Polyorogenic history of the East Greenland Caledonides

• Main Authors: Kalsbeek, Feiko, Thrane, Kristine, Higgins, A K, Jepsen, H, Leslie, A, Nutman, Allen, Frei, Robert
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Geological Society of America
• Subjects: Keywords: Archean; Caledonian orogeny; deformation mechanism; foreland basin; geochemistry; geochronology; metamorphism; metasedimentary rock; orogeny; orthogneiss; overprinting; Proterozoic; structural geology; tectonic evolution; thrust fault; Arctic; East Greenl Caledonian orogen; East Greenland; Grenvillian granites; Mesoproterozoic supracrustal rocks; Paleoproterozoic basement; Greenland
• Online Access: http://hdl.handle.net/1885/82557; https://openresearch-repository.anu.edu.au/bitstream/1885/82557/5/Nutman_2008_polyorogenic_Caledonides.pdf.jpg; https://openresearch-repository.anu.edu.au/bitstream/1885/82557/7/01_Kalsbeek_Polyorogenic_history_of_the_2008.pdf.jpg

The Caledonian orogen of East Greenland contains remnants of Archean, Paleoproterozoic, late Mesoproterozoic, and early Neoproterozoic rocks that occur within far-traveled thrust sheets, and bear witness to a complex polyorogenic history of the region prior to Caledonian orogenesis. Archean and Paleoproterozoic complexes consist mainly of granitoid orthogneisses. A succession of Paleoproterozoic tholeiitic metabasalts is present in some of the foreland windows. A major unit of late Mesoprotero zoic metasedimentary rocks (Krummedal supracrustal sequence) contains early Neoproterozoic (ca. 950 Ma) as well as Caledonian granites. There is evidence for Archean (ca. 2800-2600 Ma), Paleoproterozoic (2000-1750 Ma), and late Grenvillian (ca. 950 Ma) deformation and metamorphism, but Caledonian overprinting complicates the study of these events. This paper presents a broad overview of the various rock units with structural, geochemical, and geochronologic data. The Paleoproterozoic metabasaltic rocks from the foreland windows are described in more detail.