Name
The formation of a continental fragment due to structural inheritance: geodynamic model for the Lewisian Terrane; NW Scotland
Date & Time
Monday, May 8, 2023, 10:30 AM - 10:45 AM
Description
The opening of the North Atlantic Ocean created the Lewisian Terrane � a continental fragment separated from Greenland�s Nagssugtoqidian orogenic belt and stranded to NW Scotland. Although the paleogeographical context of this fragment is well constrained, the tectonic mechanisms required to produce such a continental sliver during continental rifting are not. A hypothesis for this continental stranding is that structural inheritance related to past tectonic events could have facilitated the separation of a 150 km wide fragment from the Nagssugtoqidian orogenic belt. The region surrounding the Lewisian Terrane has a significant history of tectonic deformation which would have created structural and/or rheological heterogeneities. The most recent being the Grampian and Scandian orogenies between 460 and 420 Ma.In this study, we use numerical models to test mechanisms for generating continental fragments by applying different pre-rift lithospheric architectures suitable for the tectonic history of the Lewisian region. The numerical experiments indicate that terrane formation can be created through sufficient structural heterogeneity within the lithosphere. The extent and geometry of the inherited lithospheric heterogeneity has a predominant impact on the width of the generated terrane. Furthermore, a range of initial lithospheric heterogeneities (e.g., structural and rheological features) produce a continental fragment in our experiments, highlighting the potential role of many different forms of structural inheritance that could be controlling deformation in this complex tectonic environment.
Location Name
Aspen
Full Address
Banff Park Lodge Resort Hotel & Conference Centre
201 Lynx St
Banff AB T1L 1K5
Canada
Abstract
The opening of the North Atlantic Ocean created the Lewisian Terrane � a continental fragment separated from Greenland�s Nagssugtoqidian orogenic belt and stranded to NW Scotland. Although the paleogeographical context of this fragment is well constrained, the tectonic mechanisms required to produce such a continental sliver during continental rifting are not. A hypothesis for this continental stranding is that structural inheritance related to past tectonic events could have facilitated the separation of a 150 km wide fragment from the Nagssugtoqidian orogenic belt. The region surrounding the Lewisian Terrane has a significant history of tectonic deformation which would have created structural and/or rheological heterogeneities. The most recent being the Grampian and Scandian orogenies between 460 and 420 Ma.In this study, we use numerical models to test mechanisms for generating continental fragments by applying different pre-rift lithospheric architectures suitable for the tectonic history of the Lewisian region. The numerical experiments indicate that terrane formation can be created through sufficient structural heterogeneity within the lithosphere. The extent and geometry of the inherited lithospheric heterogeneity has a predominant impact on the width of the generated terrane. Furthermore, a range of initial lithospheric heterogeneities (e.g., structural and rheological features) produce a continental fragment in our experiments, highlighting the potential role of many different forms of structural inheritance that could be controlling deformation in this complex tectonic environment.
Session Type
Breakout Session