Southern Ocean hotspot tracks and the Cenozoic absolute motion of the African, Antarctic, and South American plates

doi:10.1016/0012-821X(85)90106-2

Earth and Planetary Science Letters

Volume 75, Issues 2–3, October 1985, Pages 245-257

https://doi.org/10.1016/0012-821X(85)90106-2 Get rights and content

Abstract

A detailed analysis, based on an Antarctica-Africa finite reconstruction at chron C29 (64 Ma), an assumption of no relative wander between the Marion/Prince Edward and Tristan hotspots, and on recently revised bathymetric maps of the Southern Ocean region, shows that the fixed hotspot reference frame is tenable for “absolute” plate motions. Bouvet hotspot, and probably Trinidade as well, also shows little or no Cenozoic relative motion. Contrary to previous models. Bouvet hotspot is unrelated to the Meteor Rise-Cape Rise seamount chain. Instead, the bathymetric data, when compared with the predicted hotspot tracks, indicate another hotspot exists near the southernmost South Atlantic spreading ridge segment. New geochemical evidence from the latter region supports this hypothesis in showing the effects of “plume enrichment” from a source that is compositionally distinct from Bouvet. The peculiar zig-zag shape of the Cape Rise-Meteor Rise lineament is the result of this hotspot crossing the active transform segment of the Falkland-Agulhas Fracture Zone in Late Mesozoic times, followed by an early Cenozoic ridge-jump to the pre-weakened trace on the then South American plate. From the averaged Cenozoic absolute motions of the African, Antarctic, and South American plates, it is evident that Antarctica has been most nearly stationary in an absolute motion sense.

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Southern Ocean hotspot tracks and the Cenozoic absolute motion of the African, Antarctic, and South American plates

Abstract

Tectonophysics

Tectonophysics

Earth Planet. Sci. Lett.

Tectonophysics

Earth planet. Sci. Lett.

Earth Planet. Sci. Lett.

Earth Planet. Sci. Lett.

Earth Planet. Sci. Lett.

Earth Planet. Sci. Lett.

Earth Planet. Sci. Lett.

Earth Planet. Sci. Lett.

J. Volcan. Geotherm. Res.

Hotspot tracks and the opening of the Atlantic and Indian oceans

Geochemistry, mineralogy and petrogenesis of lavas erupted along the Southwest Indian Ridge between the Bouvet triple junction and 11 degrees east

J. Petrol.

General bathymetric chart of the oceans (GEBCO)—South Atlantic Chart 16

GEBCO—Southern Ocean Chart 13

GEBCO—SW Indian Chart 9

Sea floor spreading south of the Agulhas Fracture Zone

Nature

Magnetic anomalies associated with the Agulhas Fracture Zone in the area of the Cape Rise

Jnt. Geol. Surv./Univ. Cape Town Mar. Geosci. Unit Tech. Rep.

The history of ridge-crest off-set at the Falkland-Agulhas Fracture Zone from a small-circle geophysical profile

Geophys. J.R. Astron. Soc.

The Agulhas Plateau, South Atlantic opening and ridge-jumps south of the Agulhas Fracture Zone

Jnt. Geol. Surv./Univ. Cape Town Mar. Geosci. Unit Tech. Rep.