Abstract
We present early Cretaceous to present paleobathymetric reconstructions and quantitative uncertainty estimates for the South Atlantic, offering a strong basis for studies of paleocirculation, paleoclimate and paleobiogeography. Circulation in an initially salty and anoxic ocean, restricted by the topography of the Falkland Plateau, Rio Grande Ridge and Walvis Rise, favoured deposition of thick evaporites in shallow water of the Brazilian-Angolan margins. This ceased as seafloor spreading propagated northwards, opening an equatorial gateway to shallow and intermediate circulation. This gateway, together with subsiding volcano-tectonic barriers would have played a key role in Late Cretaceous climate changes. Later deepening and widening of the South Atlantic, together with gateway opening at Drake Passage would lead, by mid-Miocene (∼15 Ma) to the establishment of modern-style thermohaline circulation.
Highlights
We present early Cretaceous to present paleobathymetric reconstructions and quantitative uncertainty estimates for the South Atlantic, offering a strong basis for studies of paleocirculation, paleoclimate and paleobiogeography
The South Atlantic ocean, with its long history of growth, diverse topography of tectonic and magmatic ridges and plateaus, long continental margins, northern and southern gateways and extreme variations in sediment thickness, is a case in point. It represents a clear pathway for the transport of deep water formed at both poles, but before this it developed important gateways at Drake Passage in the Cenozoic and across its equatorial reaches in the Cretaceous, and hosted a number of large igneous provinces at a variety of latitudes
Previous attempts at modelling South Atlantic paleobathymetry were done in sketch form or at low spatial resolution owing to the quality of the datasets available for tectonic reconstructions and limited knowledge about many of the processes that have contributed to the present-day shape of the South Atlantic
Summary
We present early Cretaceous to present paleobathymetric reconstructions and quantitative uncertainty estimates for the South Atlantic, offering a strong basis for studies of paleocirculation, paleoclimate and paleobiogeography. The South Atlantic ocean, with its long history of growth, diverse topography of tectonic and magmatic ridges and plateaus, long continental margins, northern and southern gateways and extreme variations in sediment thickness, is a case in point At present, it represents a clear pathway for the transport of deep water formed at both poles, but before this it developed important gateways at Drake Passage in the Cenozoic and across its equatorial reaches in the Cretaceous, and hosted a number of large igneous provinces at a variety of latitudes. Sclater and McKenzie[2] and later Sclater et al.[3] present a number of sketches of South Atlantic paleobathymetry in which depths are dependent on seafloor age alone as defined by the rotation parameters of Bullard, Everett, and Smith[4] They attempted to incorporate the Rio Grande and Walvis ridges, prominent submarine highs that formed as large igneous provinces, in anticipation of their important role in water circulation. In discussing paleobathymetric reconstructions we will move forward in time, starting with the early stages of continent separation and maintaining the South American plate anchored in its present-day position
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
