Aspects of the Tertiary Development of the Wyville-Thomson Ridge Complex, SW Faroe Islands based on 2D digital seismic data

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1 Aspects of the Tertiary Development of the Wyville-Thomson Ridge Complex, SW Faroe Islands based on 2D digital seismic data Highlights of my Master Project at Institute of Geography and Geology, KU By Ingun Ziska Nielsen Department of the Marine Geology and Glaciology Geological Survey of Denmark and Greenland Ministry of Climate and Energy

2 Outline of Talk Location of the Investigated Area and Shotpoint Map Objectives Seismic Profiles Structural Model Conclusions Acknowledgements Ph-D Project

Location of the Investigated Area Location

000km² with line distance of 10km and 15km

3 Location of the Investigated Area Location of 2D digital reflection seismic profiles used in the study roughly covering a rectangular area of km² with line distance of 10km and 15km Divided into 3 subareas Faroe Bank Channel Basin, Rockall Trough and the Auðhumla Basin Bathymetric Map with depth in meters. Area of study is outlined

Objectives Interpret the Post Volcanic Sediments deposited in the basins

Based on these findings a Structural Model of the genesis of the

Islands The Faroe Islands constitute of subairily erupted planparallel

4 Objectives Interpret the Post Volcanic Sediments deposited in the basins above the Top Basalt (~ 58 Ma). Based on these findings a Structural Model of the genesis of the Wyville-Thomson Ridge Complex is developed General Information Faroe Islands The Faroe Islands constitute of subairily erupted planparallel Flood Basalts The volcanic activity on the Faroe Islands ceased before the opening of the NE Atlantic ~ 57 Ma and is part of the NAIP

5 Seismic Profile YMR Faroe Bank Channel Basin WNW Faroe Bank Channel Basin Munkur Basin ESE Wyville- Thomson Ridge Faroe Bank Channel Knoll Reflectors mentioned in ascending order Wyville- Thomson Ridge Blue = FBCK Red = Top Basalt Light Blue = Top Balder Fm. Orange = 10 Blue = Mid Eocene Grey = Top Eocene (*) Green = Top Oligocene (*) Orange = Mid Miocene (*) Blue = Pliocene (*) Yellow = Glacial (*) (*) = unconformity Two T Depositional Systems separated by the Faroe Bank Channel Knoll The sediment units were affected by compression till Top Eocene (grey reflector) Calmer depositional conditions after the Top Eocene (grey reflector)

6 Seismic Profile YMR Auðhumla Basin WNW ESE Auðhumla Basin NERB Ymir Ridge Drekaeyga Intrusion Ymir Ridge Red = Top Basalt Light Blue = Top Balder Fm. Orange = 10 Blue = Mid Eocene Grey = Top Eocene (*) Pink = 20 Green = Top Oligocene (*) Orange = Mid Miocene (*) Blue = Pliocene (*) Yellow = Glacial (*) (*) = unconformity The sediment units were affected by compression till Middle Miocene (orange reflector) Contourite deposits after Middle Pliocene (light blue reflector) due to strong sea currents

7 Seismic Profile YMR Rockall Trough WNW Rockall Trough ESE Sigmundur Seamount Darwin Seamount Ymir Ridge Yellow = DS Blue = SS Red = Top Basalt Light Blue = Top Balder Fm. Orange = 10 Blue = Mid Eocene Grey = Top Eocene (*) Pink = 20 Green = Top Oligocene (*) Orange = Mid Miocene (*) Pink = 30 Blue = Pliocene (*) Yellow = Glacial l (*) Fault active till Early Oligocene (pink reflector 20) (*) = unconformity Apex of Ymir Ridge rotated in Early Eocene (pink reflector 20) and in Late Oligocene (green reflector) The sediment units were affected by compression till Middle Miocene (orange reflector) Contourites and migrating sediment waves deposited after Middle Pliocene (light blue reflector)

8 Seismic Profile YMR Correlation of the 3 subareas SSW Rockall Trough Auðhumla Basin Faroe Bank Channel Basin NNE Ymir Ridge Wyville-Thomson Ridge Blue = FBCK Yellow = DS Red = Top Basalt Light Blue = Top Balder Fm. Orange = 10 Blue = Mid Eocene Grey = Top Eocene (*) Pink = 20 Green = Top Oligocene (*) Orange = Mid Miocene (*) Pink = 30 Blue = Pliocene (*) Yellow = Glacial (*) (*) = unconformity Overall seismic stratigraphic interpretation of the WTRC: The sediment units were affected by compression till Middle Miocene (orange reflector) After Middle Miocene: Contourites and migrating sediment waves deposited in the Rockall Trough Contourites depositions in the Auðhumla Basin Calm deposit conditions in the Faroe Bank Channel Basin

