Name
Mantle dynamics and the persistence of surface topography and tectonics
Date & Time
Tuesday, May 9, 2023, 11:00 AM - 11:15 AM
Description
Mantle dynamic events in the planetary interior such as thermal convection and lithospheric instability can yield diagnostic surface signals such as topography, tectonics, and volcanism. However, there is a question on the persistence of the topographic and tectonic surface expression related to mantle flow; i.e., reconciling geodynamic mechanisms with interpretations in the geologic record, which can variably indicate a long-term or near-absent coupled effect between mantle and surface. Here we explore instances where surface topography and tectonics are directly linked to mantle dynamics to illustrate specific cases of the manifestation of planetary mantle processes at the surface. In the central Mediterranean, a sustained `dynamic topographic wave' seems to have been established with the retreating continental subduction beneath the Apennines and Adriatic. Migration of a topographic low/high and subduction corner flow is consistent with calculated residual topography and gravity/topography admittance functions, and observations of syn-convergent tectonic extension. In Central Anatolia, instability and removal of the lower lithosphere yields a surface subsidence and uplift that is rapid and can yield basin and plateau development. The tectonic deformation of such activity, though, is muted. In super-Earth planets, new findings indicate that penetrative focused superplumes (PFS) with lateral extent exceeding 10,000 km and radial velocities exceeding 20 cm/yr are highly stable with no significant lateral migration for billions of years. This implies an exceptionally long-term impact on the surface, potentially manifesting in long-lived topography and tectonics.
Location Name
Aspen
Full Address
Banff Park Lodge Resort Hotel & Conference Centre
201 Lynx St
Banff AB T1L 1K5
Canada
Abstract
Mantle dynamic events in the planetary interior such as thermal convection and lithospheric instability can yield diagnostic surface signals such as topography, tectonics, and volcanism. However, there is a question on the persistence of the topographic and tectonic surface expression related to mantle flow; i.e., reconciling geodynamic mechanisms with interpretations in the geologic record, which can variably indicate a long-term or near-absent coupled effect between mantle and surface. Here we explore instances where surface topography and tectonics are directly linked to mantle dynamics to illustrate specific cases of the manifestation of planetary mantle processes at the surface. In the central Mediterranean, a sustained `dynamic topographic wave' seems to have been established with the retreating continental subduction beneath the Apennines and Adriatic. Migration of a topographic low/high and subduction corner flow is consistent with calculated residual topography and gravity/topography admittance functions, and observations of syn-convergent tectonic extension. In Central Anatolia, instability and removal of the lower lithosphere yields a surface subsidence and uplift that is rapid and can yield basin and plateau development. The tectonic deformation of such activity, though, is muted. In super-Earth planets, new findings indicate that penetrative focused superplumes (PFS) with lateral extent exceeding 10,000 km and radial velocities exceeding 20 cm/yr are highly stable with no significant lateral migration for billions of years. This implies an exceptionally long-term impact on the surface, potentially manifesting in long-lived topography and tectonics.
Session Type
Breakout Session