C2 Anett Blischke

Anett Blischke1, Ögmundur Erlendsson1, Carmen Gaina2 & Árni Hjartarsson1

1 Iceland GeoSurvey & 2 Centre for Earth Evolution and Dynamics, University of Oslo

Volcano-tectonostratigraphic characteristics of the Jan Mayen microcontinent and Iceland shelf area, lessons learned for geothermal exploration

ORKUSTOFNUNNational Energy Authority

GGW2016 Workshop, Reykjavik – 24th-25th of November 2016 – Anett Blischke

JMMC PhD Study Goals

(1) Establish a detailed tectonic and stratigraphic framework for the JMMC:

a. Assess the pre-breakup section and the JMMC relation to the surrounding areas, in particularthe East Greenland and Norway margins.

b. Investigate the stratigraphic and igneous record during first breakup.

c. Map and investigate the stratigraphic and igneous record during mid-oceanic ridge transfer.

(2) Develop a detailed kinematic model of JMMC from pre-breakup time to the present day, inparticular with respect to the second breakup phase and the forming of a microcontinent.



UpstreamNature of the resource• Geology of geothermal systems and volcanoes, structural and tectonic mapping, integration of geology, geochemistry and geophysics.• Geophysical exploration and monitoring methods, including resistivity, seismics, deformation, potential fields and other methods.

Project area database & structural elements



Bathymetry (Jakobsson et al, 2012)

Refraction and reflection seismic lines and boreholes, seabed sampling sites(NEA: National Energy Authority, Iceland; NPD: Norwegian Petroleum Directorate; Spectrum ASA; TGS; SFS seafloor samples; VBPR: Volcanic Basin Petroleum Research AS).

Blischke et al. 2016 (GSL SP447)

Refraction seismic / velocity data tie into the pre-Cenozoic section of the JMMC



Hopper et al. (2014)

Blischke et al. 2016

(GSL SP447)

Borehole control – stratigraphic chart



Iceland onshore records

time span

Smith & Sandwell (1997)


Best analogue section for comparison with onshore East Greenland




Regional reconstruction at breakup time



Blischke et al. 2016

(GSL SP447)

Volcano-stratigraphic characteristicsNorth-eastern flank of the Jan Mayen Ridge area



(A) Paleocene Volcanics (Plateau basalts ? & SDR´s)

(B) - (D) Igneous complexes / Sill intrusive on the main ridge during the Eocene to Early-Mid Oligocene

A

EW

Approx. location of regional fault-fracture zone

B C

D

Data by courtesy of

TW

T (

ms)

WE

▬ UC Late Oligocene - Miocene

▬ UC Early-Mid Oligocene

▬ Early Oligocene

▬ UC Late Eocene

▬ UC Mid-Eocene

▬ UC Early Eocene (PB/SDRs)

▬ Top Basement poss.

Blischke et al. 2014, In: Hopper et al. 2014

Kinematic model – Re-orientation of the central Northeast Atlantic



C13n

33.1Ma

A

D

D

IP

D

D

F

G

III

II

ID GIFRC

337

Igneous

activity

(40-30

Ma)

100 kmBlischke et al. 2016

(GSL SP447)



Complex igneous provinces – flank systemsIceland Faroe Ridge - 2D Multi-Channel-Seismic Mapping

SDRs Syncline axisAnticline axis LDRs SDRs

Blischke et al. 2016 (EGU2016)

Ögmundur Erlendsson & Anett Blischke (2013)

modified after Karl Gunnarsson (2010)

1.(poss. old basement,

e.g. Paleoceneplateau basalts) 1.

4. poss. latest

igneous center

2.(First

spreading ?)

2.3.

(main NAR)

Old weak- / fracture zone ???

SSW NNE

Faroe-Iceland RidgeNAR

Effects on the Iceland-Faroe Ridge - compression and large scale sill intrusive

Ægir RidgeGraben

?

