Two‐Branch Break‐up Systems by a Single Mantle Plume: Insights from Numerical Modeling. Issue 19 (4th October 2017)

• Record Type: Journal Article
• Authors: Beniest, A.; Koptev, A.; Leroy, S.; Sassi, W.; Guichet, X.
• Is Part Of: Geophysical research letters. Volume 44:Issue 19(2017)
• Page Start: 9589
• Page End: 9597
• Publication Date: 2017-10-04
• Subjects: continental breakup -- multibranch rifting -- thermomechanical modeling -- plume‐lithosphere interaction -- rheology -- North Atlantic; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2017GL074866
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: Thermomechanical modeling of plume‐induced continental break‐up reveals that the initial location of a mantle anomaly relative to a lithosphere inhomogeneity has a major impact on the geometry and timing of a rift‐to‐spreading system. Models with a warmer Moho temperature are more likely to result in "plume‐centered" mode, where the rift and subsequent spreading axis grow directly above the plume. Models with weak far‐field forcing are inclined to develop a "structural‐inherited" mode, with lithosphere deformation localized at the lateral lithospheric boundary. Models of a third group cultivate two break‐up branches (both "plume‐centered" and "structural inherited") that form consecutively with a few million years delay. With our experimental setup, this break‐up mode is sensitive to relatively small lateral variations of the initial anomaly position. We argue that one single mantle anomaly can be responsible for nonsimultaneous initiation and development of two rift‐to‐spreading systems in a lithosphere with a lateral strength contrast. Key Points: A single mantle plume can be responsible for two noncontemporaneous rift‐to‐spreading systems in a laterally nonhomogeneous lithosphere The prerift distance between a plume and a lateral lithospheric boundary between two segments controls rift‐to‐spreading systems The location of a plume with respect to lithosphere inhomogeneities is a key variable when modeling plume‐induced continental break‐up