Sedimentology and facies distribution of the Upper Triassic De Geerdalen Formation in the Storfjorden area and Wilhelmøya, eastern Svalbard Sondre Krogh Johansen Petroleum Geosciences Submission date: June 2016 Supervisor: Atle Mørk, IGB Co-supervisor: Snorre Olaussen, UNIS Norwegian University of Science and Technology Department of Geology and Mineral Resources Engineering Abstract This study investigates sediments of the Upper Triassic De Geerdalen Formation, as it is exposed on eastern Svalbard. The De Geerdalen Formation was deposited during the Early Carnian to Early Norian, on the distal area of a shallow embayment on the northern margin of Pangea. It includes a wide range of depositional environments, ranging from offshore shallow marine, paralic delta front and shoreface to coastal plain environments. The aim of the study is to document and interpret the sedimentology of the formation and the spatial and temporal evolution of depositional environments, through detailed facies analysis. Fifteen facies and eight facies associations have been defined based on observations and outcrop data. These data were collected during a one-month field season in 2015 on eastern Spitsbergen, western Barentsøya and on Wilhelmøya. The interpretation presented here is based on previous research in neighbouring areas, as well as cooperation with other master students. From the measured sections, a strong fluvial dominance is observed on the northern part of Barentsøya and interpreted to reflect a proximal position to an eastern source compared to exposures further west and north. Waves and tides become increasingly dominant towards the west, particularly in the outcrops in the Agardhbukta area and represent more distal and transitional environments compared to the succession in the eastern exposures. The succession on eastern Spitsbergen and Wilhelmøya is mostly dominated by tidal and wave processes and reflect more distal depositional environments compared to the southern and eastern part of the study area. The De Geerdalen Formation shows a typical development of multiple coarsening upwards sequences that constitute parasequences normally associated with regressive depositional systems. i ii Sammendrag Denne oppgaven undersøker avsetninger av øvre trias alder tilhørende De Geerdals- formasjonen slik den er blottet på østre Svalbard. De Geerdals-formasjonen ble avsatt mellom tidlig karn og tidlig nor på den distale enden av en grunn bukt på den nordlige kanten av Pangea. Formasjonen omfatter et bredt spekter av avsetningsmiljø fra utaskjærs marine miljø og grunnemarin, paraliske delta front avsetninger til strandskråning og kystnære avsetningsmiljø. Målet med studiet er å dokumentere og tolke sedimentologien av formasjonen, samt den romlige og tidsmessige utviklingen av avsetningsmiljøene gjennom detaljert facies analyse. Femten facies og åtte facies assosiasjoner har blitt definert med grunnlag i observasjoner av sedimentene og blotningsdata. Observasjonene ble samlet inn i løpet en felt-sesong med en måneds varighet i 2015, på Spitsbergen, vestlige deler av Barentsøya og på Wilhelmøya. Tolkningen som presenteres her er basert på tidligere forskning i nærliggende områder, samt samarbeid med andre masterstudenter. Fra de målte seksjonene er en sterk fluvial dominans under avsetning observert på den nordlige delen av Barentsøya og tolket til å reflektere en proksimal posisjon til en østlig kilde. Bølger og tidevanns-prosesser blir stadig mer dominerende mot vest, spesielt i blotninger i området Agardhbukta og avsetningene representerer distale overgangs-miljøer sammenlignet med tilsvarende blotninger i østlige områder. Lagrekka på østlige deler av Spitsbergen og på Wilhelmøya er for det meste dominert av bølge- og tidevannsprosesser og reflekterer distale avsetningsmiljøer i forhold til den sørlige og østlige delen av studieområdet. De Geerdals- formasjonen viser en typisk utvikling av flere oppgrovende sekvenser som samlet danner parasekvenser som vanligvis assosieres med regressive avsetningssystemer. iii iv Acknowledgements I would like to start this master thesis by extending my sincere and heartfelt thanks to my supervisor Atle Mørk, Professor II at NTNU without whom, I would not be able to partake in such an interesting and exciting project. Throughout the last year I have benefited from his broad experience, as well as his patience and encouragement. His honest and constructive feedbacks and thorough manuscript reviews have helped improve the quality of this thesis tremendously ever since the first, early drafts. I would also like to acknowledge my secondary supervisor at the University Centre in Svalbard (UNIS), Professor Snorre Olaussen. My understanding of the Jurassic succession in Svalbard and in arctic petroleum geology has benefited