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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

Elevation profile of selected river basins that drain the plateau towards the intracontinental Tarim-like basin.Two stages of the reference model setup are shown: a) 25 and b) 50 Myr (MS0). c) Shows the final stage of an identical setup disregarding lake evaporation (MS4). River pen size is scaled with water discharge. The colour of the river in the profiles indicates erosion (blue) and sedimentation (red) rates. The insets locate the river basin being displayed (in green) and show the distribution of erosion and sedimentation rates over the entire model domain (red and blue). Note that the river displayed in b results from a dramatic river capture of a N-draining river by a tributary of the Tarim basin (both visible in a). The Tarim basin turns a geomorphological base level for the plateau, and results 1300 m higher in MS4 (c) relative to MS0 (b).
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pone.0132252.g008: Elevation profile of selected river basins that drain the plateau towards the intracontinental Tarim-like basin.Two stages of the reference model setup are shown: a) 25 and b) 50 Myr (MS0). c) Shows the final stage of an identical setup disregarding lake evaporation (MS4). River pen size is scaled with water discharge. The colour of the river in the profiles indicates erosion (blue) and sedimentation (red) rates. The insets locate the river basin being displayed (in green) and show the distribution of erosion and sedimentation rates over the entire model domain (red and blue). Note that the river displayed in b results from a dramatic river capture of a N-draining river by a tributary of the Tarim basin (both visible in a). The Tarim basin turns a geomorphological base level for the plateau, and results 1300 m higher in MS4 (c) relative to MS0 (b).

Mentions: In Fig 8 we show the elevation vs. distance profiles of three selected rivers at 25 My and 50 My that have in common that they drain towards the Tarim block. These river long-profiles record the tectonic and drainage evolution of their catchments. The evaporitic lakes in the high-plateau play as a new local geomorphological base level unaffected by the evolution of the lower regions, until either the lake becomes overfilled by sediment, overtopped by water, tectonically undammed, or captured by a neighbour drainage basin [49]. The rivers in Fig 8 show this competition very clearly: the central part of the plateau drains first towards the west (10 Myr, Fig 3), then becomes endorheic (20 Myr), then is captured by a NE river, and finally is captured by the Tarim basin (40 Myr) when this basin becomes significantly lower than the surrounding topography. For example, the flat region at ~3400 m elevation in Fig 8b is partially inherited from the above mentioned endorheic stage in the plateau (also visible in Fig 8a), and has been partially maintained by the ongoing uplift at the sector between 500 and 1000 km (distance along the river).


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

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

Elevation profile of selected river basins that drain the plateau towards the intracontinental Tarim-like basin.Two stages of the reference model setup are shown: a) 25 and b) 50 Myr (MS0). c) Shows the final stage of an identical setup disregarding lake evaporation (MS4). River pen size is scaled with water discharge. The colour of the river in the profiles indicates erosion (blue) and sedimentation (red) rates. The insets locate the river basin being displayed (in green) and show the distribution of erosion and sedimentation rates over the entire model domain (red and blue). Note that the river displayed in b results from a dramatic river capture of a N-draining river by a tributary of the Tarim basin (both visible in a). The Tarim basin turns a geomorphological base level for the plateau, and results 1300 m higher in MS4 (c) relative to MS0 (b).
© Copyright Policy
Related In: Results  -  Collection

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

pone.0132252.g008: Elevation profile of selected river basins that drain the plateau towards the intracontinental Tarim-like basin.Two stages of the reference model setup are shown: a) 25 and b) 50 Myr (MS0). c) Shows the final stage of an identical setup disregarding lake evaporation (MS4). River pen size is scaled with water discharge. The colour of the river in the profiles indicates erosion (blue) and sedimentation (red) rates. The insets locate the river basin being displayed (in green) and show the distribution of erosion and sedimentation rates over the entire model domain (red and blue). Note that the river displayed in b results from a dramatic river capture of a N-draining river by a tributary of the Tarim basin (both visible in a). The Tarim basin turns a geomorphological base level for the plateau, and results 1300 m higher in MS4 (c) relative to MS0 (b).
Mentions: In Fig 8 we show the elevation vs. distance profiles of three selected rivers at 25 My and 50 My that have in common that they drain towards the Tarim block. These river long-profiles record the tectonic and drainage evolution of their catchments. The evaporitic lakes in the high-plateau play as a new local geomorphological base level unaffected by the evolution of the lower regions, until either the lake becomes overfilled by sediment, overtopped by water, tectonically undammed, or captured by a neighbour drainage basin [49]. The rivers in Fig 8 show this competition very clearly: the central part of the plateau drains first towards the west (10 Myr, Fig 3), then becomes endorheic (20 Myr), then is captured by a NE river, and finally is captured by the Tarim basin (40 Myr) when this basin becomes significantly lower than the surrounding topography. For example, the flat region at ~3400 m elevation in Fig 8b is partially inherited from the above mentioned endorheic stage in the plateau (also visible in Fig 8a), and has been partially maintained by the ongoing uplift at the sector between 500 and 1000 km (distance along the river).

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