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Topographic Evolution and Climate Aridification during Continental Collision: Insights from Computer Simulations.

Garcia-Castellanos D, Jiménez-Munt I - PLoS ONE (2015)

Bottom Line: For this purpose, we combine in a single computer program: 1) a thin-sheet viscous model of continental deformation; 2) a stream-power surface-transport approach; 3) flexural isostasy allowing for the formation of large sedimentary foreland basins; and 4) an orographic precipitation model that reproduces basic climatic effects such as continentality and rain shadow.At the continental scale, however, the overall distribution of topographic basins and ranges seems insensitive to climatic factors, despite these do have important, sometimes counterintuitive effects on the amount of sediments trapped within the continent.These complex climatic-drainage-tectonic interactions make the development of steady-state topography at the continental scale unlikely.

View Article: PubMed Central - PubMed

Affiliation: Group of Dynamics of the Lithosphere, Instituto de Ciencias de la Tierra Jaume Almera (ICTJA-CSIC), Barcelona, Spain.

ABSTRACT
How do the feedbacks between tectonics, sediment transport and climate work to shape the topographic evolution of the Earth? This question has been widely addressed via numerical models constrained with thermochronological and geomorphological data at scales ranging from local to orogenic. Here we present a novel numerical model that aims at reproducing the interaction between these processes at the continental scale. For this purpose, we combine in a single computer program: 1) a thin-sheet viscous model of continental deformation; 2) a stream-power surface-transport approach; 3) flexural isostasy allowing for the formation of large sedimentary foreland basins; and 4) an orographic precipitation model that reproduces basic climatic effects such as continentality and rain shadow. We quantify the feedbacks between these processes in a synthetic scenario inspired by the India-Asia collision and the growth of the Tibetan Plateau. We identify a feedback between erosion and crustal thickening leading locally to a <50% increase in deformation rates in places where orographic precipitation is concentrated. This climatically-enhanced deformation takes place preferentially at the upwind flank of the growing plateau, specially at the corners of the indenter (syntaxes). We hypothesize that this may provide clues for better understanding the mechanisms underlying the intriguing tectonic aneurisms documented in the Himalayas. At the continental scale, however, the overall distribution of topographic basins and ranges seems insensitive to climatic factors, despite these do have important, sometimes counterintuitive effects on the amount of sediments trapped within the continent. The dry climatic conditions that naturally develop in the interior of the continent, for example, trigger large intra-continental sediment trapping at basins similar to the Tarim Basin because they determine its endorheic/exorheic drainage. These complex climatic-drainage-tectonic interactions make the development of steady-state topography at the continental scale unlikely.

No MeSH data available.


Related in: MedlinePlus

Parameterization.Sediment volume vs. elastic thickness Te and precipitation P. The reference setup is located with circles.
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pone.0132252.g010: Parameterization.Sediment volume vs. elastic thickness Te and precipitation P. The reference setup is located with circles.

Mentions: The effects of the climate parameters of the model become more significant in terms of surface mass redistribution. Fig 10 shows a systematic parameterization of the total amount of eroded rock and sediment accumulation at t = 50 Myr as a function of the speed uw and humidity RH of the incoming wind and the lithospheric elastic thickness Te. All three parameters produce a comparable enhancement of erosion and sediment storage within the model domain. It is worth noting that this positive correlation does not stand for large values of uw and RH, which inhibit endorheism. Humid conditions cause the Tarim-like basin, for example, to overflow and drain towards the west, excavating a gorge along the outlet similar to what happens in model MS4 (Fig 5) and reducing the accommodation space available for sediment. This provides an alternative mechanism for the documented large-scale river captures in the east-Tibetan drainage [69], previously suggested to be a record of a late uplift event [26] perhaps related to subcrustal processes and dated as Miocene or later. The transition from endorheic to exorheic conditions may have been also triggered by a climatic change to more humid conditions.


