A Cenozoic uplift history of Mexico and its surroundings from longitudinal river profiles

Abstract

Geodynamic models of mantle convection predict that Mexico and western North America share a history of dynamic support. We calculate admittance between gravity and topography, which indicates that the elastic thickness of the plate in Mexico is 11 km and in western North America it is 12 km. Admittance at wavelengths > 500 km in these regions suggests that topography is partly supported by subcrustal processes. These results corroborate estimates of residual topography from isostatic calculations and suggest that the amount of North American topography supported by the mantle may exceed 1 km. The Cenozoic history of magmatism, sedimentary flux, thermochronometric denudation estimates, and uplifted marine terraces imply that North American lithosphere was uplifted and eroded during the last 30 Ma. We jointly invert 533 Mexican and North American longitudinal river profiles to reconstruct a continent-scale rock uplift rate history. Uplift rate is permitted to vary in space and time. Erosional parameters are calibrated using incision rate data in southwest Mexico and the Colorado Plateau. Calculated rock uplift rates were 0.15-0.2 mm/yr between 25 and10 Ma. Central Mexico experienced the highest uplift rates. Central and southern Mexico continued to uplift at 0.1 mm/yr until recent times. This uplift history is corroborated by independent constraints. We predict clastic flux to the Gulf of Mexico and compare it to independent estimates. We tentatively suggest that the loop between uplift, erosion, and deposition can be closed here. Mexico's staged uplift history suggests that its dynamic support has changed during the last 30 Ma.

Continental‐Scale Landscape Evolution: A History of North American Topography

“…Thermochronometric and incision rate histories suggest that Cenozoic denudation of the Colorado and Rocky Mountains plateaus occurred in several stages (e.g., Flowers et al., ; Karlstrom et al., ; Winn et al., ). Staged Cenozoic uplift and denudation of North America is consistent with the history of sedimentary deposition observed along the northern and western margin of the Gulf of Mexico (Galloway et al., ; Stephenson et al., ). Feng et al.…”

“…Ms = mouth of Mississippi; L = St. Lawrence; N = Nelson; Ma = Mackenzie; Y = Yukon; Cb = Columbia; Cd = Colorado. Drainage network is draped over dynamic topography that is calculated from long‐wavelength (i.e., <800 km) free‐air gravity anomalies assuming admittance, Z =25 mGal/km (GRACE mission database; Tapley et al., , Stephenson et al., ). Labeled circles indicate centers of major swells.…”

Spatial and temporal uplift history of South America from calibrated drainage analysis

“…Subsequently, Roberts et al [2012a] developed a non-linear optimization scheme that permits substantial inventories of river profiles to be simultaneously inverted by varying uplift rate history as a function of both time and space. This general scheme has been successfully applied to different continents and suggests that the empirical stream-power formulation provides a practical basis by which patterns of regional uplift through space and time can be assessed [Roberts et al, 2012b;Czarnota et al, 2014;Paul et al, 2014;Wilson et al, 2014;Stephenson et al, 2014;Richards et al, 2016].…”

Normal fault growth and linkage in the Gediz (Alaşehir) Graben, Western Turkey, revealed by transient river long‐profiles and slope‐break knickpoints

“…The time span over which rivers respond to base-level changes, and thus the timescale taken to pass effects to the surrounding landscape is fundamentally determined by knickpoint migration rates (Whipple and Tucker, 1999;Whipple et al, 2000;Whipple, 2004;Wobus et al, 2006a). A number of studies have suggested that this process can take several million years (Merritts and Bull, 1989;Snyder et al, 2000;Whipple, 2001;Whittaker and Boulton, 2012;Stephenson et al, 2014). Consequently, this makes rivers ideal natural laboratories for evaluation of the landscape response to active faulting over Pliocene to Recent timescales.…”