Ancient Geography The ancient geography of the Earth forms the basis for defining the inter-relationships of exposed continents, intervening seaways, mountains and crustal movements, and enables the conventional Pangaea, Gondwana, Laurentia, Baltica, Laurussia and Rodinia supercontinents to be quantified on an Expansion Tectonic Earth. The ancient coastlines, when plotted on Expansion Tectonic models, show that large Panthallassa, Tethys and Iapetus Oceans are not required during reconstruction. This is because on an Expansion Tectonic Earth all modern oceans are removed and continents are assembled as a single continental crust. These inferred oceans are instead replaced by smaller Panthallassa, Tethys and Iapetus Seas located on or between the ancient continents. The early Panthallassa and Iapetus Seas developed during the Early Permian to Early Jurassic periods (260 to 165 million years ago) and initiated as shallow sedimentary basins within the present north-west Pacific and North Atlantic Ocean regions respectively. These then progressively opened and extended throughout the Mesozoic and Cenozoic Eras as the modern Pacific and Atlantic Oceans. In contrast, the Tethys Sea had its origins during the Early Precambrian Era as a continental sea located within what is now Europe and Asia. This sea then progressively enlarged and extended in area during the Precambrian, Paleozoic and Mesozoic Eras during crustal extension and subsequent opening of the modern oceans. Changes in sea-level on an Expansion Tectonic Earth is then shown to occur in response to climatic change, as well as a shift in the distribution of continental seas, to crustal movements, mountain building, erosion, opening of the post-Permian modern oceans and production of new water at the mid-ocean-ridges. These changes all modified the ancient coastal outlines and resulted in a change in the exposed continental land areas. This is confirmed by the distribution of climate-dependant sedimentary rocks such as limestone reefs, and the distribution of climate-dependant marine and terrestrial fossil species. Reconstructions of the conventional Pangaea, Gondwana and Rodinia supercontinents and smaller sub-continents on an Expansion Tectonic Earth demonstrate that, instead of being the result of random dispersion-amalgamation or collisional events, each continental assemblage is progressive, and represents an evolutionary crustal-forming process. The distinguishing feature of continents constructed on each Expansion Tectonic model is the inter-relationship of continental sedimentary basins, the network of continental seas and network of crustal movements. The variation of each of these in time has resulted in changes to the distribution of exposed continental land. Supercontinent configuration is then defined by a progressive extension of continental sedimentary basins, by ongoing crustal movements, and changes in sea-levels as the modern oceans opened and rapidly increased in area to the present-day.
Posted on: Mon, 11 Nov 2013 12:30:34 +0000
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