This file was created by the TYPO3 extension publications --- Timezone: CEST Creation date: 2026-05-25 Creation time: 22:38:15 --- Number of references 42 article Kietäväinen2025 Article 2025 10.1038/s43247-025-02053-2 Communications Earth and Environment 6 1 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85218109661&doi=10.1038%2fs43247-025-02053-2&partnerID=40&md5=6eed0f70ebc65035c1139fc61f5b8148 Cited by: 1; All Open Access, Gold Open Access Riikka Kietäväinen Mari Nyyssönen Maija Nuppunen-Puputti Malin Bomberg article Nuppunen-Puputti2023 Microbial life in the deep subsurface occupies rock surfaces as attached communities and biofilms. Previously, epilithic Fennoscandian deep subsurface bacterial communities were shown to host genetic potential, especially for heterotrophy and sulfur cycling. Acetate, methane, and methanol link multiple biogeochemical pathways and thus represent an important carbon and energy source for microorganisms in the deep subsurface. In this study, we examined further how a short pulse of low-molecular-weight carbon compounds impacts the formation and structure of sessile microbial communities on mica schist surfaces over an incubation period of ∼3.5 years in microcosms containing deep subsurface groundwater from the depth of 500 m, from Outokumpu, Finland. The marker gene copy counts in the water and rock phases were estimated with qPCR, which showed that bacteria dominated the mica schist communities with a relatively high proportion of epilithic sulfate-reducing bacteria in all microcosms. The dominant bacterial phyla in the microcosms were Proteobacteria, Firmicutes, and Actinobacteria, whereas most fungal genera belonged to Ascomycota and Basidiomycota. Dissimilarities between planktic and sessile rock surface microbial communities were observed, and the supplied carbon substrates led to variations in the bacterial community composition. Copyright © 2023 Nuppunen-Puputti, Kietäväinen, Kukkonen and Bomberg. Article 2023 English 1664302X 10.3389/fmicb.2023.1054084 Frontiers in Microbiology 14 Frontiers Media S.A. acetic acid; carbon; ground water; methane; methanol; mica; RNA 16S; Actinobacteria; archaeon; Article; Ascomycetes; Basidiomycetes; bedrock; biofilm; Desulfobulbus; DNA extraction; Escherichia coli; Firmicutes; fungal community; gene sequence; microbial community; microbial diversity; microcosm; nonhuman; Proteobacteria; real time polymerase chain reaction https://www.scopus.com/inward/record.uri?eid=2-s2.0-85148343336&doi=10.3389%2ffmicb.2023.1054084&partnerID=40&md5=92b28b53725263693ec36163f2e707c3 Cited by: 0; All Open Access, Gold Open Access, Green Open Access Maija Nuppunen-Puputti Riikka Kietäväinen Ilmo Kukkonen Malin Bomberg article Loukola-Ruskeeniemi2023 Black shales host critical raw materials such as graphite and cobalt and occur in the vicinity of many types of sulphide deposits. We report the procedure for country-wide mapping of graphite- and sulphide-rich rocks and the chemical and petrophysical data of 319 samples we selected from sulphide occurrences and mines in Finland. Even though black shales are rarely outcropped in glaciated and deeply weathered terrains, they can be traced with geophysical surveys. In the Precambrian of Finland, where the metamorphic grade varies from greenschist to granulite facies, systematic airborne geophysical surveys revealed stratigraphy-related, coupled magnetic and electrically conductive patterns. Electrical conductivity was related to the graphite and sulphide contents, producing continuous and bending electromagnetic anomaly patterns. The magnetic anomalies, if present, resulted from ferrimagnetic monoclinic pyrrhotite. The petrophysical properties of black shales varied in our sample set. The densities were mainly between 2700 and 3000 kg/m3, with the mean density ~ 2800 kg/m3, where the amount of graphite had a reducing effect on density whereas sulphides increased it. The average magnetic susceptibilities were about 6000·10−6 (SI), but they showed wide variation, depending on the abundance of ferrimagnetic monoclinic pyrrhotite. The electrical conductivity of black shales appeared to be positively related to the abundance of monoclinic pyrrhotite. Conductivity variation, 1–105 1/Ωm was based on laboratory determinations of apparent resistivities. We correlated an airborne magnetic and electromagnetic survey with petrophysical and chemical data from altogether 319 drill core samples containing >1 % graphitic C and >1 % S. The samples were selected during 2009–2011 from 102 drill cores all over Finland except for the Talvivaara–Outokumpu region, which was studied during previous projects. The black-shale-hosted Talvivaara Ni–Zn–Co–Cu deposit is currently being mined. The maximum graphite concentration in the country-wide sample set was 34.3 %, and the median value was 5.7 %, a lower value than reported from the Talvivaara black-shale-hosted sulphide deposit (7.6 %). S, Co, Cu, Fe and Ni concentrations were also lower in our sample set on average than in the Talvivaara ore. However, the maximum concentration in our sample set was 397 mg/kg for Co, 0.36 % for Cu, 40.8 % for Fe and 0.28 % for Ni. The developed black shale mapping procedure can be directly applied in other parts of the world in terrains with greenschist to granulite facies regional metamorphism. Information on basic petrophysical properties, i.e., density, magnetic and electric properties, are needed to explain geophysical anomalies. If the metamorphic grade is lower than greenschist facies and there is no graphite, sulphides will increase the electromagnetic properties. If ferrimagnetic pyrrhotite exists, susceptibility increases, as well as remanence. The black shale database covering the whole of Finland is used not only in exploration and bedrock mapping, but also in regional planning and for environmental risk analyses, because sulphide-rich black shales may cause acid rock drainage when exposed to weathering and the quality of surface water and groundwater may suffer from black shale bedrock and glacial till. The scale limitations given by airborne geophysics may request detailed studies in selected sites. © 2022 The Author(s) Article 2023 English 03756742 10.1016/j.gexplo.2022.107123 Journal of Geochemical Exploration 244 Elsevier