How subduction broke up Pangaea with implications for the supercontinent cycle

Abstract

Mechanisms that can explain the Mesozoic motion of Pangaea in a palaeomagnetic mantle reference frame may also be able to explain its breakup. Calculations indicate that Pangaea moved along a non-rigid path in the mantle frame between the late Triassic and early Jurassic. The breakup of Pangaea may have happened as a response to this non-rigid motion. Tectonic forces applied to the margins of Pangaea as a consequence of subduction at its peripheries can explain both the motion and deformation of Pangaea with a single mechanism. In contrast, mantle forces applied to the base of Pangaea appear to be inconsistent with the kinematic constraints and do not explain the change in supercontinent motion that accompanied the breakup event. Top-down plate tectonics are inferred to have caused the breakup of Pangaea. Strong coupling between the mantle and lithosphere may not have been the case during the Phanerozoic eon when the Pangaean supercontinent formed and subsequently dispersed.Gold Open Access: This article is published under the terms of the CC-BY 3.0 license.The mechanisms responsible for plate tectonic change on Earth have been linked to the different stages of the supercontinent cycle (Worsley et al.

True Polar Wander: A Key Indicator for Plate Configuration and Mantle Convection During the Late Neoproterozoic

“…This degree 2 structure would then be sustained until the supercontinent is completely dislocated into small blocks. Recent works on the breakup of Pangaea show that the effect of encircling subduction zones could be a prerequisite to dislocate the supercontinent (Buiter & Torsvik, 2014;Keppie, 2016). According to their results, the convective system during a supercontinental phase is thus mainly modulated by the location and velocity of slabs pertaining to the girdle of subduction.…”

Paleotethys slab pull, self-lubricated weak lithospheric zones, poloidal and toroidal plate motions, and Gondwana tectonics

“…It is known that the force exerted by the Neotethys slab pull must have been strong enough to cause the drift of India from Gondwana to Asia between the Late Cretaceous and the early Eocene at an amazing velocity of 15-20 cm/yr (Patriat and Achache, 1984;Kumar et al, 2007). In a geodynamic context, the global significance of the Neotethys Ocean is highlighted by Keppie (2015) who linked its closure with the opening of the early Atlantic Ocean.…”

Publisher’s Note

“…Although CAMP magmatism occurred in extremely intense but relatively brief episodes around 201 Ma, the tectonic activity that led to the breakup of Pangaea was much more prolonged (Frizon De Lamotte et al, 2015;Keppie, 2016). The oldest rift basin sediments around the central Atlantic are early Carnian (Late Triassic), possibly older than 230 Ma (Olsen, 1997).…”

“…The processes that initiate the dispersal of these large continental accumulations remain controversial (Santosh et al, 2009;Audet and Bürgmann, 2011;Murphy and Nance, 2013;Nance et al, 2014;Petersen and Schiffer, 2016;Peace et al, 2017a;Petersen et al, 2018;Schiffer et al, 2018;Olierook et al, 2019). The debate primarily revolves around whether continental dispersal is driven by deep-rooted thermal anomalies (Morgan-type mantle plumes) or shallow plate tectonic processes (Storey, 1995;Dalziel et al, 2000;Beutel et al, 2005;Frizon De Lamotte et al, 2015;Pirajno and Santosh, 2015;Yeh and Shellnutt, 2016;Keppie, 2016;Petersen et al, 2018;Heron, 2018).…”