Development of a Structural Model WTR FBCB Abbreviations: AB: Auðhumla Basin DS: Darwin Seamount FBCK DI: Drekaeyga Intrusion SS RT AB DI WTR MB FBCB:

Seamount WTR: Wyville-Thomson Ridge : Ymir Ridge Depth in Sec TWT to the Top Basalt Reflector Interpreted Structures outlined by heavy black lines The

9 Development of a Structural Model WTR FBCB Abbreviations: AB: Auðhumla Basin DS: Darwin Seamount FBCK DI: Drekaeyga Intrusion SS RT AB DI WTR MB FBCB: Faroe Bank Channel Basin FBCK: Faroe Bank Channel Knoll MB: Munkur Basin DS RT NERB NERB: North East Rockall Basin RT: Rockall Trough SS: Sigmundur Seamount WTR: Wyville-Thomson Ridge : Ymir Ridge Depth in Sec TWT to the Top Basalt Reflector Interpreted Structures outlined by heavy black lines The Top Basalt belongs to the oldest Faroese Formations, the Beinisvørð Fm. The Resultant Pointing Directions of the Ridges which the Structural Model is based on

Development of a Structural Model WTR WTR FBCB FBCB FBCK FBCK SS RT AB DI WTR MB SS RT AB DI WTR MB DS NERB DS

western segments (marked by black dashed lines) most part of the Ymir/Ness Lineament (marked by yellow dashed

The north western part in the Rockall Trough is branching -The NW and SE segment have a Resultant out as a

10 Development of a Structural Model WTR WTR FBCB FBCB FBCK FBCK SS RT AB DI WTR MB SS RT AB DI WTR MB DS NERB DS NERB RT RT ENE WSW trending Fissures divide the WTRC into 3 An en echelon Transcurrent Fault being the north western segments (marked by black dashed lines) most part of the Ymir/Ness Lineament (marked by yellow dashed line). The north western part in the Rockall Trough is branching -The NW and SE segment have a Resultant out as a listric fault Compressional Direction is towards the NE - The central segment has a Resultant Compressional Direction is towards the SE NE SW trending Transfer Faults bearing the Caledonian Trend (marked by yellow dashed lines)

Development of a Structural Model WTR FBCB FBCK SS RT AB MB DI WTR DS

~ 55 Ma 40 Ma in Late Paleocene Early Eocene: a) from NE (Oceanic

causing an Anticlockwise Rotation of the Jan Mayen Microcontinent and

Greenland & Eurasia linked at a triple junction south of Greenland) c)

~ 35 Ma in Top Eocene: NW (new Spreading Axis between the Arctic & NE

~ 25 Ma in Top Oligocene: NW (the same Ridge Transition as in a: Ridge

~ 15 Ma in Middle Miocene: NW (Remnants of the structural adjustment of

11 Development of a Structural Model WTR FBCB FBCK SS RT AB MB DI WTR DS NERB RT Compressional Phases: 1. ~ 55 Ma 40 Ma in Late Paleocene Early Eocene: a) from NE (Oceanic Spreading between the Faroe Fracture Zone & the Jan Mayen Fracture Zone causing an Anticlockwise Rotation of the Jan Mayen Microcontinent and Clockwise Rotation of the WTRC) b) from SW (Seafloor Spreading between Greenland & Eurasia linked at a triple junction south of Greenland) c) from NE (the same in a: Ridge Transition and Rotations) 2. ~ 35 Ma in Top Eocene: NW (new Spreading Axis between the Arctic & NE Atlantic = toays spreading ridge) 3. ~ 25 Ma in Top Oligocene: NW (the same Ridge Transition as in a: Ridge Transition and Rotations) 4. ~ 15 Ma in Middle Miocene: NW (Remnants of the structural adjustment of the Jan Mayen Microcontinent) Lundin, E. R Atlantic Arctic seafloor spreading history. In: Eide, E. A. (coord.) BATLAS Mid Norway plate reconstructions atlas with global and Atlantic perspectives. Geological Survey of Norway,

Development of a Structural Model Compressional C i l Belts Clockwise k i Rotation from Late Paleocene Middle Miocene (marked by shaded area) oanticlockwise rotation of