B.V. Core drilling; Deposits; Electric conductivity; Geological surveys; Geophysics; Graphite; Infill drilling; Magnetic susceptibility; Oil shale; Sampling; Stratigraphy; Airborne geophysics; Black shales; Ferrimagnetics; Finland; Geophysical measurements; Greenschist; Monoclinics; Sample sets; Sulphide; Sulphide deposits; graphite; host rock; hydrocarbon exploration; hydrocarbon generation; petrography; shale; sulfide; Sulfur compounds https://www.scopus.com/inward/record.uri?eid=2-s2.0-85142126826&doi=10.1016%2fj.gexplo.2022.107123&partnerID=40&md5=e017ed42fa9292f6037cef0c108b99d4 Cited by: 1 Kirsti Loukola-Ruskeeniemi Eija Hyvönen Meri-Liisa Airo Jouni Lerssi Hilkka Arkimaa article Khajehdehi2022 Article 2022 10.1029/2021GL095199 Geophysical Research Letters 49 4 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85125789823&doi=10.1029%2f2021GL095199&partnerID=40&md5=d1efd6bc396106b41994d5457f728424 Cited by: 6; All Open Access, Bronze Open Access Omid Khajehdehi Kamran Karimi Jörn Davidsen article Nuppunen-Puputti20211 Fungi have an important role in nutrient cycling in most ecosystems on Earth, yet their ecology and functionality in deep continental subsurface remain unknown. Here, we report the first observations of active fungal colonization of mica schist in the deep continental biosphere and the ability of deep subsurface fungi to attach to rock surfaces under in situ conditions in groundwater at 500 and 967 m depth in Precambrian bedrock. We present an in situ subsurface biofilm trap, designed to reveal sessile microbial communities on rock surface in deep continental groundwater, using Outokumpu Deep Drill Hole, in eastern Finland, as a test site. The observed fungal phyla in Outokumpu subsurface were Basidiomycota, Ascomycota, and Mortierellomycota. In addition, significant proportion of the community represented unclassified Fungi. Sessile fungal communities on mica schist surfaces differed from the planktic fungal communities. The main bacterial phyla were Firmicutes, Proteobacteria, and Actinobacteriota. Biofilm formation on rock surfaces is a slow process and our results indicate that fungal and bacterial communities dominate the early surface attachment process, when pristine mineral surfaces are exposed to deep subsurface ecosystems. Various fungi showed statistically significant cross-kingdom correlation with both thiosulfate and sulfate reducing bacteria, e.g., SRB2 with fungi Debaryomyces hansenii. © 2020 by the authors. Licensee MDPI, Basel, Switzerland. Article 2021 English 20762607 10.3390/microorganisms9010064 Microorganisms 9 MDPI AG 1 – 29 1 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85098596898&doi=10.3390%2fmicroorganisms9010064&partnerID=40&md5=140c81e7b9749904d7730d8ee3a9dcd0 Cited by: 8; All Open Access, Gold Open Access, Green Open Access Maija Nuppunen-Puputti Riikka Kietäväinen Lotta Purkamo Pauliina Rajala Merja Itävaara Ilmo Kukkonen Malin Bomberg article Sharov2020253 Attempts to interpret the origin of seismic boundaries in the crystalline crust in the Fennoscandian Shield from deep drilling records and available geological and geophysical data were made by a number of authors. This article contains an overview of the most essential results reported so far. Deep drilling was conducted in several regions of the Fennoscandian Shield: Kola, Russia (SG-3), to a depth of 12,262 m (1970–1990); Gravberg (GR) and Stenberg-I, Central Sweden, to a depth of 6337 m (1986–1987); and 6529 m (1991–1992); Outokumpu (OU), SE Finland, to a depth of 2516 m (2004–2005); Pogranichnaya (P-1), Sredny Peninsula, Murmansk Region, Russia, to a depth of 5200 m (2004–2006); and Onega, Central Karelia, Russia (ON), to a depth of 3537 m (2007–2008). The results obtained were analyzed. They show considerable discrepancies between forecast seismic-geological models and the actual structure of the upper portion of the continental crust. Deep drilling has proved that heterogeneities in the upper portion of the crystalline crust, indicated by geophysical data, are due to changes in the composition and physical conditions of deep-seated rocks. Therefore, even approximate rock composition cannot be uniquely estimated from elastic wave velocities alone. Deep drilling showed the real pattern and origin of low-velocity zones in the upper portion of the crust and did not show that layers become more homogeneous with depth. The origin of intra-crustal seismic boundaries could be associated with various factors, such as variations in mineralogical composition, structural and textural differences between the rocks, and a thermodynamic setting. © 2020, Springer Nature Switzerland AG. Book chapter 2020 English 2524342X 10.1007/978-3-030-21788-4_21 Springer Proceedings in Earth and Environmental Sciences Springer Nature 253 – 261 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85125246957&doi=10.1007%2f978-3-030-21788-4_21&partnerID=40&md5=b40b0e8fdb4e7a3a6ccede2effd18300 Cited by: 3 N.V. Sharov article Lahti2019351 The Outokumpu belt in eastern Finland is known for numerous polymetallic (Cu-Co-Zn-Ni-Ag-Au) sulphide ore deposits and it is a potential area for new discoveries. Audiomagnetotelluric (AMT) data have recently been collected to image the subsurface conductivity structure of the belt. The data were acquired along five profiles aiming to explore deep conductors, study their geometry and investigate the deep conductivity structure of the belt.The acquired AMT data were mostly adequate for 2D inversion, as the survey area is characterised by thin, laterally extensive conductors indicated by airborne electromagnetic data, deep drillings and regional strike analysis of the impedance tensor data. 2D smooth inversion was carried out jointly for transverse electric and transverse magnetic data. The results show southeast-dipping and sub-horizontal continuous conductors southeast of the Outokumpu old mine, suggesting the presence of prospective Outokumpu assemblage rocks. One ∼ 1 km deep sub-horizontal conductor is verified by a deep drill-hole located ∼ 8 km southeast of the mine. The results demonstrate a similar southeast-dipping structure in the Vuonos mine area, which is located ∼ 7 km northeast of the Outokumpu old mine. An eastwards-dipping conductor detected in the Miihkali