Africa-Eurasia plate boundary west of Gibraltar

Discussions about current knowledge and theories of the structure of Earth, in particular all aspects of plate tectonics, including history, fundamental aspects, flaws...
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sathearn
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Joined: Sun Jul 10, 2011 3:28 pm

Africa-Eurasia plate boundary west of Gibraltar

Post by sathearn »

On first consideration it is not obvious why "the structurally unified eastern half of the Atlantic Ocean" (Yu. V. Chudinov, 1998, p. 162) should be thought of as the location of a boundary dividing the African Plate from the Eurasian Plate.

If it is taken to be such a boundary, what type of plate interaction is supposed to be happening there? Since Africa is supposedly converging with Eurasia, are there any data currently being interpreted in terms of convergence at the oceanic boundary between the two plates? Or is the movement at this boundary taken to be solely or mainly of the transform or strike-slip variety? In the latter case, can these be distinguished from movements at other transform faults and fracture zones offsetting the Atlantic ridge? There seems to be evidence for considerable lengthwise extension of oceanic spreading ridges, and it has been argued (Gudmundsonn, 1993) that such extension may be key to the initial formation of transform faults/fracture zones. Would there also be evidence for such extension at the alleged plate boundary itself? Are there any interesting implications of plate reconstructions over a somewhat longer geological time interval (i.e. during the opening of the Atlantic) for how these developing plates should interact at their oceanic boundary?

Though I have nothing particular to say about it yet, the following paper might be a useful place to start (Zitellini et al., 2009): http://scholar.google.com/scholar_url?u ... s=1366x567

Before attempting to evaluate all this it would be useful to get clear about what the relevant proposals within plate tectonics actually are.

References:
Chudinov, Yu. V. (1998). Global eduction tectonics of the expanding Earth, VSP, pp. 201.
Gudmundsson, A. (1993). On the structure and formation of fracture zones. Terra Nova, 5(3), 215-224.
Zitellini, N., Gràcia, E., Matias, L., Terrinha, P., Abreu, M. A., DeAlteriis, G., ... & Diez, S. (2009). The quest for the Africa–Eurasia plate boundary west of the Strait of Gibraltar. Earth and Planetary Science Letters, 280(1), 13-50.
Florian
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Re: Africa-Eurasia plate boundary west of Gibraltar

Post by Florian »

I believe that the description made in Zitenilli et al is quite complete.
I would say as a ultrashort summary that the Alboran orogenic arc encounters a transform fault...
If 50 million believe in a fallacy, it is still a fallacy. Sam W Carey
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