greatly from his experience on the subject. He has also helped facilitate my position as a guest master student at UNIS, making fieldwork in Svalbard and logistical support from UNIS possible. Thanks to UNIS for logistical support and for providing me with an office space during my stay in Longyearbyen. Fieldwork on eastern Svalbard would not have been possible without the generous financial support from several institutions. Svalbard Science Forum (SSF) gave support through the Arctic Field Grant. The Norwegian Petroleum Directorate (NPD) and Capricorn AS are thanked for their generous financial support, allowing the use of the vessel M/V Sigma and enabled us to visit a great number of localities Simen Jenvin Støen and Turid Haugen have been great partners, both if the field and in the office, and they have put their signature on this thesis in more than one way. Thank you for the great cooperation throughout this last year. Thanks are also forwarded to my friend and colleague PhD-candidate Gareth Steven Lord for great discussions, and helpful advice, both personal and scientific. A special thanks to my friends and fellow master students Bård Heggem, Cathinka Schaanning Forsberg and Nina Bakke for excellent cooperation and assistance in the field. Last, but not least, I would like to thank my parents and my siblings for all their encouragement and support throughout my life. v vi Preface This thesis is part of a master`s degree in petroleum geology at the Department of Geology and Mineral Resources Engineering (IGB) at the Norwegian University of Science and Technology (NTNU). The thesis is supported by a project work, equivalent to 15 ECTS conducted during the fall of 2015. The topic of the project was the stratigraphy of the Triassic to mid-Jurassic succession of eastern Svalbard. The main supervisor for this thesis has been Professor II Atle Mørk at NTNU. Secondary supervisor has been Professor Snorre Olaussen at the University Centre in Svalbard (UNIS). Chapter 1 (Introduction), Chapter 2 (Regional geologic setting) and Chapter 3 (Stratigraphy of the Triassic to mid-Jurassic succession) are adapted in its entirety from the project work with only minor alterations. Chapter 4 (Methods) outlines the study area and methodology of fieldwork. Chapter 5 (Facies) and Chapter 6 (Facies Associations) are written in collaboration with fellow master students at NTNU and UNIS, Turid Haugen and Simen Jenvin Støen. The facies scheme presented here is inspired by research started in 2007-2009 and partially extended with the definition of sub-facies associations. Chapter 7 (Results and interpretations) presents the studied localities and interpretations of measured sections. Chapter 8 (Discussion) is also supported by the project work, it has been modified and greatly extended in order to incorporate elements, results and interpretations presented in this master thesis. Chapter 9 (Conclusions) summarizes the main findings from this study and includes recommendations for future work. During the fieldwork, the students have worked closely together in teams of two or three. As this thesis and that of Simen Jenvin Støen is focusing on the part of De Geerdalen Formation underlying the Isfjorden Member, it has been natural for us to work on the same parts of the section. Many of the sections presented here is therefore also included in his thesis. Turid Haugen has been focusing mostly on the delta-top sediments including the Isfjorden Member and will submit her thesis at a later date. All photographs are taken during fieldwork in august 2015 by students from NTNU, unless otherwise stated. vii viii Table of contents ABSTRACT ............................................................................................................................... I SAMMENDRAG ................................................................................................................... III ACKNOWLEDGEMENTS .................................................................................................... V PREFACE ............................................................................................................................. VII TABLE OF CONTENTS ....................................................................................................... IX 1. INTRODUCTION ............................................................................................................ 1 1.1 Study area ................................................................................................................... 1 1.2 Purpose of study ......................................................................................................... 1 1.3 Previous research .......................................................................................................