serpentinite area indicates deep exploration potential in this area. Besides the smooth 2D inversion, a sharp-boundary 2D inversion was performed and the resulting model was assessed with the existing geological interpretation of the Miihkali area. In the area of the Sotkuma gneiss inlier, conductors are absent from the uppermost ∼ 6 km. This feature may represent an uplifted fault block rather than a thin thrust sheet of Archaean basement rocks. © 2019 Australian Society of Exploration Geophysics. Article 2019 English 08123985 10.1080/08123985.2019.1606200 Exploration Geophysics 50 Taylor and Francis 351 – 363 4 Finland; Outokumpu; Pohjois-Karjala; Gold compounds; Gold deposits; Infill drilling; Magnesite; Magnetotellurics; Sulfur compounds; Surveys; Zinc deposits; 2D modelling; Airborne electromagnetic; Conductivity structures; Exploration potential; Geological interpretation; Horizontal conductors; Transverse electrics; Transverse magnetic; Archean; basement rock; fault zone; geometry; gneiss; mineral exploration; mining industry; ore body; serpentinite; Mineral exploration https://www.scopus.com/inward/record.uri?eid=2-s2.0-85066971435&doi=10.1080%2f08123985.2019.1606200&partnerID=40&md5=d3a462f1cca18710c5ebe7617771144f Cited by: 2 Ilkka Lahti Asko Kontinen Vesa Nykänen article Nuppunen-Puputti2018 The deep biosphere contains a large portion of the total microbial communities on Earth, but little is known about the carbon sources that support deep life. In this study, we used Stable Isotope Probing (SIP) and high throughput amplicon sequencing to identify the acetate assimilating microbial communities at 2260 m depth in the bedrock of Outokumpu, Finland. The long-term and short-term effects of acetate on the microbial communities were assessed by DNA-targeted SIP and RNA targeted cell activation. The microbial communities reacted within hours to the amended acetate. Archaeal taxa representing the rare biosphere at 2260 m depth were identified and linked to the cycling of acetate, and were shown to have an impact on the functions and activity of the microbial communities in general through small key carbon compounds. The major archaeal lineages identified to assimilate acetate and metabolites derived from the labelled acetate were Methanosarcina spp., Methanococcus spp., Methanolobus spp., and unclassified Methanosarcinaceae. These archaea have previously been detected in the Outokumpu deep subsurface as minor groups. Nevertheless, their involvement in the assimilation of acetate and secretion of metabolites derived from acetate indicated an important role in the supporting of the whole community in the deep subsurface, where carbon sources are limited. © 2018 by the authors. Licensee MDPI, Basel, Switzerland. Article 2018 English 20763263 10.3390/geosciences8110418 Geosciences (Switzerland) 8 MDPI AG 11 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85056812256&doi=10.3390%2fgeosciences8110418&partnerID=40&md5=a1d5c3c27e99504453497dc73653bc3c Cited by: 11; All Open Access, Gold Open Access, Green Open Access Maija Nuppunen-Puputti Lotta Purkamo Riikka Kietäväinen Mari Nyyssönen Merja Itävaara Lasse Ahonen Ilmo Kukkonen Malin Bomberg article Sharma20161549 Over the last two decades, the flowing fluid electric conductivity (FFEC) logging method has been applied in boreholes in the well-testing mode to evaluate the transmissivity, hydraulic head, and formation water electrical conductivity as a function of depth with a resolution of about 10–20 cm. FFEC profiles along the borehole are obtained under both shut-in and pumping conditions in a logging procedure that lasts only 3 or 4 days. A method for analyzing these FFEC logs has been developed and successfully employed to obtain formation parameters in a number of field studies. The present paper concerns the analysis of a unique set of FFEC logs that were taken from a deep borehole reaching down to 2.5 km at Outokumpu, Finland, over a 6-year time period. The borehole intersects paleoproterozoic metasedimentary, granitoid, and ophiolite-derived rocks. After the well was drilled, completed, and cleaned up, FFEC logs were obtained after 7, 433, 597, 948, and 2036 days. In analyzing these five profiles, we discovered the need to account for salinity diffusion from water in the formation to the borehole. Analysis results include the identification of 15 hydraulically conducting zones along the borehole, the calculation of flow rates associated with these 15 zones, as well as the estimation of the variation of formation water electrical conductivity as a function of depth. The calculated flow rates were used to obtain the tentative hydraulic conductivity values at these 15 depth levels. © 2015, Springer-Verlag Berlin Heidelberg. Article 2016 English 14373254 10.1007/s00531-015-1268-x International Journal of Earth Sciences 105 Springer Verlag 1549 – 1562 5 Finland; Outokumpu; Pohjois-Karjala; borehole logging; deep drilling; diffusion; electrical conductivity; formation water; hydraulic conductivity; hydraulic structure; monitoring; salinity; well logging https://www.scopus.com/inward/record.uri?eid=2-s2.0-84946762962&doi=10.1007%2fs00531-015-1268-x&partnerID=40&md5=c4f1a82fb2ce682c77f659588ac65df1 Cited by: 8 Prabhakar Sharma Chin-Fu Tsang Ilmo T. Kukkonen Auli Niemi conference Heinonen201626 The Kylylahti copper mine is located in the Outokumpu Cu-Co-Zn-Ni ore district in eastern Finland. We used high resolution reflection seismic profiles imaging the subsurface structures down to depth of 5 km and ZTEM (Z-axis Tipper Electromagnetic) inversion results revealing deep conductivity anomalies to study the deep exploration potential of the Kylylahti area. Regional interpretation of these deep penetrating data suggest that peridotite body of Kylylahti has substantial down plunge extend towards south and underneath the current mine. Additionally to regional interpretation, we have interpolated the densities measured in laboratory from drill-core samples to create a 3D-subsurface density distribution grid and compared it with the seismic reflection data. Overall correlation of reflectivity and density patterns is excellent: high density values correlate particularly well with high amplitude reflections while no prominent reflectivity is observed in the areas