Constraining South Atlantic growth with seafloor spreading data


Contact
graeme.eagles [ at ] awi.de

Abstract

Recent models of South Atlantic opening history focus on early plate divergence by incorporating intracontinental deformation, which is poorly constrained. Aiming to avoid the uncertainties in this approach, we model the entire divergence history with a joint inversion for seafloor spreading data. For this history, the pre-Campanian motion parameters are the first to feature formal uncertainty estimates. We date the onset of spreading at 138Ma, with movement along intracontinental accommodation zones leading to the assembly of South America by 123Ma and Africa by 106Ma. Part of the ridge in the Agulhas Basin jumped westward soon afterward toward the Bouvet plume, initiating the motion of a short-lived Malvinas Plate. The NE Georgia and Maud rises and Agulhas Plateau formed as a large igneous province over the plume. Farther north, part of the ridge jumped eastward toward the Tristan plume around 9493Ma but seems not to have resulted in independent plate motion. Our results show that the South Atlantic grew by diachronous breakup of continents on just two plates. Cretaceous intracontinental deformation in South America and Africa can be interpreted in terms of the accommodation of stress associated with northward propagation of this process. The pattern of accommodation is usually envisaged as focusing all of the strain in narrow belts. With our rotations, a commonly used set of such belts accounts instead for just 4267% of the implied total strain. We suggest that the remainder was accommodated at all scales within the continental interiors and the extended continental margins.



Item Type
Article
Authors
Divisions
Primary Division
Programs
Primary Topic
Peer revision
ISI/Scopus peer-reviewed
Publication Status
Published
Eprint ID
36489
DOI https://www.doi.org/10.1002/2014tc003644

Cite as
Pérez-Díaz, L. and Eagles, G. (2014): Constraining South Atlantic growth with seafloor spreading data , Tectonics, 33 (9), pp. 1848-1873 . doi: https://www.doi.org/10.1002/2014tc003644


Download
[thumbnail of PerezDiaz_Eagles_2014.pdf]
Preview
PDF
PerezDiaz_Eagles_2014.pdf

Download (20MB) | Preview
Cite this document as:

Share


Citation

Geographical region

Research Platforms
N/A

Campaigns
N/A


Actions
Edit Item Edit Item