Plateau reduction by drainage divide migration in the Eastern Cordillera of Colombia defined by morphometry and ¹⁰Be terrestrial cosmogenic nuclides

Abstract

Catchment‐wide erosion rates were defined using 10Be terrestrial cosmogenic nuclides for the Eastern Cordillera of the Colombian Andes to help determine the nature of drainage development and landscape evolution. The Eastern Cordillera, characterized by a smooth axial plateau bordered by steep flanks, has a mean erosion rate of 11 ± 1 mm/ka across the plateau and 70 ± 10 mm/ka on its flanks, with local high rates >400 mm/ka. The erosional contrast between the plateau and its flanks was produced by the increase in the orogen regional slope, derived from the progressive shortening and thickening of the Eastern Cordillera. The erosion rates together with digital topographic analysis show that the drainage network is dynamic and confirms the view that drainage divides in the Eastern Cordillera are migrating towards the interior of the mountain belt resulting in progressive drainage reorganization from longitudinal to transverse‐dominated rivers and areal reduction of the Sabana de Bogotá plateau. Copyright © 2016 John Wiley & Sons, Ltd.

Erosion rates and sediment flux within the Potomac River basin quantified over millennial timescales using beryllium isotopes

“…Understanding the effects that human land-use practices have on landscapes requires knowledge of background (geological) rates of sediment erosion and denudation, transport, and deposition (Hooke et al, 2012;Pelletier et al, 2015). Despite several decades of intensive data collection (Judson, 1968;McLennan, 1993;Milliman and Syvitski, 1992;Portenga and Bierman, 2011), there remain many landscapes for which there is little quantitative information about natural or background rates of landscape change (e.g., Arkle et al, 2017;Jonell et al, 2016;Mandal et al, 2015;Reusser et al, 2015, Struth et al, 2017. The Potomac River basin along the United States' east coast is a landscape where large volumes of sediment deposition in Chesapeake Bay are known to have resulted from widespread erosion associated with intensive European-American land-use practices in the 1700-1800s ( Fig.…”

Influencia de la actividad tectónica y volcánica reciente en la dinámica fluvial del río Anaime (Cajamarca, Cordillera Central de Colombia)

“…Los procesos de capturas fluviales en paisajes en desequilibrio y que han sido afectados por actividad tectónica reciente son bien conocidos en diferentes ambientes tectónicos del mundo (e.g. Clark et al, 2004;Mikesell et al, 2010;Perucca et al, 2018;Prince et al, 2011) e incluso estos procesos han sido reportados para la Cordillera Oriental (Tesón et al, 2015;Struth et al, 2017). Es importante resaltar que los drenajes que se han visto afectados por las capturas fluviales corresponden a la red de drenaje estable a término largo y las cuales drenaban los paisajes relictos de Las Marías (FIGURA 8F) y del Páramo Los Valles.…”

“…Es importante resaltar que los drenajes que se han visto afectados por las capturas fluviales corresponden a la red de drenaje estable a término largo y las cuales drenaban los paisajes relictos de Las Marías (FIGURA 8F) y del Páramo Los Valles. Esta dinámica fluvial como respuesta a un desequilibrio en el nivel base en la cual la red de drenaje relicta (drenajes tributarios en dirección ONO-ESE) se ve afectada por una red de drenaje más joven y en desequilibrio (drenajes N-S) ha sido propuesta para explicar la evolución del paisaje reciente de la Cordillera Oriental y las altas tasas de erosión de los drenajes transversales (Babault et al, 2013;Struth et al, 2017). Para el caso del VRA, los drenajes tributarios N-S han entrado en desequilibrio por la ola de incisión aguas arriba generada por el levantamiento de la superficie a lo largo del SFP y el rejuvenecimiento de los drenajes principales de las quebradas Carrizales, Maravelez y Las Marías.…”

Geomorphic response to active tectonics: Numerical and field‐based approaches

“…For instance, Goren et al (2015) based their identification of basin rotation in the Lebanon restraining bend of the Dead Sea fault system on the chi metric, allowing inferences about the modes and rates of horizontal deformation. Here, Struth et al (2017) combine a chi-based digital topographic analysis of the drainage network in the Eastern Cordillera of Colombia with 10 Be-constrained denudation rates to evaluate drainage divide migration and plateau size reduction. Here, Struth et al (2017) combine a chi-based digital topographic analysis of the drainage network in the Eastern Cordillera of Colombia with 10 Be-constrained denudation rates to evaluate drainage divide migration and plateau size reduction.…”

“…Yang et al (2015) also relied on chi estimations, complemented by numerical landscape evolution modelling, to discuss the origin of high-elevation, low-relief surfaces on the southeastern margin of the Tibetan plateau. Here, Struth et al (2017) combine a chi-based digital topographic analysis of the drainage network in the Eastern Cordillera of Colombia with 10 Be-constrained denudation rates to evaluate drainage divide migration and plateau size reduction. They show how higher profile steepness (and derived stream power estimates) and higher denudation rates along the plateau's flanks than in its interior, as well as chi contrast across divides, consistently highlight focused erosion of the steepened flanks of the plateau and the latter's subsequent reduction, caused by progressive shortening and thickening of the Eastern Cordillera.…”