Advances in Deformable Plate Tectonic Models: 1. Reconstructing Deformable Continental Blocks and Crustal Thicknesses Back Through Time

Abstract

Deformable plate tectonic models have been demonstrated to be a useful technique for quantifying temporal variations in strain rate and crustal thickness within recent plate kinematic studies. Using the GPlates software, deformable plate models offer an approach to visualize and assess the interplay of plate kinematics and deformation. However, several assumptions are imposed in previous studies that limit their ability to explain the crustal evolution of various tectonic regimes. Examples of these assumptions include, but are not limited to, the rigid nature of continental blocks and boundaries used to define deformable regions, and uniform crustal thickness assumptions at model start times. In this study, we address these assumptions with newly presented applications using the interplay of GPlates and its python programming library, pyGPlates. In particular, we demonstrate the ability to create deformable continental blocks, reconstruct present day crustal thickness estimates back through time, and how the landward extent of present day crustal thickness estimates can be used to define the limits of deformable plate models and rift domain boundaries a priori. To demonstrate their application and validity, these concepts are evaluated using a previously published deformable plate model of the southern North Atlantic that is tested using 4 modeling scenarios herein to assess the impact of variable model inputs. These models provide insight regarding the pre-Jurassic (200 Ma) crustal thickness template of the southern North Atlantic, the evolution of continental blocks during rift-related deformation, and the potential impact of ancient orogenic terranes during subsequent rifting within the North Atlantic.