Details
| Original language | English |
|---|---|
| Pages (from-to) | 1133-1155 |
| Number of pages | 23 |
| Journal | International Journal of Earth Sciences |
| Volume | 112 |
| Issue number | 4 |
| Early online date | 9 Feb 2023 |
| Publication status | Published - Jun 2023 |
Abstract
Subsurface salt flow is driven by differential loading, which is typically caused by tectonics or sedimentation. During glaciations, the weight of an ice sheet represents another source of differential loading. In salt-bearing basins affected by Pleistocene glaciations, such as the Central European Basin System, ice loading has been postulated as a trigger of young deformation at salt structures. Here, we present finite-element simulations (ABAQUS) with models based on a simplified 50-km long and 10-km-deep two-dimensional geological cross-section of a salt diapir subject to the load of a 300-m-thick ice sheet. The focus of our study is to evaluate the sensitivity of the model to material parameters, including linear and non-linear viscosity of the salt rocks and different elasticities. A spatially and temporarily variable pressure was applied to simulate ice loading. An ice advance towards the diapir causes lateral salt flow into the diapir and diapiric rise. Complete ice coverage leads to downward displacement of the diapir. After unloading, displacements are largely restored. The modelled displacements do not exceed few metres and are always larger in models with linear viscosity than in those with non-linear viscosity. Considering the low stresses caused by ice-sheet loading and the long time-scale, the application of linear viscosity seems appropriate. The elastic parameters also have a strong impact, with lower Young's moduli leading to larger deformation. The impact of both the viscosity and the elasticity highlights the importance of a careful parameter choice in numerical modelling, especially when aiming to replicate any real-world observations.
Keywords
- Finite-element modelling (ABAQUS), Glaciation, Ice-sheet loading, Salt mechanics, Salt structures
ASJC Scopus subject areas
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In: International Journal of Earth Sciences, Vol. 112, No. 4, 06.2023, p. 1133-1155.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Deformation of salt structures by ice-sheet loading
T2 - insights into the controlling parameters from numerical modelling
AU - Lang, Jörg
AU - Hampel, Andrea
N1 - Funding Information: We thank J. Adam, an anonymous reviewer and editor U. Riller for constructive comments, which greatly helped to improve the manuscript. S. Mayr, V. Noack and J.R. Weber are thanked for discussion. Comments by R. Eickemeier, G. Maniatis, J. Maßmann and J. Thiedau on an earlier draft of this manuscript are highly appreciated.
PY - 2023/6
Y1 - 2023/6
N2 - Subsurface salt flow is driven by differential loading, which is typically caused by tectonics or sedimentation. During glaciations, the weight of an ice sheet represents another source of differential loading. In salt-bearing basins affected by Pleistocene glaciations, such as the Central European Basin System, ice loading has been postulated as a trigger of young deformation at salt structures. Here, we present finite-element simulations (ABAQUS) with models based on a simplified 50-km long and 10-km-deep two-dimensional geological cross-section of a salt diapir subject to the load of a 300-m-thick ice sheet. The focus of our study is to evaluate the sensitivity of the model to material parameters, including linear and non-linear viscosity of the salt rocks and different elasticities. A spatially and temporarily variable pressure was applied to simulate ice loading. An ice advance towards the diapir causes lateral salt flow into the diapir and diapiric rise. Complete ice coverage leads to downward displacement of the diapir. After unloading, displacements are largely restored. The modelled displacements do not exceed few metres and are always larger in models with linear viscosity than in those with non-linear viscosity. Considering the low stresses caused by ice-sheet loading and the long time-scale, the application of linear viscosity seems appropriate. The elastic parameters also have a strong impact, with lower Young's moduli leading to larger deformation. The impact of both the viscosity and the elasticity highlights the importance of a careful parameter choice in numerical modelling, especially when aiming to replicate any real-world observations.
AB - Subsurface salt flow is driven by differential loading, which is typically caused by tectonics or sedimentation. During glaciations, the weight of an ice sheet represents another source of differential loading. In salt-bearing basins affected by Pleistocene glaciations, such as the Central European Basin System, ice loading has been postulated as a trigger of young deformation at salt structures. Here, we present finite-element simulations (ABAQUS) with models based on a simplified 50-km long and 10-km-deep two-dimensional geological cross-section of a salt diapir subject to the load of a 300-m-thick ice sheet. The focus of our study is to evaluate the sensitivity of the model to material parameters, including linear and non-linear viscosity of the salt rocks and different elasticities. A spatially and temporarily variable pressure was applied to simulate ice loading. An ice advance towards the diapir causes lateral salt flow into the diapir and diapiric rise. Complete ice coverage leads to downward displacement of the diapir. After unloading, displacements are largely restored. The modelled displacements do not exceed few metres and are always larger in models with linear viscosity than in those with non-linear viscosity. Considering the low stresses caused by ice-sheet loading and the long time-scale, the application of linear viscosity seems appropriate. The elastic parameters also have a strong impact, with lower Young's moduli leading to larger deformation. The impact of both the viscosity and the elasticity highlights the importance of a careful parameter choice in numerical modelling, especially when aiming to replicate any real-world observations.
KW - Finite-element modelling (ABAQUS)
KW - Glaciation
KW - Ice-sheet loading
KW - Salt mechanics
KW - Salt structures
UR - http://www.scopus.com/inward/record.url?scp=85147778849&partnerID=8YFLogxK
U2 - 10.1007/s00531-023-02295-5
DO - 10.1007/s00531-023-02295-5
M3 - Article
VL - 112
SP - 1133
EP - 1155
JO - International Journal of Earth Sciences
JF - International Journal of Earth Sciences
SN - 1437-3254
IS - 4
ER -