Main Tectonic Features of North Pacific Mobile Belt1
Published:January 01, 1973
B. Kh. Egiazarov, B. V. Ermakov, V. A. Vakar, N. G. Zagorskaya, G. I. Kameneva, T. N. Kopylova, E. M. Litvinov, G. K. Pichugina, N. P. Anikeyev, I. E. Drabkin, V. A. Titov, D. E. Gershanovich, M. I. Itsikson, V. I. Berger, 1973. "Main Tectonic Features of North Pacific Mobile Belt", Arctic Geology, Max G. Pitcher
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The Koryak-Kamchatka-Kuril and Alaska-Aleutian areas form the northern part of the Pacific mobile belt (Pacifides). The Koryak-Kamchatka-Kuril system represents the polycyclic migration areas of eu-and miogeosynclinal style of development and the general migration of géosynclinal systems (Mesozoides, Cenozoides, modern Kuril geosyncline) in a southeast direction from the continent to the ocean. This migration is emphasized by a system of reentrant angles formed by the intersection of zones of deep-seated faults which border the geosynclines. The bisectors of the reentrant angles show the general direction of migration of the géosynclinal processes which occurred along and across the general trend of the area.
The Alaska-Aleutian area represents the polycyclic type of eu- and miogeosynclinal development. The migration of the géosynclinal processes occurred along the Cordilleran belt (early Mesozoides, late Mesozoides, modern Aleutian geosyncline). The fact that géosynclinal formations synchronous to the Cenozoides of the Olyutorskiy-East Kamchatka system are absent in Alaska reflects the asymmetric structure of the northern part of the Pacifides. The character of the junction of the Aleutian arc with the Kamchatka Cenozoides (through the Komandorskiy Islands) in the west and with the Alaska Mesozoides in the east also shows the asymmetry. The development of the géosynclinal systems of the northern part of the eastern Asian-coastal Pacific zones is mainly associated with tensional tectonic movements. Systems of North America have compressional movements. This fact is confirmed by the structural-formational and tectonic-magmatic features of the de-velopment of the géosynclinal systems of the northern part of the Pacific belt.
The fold systems of the adjoining areas of the Arctic mobile belt (Arctides)—North Alaska and Novosibirsk-Chukofsk—join the Pacifides along the zone of the Mackenzie-Lena deep-seated faults. The systems are characterized by monocyclic and miogeosynclinal types of development.
The metallogenic character of the Pacifides and adjoining Arctides is one of diverse late Mesozoic and Cenozoic ores (gold, mercury, copper, and polymetals, and tin and tungsten—in the Arctides especially); low-temperature ores prevail. It may be assumed that the possible oil and gas basins of Arctic Canada, North Alaska, the Chukotsk Peninsula, and the Chukchi and East Siberian Seas compose a single hydrocarbon belt timed tectonically to the Arctides. The existence of a North Pacific belt of oil and gas accumulations, including the oil and gas basins of the Kamchatka-Koryak and the Cordilleran-Alaska areas, is also assumed.
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Following the discovery of Prudhoe Bay oil field in 1968, much attention was turned to the Arctic in the search for giant hydrocarbon accumulations. The Soviets had already proved giant reserves in their West Siberian Basin, and exploration was moving ahead quickly in the Canadian Arctic. Plans were drawn up for an AAPG Symposium on Arctic Geology and held in February 1971. Papers were selected from the Symposium for this publication and cover seven topical groupings: Regional Arctic Geology of Canada, Regional Arctic Geology of the Nordic Countries, Regional Arctic Geology of the USSR, Regional Arctic Geology of Alaska, Comparisons in the North Atlantic Borders, Evolution of the Arctic Ocean Basin, and Economics of Petroleum Exploration and Production in the Arctic.