Regional Geology of the North-Atlantic Area
Accummulation and Storage of Hydrocarbons and Implications for the
Jan Mayen Ridge
Michael Larsen & Gregers Dam
ABRIDGED VERSION
Acknowledgements
• Finn Surlyk
• Snorre Olaussen
• Henrik Nøhr-Hansen and Lars Stemmerik
• Andrew G. Whitham and Simon R.A. Kelly
• Sindri Group
• Geological Survey of Denmark and Greenland (GEUS)
North-Atlanic Licenses and Discoveries
Greenland
Jan Mayen
Northern
Dreki Area
Iceland
Faroes
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UK
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Outline
 Introduction
 Evolution of the North Atlantic
 Pre break-up stratigraphy – the Mesozoic-Paleocene of East Greenland
 Transect of a volcanic margin – Kangerlussuaq, SE Greenland
 Risk Assessment in Frontier Basins
 Dreki Area Opportunities and Challenges
Paleocene/Eocene Palaeogeography (Anomaly 24)
Palaeogeopgraphic compilations by NGU (BATLAS, 2002)
Possible impact of Proto Icelandic mantle plume (short-lived uplift event)
Subaerial volcanism in West and East Greenland
Prior to onset of North Atlantic seafloor spreading
Middle Eocene Palaeogeography (Anomaly 21)
Active seafloor spreading
Spreading along Reykjanes, Aegir and Mohns Ridge
Maximum rifting in NE Greenland offshore areas and Barents Sea
Proto-Icelandic plume reaches the East coast of Greenland (Kangerlussuaq)
Early Oligocene Palaeogeography (Anomaly 13)
Spreading along Aegir Ridge
Initial extension takes places between Jan Mayen and East Greenland
Proto-Icelandic Plumes moves into the offshore
Important change in spreading direction between Greenland and Norway
Late Oligocene Palaeogeography (Anomaly 7)
Ridge jump
Spreading transferred to Kolbeinsey Ridge
Abandonment of the Aegir Ridge
Separation of East Greenland and Jan Mayen micro-continent
Early Miocene Palaeogeography (Anomaly 6)
Spreading focused along Kolbeinsey Ridge
Jan Mayen micro-continent becomes isolated from East Greenland continent
Summary - Jan Mayen Ridge
 Micro-continent with crystalline basement core
 Attached to East Greenland (Liverpool Land)
before seafloor spreading in Oligocene
 Potential presence of Mesozoic sedimentary
section comparable to the East Greenland Rift
www.keeponliving.net/
 Initial Palaeogene spreading along Aegir Ridge (East side of Jan Mayen)
 Late Oligocene ridge jump to Kolbeinsey Ridge (West side of Jan Mayen) active spreading
and compression
 Northern boundary at the Jan Mayen lineament (major NW-SE oriented transfer zone)
 Locally covered by Paleogene-Recent lavas. Still active volcanism (Eruptions in 1970,
1973 and 1985 on Jan Mayen Island)
 Neogene tectonics with faults extending to seabottom and frequent earth quakes along
plate boundaries
Outline
 Introduction
 Evolution of the North Atlantic
 Pre break-up stratigraphy – the Mesozoic-Paleocene of East Greenland
 Transect of a volcanic margin – Kangerlussuaq, SE Greenland
 Risk Assessment in Frontier Basins
 Dreki Area Opportunities and Challenges
Onshore Analogues
 NE Greenland basin Jurassic–Cretaceous rifting Carboniferous rifting
 Jameson Land basin Carboniferous rifting followed by thermal sagging
 Kangerlussuaq basin Cretaceous post-rift basin
Middle Jurassic Pelion Formation
Palaeocene Sediment Input to the Jan Mayen Area?
• Late Paleocene uplift along the
margins of the North Atlantic
• Erosion of Cretaceous and older
sediments
• Sediment input points in NE
Greenland, Kangerlussuaq and
Scoresby Sund?
