Paleogeographic evolution of earth: 180 my ago to present
A series of paleogeographic maps at 20-m.y. intervals (conformal mercator and stereographic projections such that the whole earth is displayed) from 180 m.y. ago to the present are produced with the continents placed in their correct relative positions using sea-floor spreading data and initial cont...
| Other Authors: | , , |
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| Format: | Article in Journal/Newspaper |
| Language: | English |
| Subjects: | |
| Online Access: | http://n2t.net/ark:/85065/d70k28c0 |
| Summary: | A series of paleogeographic maps at 20-m.y. intervals (conformal mercator and stereographic projections such that the whole earth is displayed) from 180 m.y. ago to the present are produced with the continents placed in their correct relative positions using sea-floor spreading data and initial continental reconstructions. The absolute location of the reconstructions with respect to the spin axis of the earth is based on averaged paleomagnetic pole positions. The locations of past shoreline positions are based on comprehensive regional paleogeographic analyses. There remain aspects of the reconstructions which are controversial because data do not constrain the models. In addition to providing maps of land-sea distribution through time, the global paleogeographic analysis has several additional interesting results including: (1) a discrepancy in the tectonic evolution of the North Atlantic which is not evident from regional analyses; (2) a revised interpretation of the evolution of the Arctic Ocean; (3) latitudinal variations in land area with important implications for Mesozoic-Cenozoic paleoclimatology; and (4) evidence relating the distribution of evaporites and carbonates to sea level and the distribution of shallow seas, rather than the displacement of climatic zones. |
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