Pre-Quaternary History of North Greenland: Regional Arctic Geology of the Nordic Countries

摘要: In North Greenland, the crystalline basement is unconformably overlain by a late Precambrian to early Paleozoic sedimentary sequence. The Inuiteq So Formation, containing conspicuous basic intrusions, at least 1,000 m.y. old; youngest dated strata are Middle Late Silurian. A southern platform sequence of unmetamorphosed homoclinal passes northward into east-west-trending Greenland fold belt, in which mainly Cambrian Silurian rocks exposed. western upper part section reef complex showing facies changes between carbonate and offreef argillaceous rocks. eastern Peary Land, folded lower beds underlie cover less severely deformed Pennsylvanian, Permian, Triassic, Cretaceous-Tertiary show effects Tertiary deformation. northern metasedimentary units have been transported over Kap Washington Group bedded lavas tuffs along Cannon thrust. These volcanic given minimum K-Ar age 35 where widest belt exposed, five tectonic-metamorphic zones recognized; deformational metamorphic increase northward. subjected Phanerozoic-Paleozoic tectonic history. orogenesis (Late Devonian) involved polyphase deformation produced three essentially coaxial phases. Rocks affected these phases folding overturned toward highest grade rocks, Land contain amphibolitefacies assemblages. Cretaceous ages suggest subsequent thermal event regional importance. indicated evidence folding, thrusting, regiona faulting, mylonitization low-grade metamorphism associated with