where density is uniformly low. The combination of reflectivity and interpolated density distribution suggest that the high density rock units possibly hosting the sulfide ore occur in a steeply dipping feature continuing northwest from the Kylylahti mine along the seismic profile. Results of this study highlight the deep exploration potential of the rock volumes below currently drilled depths in the Kylylahti area. Conference paper 2016 English 978-151082247-4 10.3997/2214-4609.201600032 EAGE/DGG Workshop on Deep Mineral Exploration 2016: Chasing Both Land and Sea Deposits European Association of Geoscientists and Engineers, EAGE 26 – 30 Cobalt alloys; Copper alloys; Copper mines; Core drilling; Deposits; Infill drilling; Potassium alloys; Reflection; Seismic waves; Seismology; Sulfur compounds; Zinc alloys; Conductivity anomalies; Density distributions; Exploration potential; High resolution reflection seismic; Inversion results; Seismic reflection data; Subsurface density; Subsurface structures; Mineral exploration https://www.scopus.com/inward/record.uri?eid=2-s2.0-84973897667&doi=10.3997%2f2214-4609.201600032&partnerID=40&md5=43cd6eb29c6ca9b25bf2e50b42c682c4 Cited by: 0 S. Heinonen A. Kontinen P. Sorjonen-Ward S. Aatos book Haapala20151 Historically documented mining in Finland started in the 1530s when the area formed part of Sweden. The post of commissioner of mines was founded in 1638. The Swedish government activated mineral exploration in Finland in the seventeenth century and, during the Age of Utility, in the eighteenth century. Numerous small iron, copper, and lead occurrences were found, as well as the larger Orijärvi copper deposit. During 1809-1917 when Finland was a Grand Duchy within the Russian Empire, exploration was reorganized and strengthened. New, generally small iron deposits were discovered to supply iron works. Deposits found in the Pitkäranta area were mined for copper, tin, zinc, and iron. The Geological Survey of Finland was established in 1885. The large and rich Outokumpu copper deposit was discovered in 1910 as a result of scientific exploration by Otto Trüstedt of the Geological Survey. Since then, boulder tracing (later also till geochemistry), geophysical measurements, and diamond drilling have been the standard exploration methods. After Finland declared independence in 1917, mineral exploration was considered important for the development of domestic industry. In 1921 the Geological Survey discovered the nickel-copper ore field of Petsamo, and by the end of the 1930s, several other deposits, including the Otanmäki iron-titanium-vanadium deposit, were discovered. After the Second World War, the Geological Survey was reorganized and strengthened, and in the following decades it discovered numerous important ore deposits, including the Vihanti zinc-copper deposit (1951) and the Kemi chromium deposit (1960). The state-owned mining companies Outokumpu Oy and Rautaruukki Oy established their own exploration departments in the 1950s. Outokumpu Oy discovered the Kotalahti (1956), Vammala, and Kylmäkoski nickel-copper deposits, the Pyhäsalmi copper-zinc deposit (1958), the Vuonos (1965) and Kylylahti (1984) Outokumpu-type deposits, and several gold deposits. Otanmäki Oy/Rautaruukki Oy discovered several iron deposits in Lapland, as well as the large apatite-rich Sokli carbonatite complex. Rautaruukki Oy terminated their exploration activities in 1985 and Outokumpu Oy in 2003. Finnish private companies also carried out successful mineral exploration. After becoming a member of the European Union in 1995, the role of international mining and exploration companies has strongly increased in Finland, the main interest being in precious metal deposits. © 2015 Elsevier Inc. All rights reserved. Book chapter 2015 English 978-012410476-1; 978-012410438-9 10.1016/B978-0-12-410438-9.00001-7 Mineral Deposits of Finland Elsevier Inc. 1 – 38 Copper nickel deposits; Copper zinc deposits; Deposits; Diamond drilling; Economic geology; Geological surveys; History; Iron deposits; Military operations; Mineral exploration; Mineral industry; Natural resources exploration; Nickel; Nickel deposits; Ore deposits; Ores; Phosphate minerals; Tin deposits; Titanium deposits; Vanadium deposits; Domestic industries; Exploration company; Exploration methods; Finland; Geophysical measurements; Outokumpu Oy; Rautaruukki Oy; Scientific exploration; Gold deposits https://www.scopus.com/inward/record.uri?eid=2-s2.0-84939785457&doi=10.1016%2fB978-0-12-410438-9.00001-7&partnerID=40&md5=6300126fb0e1e454d46f3c82b01e80a0 Cited by: 8 I. Haapala H. Papunen article Chan20151549 The availability of a deep borehole in northeastern Alberta provides an unprecedented opportunity to study the in situ metamorphic craton rocks. This borehole reaches a depth of 2.4 km, with 1.8 km in the crystalline rocks, and is the only known borehole allowing access into the deeper rocks of the metamorphic Canadian Shield. In 2011, a zero-offset vertical seismic profile (VSP) was acquired to assist in the interpretation of seismic reflection data and geophysical logs. Three sets of upgoing tube waves interpreted from the raw profile correspond to the small-scale fluctuations in the borehole diameters and fracture zone in the crystalline rocks. A comparison between sonic log velocities and VSP velocities reveals a zone with increased velocity that could be due to the change in rock composition and texture in the basement rocks. The final processed profile is used to generate corridor stacks for differentiating between primary reflections and multiples in the seismic reflection profile. Analysis of the zero-offset VSP verifies existing log interpretation on the presence of fractures and the possible lithological changes in the metamorphic rocks of the Canadian Shield. © 2014, The Author(s). Article 2015 English 14373254 10.1007/s00531-014-1110-x International Journal of Earth Sciences 104 Springer Verlag 1549 – 1562 6 Alberta; Canada; Canadian Shield; borehole; craton; metamorphic rock; seismic reflection; seismic velocity; vertical seismic profile https://www.scopus.com/inward/record.uri?eid=2-s2.0-84940959788&doi=10.1007%2fs00531-014-1110-x&partnerID=40&md5=1f312df547f362767159541c1a79e9ec Cited by: 7; All Open Access, Hybrid Gold Open