Coupled influence of tectonics, climate, and surface processes on landscape evolution in southwestern North America

Abstract

The Cenozoic landscape evolution in southwestern North America is ascribed to crustal isostasy, dynamic topography, or lithosphere tectonics, but their relative contributions remain controversial. Here we reconstruct landscape history since the late Eocene by investigating the interplay between mantle convection, lithosphere dynamics, climate, and surface processes using fully coupled four-dimensional numerical models. Our quantified depth-dependent strain rate and stress history within the lithosphere, under the influence of gravitational collapse and sub-lithospheric mantle flow, show that high gravitational potential energy of a mountain chain relative to a lower Colorado Plateau can explain extension directions and stress magnitudes in the belt of metamorphic core complexes during topographic collapse. Profound lithospheric weakening through heating and partial melting, following slab rollback, promoted this extensional collapse. Landscape evolution guided northeast drainage onto the Colorado Plateau during the late Eocene-late Oligocene, south-southwest drainage reversal during the late Oligocene-middle Miocene, and southwest drainage following the late Miocene.

Rheological Heterogeneities Control the Non‐Progressive Uplift of the Young Iranian Plateau

“…Our models cannot reproduce absolute topography since surface processes (e.g., erosion and sedimentation), isostatic adjustment, and mantle flow‐related dynamics are not included. All these factors could exert impacts on absolute topography and may lead to lateral variations in elevation (Bahadori et al., 2022; Faccenna & Becker, 2010; Wolf et al., 2022), but they cannot simultaneously explain the more prominent uplift and corresponding more significant shortening of the northern plateau than the central plateau. The far‐field compression associated with the Arabia‐Eurasia collision should be the dominant factor.…”

Hydrothermal Ore Deposits Record the Oxygen Isotope Composition of Meteoric Paleo‐Waters in the San Juan Volcanic Field, Colorado, USA

“…The paleotopographic evolution of the southern Rocky Mountains is enigmatic because they currently are anomalously high given their location far from an active plate boundary (Bahadori et al., 2022; Lipman et al., 1973). We focus here on several sites in the San Juan Volcanic Field (SJVF, Figure 1) of the southern Rocky Mountains of CO, USA.…”

The role of gravitational body forces in the development of metamorphic core complexes

“…1 ). Recent numerical modeling efforts 39 , 40 have shown that the crustal extension and topographic collapse in SWNA was caused by tensional deviatoric stresses associated with high gravitational potential energy (GPE) of this mountain chain, as plate motion boundary conditions transitioned from subduction to transform motion and as the lithosphere was progressively weakened by heat, fluids, and volcanism during the slab rollback history 39 , 40 . The proximity of restored locations of MCCs along the chain of high paleo-topography 37 (Fig.…”