Structural-kinematic history of crustal-scale lineaments along the South Atlantic continental margins

• Applicants: Professor Dr. Hartwig E. Frimmel; Professor Thomas Michael Will, Ph.D.
• Subject Area: Mineralogy, Petrology and Geochemistry ; Palaeontology
• Term: from 2010 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 172804908

• Final Report Year: 2016

Final Report Abstract

Conclusions: The opening of the initial rifting of South Atlantic was controlled by and followed the orientations of inherited older structural trends and discontinuities. - The main Neoproterozoic SW Gondwana suture between the Río de la Plata and Kalahari cratons lies to the west of the Dorn Feliciano Belt in eastern South America. - The South Atlantic did not open along this suture but along the axis of a Neoproterozoic back-arc basin on top of a comparatively thin and Theologically weak lithosphere. - SW Gondwana break-up, initial rifting and the opening of the South Atlantic at c. 135-125 Ma were unrelated to an upwelling hot mantle plume. - In contrast, the formation of the youngest Möwe Bay dykes and the easternmost segment of the contemporaneous Walvis Ridge at c. 113 Ma was related to a hotspot underneath NW Namibia and SE Atlantic Ocean. - A substantial increase in spreading rate and the opening of the Equatorial Atlantic at that time may have been responsible for the changes in extension directions from E-W to NE-SW between 135 and 113 Ma in NW Namibia.

Publications

• 2013. A new lithostratigraphic subdivision and geodynamic model for the Pan-African western Saldania Belt, South Africa. Precambrian Research 231, 218-235
  Frimmel, H.E., Basei, M.A.S., Correa, V.X., Mbangula, N.
  (See online at https://doi.org/10.1016/j.precamres.2013.03.014)
• 2013. Southern African perspectives on the long-term morphotectonic evolution of cratonic interiors. Tectonophysics 601, 177-191
  Kounov, A., Viola, G., Dunkl, I., Frimmel, H.E.
  (See online at https://doi.org/10.1016/j.tecto.2013.05.009)
• 2013. The influence of inherited structures on dyke emplacement during Gondwana break-up in southwestern Africa. J Geol 121: 455-474
  Will, T.M., Frimmel, H.E.
  (See online at https://doi.org/10.1086/671398)
• 2014. Geochemical and isotopic composition of Pan-African metabasalts from southwestern Gondwana: Evidence of Cretaceous South Atlantic opening along a Neoproterozoic back-arc. Lithos 202-203, 363-381
  Will, T.M., Frimmel, H.E., Gaucher, C., Bossi, J.
  (See online at https://doi.org/10.1016/j.lithos.2014.05.034)
• Möwe Bay Dykes, Northwestern Namibia: Geochemical and geochronological evidence for different mantle source regions during the Cretaceous opening of the South Atlantic. Chemical Geology Volume 444, 9 December 2016, Pages 141-157
  Will, T.M., Frimmel, H.E., Pfänder, J.A.
  (See online at https://doi.org/10.1016/j.chemgeo.2016.08.040)