Access Judith Chan Douglas R. Schmitt article Rajala201517 Microorganisms in the deep biosphere are believed to conduct little metabolic activity due to low nutrient availability in these environments. However, destructive penetration to long-isolated bedrock environments during construction of underground waste repositories can lead to increased nutrient availability and potentially affect the long-term stability of the repository systems, Here, we studied how microorganisms present in fracture fluid from a depth of 500 m in Outokumpu, Finland, respond to simple carbon compounds (C-1 compounds) in the presence or absence of sulphate as an electron acceptor. C-1 compounds such as methane and methanol are important intermediates in the deep subsurface carbon cycle, and electron acceptors such as sulphate are critical components of oxidation processes. Fracture fluid samples were incubated in vitro with either methane or methanol in the presence or absence of sulphate as an electron acceptor. Metabolic response was measured by staining the microbial cells with fluorescent dyes that indicate metabolic activity and transcriptional response with RT-qPCR. Our results show that deep subsurface microbes exist in dormant states but rapidly reactivate their transcription and respiration systems in the presence of C-1 substrates, particularly methane. Microbial activity was further enhanced by the addition of sulphate as an electron acceptor. Sulphate-and nitrate-reducing microbes were particularly responsive to the addition of C-1 compounds and sulphate. These taxa are common in deep biosphere environments and may be affected by conditions disturbed by bedrock intrusion, as from drilling and excavation for long-term storage of hazardous waste. © 2015 by the authors; licensee MDPI, Basel, Switzerland. Article 2015 English 20762607 10.3390/microorganisms3010017 Microorganisms 3 MDPI AG 17 – 33 1 https://www.scopus.com/inward/record.uri?eid=2-s2.0-84937149116&doi=10.3390%2fmicroorganisms3010017&partnerID=40&md5=f3f50844f63d003e2e063a46d3fee4b3 Cited by: 30; All Open Access, Gold Open Access, Green Open Access Pauliina Rajala Malin Bomberg Riikka Kietäväinen Ilmo Kukkonen Lasse Ahonen Mari Nyyssönen Merja Itävaara article Kietäväinen2014159 Noble gas residence times of saline groundwaters from the 2516m deep Outokumpu Deep Drill Hole, located within the Precambrian crystalline bedrock of the Fennoscandian Shield in Finland, are presented. The accumulation of radiogenic (4He, 40Ar) and nucleogenic (21Ne) noble gas isotopes in situ together with the effects of diffusion are considered. Fluid samples were collected from depths between 180 and 2480m below surface, allowing us to compare the modelled values with the measured concentrations along a vertical depth profile. The results show that while the concentrations in the upper part are likely affected by diffusion, there is no indication of diffusive loss at or below 500m depth. Furthermore, no mantle derived gases were found unequivocally. Previous studies have shown that distinct vertical variation occurs both in geochemistry and microbial community structuring along the drill hole, indicating stagnant waters with no significant exchange of fluids between different fracture systems or with surface waters. Therefore in situ accumulation is the most plausible model for the determination of noble gas residence times. The results show that the saline groundwaters in Outokumpu are remarkably old, with most of the samples indicating residence times between ~20 and 50Ma. Although being first order approximations, the ages of the fluids clearly indicate that their formation must predate more recent events, such as Quaternary glaciations. Isolation within the crust since the Eocene-Miocene epochs has also direct implications to the deep biosphere found at Outokumpu. These ecosystems must have been isolated for a long time and thus very likely rely on energy and carbon sources such as H2 and CO2 from groundwater and adjacent bedrock rather than from the ground surface. © 2014 Elsevier Ltd. Article 2014 English 00167037 10.1016/j.gca.2014.09.012 Geochimica et Cosmochimica Acta 145 Elsevier Ltd 159 – 174 Baltic Shield; East European Craton; Finland; Outokumpu; Pohjois-Karjala; bedrock; carbon dioxide; diffusion; groundwater; hydrochemistry; hydrogen; isotopic composition; noble gas; residence time https://www.scopus.com/inward/record.uri?eid=2-s2.0-84908361183&doi=10.1016%2fj.gca.2014.09.012&partnerID=40&md5=fd4d141c3d16769d7903030f81ff7fa2 Cited by: 32; All Open Access, Green Open Access Riikka Kietäväinen Lasse Ahonen Ilmo T. Kukkonen Samuel Niedermann Thomas Wiersberg article Kontny2014224 The Outokumpu (OKU) assemblage was studied in drill cores from the 2516m deep OKU Deep Drill Hole, Finland, and we observed that the strongest magnetic anomalies found in borehole measurements are related to three ferrimagnetic metaperidotite units with magnetic susceptibilities of up to 93×10-3SI separated by paramagnetic rock units. The main ferrimagnetic minerals are magnetite and minor pyrrhotite. Magnetic fabric studies were done in order to examine deformation within the OKU assemblage during the collisional deformation event 1.9Ga ago. Well-defined magnetic axes (kmax, kmin) and nearly horizontal magnetic foliation subparallel to the macroscopic foliation occur at the top and the bottom of the OKU formation. Low- and high-field AMS measurements showed that ferri- and paramagnetic subfabrics are coaxial. Paramagnetic units intercalated between the ferrimagnetic units show mostly triaxial magnetic fabrics, and low degrees of magnetic anisotropy values (P'<1.3) with a high variation of the shape factor (T) from prolate to oblate shapes. P' of the ferrimagnetic metaperidotite is high and range between 1.3 and 3.6 and T tends to more oblate shapes (T>0). Ferrimagnetic unit 2 shows the highest magnetic susceptibility and P' up to 5.6, which is related to a high amount of magnetite and pyrrhotite mostly concentrated in huge aggregates and veins. Alignment of magnetic minerals parallel with the structural foliation and the high P' values in the ferrimagnetic metaperidotite indicate that magnetic fabric was acquired in a high strain zone. The magnetic fabrics represent shear zone (SC) fabrics, which