Caribbean Program - Movie

TAL Caribbean Tectonic Model - The Movie

Since 1982 we have developed and refined tectonic models for the Caribbean region and surrounding areas such as the Gulf of Mexico, the Andes and the margins of the Equatorial Atlantic. Our most recent systhesis will be published in a forthcoming Geological Society of London Special Publication, and this paper is the basis of the movie presented below.

The highlight of this work is a series of palaeotectonic maps drawn in an Indo-Atlantic hotspot reference frame. Although based on the work of Müller et al. (1993), there is no substantial difference for Late Cretaceous and younger time compared to recently published hybrid reference frames such as that of Torsvik et al. (2008).

About the movie:

The first step in making the movie is to develop a robust kinematic framework for relative motions of North America, South America and Africa. Geologic data, such as geochronology, metamorphic petrology, structural observations, basin analysis of diachronous foreland basins, from around the Caribbean are then used to put the Caribbean Plate into position with respect to the Americas. While it is now widely recognised that there is no global fixed hotspot reference, it still appears that over large areas hotspots drift only relatively slowly with respect to each other, and that Pacific and Indo-Atlantic hotspots can be used to define two more or less hemispheric reference frames which move respect to each other. The final step applied here is to plot the resulting maps in a fixed Indo-Atlantic hotspot reference frame (here we use Müller et al., 1993). Although the maps could have been plotted in any alternative reference frame (such as fixed North America), these maps serve to emphasize that, at least since the Late Cretaceous, the Caribbean Plate has been more or less fixed with respect to the Indo-Atlantic hotspot reference frame, and that it is the westward flight of the Americas during Pangea breakup, rather than eastward motion of the Caribbean Plate with respect to the former core of Pangea, that drove the development of the Caribbean Plate boundaries.

The bold orange lines show the approximate shapes of the continental-ocean boundaries of the North American and South American Plates. The bold grey line is the outline of the present day deep Caribbean Basin. The blue areas are oceanic crust which is subducted before the next youngest frame. The pink shape delineates a slab gap which must have developed where the Campanian and older spreading centre in the Proto-Caribbean Seaway (connected to the Atlantic) was subducted beneath the Antilles. The green areas show possible plume-related volcanic centres.

<a href="Carib_HSRF_animation_small.swf">[View Flash File]</a>

Implication for Caribbean relations to the Galapagos hot spot

A further interesting feature of the maps is that we can roughly estimate the drift of the Pacific and Indo-Atlantic hotspots with respect to one another by comparing the Americas to Nazca/Farallon plate circuit (e.g. Doubrovine & Tarduno) back to 84 Ma with hotspot tracks on the Pacific Plate (e.g. Wessel et al., 2006; Wessel & Kroenke, 2008) with the motions of the Americas and Africa in an Indo-Atlantic reference frame (e.g. Müller et al., 1993 or Torsvik et al., 2008). The comparison suggests that, seen from the eastern Pacific near the Caribbean, Pacific hotspots have driven to the west since the Late Cretaceous. Furthermore, some mantle flow models (e.g. Steinberger et al., 2002) suggest that there may be a tendency for hotspots close to the eastern Pacific subduction zones to drift away from them towards the central Pacific hotspots (the Wessel Pacific hotspot reference frame is constrained principally by the Hawaii and Louisville hotspots) as a result of a deep mantle return flow . The combined effect of these two motions may be to allow the Galapagos hotspot, if it existed in the Late Cretaceous, to have drifted west by perhaps 2000-2500 km.

The upshot is that a "proto-Galapagos hotspot" may indeed have been the origin of the Late Cretaceous Caribbean Large Igneous Province plateau basalts, something which would be impossible were Pacific and Indo-Atlantic hotspots fixed with respect to one another. Around and around we go.

This figure shows a possible migration path since 92 Ma (bold red line) of the Galapagos hot spot relative to the Indo-Atlantic reference frame of our movie. Ellipses show qualitatively estimated errors - we've yet to do the calculations in detail. Finer weight curves emanating from the Galapagos Islands: calculated motion histories of the Pacific hot spot reference frame relative to the Indo-Atlantic frame, determined for the Galapagos hot spot (0¡/90¡W); brown line, Pilger (2003); purple lines, Wessel (2006, 2008). Heavy arrow is a subjective correction to the above curves following concepts of Steinberger (2002). Slant-ruled area is the estimated position of the Proto-Caribbean slab gap at 92 Ma, interpolated from the regional maps.

The proposed Late Cretaceous position of the "proto-Galapagos hotspot" lies entirely in line with the slab gap, which we may have allowed a deep mantle plume to reach the base of the Caribbean Plate. The Caribbean interior basin at 92 Ma is shown in grey. Also, the note that the deep hot spot probably passed west beneath the Panama-Costa Rica Trench in the Maastrichtian-Paleocene, just after arc inception (when the slab did not penetrate deep into the mantle), but following most plateau magmatism. Paleogene plateau-type basalts at Azuero Peninsula (Hoernle et al. 2002) were likely accreted from the subducting plate after the passage of the hot spot beneath the arc, but some Paleogene basalts along Central America may pertain directly to the passage of the hot spot beneath the arc itself.

Additional References

  • Doubrovine, P. V. & Tarduno, J. A. 2008. A Revised Kinematic Model for the Relative Motion between Pacific Oceanic Plates and North America since the Late Cretaceous. Journal of Geophysical Research, 113, B12101.
  • Hoernle, K., van den Bogaard, P., Werner, R., Lissinna, B., Hauff, F., Alvarado, G. & Garbe-Schonberg, D., 2002, Missing history (16-71 Ma) of the Galpapagos hot spot: Implications for the tectonic and biological evolution of the Americas. Geology, 30, 795-798.
  • Steinberger, B., 2002, Motion of the Easter hot spot relative to Hawaii and Louisville hot spots. Geochemistry Geophysics Geosystems, 3, 8503.
  • Wessel, P. & Kroenke, L. W., 2008, Pacific absolute Plate motion since 145 Ma: An assessment of the fixed hot spot hypothesis, Journal of Geophysical Research, 113, B06101.
  • Wessel, P., Harada, Y. & Kroenke, L. W., 2006, Toward a self-consistent, high-resolution absolute plate motion model for the Pacific. Geochemistry Geophysics Geosystems, 7, Q03L12.
  • All these maps were created with the GMT mapping software package (Wessel, P. & Smith, W. H. F. 1991, Free software helps map and display data, EOS Transactions, AGU, 72, 441).