Jan
Mayen
Greenland
Norway
UK
14
Outline
 Introduction
 Evolution of the North Atlantic
 Pre Break-up Stratigraphy – the Mesozoic-Paleocene of East Greenland
 Transect of a Volcanic Margin – Kangerlussuaq, SE Greenland
 Risk Assessment in Frontier Basins
 Dreki Area Opportunities and Challenges
Kangerlussuaq Basin
Volcanic Basins Play Types
 Sub-basaltic play (Depositional system influenced by initial volcanic processes)
 Intra-basaltic play
 One system
 Two systems interfingering along the edges of the volcanic province
Plateau basalt
Hyaloclastites (lavadelta)
Volcanic tuffs (initial volcanism)
Fluvial sandstone
17
Pre-volcanic Uplift
Fluvial sheet
sandstone ~ 15 m
thick, across the
entire basin
18
Intra-basaltic Sandstones
10m
19
Magmatic Intrusions/Sill Complexes
Amplitude extraction on 3-D Survey Q208
200m
Palaeogene sills intruding Upper Cretaceous Mudstones, East Greenland
• Create local uplift
•Thermal effects on sediments
• Contact metamorphism
• Regional gradients
• Mask seismic images
Doc.
20info
North Atlantic Igneous Province
• Subaerial plateau lavas
• 4–6 km in stratigraphic thickness
• Extruded within a few million years
• Latest Paleocene – Early Eocene
Post-basaltic Sediments at Kap Dalton
Eocene sediments
Plays of the Volcanic Margins
 Depositional systems influenced by volcanic processes
 Heat pulse caused shortlived uplift (200m to >1000 m) and widespread
erosion
 Siliciclastic sediments in the early volcanic succession often related to
interfingering systems along the edges of the volcanic province
 Intra-basaltic sediments may represent basinwide flooding events in the
early volcanic phase (intermittent volcanic activity or translation of
extrusion sites)
 Reservoir and source affected by magmatic intrusions
 Proven plays in Faroe-Shetland Basin
Outline - Exploring at the Edge of Continental Break-up
 Introduction
 Evolution of the North Atlantic
 Pre break-up stratigraphy – the Mesozoic-Paleocene of East Greenland
 Transect of a volcanic margin – Kangerlussuaq, SE Greenland
 Risk Assessment in Frontier Basins
 Dreki Area Opportunities and Challenges
Exploring Beneath Basalts
Analogues in Risk Assessment of Frontier Sub-basalt Basins
 Scope:
Allow relative ranking and demonstrate the exploration potential of licence
blocks and select block(s) for application
 Data:
Open grid of conventional 2D seismic with poor (no) sub-basalt imaging
Few exploration wells located several hundreds of kilometres away from
licence area
Excellent outcrops in onshore basins
Relative Play Risking with Onshore Analogues – An example
Risk
parameters
No onshore
knowledge
Onshore
knowledge
Comments
Trap
0.5
0.6
Presence of rotated fault blocks
2 tectonic episodes
Reservoir
0.4
0.9
Located 800 km from closest
penetration/presence of reservoir
sandstones. Well did not penetrate any
sandstones
Seal
0.9
0.9
Thick succession of mudstones
penetrated in well
Source
0.5
0.8
Possible satellite slicks
Relative
POS
0.09
0.39
Only physical parameters – not dynamic, Only presence, not thickness, quality etc.
 Onshore informations have increased the relative chance for presence of the physical
play elements from POS 9% to 39%!
 Onshore analogues are of crucial importance in preparation of early exploration in
volcanic basins
 Makes the difference between GO and NO-GO
Outline
 Introduction
 Evolution of the North Atlantic
 Pre break-up stratigraphy – the Mesozoic-Paleocene of East Greenland
 Transect of a volcanic margin – Kangerlussuaq, SE Greenland
 Risk Assessment in Frontier Basins
 Dreki Area Opportunities and Challenges
Dreki Area Plays
Dreki Area Plays
Classic rift basin play
Dreki Area Plays
Sub-basaltic uplift play
Classic rift basin play
Dreki Area Plays
Intra-basaltic play
Sub-basaltic uplift play
Classic rift basin play
Dreki Area Plays
Post-basaltic play
Intra-basaltic play
Sub-basaltic uplift play
Classic rift basin play
Conclusions
 Challenging new area
 Mesozoic plays with analogues in the East Greenland Rift Basins (Key to
unravel the offshore geology)
 Paleocene–Eocene plays controlled by volcanic processes – analogues in
southern East Greenland and Faroes/West of Shetland region
 Many un-conventional uncertainties are associated with volcanic basins
(seismic imaging, hydrothermal activities, volcanic barriers, interaction
between siliciclastics and volcanic rocks ect.)
 Onshore analogues have major implications for the risk assessment in the
offshore volcanic basins during the early exploration phase and can be the
difference between a GO and a NO-GO