have been formed during early obduction-related deformation of the Svecofennian orogeny. The stacked sequence of the ferri- and paramagnetic metaperidotite bodies can be interpreted as a thrust system with an imbricate fan, in which three individual listric thrust sheets occur. This interpretation is in accordance with previous tectonic models of the Outokumpu area. © 2014 Elsevier B.V. Article 2014 English 00401951 10.1016/j.tecto.2014.04.011 Tectonophysics 629 Elsevier B.V. 224 – 237 Finland; Outokumpu; Pohjois-Karjala; Deformation; Drills; Ferrimagnetism; Horizontal wells; Infill drilling; Iron ores; Magnetic anisotropy; Magnetic susceptibility; Magnetite; Paramagnetism; Core drilling; Magnetism; Tectonics; Borehole measurements; Deep drilling; Ferrimagnetic minerals; Finland; Magnetic anomalies; Magnetic fabrics; Magnetic foliation; Outokumpu area; High-strain zones; Magnetic minerals; crustal structure; deformation; magnetic anisotropy; magnetic anomaly; magnetic fabric; magnetic mineral; magnetic susceptibility; peridotite; shear zone; deep drilling; geomagnetism; petrofabric; tectonic setting; Core drilling; Magnetic anisotropy https://www.scopus.com/inward/record.uri?eid=2-s2.0-84922777844&doi=10.1016%2fj.tecto.2014.04.011&partnerID=40&md5=c14374c7656a43dbd44d9aa3aee19aec Cited by: 2 Agnes Kontny Frank Dietze conference Heinonen2014117 A network ofhigh resolution seismic reflection profiles was acquired in Outokumpu, Finland. Outokumpu is one of the most important mining regions in Finland where active sulphide exploration is ongoing. Over 5 km long spread with 402 active channels and nominal vibroseismic source point interval of 25 m guarantee high fold and good signal-to-noise ratio of the seismic data. These high quality data have been commercially processed by Vniigeofizika, Moscow with standard hardrock seismic processing flow including careful static corrections. Seismic sections were migrated and depth converted with constant velocity (5400 m/s) that corresponds approximately to the seismic P-wave velocity in the main lithology of the area, mica schist. Additionally to seismic velocities, also densities of the main lithologies have been measured from the 2.5 km long drill hole. This enables estimation of the main sources of reflectivity in the Outokumpu area. Encouragingly, typical ore hosting lithological assemblage was found to be brightly reflective both externally and internally due to interlayers ofhigh acoustic impedance skarns and low acoustic impedance serpentinites. All together nine interconnected seismic profiles combined with the drill hole logging data and other geophysical data, including ZTEM survey, enable the 3D-modeling of the Outokumpu subsurface structures. Conference paper 2014 English 978-163266695-6 10.3997/2214-4609.20140520 76th EAGE Conference and Exhibition 2014, Workshops EAGE Publishing BV 117 – 119 3D modeling; Acoustic impedance; Infill drilling; Lithology; Mica; Mineral exploration; Rock drills; Seismology; Signal to noise ratio; Sulfur compounds; Wave propagation; Constant velocities; High quality data; Seismic processing; Seismic reflection profiles; Seismic reflections; Seismic velocities; Static correction; Subsurface structures; Seismic waves https://www.scopus.com/inward/record.uri?eid=2-s2.0-84907346055&doi=10.3997%2f2214-4609.20140520&partnerID=40&md5=6ca6d352659aff15b2939247e04d80f6 Cited by: 0; All Open Access, Bronze Open Access, Green Open Access S.E. Heinonen S. Aatos P.J. Heikkinen N. Hellqvist M. Kurimo H. Levaniemi I.T. Kukkonen article Kietäväinen201337 Article 2013 10.1016/j.apgeochem.2012.10.013 Applied Geochemistry 32 37 – 51 https://www.scopus.com/inward/record.uri?eid=2-s2.0-84876308246&doi=10.1016%2fj.apgeochem.2012.10.013&partnerID=40&md5=ff0458c69bff4d9a1e8bed0d61ddbffd Cited by: 44 Riikka Kietäväinen Lasse Ahonen Ilmo T. Kukkonen Nina Hendriksson Mari Nyyssönen Merja Itävaara article Kukkonen2012WC213 Seismic reflection data was applied to a study of the upper crustal structures in the Outokumpu mining and exploration area in eastern Finland. The Cu-Co-Zn sulfide ore deposits of the Outokumpu area are hosted by Palaeoproterozoic ophiolite-derived altered ultrabasic rocks (serpentinite, skarn rock, and quartz rock) and black schist within turbiditic mica schist. Mining in the Outokumpu area has produced a total of 36 Mt of ore from three historical and one active mine. Seismic data comprises 2D vibroseis data surveyed along a network of local roads. The seismic sections provide a comprehensive 3D view of the reflective structures. Acoustic rock properties from downhole logging and synthetic seismograms indicate that the strongly reflective packages shown in the seismic data can be identified as the host-rock environments of the deposits. Reflectors show excellent continuity along the structural grain of the ore belt, which allows correlating reflectors with surface geology, magnetic map, and drilling sections into a broad 3D model of the ore belt. Massive ores have acoustic properties that make them directly detectable with seismic reflection methods assuming the deposit size is sufficient for applied seismic wavelengths. The seismic data revealed numerous interesting high-amplitude reflectors within the interpreted host-rock suites potentially coinciding with sulfides. © 2012 Society of Exploration Geophysicists. Article 2012 English 00168033 10.1190/geo2012-0029.1 Geophysics 77 Society of Exploration Geophysicists WC213–WC222 5 Finland; Outokumpu; Pohjois-Karjala; 3D modeling; Acoustic impedance; Acoustic logging; Cobalt alloys; Cobalt compounds; Copper alloys; Copper compounds; Deposits; Geophysical prospecting; Magnesite; Mica; Mica deposits; Ores; Reflection; Seismic response; Seismic waves; Structural geology; Sulfur compounds; Ternary alloys; Zinc alloys; Zinc deposits; Zinc sulfide; Europe; High resolution seismic; Reflective structure; Seismic impedance; Seismic reflection data; Seismic reflection method; Synthetic seismogram; Vibroseis; acoustic property; cobalt; copper; crustal structure; host rock; logging (geophysics); massive sulfide; mica; mining; ophiolite; ore deposit; reflectivity; schist; seismic data; seismic reflection; seismic wave; seismogram; upper crust; vibroseis; wavelength; zinc; Rocks