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Lessons learned while playing with the Arctic plate tectonic puzzleтезисы доклада
- Авторы: Skogseid J., Meisling K.E., Miller E.L., Nikishin A.M.
- Сборник: American Geophysical Union (AGU) 2013 Fall Meeting
- Серия: Proceedings of AGU Fall Meeting
- Том: 1
- Тезисы
- Год издания: 2013
- Издательство: American Geophysical Union
- Местоположение издательства: United States
- Первая страница: 04
- Аннотация: The plate tectonic evolution of the Amerasia Basin in the Arctic Ocean is controversial, and a number of models have been suggested in which the common denominator is that they are all poorly constrained. In general the Canada Basin and the Makarov-Podvodnikov Basin, are separated by the Alpha-Mendeleev Ridge, which has a bathymetric and geophysical signature indicating either over-thickened oceanic crust or magmatically overprinted continental fragments. Both interpretations imply that the ridge has a connection to the High Arctic Large Igneous Province probably associated with a mantle plume emplacement beneath the lithosphere, causing excess magmatism in the region starting at about 125 Ma. It is widely accepted that the ';windshield wiper' model of Lawver et al. (2002) is applicable for the Canada Basin proper, yet it is still debated whether the boundary transform is located close to the Lomonosov Ridge, beneath the Alpha-Mendeleev Ridge, or on the Alaskan side of the Chukchi Borderland and Northwind Ridge. It remains a major uncertainty where large offset regional shear zones required by some models could be hidden beneath the Arctic continental shelves and how they were linked into the South Anhui Paleo-Ocean. The approach taken in this study is to dissect the Chukotka terranes, formed by long-lived compressional tectonism associated with the Pacific subduction system, to explore different scenarios for South Anhui Ocean evolution and consider potential Paleo-Pacific driving mechanisms for Amerasia Basin opening. The Chukotka terranes represent a complex of magmatic and sedimentary units younging towards the subduction zone, thus allowing restoration by ';undocking' them one by one. The remaining elements of the Alaskan and Siberian shelves are subsequently linked to conjugate elements on the North American and Eurasian plates based on correlation of geochemical and stratigraphic ';tie-points'. The study utilizes available geological markers, crustal cross sections, gravity and magnetic data, and mantle tomography models, seeking to discover pros and cons for different plate tectonic scenarios, with the ultimate goal of a unified model.
- Добавил в систему: Никишин Анатолий Михайлович