Blischke et al. 2016 (EGU2016)

2D MCS data source:

Talwani et al. (1978) at Lamont-Doherty Earth Observatory (LDEO), Bryndís Brandsdóttir

(University of Iceland)

SSE NNW

33

.1 M

a

< 33.1 Ma ???

>40 km

A A´

A

A´

TW

T (

s)

2

3

4

1



Rifting and separation of the western flank of the JMMC from the Central East Greenland main land causing compression on the older already established ridge formations to the East, e.g. the Faroe-Iceland Ridge.

Kinematic model – Second breakup



C6b

21.56Ma

A

D

D

D

III

II

I

D

ICELAND

SHELF

III

348

IP

H

D

100 kmBlischke et al. 2016

(GSL SP447)

Conclusions – Regional model tie-in to geothermal exploration

Moving from a conceptual model to a model that is reconstructed with mapped features and sub-regions within a coordinate system.Use regional settings for exploration strategy to constrain the area not just in a 3-dimensional space, but also in time:

- Regional settings are 4-dimensional x-y-z-time.- Underlying deep structures governed the forming of the microcontinent and is directly linked to the structural igneous development of the Greenland-Iceland Faroe Ridge

Complex (GIFRC) and adjacent fracture zone systems.- The kinematic dataset re-constructions indicated that in order to keep a time-space balance, the map has to be 3-dimensional.

Considerations for high, mid- to low-range temperature areas:

- One exploration template doesn´t fit all - each area has it´s unique set of boundary conditions, which have to be mapped.- Exploration in different micro-plate settings have their own tectonic history.

“Because fault-fracture zones do not show up on seismicity today doesn´t mean they are not there and have present day fluid pathways”.

Tectonic and structural analysis should be a standard part of research and science for geothermal exploration and exploitation in Iceland.

• The mid-oceanic rift system of the Greenland-Iceland-Faroe Ridge Complex is very complex and a mixture of extensional, transform, and wrench fault tectonic systems that have been re-activated in the past.

Previously published works e.g. Clifton, A. & Einarsson, P. (2000); Einarsson, P. (2008); Hjartardóttir, A.R. (2012); Khodayar, M. (2014); Proett, J.A. (2015); Sigmundsson, F. et al. (2016); Karson, A.J. et al. 2016; Blischke, A. et al. (2016); Hjartarson, A. et al. (in review), and many others.

Structural analysis should include on a regular basis for applied exploration data methods :

• Detailed geological and structural surface mapping (2-dimensional)• High resolution seismic refraction and reflection data acquisition, where possible for deep velocity structure imaging in addition the seismicity studies (add

the 3rd dimension)• Borehole sonic formation and ultrasonic structural logging (BHTV - Borehole Televiewer) (add the 3rd dimension)• High-resolution age grid analysis for areal reconstructions by area, assigning structural elements to a possible timeframe (magnetic anomaly data, petro-

chemistry, age dating , etc. where possible)



Acknowledgements:

Project support by:

Orkustofnun

NAG-TEC Group.

Project data support by:

Data support by NPD, Spectrum AS,

TGS, GEUS & BGR.

PhD Project supervisor:

Bryndís Brandsdóttir, University of Iceland (HÍ)

Project collaborators:

Gwenn Peron-Pinvidic (NGU)

John R. Hopper (GEUS) & NAGTEC

Pierpaolo Guarnieri (GEUS)

Thomas Funck (GEUS)

Ögmundur Erlendsson (ÍSOR)

Jana Ólafsdottir (Jarðfengi)

PhD Project committee:

Bryndís Brandsdóttir (University of Iceland (HÍ))

Þórarinn S. Arnarson (National Energy Authority of Iceland (OS))

Martyn Stoker (BGS, Edinburgh)

Carmen Gaina (CEED, University of Oslo)

Ólafur G. Flóvenz (Iceland GeoSurvey)



Takk fyrir!



C2 Anett Blischke

Engineering