Large Scale Terrain Generation from Tectonic Uplift and Fluvial Erosion

Abstract. This study provides an inventory of geomorphological landforms in Eastern Bolivia at different spatial scales. Landforms and associated processes are interpreted and discussed regarding landscape evolution and paleoclimatic significance. Thereby, preliminary conclusions about past climate changes and the geomorphic evolution in Eastern Bolivia can be provided. Fluvial and aeolian processes are presently restricted to a few locations in the study area. A much more active landscape has been inferred from large-scale Channel shifts and extensive paleodune Systems. Mobilization. transport and deposition of Sediments are thought to be the result of climatic conditions drier than today. However. there are also indications of formerly wetter conditions such as fluvial erosion and paleolake basins. In conclusion, the documentation and interpretation of the manifold landforms has shown to contain a considerable amount of paleoecological information, which might serve as the base for further paleoclimatic research in the central part of tropical South America.

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A rock volume accumulation curve for the late Ordovician-Silurian Welsh Basin

Geological Magazine ◽

10.1017/s0016756800012140 ◽

1994 ◽

Vol 131 (4) ◽

pp. 539-544 ◽

Cited By ~ 4

Author(s):

Chris J. Clayton

Keyword(s):

Climate Change ◽

Large Scale ◽

Late Ordovician ◽

Tectonic Uplift ◽

Sudden Increase ◽

Submarine Fan ◽

Accumulation Curve ◽

River Capture ◽

Iapetus Ocean ◽

Rate Of Sedimentation

AbstractA rock accumulation curve is presented for the Ordovician-Silurian Welsh Basin, based on the volume of sediment entering the basin during each graptolite biozone. Even allowing for its inherent uncertainties, the curve still illustrates a significant and sudden increase in the rate of sedimentation in early Silurian time. This may be explained by submarine fan migration, large scale climate change, or river capture in the hinterland, but is most likely caused by tectonic uplift at source. This would support models for either an early Silurian, or late Ordovician closure of the Iapetus Ocean

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Research on Large Scale Terrain Generation Method Based on Geometry Clipmap Algorithm

2018 IEEE 4th Information Technology and Mechatronics Engineering Conference (ITOEC) ◽

10.1109/itoec.2018.8740772 ◽

2018 ◽

Author(s):

Guannan He ◽

Feng Tian ◽

Guanglei Meng ◽

Yan Tian

Keyword(s):

Large Scale ◽

Terrain Generation

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A stream-power law for glacial erosion and its implementation in large-scale landform-evolution models

10.5194/esurf-2021-1 ◽

2021 ◽

Author(s):

Stefan Hergarten

Keyword(s):

Sediment Transport ◽

Large Scale ◽

Numerical Models ◽

Stream Power ◽

Glacial Erosion ◽

Simple Formulation ◽

Landform Evolution ◽

Fluvial Erosion ◽

Numerical Effort ◽

Long Time

Abstract. Modeling glacial landform evolution is more challenging than modeling fluvial landform evolution. While several numerical models of large-scale fluvial erosion are available, there are only a few models of glacial erosion, and their application over long time spans requires a high numerical effort. In this paper, a simple formulation of glacial erosion which is similar to the fluvial stream-power model is presented. The model reproduces the occurrence of overdeepenings, hanging valleys, and steps at confluences at least qualitatively. Beyond this, it allows for a seamless coupling to fluvial erosion and sediment transport. The recently published direct numerical scheme for fluvial erosion and sediment transport can be applied to the entire domain, where the numerical effort is only moderately higher than for a purely fluvial system. Simulations over several million years on lattices of several million nodes can be performed on standard PCs. An open-source implementation is freely available as a part of the landform evolution model OpenLEM.

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Modeling large-scale fluvial erosion in geographic information systems

Geomorphology ◽

10.1016/s0169-555x(02)00351-3 ◽

2003 ◽

Vol 53 (1-2) ◽

pp. 147-164 ◽

Cited By ~ 67

Author(s):

David P. Finlayson ◽

David R. Montgomery

Keyword(s):

Information Systems ◽

Geographic Information Systems ◽

Large Scale ◽

Geographic Information ◽

Fluvial Erosion

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A new surface-processes model combining glacial and fluvial erosion

Annals of Glaciology ◽

10.3189/172756499781821797 ◽

1999 ◽

Vol 28 ◽

pp. 282-290 ◽

Cited By ~ 72

Author(s):

Jean Braun ◽

Dan Zwartz ◽

Jonathan H. Tomkin

Keyword(s):