https://www.scopus.com/inward/record.uri?eid=2-s2.0-84866458793&doi=10.1190%2fgeo2012-0029.1&partnerID=40&md5=5c09d6d532d34310b185d64a6766c86d Cited by: 20 I.T. Kukkonen S. Heinonen P. Heikkinen P. Sorjonen-Ward article Savchenko201231 The stressed state of the rock mass in the area of the Outokumpu deep drill hole, Finland, was investigated by the boundaryelement method in three mutually orthogonal planes with regard for the massif geological structure. It was found that subhorizontal components of the stress field are determined by tectonic forces acting on the boundaries of the European part of the Eurasian lithospheric plate. In the drill hole vertical section the widest variations of this field gradient occur at the depths of an ophiolite sequence in the range of 1.8-2.0 km. Article 2012 English 12149705 Acta Geodynamica et Geomaterialia 9 31 – 42 1 https://www.scopus.com/inward/record.uri?eid=2-s2.0-84859167332&partnerID=40&md5=1b5dadc38e3abc6dd3400586d7e625a0 Cited by: 2 Stepan Savchenko Feliks Gorbatsevich article Wenk2012123 A sample of biotite gneiss from the Outokumpu deep drilling project in Finland was investigated by Kern et al. (2008) for crystal preferred orientation and elastic anisotropy. Considerable differences between measured acoustic velocities and velocities calculated on the basis of texture patterns were observed. Measured P-wave anisotropy was 15.1% versus a Voigt average yielding 7.9%. Here we investigate the same sample with different methods and using different averaging techniques. Analyzing time-of-flight neutron diffraction data from Dubna-SKAT and LANSCE-HIPPO diffractometers with the Rietveld technique, much stronger preferred orientation for biotite is determined, compared to conventional pole-figure analysis reported previously. The comparison reveals important differences: HIPPO has much better counting statistics but pole figure coverage is poor. SKAT has better angular resolution. Using the new preferred orientation data and applying a self-consistent averaging method that takes grain shapes into account, close agreement of calculated and measured P-wave velocities is observed (12.6%). This is further improved by adding 0.1. vol.% flat micropores parallel to the biotite platelets in the simulation (14.9%). © 2012. Article 2012 English 00401951 10.1016/j.tecto.2012.06.023 Tectonophysics 570-571 123 – 134 Finland; Outokumpu; Pohjois-Karjala; Acoustic wave velocity measurement; Anisotropy; Neutron diffraction; Poles; Seismic waves; Textures; Angular resolution; Averaging method; Averaging technique; Biotite gneiss; Counting statistics; Crystal preferred orientations; Deep drilling; Drill hole; Elastic anisotropy; Finland; Gneiss; Grain shapes; Micropores; Neutron diffraction data; P-wave velocity; Pole figure; Pole figure analysis; Preferred orientations; Rietveld technique; Self-consistent averaging; Texture measurement; Texture patterns; Time of flight; Velocity calculations; biotite; crystal property; elastic property; gneiss; measurement method; neutron diffraction; P-wave; preferred orientation; seismic anisotropy; seismic velocity; texture; Mica https://www.scopus.com/inward/record.uri?eid=2-s2.0-84866516721&doi=10.1016%2fj.tecto.2012.06.023&partnerID=40&md5=1932f53c9a1dac9a24d480fa513391f4 Cited by: 46 H.-R. Wenk R.N. Vasin H. Kern S. Matthies S.C. Vogel T.I. Ivankina article Schijns2012541 Seismic velocity anisotropy measurements are made of a fractured metamorphic formation from the 2.5-km-deep International Continental Scientific Drilling Programme (ICDP) borehole in Outokumpu, Finland. Three component walk-away vertical seismic profile (VSP) measurements are made along two source-line azimuths at three receiver depths (1000, 1750 and 2500 m) and incidence angle-dependent qP- and qS-wave velocities are extracted with a τ-p method. The highest qP-wave anisotropy, 13.6 per cent (v fast= 6160 m s -1, v slow= 5370 m s -1), is measured between 1000- and 1750-m depth, with anisotropy of up to 9.4 per cent (v fast= 6090 m s -1, v slow= 5540 m s -1) measured between 1750 and 2500 m depth. The top ∼1300 m of the region is composed of a homogeneous, strongly intrinsically anisotropic biotite-rich schist, and is sampled by the shallowest walk-away profile. Anisotropy of up to 11.1 per cent (v fast= 5950 m s -1, v slow= 5320 m s -1) is measured by the walk-away VSP between 50 and 1000 m depth, along with shear wave splitting averaging 5 per cent (180 m s -1). Laboratory-derived intrinsic anisotropy of the schist cannot by itself explain the degree or orientation of the anisotropy measured in the walk-away VSPs, however, a model which modifies the intrinsic stiffnesses by the inclusion of a single set of dipping, aligned cracks allows the observed in situ velocities to be reproduced. Forward modelling of the qP-wave walk-away VSP measurements from 50 to 1000 m depth is undertaken using an effective medium model to develop a 3-D velocity model of this region. An orthorhombic medium is used to represent the intrinsic anisotropy of the biotite-rich schist, and a single set of aligned cracks is added to give a bulk elastic stiffness. The resulting model predicts the schist to have an overall anisotropy of 16.8 per cent, with qP-wave velocities of up to 6315 m s -1. The accuracy of the model is assessed through its fit to the walk-away VSP measurements as well as a comparison to known geology of the region. © 2012 The Authors Geophysical Journal International © 2012 RAS. Article 2012 English 1365246X 10.1111/j.1365-246X.2012.05358.x Geophysical Journal International 189 541 – 553 1 Finland; Outokumpu; Pohjois-Karjala; Anisotropy; Cracks; Mica; Seismology; Stiffness; Three dimensional; Velocity; Angle-dependent; Cratons; Downholes; Effective medium model; Elastic stiffness; Finland; Forward modelling; In-situ; Intrinsic anisotropy; Scientific drilling; Seismic anisotropy; Seismic velocities; Shear wave splitting; Three component; Upper crust; Velocity model; Vertical seismic profiles; accuracy assessment; biotite; borehole; crystallization; forward modeling; fracture zone; homogeneity; in situ measurement; observational method; P-wave; S-wave; seismic anisotropy; seismic velocity; stiffness; three-dimensional modeling; upper crust; wave splitting; well logging; Seismic prospecting