Topographic Evolution and Climate Aridification during Continental Collision: Insights from Computer Simulations.

Garcia-Castellanos D, Jiménez-Munt I - PLoS ONE (2015)

Parameterization.Sediment volume vs. elastic thickness Te and precipitation P. The reference setup is located with circles.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4526229&req=5

pone.0132252.g010: Parameterization.Sediment volume vs. elastic thickness Te and precipitation P. The reference setup is located with circles.
Mentions: The effects of the climate parameters of the model become more significant in terms of surface mass redistribution. Fig 10 shows a systematic parameterization of the total amount of eroded rock and sediment accumulation at t = 50 Myr as a function of the speed uw and humidity RH of the incoming wind and the lithospheric elastic thickness Te. All three parameters produce a comparable enhancement of erosion and sediment storage within the model domain. It is worth noting that this positive correlation does not stand for large values of uw and RH, which inhibit endorheism. Humid conditions cause the Tarim-like basin, for example, to overflow and drain towards the west, excavating a gorge along the outlet similar to what happens in model MS4 (Fig 5) and reducing the accommodation space available for sediment. This provides an alternative mechanism for the documented large-scale river captures in the east-Tibetan drainage [69], previously suggested to be a record of a late uplift event [26] perhaps related to subcrustal processes and dated as Miocene or later. The transition from endorheic to exorheic conditions may have been also triggered by a climatic change to more humid conditions.

Bottom Line: For this purpose, we combine in a single computer program: 1) a thin-sheet viscous model of continental deformation; 2) a stream-power surface-transport approach; 3) flexural isostasy allowing for the formation of large sedimentary foreland basins; and 4) an orographic precipitation model that reproduces basic climatic effects such as continentality and rain shadow.At the continental scale, however, the overall distribution of topographic basins and ranges seems insensitive to climatic factors, despite these do have important, sometimes counterintuitive effects on the amount of sediments trapped within the continent.These complex climatic-drainage-tectonic interactions make the development of steady-state topography at the continental scale unlikely.

View Article: PubMed Central - PubMed

Affiliation: Group of Dynamics of the Lithosphere, Instituto de Ciencias de la Tierra Jaume Almera (ICTJA-CSIC), Barcelona, Spain.

ABSTRACT
How do the feedbacks between tectonics, sediment transport and climate work to shape the topographic evolution of the Earth? This question has been widely addressed via numerical models constrained with thermochronological and geomorphological data at scales ranging from local to orogenic. Here we present a novel numerical model that aims at reproducing the interaction between these processes at the continental scale. For this purpose, we combine in a single computer program: 1) a thin-sheet viscous model of continental deformation; 2) a stream-power surface-transport approach; 3) flexural isostasy allowing for the formation of large sedimentary foreland basins; and 4) an orographic precipitation model that reproduces basic climatic effects such as continentality and rain shadow. We quantify the feedbacks between these processes in a synthetic scenario inspired by the India-Asia collision and the growth of the Tibetan Plateau. We identify a feedback between erosion and crustal thickening leading locally to a <50% increase in deformation rates in places where orographic precipitation is concentrated. This climatically-enhanced deformation takes place preferentially at the upwind flank of the growing plateau, specially at the corners of the indenter (syntaxes). We hypothesize that this may provide clues for better understanding the mechanisms underlying the intriguing tectonic aneurisms documented in the Himalayas. At the continental scale, however, the overall distribution of topographic basins and ranges seems insensitive to climatic factors, despite these do have important, sometimes counterintuitive effects on the amount of sediments trapped within the continent. The dry climatic conditions that naturally develop in the interior of the continent, for example, trigger large intra-continental sediment trapping at basins similar to the Tarim Basin because they determine its endorheic/exorheic drainage. These complex climatic-drainage-tectonic interactions make the development of steady-state topography at the continental scale unlikely.

No MeSH data available.


Related in: MedlinePlus