Australia: The Land Where Time Began

A biography of the Australian continent 

Continental Domain Reconstruction – 200 Ma to Present

The breakup of the supercontinent Pangaea and the redistribution of the resulting fragments occurred in this period (e.g., Ford & Golonka, 2003; Golonka et al., 2003, and references therein), the initiation of rifting of Pangaea occurring in the Early Triassic.

~200 Ma The drift-rift transition in the southeastern US began;

198-173 Ma Breakup of Africa from India/Antarctica occurred in this period;

~185 Ma maritime Canada;

~180 Ma Madagascar/India began separating from Africa;

   175 Ma seafloor spreading began in the central Atlantic;

   136 Ma Greater India separated from Australia (Müller et al., 1998);

~134 Ma India began separating from Antarctica;

   130 Ma the initial opening of the South Atlantic between Africa and South America;

   112 Ma separation of Madagascar/India from Africa was stable relative to Africa (Coffin & Rabinowitz, 1988);

~ 95 Ma the Central Atlantic propagated towards the North Atlantic and the onset of seafloor spreading of the Rockall Trough began;

~ 88 Ma India began separating from Madagascar (Ramana et al., 2001; Storey et al., 1997);

   85 Ma Seafloor spreading led to Australia separating from Antarctica (Norvick & Smith, 2001);

   62 Ma the Labrador Sea began opening (Saunders et al., 1997);

~50 Ma South America began drifting away from Antarctica (Livermore et al., 2005);

Large volumes of continental flood basalts were extruded in this period;

201-197 Ma Central Atlantic Magmatic Province (CAMP) (Marzoli et al., 1999a,b);

~180 Ma Karoo-Ferrar basalts (e.g. Marsh et al., 1997);

138-131 Ma Paraná-Etendeka basalts (Stewart et al., 1996);

 116 Ma Rajmahal Basalt (Pringle et al., 1994);

  88 Ma Madagascar Basalt (Storey et al., 1995);

~66 Ma the Deccan Traps (e.g. Baksi, 1994);

~60 ± 1 Ma North Atlantic Volcanic Province (NAVP) (Eldholm & Grue, 1994);

  30 Ma Ethiopian and Yemen Traps (Hofmann et al., 1997).

  6-17 Ma the Columbia River basalts (Baksi, 1989; Tolan et al., 1989);

‘The age and distribution of NAVP, the Madagascar, Rajmahal, Paraná-Etendeka, and Karoo-Ferrar basalts and the CAMP indicate the initial stage of opening or breakup of the North Atlantic Ocean, Madagascar/India, India/Antarctica, South Atlantic Ocean, Africa/Antarctica, Central Atlantic Ocean, respectively.’¹ According to Utsunomiya et al. with the exception of NAVP, these LIPs were generated directly or nearly on the African low velocity area in the lower mantle. The African Superplume region is the location of the main breakup event in Pangaea. In the Ferrar Igneous Province the ultramafic lamprophyres have a HIMU-signature (Riley et al., 2003), which suggests the breakup of Pangaea was controlled by upwelling of the lower mantle.

Sources & Further reading

1. Atsushi Utsunomiya, Tsutomu Ota, Brian F. Windley, Norihito Suzuki, Yuko Uchio, Kuniko Munekata,and Shigenori Maruyama in Yuen, D.A., Maruyama, S, Karato, Shun-ichiro & Windley, B., (Eds), 2007, Superplumes: Beyond Plate Tectonics, Springer