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A Reconstruction of the Depositional History and Palaeoenvironment of the Plio-Pleistocene of Northeast Iceland

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A Reconstruction of the Depositional History and Palaeoenvironment of the Plio-Pleistocene of Northeast Iceland FACULTY OF SCIENCES A reconstruction of the depositional history and palaeoenvironment of the Plio-Pleistocene of northeast Iceland A combined terrestrial and marine palynological approach Koen Verhoeven Thesis submitted in partial fulfilment to achieve the degree of Doctor in Sciences, Geology Academic year 2011-2012 Ghent University Faculty of Sciences, Department of Geology and Soil Sciences Research Unit Palaeontology Krijgslaan 281, S8, WE 13, B-9000 Ghent, Belgium Promotor: Prof. Dr. Stephen Louwye Co-promotor: Prof. Dr. Jacques Verniers Members of the reading committee: 1. Prof. dr. Jacques Verniers (Ghent University) 2. Prof. dr. Jón Eiríksson (University of Iceland; University of Copenhagen, Denmark) 3. Prof. dr. David Van Rooij (Ghent University) 4. Dr. Stijn De Schepper (University of Bergen, Norway) Members of the examination committee: 1. Prof. dr. Stephen Louwye (Ghent University) – Promotor 2. Prof. dr. Jacques Verniers (Ghent University) – co-promotor 3. Prof. dr. Peter Van den haute (Ghent University) – chairman 4. Prof. dr. David Van Rooij (Ghent University) 5. Dr. Jan De Coninck (Ghent University) 6. Prof. dr. Etienne Steurbaut (Royal Institute for Natural Sciences; Catholique University of Leuven) 7. Prof. dr. Jón Eiríksson (University of Iceland; University of Copenhagen, Denmark) 8. Dr. Stijn De Schepper (University of Bergen, Norway) Public thesis defence: Thursday, December 20th 2012 at 4.00 p.m., Ghent University, Auditorium A3, S9, Krijgslaan 281, 9000 Ghent To refer to this thesis: Verhoeven, K. 2012. A reconstruction of the depositional history and plaeoenvironment of northeast Iceland: a combined terrestrial and marine palynological approach. PhD thesis, Ghent University, Belgium, 192 pp. The autor and the promotor give the authorization to consult and copy parts of this work for personal use only. Every other use is subjected to copyright laws. Permission to reproduce any material contained in this work should be obtained from the author. Front cover: Picture taken by the author in september 2007 in Tungubakkar on the eastcoast of the Skjálfandi Bay, northeast Iceland. The picture gives a view of the coastal cliffs of the Tjörnes Peninsula in the direction of Höskuldsvík. The marine sediment of the Serripes Zone are visible and have a NW dip. TABLE OF CONTENTS Table of Contents Acknowledgements ....................................................................................................................................... 7 List of figures, tables and plates ..................................................................................................................... 11 Preface .......................................................................................................................................................... 15 1. Introduction: Tjörnes and Flatey as key localities to understand Plio-Pleistocene cooling in the northern hemisphere ................................................................................................................................................... 19 1. Geology .................................................................................................................................................... 19 1.1 Tectonic framework ................................................................................................................................ 19 1.2 Stratigraphy of the Tjörnes section ........................................................................................................ 22 2. �������The geo�og�������ca� ti������e per�o st������e ����������������������������������������������������������������������������������������������������������.......................................................................................................... 24 3. Area of �nterest an pa�aeoceanography ................................................................................................. 26 4. �����������������������������������������������������������������������������������������������������������������������������������������������������������alynology ................................................................................................................................................ 29 4.1 ��no���age��������������������������������������������������������������������������������������������������������������������������������������������ate cysts ................................................................................................................................ 29 4.1.1 Eco�og�ca� s�gn�ficance ......................................................................................................................... 29 4.1.2 �����������reparation� ����etho ............................................................................................................................ 31 4.2 �o�������en an Spores������������������������������������������������������������������������������������������������������������������������������������������ ................................................................................................................................... 32 4.2.1 Eco�og�ca� s�gn�ficance ......................................................................................................................... 32 4.2.2 �����������reparation� m��������etho ����������������������������������������������������������������������������������������������������������������������������............................................................................................................................ 33 5. ������������egetation �o er��e �n �ce�an fro��������� the ������e ��ocene���������������������������������������������������������������������� to recent ...................................................... 33 6. ���re��o�����s pa�yno�og������������������ca� s.s. research ��������������n the Tjörnes �en�ns����������������������������������������������������������������������a .................................................................. 35 7. ��ants fro� the Tjörnes section no �onger present on �ce�an ................................................................ 37 8. Rationa�e of the st�y .............................................................................................................................. 38 2. A new age model for the Pliocene-Pleistocene Tjörnes section on Iceland: Its implication for the timing of North Atlantic-Pacific palaeoceanographic pathways ..................................................................................... 39 Abstract ........................................................................................................................................................ 39 1. �ntro�ction ............................................................................................................................................. 39 2. Geo�og�ca� setting an pre��o�s age �oe�s for the Tjörnes section ....................................................... 42 2.1 Geo�og�ca� setting ................................................................................................................................... 42 2.2 �a�aeo�agnetic st��es an ex�sting age �oe�s for the Tjörnes section ............................................. 43 3. �ater�a�s an �ethos ............................................................................................................................ 48 4. Res��ts ...................................................................................................................................................... 50 4.1 General ................................................................................................................................................... 50 4.2 Stratigraph�ca��y s�gn�ficant �noage��ate cysts ..................................................................................... 53 4.2.1 Tjörnes bes ........................................................................................................................................ 53 4.2.2 Bre�a�ík Gro�p: Hörg� For�ation ...................................................................................................... 54 4.2.3 Bre�a�ík Gro�p: S�artha�ar �e�ber (Threng�ngar For�ation) an Torfhó�� �e�ber (�áná For- �ation) ......................................................................................................................................................... 56 5. ��sc�ss�on ................................................................................................................................................ 57 5.1 Ne age �oe� for the Tjörnes section ................................................................................................. 57 5.1.1 ��noage��ate cyst ata ....................................................................................................................... 57 5.1.2 A ne corre�ation of the pa�aeo�agnetic ata ................................................................................... 57 5.1.3 K/Ar ate �a�a �ayers .......................................................................................................................... 60 5.2 Age �oe� co�par�son ........................................................................................................................... 60 5.3 Corre�ation �th other North At�antic �n�ts ........................................................................................... 61 5.4
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