Geography Notes

On an Expansion Tectonic Earth the configuration of ancient supercontinents and modern continents is defined by the distribution of the ancient continental seas and modern oceans respectively. This transition, from ancient continental seas to modern oceans, occurred during the late-Permian Period (some 250 million years ago) when the Pangaean supercontinent began to rupture and break apart. At that time the waters from the ancient seas progressively drained into the emerging ocean basins and new water was expelled, along with basaltic lava, along the mid-ocean-rift zones.

In order to define this distribution and configuration of seas and oceans, published coastline data, representing location of the ancient shorelines, were plotted on each of the geology models.The coastline data used to recreate the ancient seas and lands shown on each of the small Earth models on this website are based on the publications of:

SCOTESE C. R. 1994. Paleogeographic maps. In: Klein, G. D. ed. Pangea: paleoclimate, tectonics, and sedimentation during accretion, zenith, and breakup of a supercontinent. Geological Society of America Special Paper 288.

SMITH A. G., SMITH D. G. & FUNNELL B. M. 1994. Atlas of Mesozoic and Cenozoic coastlines. Cambridge University Press.

The conventional coastline reconstructions shown in each of these publications include only the Cambrian to present-day and no attempt has been made to reconstruct the coastlines beyond the Cambrian to include Precambrian geography on the small Earth models. The lack of coastline data on the Precambrian models does not imply that there were no ancient seas during that time, only a reflection of the lack of published data.

The coastal outlines shown on each of the Palaeozoic small Earth models define the ancient land surfaces (supercontinents) as well as a network of continental seas surrounding the emergent lands. These emergent lands equate to the conventional Rodinia, Gondwana and Pangaean supercontinental assemblages. see: The network of seaways shown on each small Earth model is shown to be coincident with the distribution of continental sedimentary basins.

For more information see elsewhere on this website.