The “badland trilogy” of the Desierto de la Tatacoa, upper Magdalena Valley, Colombia, a result of geodynamics and climate

With a review of badland landscapes

verfasst von

Harald G. Dill, Buzatu Andrei, Balaban Sorin-Ionut, Ufer Kristian, Gómez Tapias Jorge, Bîrgăoanu Daniel, Cramer Thomas

Abstract

The badlands of the “Desierto de la Tatacoa” (DDT) form part of the alluvial-fluvial system and are characterized by a landform trilogy: (1) gully zone, (2) wadi zone, (3) hillwash plain/mesa zone. This facies differentiation is controlled by the fluvial regimes and their degree of sinuosity of channels. The hydraulic and hydrographic systems of the badland trilogy depend on the geodynamic setting and climate (1st order) and on the bedrock lithology and tectonics (2nd order). Allogenic heavy minerals attest to two counteracting palaeogradients which interdigitate where the badlands evolved and authigenic heavy and light minerals furnish evidence of the physical-chemical regime to be governed by alkaline meteoric solutions and oxidizing conditions driven by the climate and the parent rocks. It is the high solubility of sulfates and chlorides and the differential expandability of smectite which impacted on the development of the individual badland zones. Large 1st order synclines plunging to the W and 2nd order fold structures account for the traps and conduits of the subsurface water system. The key to the hydraulic evolution of the badland lies within the hinterland hampering surface alteration and favoring the subsurface hydrogeological system to corrode the gully zone from below. The binary genetic model of the badlands in the DDT reveals, on a local scale, a “fight for dominance” of different fluvial drainage systems at the edge of the badlands as a hydrological consequence of neotectonics while, on a regional scale, badland formation is an upstream expression of a eustatic sea level oscillation in the Caribbean Sea. A review of true, false and pseudo-badlands concludes the study and underscores the reference character of the DDT badlands among the true badland series.

Organisationseinheit(en)

Institut für Mineralogie

Externe Organisation(en)

Al. I. Cuza University
Birkbeck University of London
Bundesanstalt für Geowissenschaften und Rohstoffe (BGR)
Geological Society of Colombia (CGS)
Institutul Geologic al României
Universidad Nacional de Colombia

Typ

Artikel

Journal

Catena

Band

194

ISSN

0341-8162

Publikationsdatum

11.2020

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Erdoberflächenprozesse

Ziele für nachhaltige Entwicklung

SDG 13 – Klimaschutzmaßnahmen

Elektronische Version(en)

https://doi.org/10.1016/j.catena.2020.104696 (Zugang: Geschlossen)