Plume driven plate motion changes: New insights from the South Atlantic realm

Stotz, Ingo; Vilacís, Berta; Hayek, Jorge N.; Carena, Sara; Bunge, Hans‐Peter

doi:10.1016/j.jsames.2023.104257

Cited by 1 publication

(2 citation statements)

References 65 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is made possible because the slab arrives almost vertically at the 660‐km discontinuity and the upper plate is shortened, favoring trench advance and slab roll‐over. Velocities for horizontal upper mantle flow exceeding 5 cm/yr have been proposed to result for instance for the South Atlantic region from pressure‐induced upper mantle flow related to plume activity, explaining changes in South America directional plate motion in the Paleocene and in the Late Eocene/Oligocene (Colli et al., 2014; Stotz et al., 2023). Slab geometry and upper plate tectonic regime do not evolve together in our models.…”

Section: Discussionmentioning

confidence: 99%

“…Previous studies, based on models considering density‐driven buoyancy variations determined from seismic investigations at the global scale, suggest that horizontal present‐day upper mantle flow velocities could reach values up to 5 cm/yr (Becker et al., 2008; Bull et al., 2010). Additionally, global geodynamic models (Weismüller et al., 2015), and regional models considering Poiseuille flow in the asthenosphere resulting from plume activity (Colli et al., 2014; Stotz et al., 2023) propose that horizontal asthenosphere flow could reach velocities exceeding 10 cm/yr. In our study, we decided to systematically explore scaled velocities up to 10 cm/yr to account for possible uncertainties on present‐day upper mantle horizontal velocity and variations of mantle flow in the past, by performing a total of 11 models.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Role of Mantle Drag on the Tectonics of Subduction Zones: Insights From Laboratory Models

Geffroy,

Guillaume,

Simoes

et al. 2023

Tectonics

View full text Add to dashboard Cite

Along convergent boundaries, the role played by mantle drag remains poorly understood despite its potential impact on subduction dynamics and in turn on the deformation regime of the overriding plate. In this study, we present 11 three‐dimensional analog models of subduction including an overriding plate, in which mantle drag at the base of the lower or upper plate results from an imposed unidirectional horizontal mantle flow perpendicular to the trench, and in which the plate opposite to the flow is fixed. We varied the direction and the velocity of the imposed horizontal mantle flow between 0 and 10 cm/yr to quantify its impact on horizontal and vertical upper plate deformation, velocities of plates and subduction, and slab geometry. In our experiments, we show that a mantle flow lower than 5 cm/yr tends to laterally translate the slab rather than to generate internal deformation, resulting in limited differences in slab geometries between models. We also show that plate velocity correlates linearly with the imposed mantle flow velocity and associated mantle drag. The upper plate most often deforms by trench‐orthogonal shortening, with shortening rates increasing linearly with mantle flow. Shortening rates are higher when mantle flow is directed toward the fixed upper plate and when the slab has not yet reached the upper‐lower mantle discontinuity. Minimum trench‐orthogonal shortening rates of 2.5 × 10−15 s−1 are required to thicken upper plates. This study suggests that mantle drag can exert first‐order controls on the dynamics of subduction zones and associated tectonics.

show abstract

Section: Discussionmentioning

confidence: 99%