The Scientific Case for EXPANSION TECTONICS

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PACIFIC OCEAN


The Pacific Ocean occupies nearly half the surface area of the Earth and can be arbitrarily subdivided into North Pacific, Central Pacific, and South Pacific Ocean regions. In all plate tectonic reconstructions, the precursor to the Pacific Ocean was a much larger ancient Panthalassa Ocean. This largely hypothetical early-Mesozoic Panthalassa Ocean is inferred to have possessed an old seafloor crust, which was formed by spreading along ancient mid-ocean-ridge zones during the Palaeozoic Era—the era prior to the Mesozoic Era—extending into the Triassic Period.


On all plate tectonic reconstructions, the North American continent progressively overrides the eastern North Pacific Ocean region. This supposedly occurs during a westward displacement of the North American continent during opening of the North Atlantic Ocean. The North Pacific Ocean spreading ridge is then inferred to have been entirely overridden and subsequently dislocated beneath the Pacific margin of the North American continent.


North Pacific Ocean Expansion Tectonic small Earth spreading history, extending from the present-day back to the early-Jurassic.


In contrast, on an Expansion Tectonic Earth an expansive pre-Mesozoic Panthalassa Ocean, and similarly an ancient Tethys Ocean, did not exist. Subduction of between 5,000 to 15,000 lineal kilometres of pre-existing East Pacific seafloor crust beneath the American continent is also not required. The Pacific Ocean is instead shown to originate during early-Jurassic times as two separate marine sedimentary basins. A North Pacific basin was located between northwest Australia, Canada, and China, and a South Pacific basin was located between east Australia, South America, New Zealand and Antarctica.


South Pacific Ocean Expansion Tectonic small Earth spreading history, extending from the present-day back to the early-Jurassic.


Both of these marine basins progressively opened to the south and north, along the west coasts of North and South America respectively. These basins then merged to form a single Pacific Ocean basin during the mid- to late-Jurassic Period. Remnants of this early basin history are now preserved as continental margin and marine plateau sediments within the South East Asian and Coral Sea regions—shown as white areas.


On an Expansion Tectonic Earth, the subsequent evolution of the North and South Pacific Oceans involved a period of rapid northeast to southwest crustal extension and opening between North America, South America, and Australia. By the late-Jurassic, a deep ocean had extended southeast and south along the west coasts of North and South America. This coincided with the initiation, exposure, and preservation of new volcanic seafloor crust in the South Pacific Ocean.


Throughout the Mesozoic Era the North Pacific Ocean underwent a very rapid enlargement, with spreading axes extending southeast into the South Pacific region. This spreading and mid-ocean-ridge development curved along the west coasts of North and South America and extended west into the Coral Sea region during the Cretaceous.


During the mid- to late-Jurassic, crustal rifting and opening between New Zealand, New Caledonia, South America, Australia, and Antarctica isolated the Coral Sea plateau, as well as the Lord Howe Rise and New Zealand. This rifting phase then left New Zealand as an island continent, which has remained isolated from surrounding continents to the present-day.


Development of the Pacific Ocean on an Expansion Tectonic Earth during the Cenozoic Era is characterised by the initiation and rapid development of symmetric-style seafloor spreading. This initially commenced in the Tasman Sea region, located southeast of Australia, during the Paleocene and continued to extend east towards South America during the Eocene. From there spreading continued north, forming the present East Pacific spreading ridge, then continued along the west coast of North America to its present location adjacent to California to Alaska.


The opening and formation of the Pacific Ocean on an Expansion Tectonic Earth differs slightly to each of the other oceans. Because of the long period of time involved in opening the Pacific Ocean, the large area of older seafloor crust in the North Pacific region has been subject to considerable crustal stretching and distortion as a result of the changing surface curvature of the Earth. This changing surface curvature is generally absorbed as extension within the thin seafloor crust, but it also gave rise to complex plate interaction and jostling between and along adjoining plates, in particular between the various seafloor and continental plate margins.


Between the North Pacific Ocean plate and the Australian, South East Asian, and Chinese plates, complex crustal interaction has also given rise to the South East Asian island-arc-trench systems, which are now characteristic of the western Pacific region. On an Expansion Tectonic Earth, this region represents a complex interplay of plate motions that were generated during on-going adjustments to surface curvature, especially within the older North Pacific Ocean region.