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The hierarchical plate hypothesis of geologic history includes the concept that the North American continental block has been circling the Pacific Basin plate in a counterclockwise sense and rotating in the same sense, with an approximate period of 109 years. Implications inherent in the hypothesis, for comparison with the actual history of North America during its latest 109 years of development, include the following.
Continental glaciation about 109 years ago; warming during late Precambrian. Tropical during Paleozoic; much carbonate deposition; widespread coal in late Paleozoic. Cooling during Mesozoic and Cenozoic, climaxing in new glaciation.
2. Appalachian Mountains:
Left lateral movement plus compression during Paleozoic. Right lateral movement plus tension during Mesozoic and Cenozoic.
Developed initially about end of Paleozoic--beginning of Mesozoic. Strike-slip margins on north and south.
4. Gulf of Mexico:
Tensional feature; developed initially about end of Paleozoic-beginning of Mesozoic.
Major drainage toward south (ambient coordinates), producing very large sediment volumes in Gulf of Mexico.
Shifting location toward north and east, from Texas into Louisiana, due to continental rotation during post-Paleozoic.
7. Stream patterns:
Reorientation, due to continental rotation, through Mesozoic and Cenozoic in clockwise sense for first-order drainage, counter-clockwise for second-order drainage in mid-continent area; much piracy.
8. Eastern and western margins:
Lateral shrinking subsidence, and formation of north-south grabens, during post-Paleozoic.
Dikes, plugs, volcanoes, and salt domes (where salt was available) along western, southern, and eastern margins, during Mesozoic and Cenozoic.
10. Probable geosyncline:
Short-lived, late Paleozoic age; near southern edge of continent; orientation now northeast-southwest.
These predictions compare favorably with the actual history of the continent.
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