent Regions: Implications for Deep Tectonics, Dynamics, and Metallogeny

Abstract

The Pamir Plateau, located in the western syntaxis of the Tibetan Plateau, is a critical region for understanding continental collision dynamics and associated metallogenic processes. First, on the basis of the spherical coordinate system, Bouguer gravity anomalies were derived from satellite gravity data covering the Pamir Plateau and adjacent regions. A three-dimensional density structure model spanning crustal to upper mantle depths (0–200 km) was subsequently inverted through an advanced three-dimensional physical property inversion methodology. Finally, the depth of the Moho surface in the study area was calculated using an interface inversion method with variable density, which was improved on the basis of the Parker–Oldenburg formula. Our results reveal significant lateral density variations: Moho depths exhibit a mirror-image relationship with surface topography, and steep Moho gradients align with major tectonic boundaries, indicating deep structural controls on crustal thickening and plateau uplift. The Pamir uplift was driven by crustal thickening, mantle upwelling following slab break-off, and erosion-isostatic feedback. Lateral extrusion of Pamir material, constrained by the rigid Tarim Basin, further shapes the plateau's asymmetric topography. High-density anomalies at mid-crustal depths correlate with magmatic intrusions and fault systems, providing pathways for ore-forming fluids. The spatial associations of porphyry Cu-Au and skarn Fe deposits with Moho depth underscore the importance of crust–mantle interactions in mineralization.

Keywords

3D density structure / gravity inversion / continental collision / Moho / Pamir Plateau

RIGHTS & PERMISSIONS

2025 Geological Society of China