Geodynamics & Tectonics

We study the deformation and flow in the Earth from the microscale to the mantle scale, and investigate the driving forces responsible for such deformation and flow.

We use laboratory-based (analogue) and numerical modelling techniques as well as field studies, marine expeditions and tectonic reconstructions to quantify the velocities, forces, stresses deformation and structures associated with large-scale geodynamic processes such as subduction, mountain building, continental rifting, backarc spreading and strike-slip faulting. In this framework, our research also concerns the study of the geodynamic evolution of the shallow crustal parts of orogenic systems, ocean basins, and more.

The Geodynamics & Tectonics group focusses both on generic, process-oriented, research (including research on subduction, orogenesis, rifting, and crustal deformation) and research applied to specific geological settings and geographical locations (e.g. Andes, Himalaya-East Asia, Scotia Sea, Pyrenees, Southwest Pacific, Cyprus, Aegean).

The group manages the Kuenen-Escher Geodynamics Laboratory (KEG Lab) [https://vu.nl/en/about-vu/more-about/kuenen-escher-geodynamics-laboratory], which is a modelling facility in which crustal and mantle-scale geodynamic processes are simulated using analogue experiments at small spatial scales and short temporal scales.

Subduction Dynamics
Subduction zones are arguably the most significant tectonic features on Earth as they are the main driver of plate motion and mantle flow, and they play a dominant role in shaping the Earth’s topography through formation of mountain belts and ocean basins, thereby affecting atmospheric and ocean circulation, causing long-term climate change. Furthermore, they are associated with many different types of mineral deposits and with sedimentary basins that can be used for geothermal energy extraction and/or carbon capture and storage (CCS). Lastly, subduction zones produce the most destructive volcanoes and earthquakes (and related tsunami) on Earth, including the December 2004 Sumatra-Andaman earthquake and March 2011 Japan earthquake. Therefore, there is both a scientific and societal need to increase our understanding of subduction zone processes.

Main topics of research:

Subduction zone evolution and subduction-induced mantle flow.
Cordilleran mountain building at subduction zones (e.g. Andes).
Backarc basin formation at subduction zones (e.g. Aegean Sea, Scotia Sea).
Dynamic topography and (past) subduction (e.g. SW Pacific, Australia).
Continental subduction and orogenesis (e.g. Himalaya).
Subduction termination, ophiolite obduction (e.g. New Guinea, New Zealand).
Subduction initiation (e.g. Scotia subduction zone).

Contact: Wouter P. Schellart (w.p.schellart@vu.nl)
https://research.vu.nl/en/persons/wouter-pieter-schellart

Geodynamic Modelling
We use geodynamic models to provide quantitative insight into crustal, lithospheric and mantle-scale processes. We use both scaled laboratory modelling (analogue modelling) and numerical modelling techniques to investigate a variety of upper crustal to mantle scale processes. The analogue experiments are carried out in the Kuenen-Escher Geodynamics Laboratory (KEG Lab) [https://vu.nl/en/about-vu/more-about/kuenen-escher-geodynamics-laboratory], which houses a variety of equipment (e.g. rheometer, density meter) to assess the physical properties of the modelling materials, modelling tanks and sandboxes to run the experiments, and cameras and a Particle Image Velocimetry (PIV) System to record, visualize, quantify and post-process the experiments.

For the numerical modelling we use the open source code Underworld [https://www.underworldcode.org], which has been developed at Monash University and the University of Melbourne in Australia by Louis Moresi and colleagues. This is a particle-in-cell finite element code that has been specifically designed to simulate the evolution of large-scale geodynamic processes in three-dimensional space.

Main topics of research:

Subduction zone processes and mantle flow.
Mountain building.
Continental deformation.
Rheology of analogue materials.
Fold-and-thrust belts.
Strike-slip deformation.

Contact: Wouter P. Schellart (w.p.schellart@vu.nl)
https://research.vu.nl/en/persons/wouter-pieter-schellart

Tectonic Plates In Extention
Extension of tectonic plates is controlled by the interplay between diverging forces that cause tension in and mantle upwelling that causes heating of the tectonic plate that is in extension. If a tectonic plate is under extension for an extended period of time, the surface expression will show basins and depressions in various sizes, shapes and depth. These depressions will initially fill in with water and sediments. Continuous extension over millions of years will lead to extreme thinning of a plate causing it to break-apart, forming an oceanic spreading center.

At the VU, we investigate how plates with different rheological compositions evolve when they are in extension. We do this by participating in geophysical and geological data acquisition expeditions with international partners. We use numerical modelling techniques to simulate and quantify how plates in extension behave and we perform field work to understand the geological conditions of extending tectonic plates.

Main topics of research:

Active rift- and spreading systems (e.g. East African Rift)
Failed rift and aborted extensional systems (e.g. North Sea)
Passive margins (e.g. South Atlantic margins)
Mid-Ocean Ridges and Transform systems (e.g. Mid-Atlantic Ridge)
Back-arc basins (e.g. Scotia Sea, Aegean Sea)

Contact: Anouk Beniest (a.beniest@vu.nl)

https://research.vu.nl/en/persons/anouk-beniest

Sea Floor Mapping
Approximately 70% of the Earth’s surface is covered with water, with ocean depths ranging between a few meters close to shore to more than 10 kilometers at the deepest trenches (e.g. Mariana Trench). This vast region hosts a treasure of information, including seamounts, long mountain ranges, hydrothermal vents and resources, which all form in response to tectonic activity. Because our oceans are submerged, it is quite challenging to understand how these bathymetric features form, what resources they host and what hazards they may produce. Especially geological data, including rock samples and measurements, are very difficult to gather, even though they inform us about the processes that occur in the oceanic crust.

Using existing geophysical datasets and machine learning, we develop offshore mapping techniques that allow the identification of geological data (e.g. rock type) in the offshore domain. We use this information for paleogeographic reconstructions of complex tectonic settings in the offshore domain.

Main topics of research:

Developing numerical mapping techniques for submerged domains
Investigating oceanic gateway opening and closure
Paleogeographic reconstructions of back-arc basins

Contact: Anouk Beniest (a.beniest@vu.nl)
https://research.vu.nl/en/persons/anouk-beniest