GTK Geophysics. Deep electromagnetic sounding, Western Greenland, 2013

Transcription

1 GTK Geophysics Deep electromagnetic sounding, Western Greenland, 2013 Heikki Vanhala, 2014

2 Geophysicists in GTK Rovaniemi kokkola Northern Finland Office Kuopio & KP Espoo Academic degree: M.Sc. 25 Dr. 6 Total 31 *end of 2014 Western Finland Office Kokkola Loppi Espoo Rovaniemi (3) Eastern Finland Office Kuopio (4) (6) (20) Outokumpu Southern Finland Office

3 Most geophysicists work with mineral resources - In projects related to: LAND USE & CONSTRUCTIONS Ground water Constructions Eco-efficient Mining Deep exploration / modeling Sediments & aggregates Modeling ore zones MINERAL RESOURCES Global change ENERGY & ENVIRONMENT Geo-energy Mineral potential mapping * Based on 2013 data/interviews

4 Highlights of geophysics in GTK 1. Geophysical mapping programs, databases & research Airborne geophysical mapping 1950 s 2007 Regional gravity (cont) Petro physical program 1950 s 1990 (cont) Marine mapping program (cont) Deep seismic projects (FIRE, HIRE) 2. Geophysical field measurements field groups - all base methods (EM, IP, magnetic, gravity) - special methods (especially for deep EM), bore-hole, etc EM Survey Deep seismic survey (HIRE)

5 Highlights of geophysics in GTK 3. Engineering & environmental applications Increased use of geophysics for engineering, environmental and groundwater studies since 1990 s 4. Export projects - Geophysical (airborne) mapping project in Africa and Europe in 1990 s and 2000 s - Afghanistan geophysics ( ) 5. R&D and instrumentation Airborne systems, especially the electromagnetics, also software for map production & interpretation petrophysical laboratory, other EM instruments

6 Airborne mapping program (1950 s 2007) Started in Magnetic 1954 EM 1956 Gamma radiation Since 1956 Magn + EM + radition Airborne data cover whole country Magnetic gamma radiation Electrical conductivity tot K, Th, U, tot Re, Im, ρa (1, 2 or 4 freq) I National survey project (highaltitude survey) 400 m line spacing, 150 m flight altitude Magnetic, EM, radiometric Competed 1972 II National survey project (low altitude, high resolution) Started in 1972 Completed in m line spacing, 30 m flight altitude EM, magnetic, radiometric 1, 2 or 4 frequencies

7 Regional gravity mapping program Regional gravity database 1-8 points/km2 GTK and FGI data, km 2 Airborne gravity, km 2 The program has ended, but measurements continue 2-3 teams in operation whole year (groundwater & minerals)

8 Petrophysical mapping program 1950 s 1990 (cont.) Petrophysical database > samples - magnetic, density - (radiation, conductivity, IP, seismic) Program ended, but 3 laboratories measures -magnetic (susc, reman, ams) - res/ip, conductivity, seismic vp, - porosity, density, thermal properties - gamma radiatiation, magn. mineral.

9 Ground geophysics program Ground geophysics database all old data of EM (Slingram), Magn, Grav, IP and VLF (and some others) 5 field teams measure (systematic) Gravity Magnetic Electromagnetic IP/RES. Other field measurements - TEM (30-300m) - FEM/Sampo ( m) - FEM/AMT (>1000m)) Seismic, ERT Bore-hole techniques

10 Examples of recent geophysical activities Mineral Resources: Airborne TEM mapping of Vihanti and Keitele (2008) data integration Airborne TEM mapping of Enontekiö (2012) Airborne gravity of Salla and Savukoski (2011) Airborne EM of Outokumpu (2013) 3D modeling of ore potential zones (starting) Reflection seismic & integration Research of petrophysics for exploration Energy and Environment: Permafrost characterization in Canada, Russia and Greenland Modeling low temperature geothermal systems Groundwater : 3D modeling of groundwater areas Integration of seismic, electrical conductivity and drilling data (Vihanti are 2008)

11 Research by GTK geophysicists Petrophysics, Emplacement and magnetic fabric of rapakivi granite intrusions within Wiborg and Åland rapakivi granite batholiths in Finland, 2014 (Karell, F., Ehlers, C. & Airo, M-L, Tectonophysics) Precambrian Supercontinents, 2014 (Pesonen, L, Halls & Mertanen S, editors, Precambrian Research) Paleomagnetic and geochemical studies of the Mesoproterozoic Satakunta dyke swarms, Finland, with implications for a Northern Europe North America (NENA) connection within Nuna supercontinent, 2014 (Salminen J, Mertanen S, Evans D.A.D., Wang Z., Precambrian Research) Paleomagnetism of Mesoproterozoic Satakunta sandstone, Western Finland, 2014 (Klein, R., Pesonen, L.J., Salminen, J., Mertanen, S., Precambrian Research) Geophysical characteristics of Aswa shear, Nagasongola discontinuity and ring dyke complex in Uganda, 2014 (Ruotoistenmäki, Journal of African Earth Sciences) 3D modelling of ore zones 2D reflection seismic investigations at the Kevitsa Ni-Cu-PGE deposit, northern Finlands, 2012 (Koivisto, E, Alireza, M., Heikkinen, P, Heinonen, S and Kukkonen I., Geophysics) Delineating ophiolite-derived host rocks of massive sulfide Cu-Co-Zn deposits with 2D high-resolution seismic reflection data in Outokumpu, Finland, 2012 (Kukkonen, I, Heinonen, S., Heikkinen P., Sorjonen-Ward. P, Geophysics) EM and bore-hole applications High-resolution Magnetotelluric studies of the Archean-Proterozoic Border zone in the Fennoscandian Shield, Finland (Vaittinen, T., Korja, T., lahti, I., Geophysical Journal International) Geotomographic studies for ore explorations with the EMRE system, (Korpisalo, Arto, Measurement) Borehole Antenna Considerations in the EMRE System: Frequency Band khz, (Korpisalo, A., The Open Geology Journal). Radiowave imaging (RIM) for determining the electrical conductivity of the rock in borehole section OL-KR4-OL-KR10 at Olkiluoto, 2005, 2014 (Korpisalo, A. & Heikkinen, Exploration Geophysics)

12 Example of R&D RIM conductivity mapping space between bore-holes International Journal of Geophysics, Volume Characterization of Geotomographic Studies with the EMRE System. Arto Korpisalo