Geological Survey of Denmark and Greenland Bulletin 6, 1-4 1 GEOLOGICAL SURVEY OF DENMARK AND GREENLAND BULLETIN 6 · 2004 East Greenland Caledonides: stratigraphy, structure and geochronology Edited by A.K. Higgins and Feiko Kalsbeek GEOLOGICAL SURVEY OF DENMARK AND GREENLAND MINISTRY OF THE ENVIRONMENT GEUS Bulletin 6.pmd 10-02-2005, 09:531 2 Geological Survey of Denmark and Greenland Bulletin 6 Keywords Caledonides, East Greenland, geochronology, stratigraphy, structure. Cover West-dipping white and rusty brown quartzites of the Lower Cambrian Slottet Formation, at Slottet in the Eleonore Sø foreland window, resting unconformably on dark clastic sediments of the Palaeoproterozoic Eleonore Sø complex. The summit of Slottet (1933 m high) is 600 m above the glacier surface. Chief editor of this series: Adam A. Garde Scientific editors of this volume: A.K. Higgins and Feiko Kalsbeek Editorial secretaries: Esben W. Glendal and Birgit Eriksen Critical readers: Arild Andresen (Norway), Brian Chadwick (UK), Lars Clemmensen (Denmark), Clark R.L. Friend (UK), David G. Gee (Sweden), John S. Peel (Sweden), John E. Repetski (USA), Minik Rosing (Denmark), Rob Strachan (UK) and Martin Whitehouse (Sweden) Illustrations: Helle Zetterwall Digital photographic work: Benny M. Schark and Jakob Lautrup Graphic production: Knud Gr@phic Consult, Odense, Denmark Printers: Schultz Grafisk, Albertslund, Denmark Manuscripts submitted: 10 November 2003 Final versions approved: 9 June – 14 September 2004 Printed: 30 December 2004 ISBN 87-7871-148-7 Geological Survey of Denmark and Greenland Bulletin The series Geological Survey of Denmark and Greenland Bulletin replaces Geology of Denmark Survey Bulletin and Geology of Greenland Survey Bulletin. Citation of the name of this series It is recommended that the name of this series is cited in full, viz. Geological Survey of Denmark and Greenland Bulletin. If abbreviation of this volume is necessary, the following form is suggested: Geol. Surv. Den. Green. Bull. 6, 93 pp. Available from Geological Survey of Denmark and Greenland (GEUS) Øster Voldgade 10, DK-1350 Copenhagen K, Denmark Phone: +45 38 14 20 00, fax: +45 38 14 20 50, e-mail: geus@geus.dk or Geografforlaget ApS Rugårdsvej 55, DK-5000 Odense C, Denmark Phone: +45 63 44 16 83, fax: +45 63 44 16 97, e-mail: go@geografforlaget.dk © Danmarks og Grønlands Geologiske Undersøgelse (GEUS), 2004 GEUS Bulletin 6.pmd 10-02-2005, 09:532 3 Contents Preface A.K. Higgins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Lower Palaeozoic stratigraphy of the East Greenland Caledonides M.P. Smith, J.A. Rasmussen, S. Robertson, A.K. Higgins and A.G. Leslie . . . . . . . . . . . . . . . . . . . . . . . . . 5 The Neoproterozoic Rivieradal Group of Kronprins Christian Land, eastern North Greenland M.P. Smith, A.K. Higgins, N.J. Soper and M. Sønderholm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 The Caledonian thin-skinned thrust belt of Kronprins Christian Land, eastern North Greenland A.K. Higgins, N.J. Soper, M.P. Smith and J.A. Rasmussen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Palaeoproterozoic age of a basement gneiss complex in the Charcot Land tectonic window, East Greenland Caledonides K. Thrane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 Reconnaissance Pb-Pb dating of single mineral phases by the step-leaching method: results from the Caledonides of East Greenland K. Thrane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 The Eleonore Sø and Målebjerg foreland windows, East Greenland Caledonides, and the demise of the ‘stockwerke’ concept A.K. Higgins and A.G. Leslie . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 GEUS Bulletin 6.pmd 10-02-2005, 09:533 4 Preface The East Greenland Caledonides extend from 70° to 81°30′N, and have been the subject of a series of re- gional mapping programmes between 1968 and 1998. The entire orogen is now covered by five published 1:500 000 geological map sheets. The six papers in this bulletin concern a variety of topics relating mainly to Kronprins Christian Land (79°–81°30′N) and the Kong Oscar Fjord region (72°–75°N). The paper by Smith et al. on Lower Palaeozoic strati- graphy proposes amendments to several stratigraph- ical units that occur in Kronprins Christian Land and nearby Lambert Land. In the Kong Oscar Fjord re- gion, two new formations are defined for quartzite and limestone/dolostone units that crop out in fore- land windows, and the Lower Palaeozoic succession of the fjord region of East Greenland is formally placed in the Kong Oscar Fjord Group. The second paper by Smith et al. describes and formally defines the Neo- proterozoic Rivieradal Group of Kronprins Christian Land. The paper by Higgins et al. analyses the thin- skinned fold-and-thrust belt that marks the transition between foreland and orogen in Kronprins Christian Land, and presents a balanced cross-section restora- tion. The two geochronological papers by Thrane report the results of ion microprobe zircon analyses from orthogneisses in the Charcot Land window (72°N), and results of reconnaissance Pb-Pb dating by the step- leaching method. The final paper by Higgins & Leslie reviews the history of geological research in the Eleonore Sø and Målebjerg areas of the Kong Oscar Fjord region (72°– 75°N). Recognition that the two areas are part of the Caledonian foreland implies that the two thrust sheets structurally overlying the Eleonore Sø and Målebjerg windows have large displacements (~ 100 km each), and that the ‘stockwerke’ concept of the orogen that focused on in situ vertical movements can finally be laid to rest. A.K. Higgins GEUS Bulletin 6.pmd 10-02-2005, 09:534