Ordovician to Devonian Development of the Iapetus Ocean (Paleoceanographic Mapping Project Report No. 08-0185)

The recognition of many small terranes bordering the Early Paleozoic Iapetus Ocean has entailed the revision of previous models, that only discussed the relations between the major continents. In this paper we illustrate the development of Iapetus through 1OO Ma by means of six maps drawn by computer graphics. In addition to paleomagnetic data, we have used biogeographic affinities, sedimentary facies, tectonic events and the distribution of igneous rocks to develop our assessment of continental and terrane distributions, and the positions of arcs and trenches. The tectonic model presented here is thus much more complex than the model first postulated by Wilson (1966) invoking the presence of a "Wide ocean in the Caledonides and Northern Appalachians, or the original plate tectonic model proposed by Dewey (1969). Subsequent models for the development of Iapetus have been proposed which we have taken into account in this review.UT Institute for Geophysics Paleoceanographic Mapping Project (POMP)Institute for Geophysic