12 Development of a Structural Model Compressional C i l Belts Clockwise k i Rotation from Late Paleocene Middle Miocene (marked by shaded area) oanticlockwise rotation of the Jan Mayen Microcontinent Tilting towards the southeast othermal area cooling: - at the Thulean Volcanic Line located south of the WTRC - the mafic laccolith in the NERB

Conclusions The Top Basalt belongs to the Beinisvørð Fm being the oldest of the three Faroese Formations ~ 58 Ma which is prior to the Opening of the NE Atlantic Ocean ~ 57 Ma The Core of the Ridges

13 Conclusions The Top Basalt belongs to the Beinisvørð Fm being the oldest of the three Faroese Formations ~ 58 Ma which is prior to the Opening of the NE Atlantic Ocean ~ 57 Ma The Core of the Ridges constitutes of Sediments and Flood Basalts and is a potential source for finding oil The entire opening of the NE Atlantic Ocean is reprinted within the Wyville-Thomson Ridge Complex It is a small but complex area as the Structural Model indicates

14 Acknowledgment Fugro-Geoteam for Providing Data for the Thesis Geographix

15 Acknowledgment Fugro-Geoteam for Providing Data for the Thesis Geographix However Now I work with High-resolution Acoustic Data and Sediment Cores as a PhD at GEUS Title of the Project is Sea-Change Supervisors: Lars Ole Boldreel (IGG) Jørn Bo Jensen (GEUS) Antoon Kuijpers (GEUS) Tove Nielsen (GEUS) Marit-Solveig Seidenkrantz (AU)

16 Location of the Investigated Area Reference: Galathea 3 webpage. Forskning/Miljø og klimaændringer, Sydgrønland/Projektbeskrivelse/Appendix1

17 Location of the Investigated Area The aim: To investigate the spatial pattern of sea bottom bedforms (moraines, conturites, iceberg plough marks) caused by the drift of iceberg and current related sedimentary processes, by looking into the changes in the climate, sea-level and sea-current since the Late Glacial Maximum (~ ka) in the Holocene Reference: Galathea 3 webpage. Forskning/Miljø og klimaændringer, Sydgrønland/Projektbeskrivelse/Appendix1

18 Location of the Investigated Area The aim: To investigate the spatial pattern of sea bottom bedforms (moraines, conturites, iceberg plough marks) caused by the drift of iceberg and current related sedimentary processes, by looking into the changes in the climate, sea-level and sea-current since the Late Glacial Maximum (~ ka) in the Holocene High-Resolution Acoustic Data Types: Multibeam Echo-Sounder Sub-bottom Profiler Sparker Side Scan Sonar Sediment Cores Reference: Galathea 3 webpage. Forskning/Miljø og klimaændringer, Sydgrønland/Projektbeskrivelse/Appendix1

19 Location of the Investigated Area The aim: To investigate the spatial pattern of sea bottom bedforms (moraines, conturites, iceberg plough marks) caused by the drift of iceberg and current related sedimentary processes, by looking into the changes in the climate, sea-level and sea-current since the Late Glacial Maximum (~ ka) in the Holocene Area 1 Davis Strait Area 2 High-Resolution Acoustic Data Types: Multibeam Echo-Sounder Sub-bottom Profiler Sparker Side Scan Sonar Sediment Cores Area 3 Reference: Galathea 3 webpage. Forskning/Miljø og klimaændringer, Sydgrønland/Projektbeskrivelse/Appendix1

20 Location of the Investigated Area The aim: To investigate the spatial pattern of sea bottom bedforms (moraines, conturites, iceberg plough marks) caused by the drift of iceberg and current related sedimentary processes, by looking into the changes in the climate, sea-level and sea-current since the Late Glacial Maximum (~ ka) in the Holocene Area 1 Area 2 High-Resolution Acoustic Data Types: Multibeam Echo-Sounder Sub-bottom Profiler Sparker Side Scan Sonar Sediment Cores Area 3 Thank You Reference: Galathea 3 webpage. Forskning/Miljø og klimaændringer, Sydgrønland/Projektbeskrivelse/Appendix1

DANCORE-Day. Master s Thesis

DANCORE-Day. Master s Thesis DANCORE-Day Master s Thesis Interpretation of Shallow Seismic and Sediment Cores from the Area stretching from the Southern Part of Kattegat to the Great Belt in the Period Late-Weichselian to Early Holocene.