This review of the chiefly magmatic Tertiary rocks in the central parts of East and West Greenland shows that the most abundant magmas were tholeiitic, and the most primitive magmas probably formed the picrites of West Greenland. The voluminous quartz tho-leiites are very similar in composition to those of other plateau-basalt areas. Present in smaller amounts are alkalic basalt and nephelinitic types. The predominant salic magma was a nordmarkite, which differentiated to foyaite and peralkaiic granite. Stratigraphic and radiometric evidence shows that magmatic activity was limited to the Paleocene and Eocene, and indicates that the lava was extruded at roughly the same rate as were postglacial Icelandic lavas. Tectonism was characterized by uplift of continental b!ocks and subsidence of adjoining areas. The abundant tholeiitic volcanism was associated with early rifting in the Paleocene, whereas the production of alkalic rock types probably occurred after the area had migrated away from the most active zone.
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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.