Large Scale ◽

Surface Processes ◽

Glacial Cycles ◽

Forming Process ◽

Glacial Erosion ◽

Fluvial Erosion ◽

Erosion Rates ◽

Model Combining ◽

Hill Slope ◽

Glacial Periods

AbstractWe have developed a new surface-processes model incorporating large-scale fluvial processes, local hill-slope processes and glacial erosion. Ice thickness and velocity are calculated under a shallow-ice approximation. Simulation experiments in fast-growing orogens comparing the efficiencies of fluvial and glacial erosion, where the two are operating simultaneously over several glacial cycles, show that: glacial landscapes can support greater ice masses than fluvial landscapes; glacial valley and lake shapes create a disequilibrium between landform and land-forming process that leads to pulses of high erosion at the end of glacial periods; glacial erosion rates can reach a constant value in a uniformly growing orogen; and glacial erosion is capable of eroding drainage divides when the ice is moderately thick.

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The Devil Lake pothole (Ontario): Evidence of subglacial fluvial processes

Géographie physique et Quaternaire ◽

10.7202/004823ar ◽

2002 ◽

Vol 54 (2) ◽

pp. 245-250 ◽

Cited By ~ 4

Author(s):

Robert Gilbert

Keyword(s):

Stream Flow ◽

Large Scale ◽

Topographic Maps ◽

Laurentide Ice Sheet ◽

Maximum Diameter ◽

Rock Surface ◽

Acoustic Survey ◽

Fluvial Erosion ◽

Bedrock Topography ◽

The Devil

Abstract A pothole 1.93 m deep and 1.3 m maximum diameter is located near the crest of a ridge that forms one arm of an eroded anticline in para-gneiss of the Precambrian Shield in southeastern Ontario. It's position on high ground in a region of more than 100 m relief on the bed rock precludes its formation by modern subaerial stream flow or by streams that could have come from the retreating late Pleistocene glacier. The regional bedrock topography determined from topographic maps and a subbottom acoustic survey of nearby lakes exhibits a pattern of large-scale subglacial fluvial erosion reported for other sites in the region. The pothole formed in subglacial flow where discharge was concentrated along the limb of the anticline. As flow streamed around a small rock knob, a vortex was established at a fracture in the rock surface and initiated the erosion of the pothole. This configuration insured that subsequent flows were similarly focused. The occurrence of this pothole is further evidence of the importance of subglacial water as an agent of erosion and the shaping of landscape beneath the Laurentide Ice Sheet.

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The influence of upper-plate advance and erosion on overriding plate deformation in orogen syntaxes

Solid Earth ◽

10.5194/se-9-1207-2018 ◽

2018 ◽

Vol 9 (6) ◽

pp. 1207-1224 ◽

Cited By ~ 2

Author(s):

Matthias Nettesheim ◽

Todd A. Ehlers ◽

David M. Whipp ◽

Alexander Koptev

Keyword(s):

Shear Zones ◽

Climatic Conditions ◽

Tectonic Uplift ◽

Lithostatic Pressure ◽

Fluvial Erosion ◽

Plate Deformation ◽

Driving Mechanisms ◽

Dip Angle ◽

Basal Detachment ◽

Indenter Geometry

Abstract. Focused, rapid exhumation of rocks is observed at some orogen syntaxes, but the driving mechanisms remain poorly understood and contested. In this study, we use a fully coupled thermomechanical numerical model to investigate the effect of upper-plate advance and different erosion scenarios on overriding plate deformation. The subducting slab in the model is curved in 3-D, analogous to the indenter geometry observed in seismic studies. We find that the amount of upper-plate advance toward the trench dramatically changes the orientation of major shear zones in the upper plate and the location of rock uplift. Shear along the subduction interface facilitates the formation of a basal detachment situated above the indenter, causing localized rock uplift there. We conclude that the change in orientation and dip angle set by the indenter geometry creates a region of localized uplift as long as subduction of the down-going plate is active. Switching from flat (total) erosion to more realistic fluvial erosion using a landscape evolution model leads to variations in rock uplift at the scale of large catchments. In this case, deepest exhumation again occurs above the indenter apex, but tectonic uplift is modulated on even smaller scales by lithostatic pressure from the overburden of the growing orogen. Highest rock uplift can occur when a strong tectonic uplift field spatially coincides with large erosion potential. This implies that both the geometry of the subducting plate and the geomorphic and climatic conditions are important for the creation of focused, rapid exhumation.

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