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The Wilson Cycle:
As the concept of sea floor spreading gained acceptance in the late 60's, the consequences for geology gradually began to dawn. One of the first to recognise how plate tectonics could be applied to the geological record was J. Tuzo Wilson. If continents rift apart to form ocean basins, other oceans must close to provide space. This opening and closing cycle is known as the Wilson Cycle: |
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(1) Rifting of continents by mantle diapirism
(2) Continental drift, seafloor spreading & formation of ocean basins
(3) Progressive closure of ocean basins by subduction of ocean lithosphere
(4) Continental collision and final closure of ocean basin
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The two diagrams below illustrate some simple concepts of continental rifting at the start of the Wilson Cycle. Uprising plume causes doming of crust with magma chamber developing underneath. As extension continues, an ocean basin forms, and thick sedimentary sequences develop at continental margins as rivers dump sediments in deep water. However in reality may be a bit more complex . . . |
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| From Tarney, Leicester Uni. |
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