https://www.scopus.com/inward/record.uri?eid=2-s2.0-84858620250&doi=10.1111%2fj.1365-246X.2012.05358.x&partnerID=40&md5=77464191488347b5075a50fc3d73bde2 Cited by: 25; All Open Access, Bronze Open Access Heather Schijns Douglas R. Schmitt Pekka J. Heikkinen Ilmo T. Kukkonen article Itävaara2011199 Three sampling campaigns were performed during the years 2007-2009 to develop microbiological sampling techniques and to study the deep biosphere in the Outokumpu Deep Drill Hole R2500, drilled into a Palaeoproterozoic sequence of rocks consisting of metasediments, ophiolite-derived altered ultramafic rocks and pegmatitic granite. The results revealed the presence of microbial communities in the saline fluids sampled from the open borehole and fracture systems in the low-porosity crystalline bedrock in Outokumpu. According to the microbiological analyses, the microbial cell density varies from 105 cells ml-1 at the surface to 103 ml-1 at 2350 m depth. The composition of microbial communities in the borehole was found to vary with sampling depth, and the changes appear to be connected to both geological and geochemical factors as well as to fracture zones in the bedrock. Sulphate reducing bacteria and methanogenic archaea are present throughout the borehole water column. Article 2011 English 978-952217152-8 07828535 Special Paper of the Geological Survey of Finland 2011 Kukkonen I.T. 199 – 206 51 Finland; Ita Suomen; Outokumpu; Bacteria (microorganisms); bacterium; bedrock; biosphere; borehole; fracture; granite; groundwater; metasedimentary rock; microbiology; microorganism; sampling; ultramafic rock; water column https://www.scopus.com/inward/record.uri?eid=2-s2.0-80051902876&partnerID=40&md5=5e3e8404d16f6213e756969b770e88d6 Cited by: 13 Merja Itävaara Mari Nyyssönen Malin Bomberg Anu Kapanen Aura Nousiainen Lasse Ahonen Jenni Hultman Lars Paulin Petri Auvinen Ilmo T. Kukkonen article Virgil2011119 In September 2008, the magnetic field in the Outokumpu Deep Drill Hole (OKU R2500) was measured with the Göttinger Bohrloch Magnetometer (GBM). Unlike previous total field measurements with other tools, the three components of the magnetic field and the tool attitude were measured continuously with a resolution of up to 5 cm. This became possible by utilizing a unique orientation system consisting of three fibre optic gyros. After extensive data processing, the magnetic anomalies along the borehole were obtained in the geographic coordinates North, East and Vertical (WGS-84). Two intervals with significant magnetic anomalies were detected. While the disturbances in the first interval (70-300 m) are either manmade or caused by thin layers of black schist, the second interval (1328-1440 m) is dominated by magnetized rocks of the Outokumpu assemblage. The combined interpretation of core data and in-situ measurements indicates less carbonated serpentinite as the host for magnetic minerals. Furthermore, statistical studies of the magnetisation direction, derived from the GBM measurements, suggest a different geological evolution of the host rocks of the upper and lower section of the Outokumpu assemblage. Article 2011 English 978-952217152-8 07828535 Special Paper of the Geological Survey of Finland 2011 Kukkonen I.T. 119 – 132 51 Finland; Ita Suomen; Outokumpu; Gyros; borehole logging; data processing; deep drilling; magnetic anomaly; magnetic field; magnetometer; metamorphic rock; remanent magnetization https://www.scopus.com/inward/record.uri?eid=2-s2.0-80051894711&partnerID=40&md5=ebfeaf2f0dc88721e341ffd0960577b0 Cited by: 4 Christopher Virgil Andreas Hördt Martin Leven Erich Steveling Jochem Kück Frank Dietze article Taran2011219 Graphitic schists from the Outokumpu Deep Drill Hole were investigated in order to reconstruct the structure and composition of organic matter and stable isotope carbon and sulphur geochemistry of graphite, pyrite and pyrrhotite. Core samples of graphitic schists were collected from three depth levels of the Outokumpu Deep Drill Hole. The studied rocks were biotite-(tremolite-) graphite and, occasionally, muscovite (sericite)- and titanite-bearing schists and quartzitic schists. All samples were enriched in sulphides (mostly pyrite and pyrrhotite). Carbon isotope δ13C values of graphitic C were found to vary from -18.4 to -27.4‰. Graphitic schists from the middle part of the core in association with ophiolite-derived serpentinite and other altered ultramafic rocks showed more elevated δ13C values. This suggests incorporation of isotopically heavy carbon species during metamorphism, probably resulting from decarbonation reactions in carbonatebearing rocks. d34S values in the graphitic schists of the Outokumpu Deep Drill Hole were determined to be in range of -3.0 to -9.9‰ for pyrite and -3.8 to -10.8‰ for pyrrhotite. These concentrations could be explained by bacterial reduction of seawater sulphate and, to some extent, by the addition of hydrothermal sulphur. The predominance of aliphatic and oxygen-bearing groups in the bitumen structure suggests a sapropelic origin of the organic matter. Particularities in the distribution of Corganic and chemical changes in the bitumen composition along the core section could be interpreted as evidence of different sources and possibly the re-deposition of organic matter. Article 2011 English 978-952217152-8 07828535 Special Paper of the Geological Survey of Finland 2011 Kukkonen I.T. 219 – 228 51 Finland; Ita Suomen; Outokumpu; Bacteria (microorganisms); bitumen; borehole; carbon isotope; concentration (composition); geochemistry; graphite; isotopic analysis; metamorphism; metasedimentary rock; muscovite; organic carbon; organic matter; Proterozoic; schist; serpentinite; stable isotope; sulfide; ultramafic rock https://www.scopus.com/inward/record.uri?eid=2-s2.0-80051880869&partnerID=40&md5=a3dadf5ab721cdbc0655ad2f3aaf3caa Cited by: 8 Ludmila N. Taran Mariya P. Onoshko Nikolaj D. Mikhailov article Airo201163 Petrophysical laboratory measurements of the Outokumpu Deep Drill Core were carried out in 2005-2008 at the Geophysical Laboratory of the Geological Survey of Finland (GTK). This report describes the pre-processing and measurement procedures and summarizes the measurement results of a total of 1992 samples taken at one-metre intervals along the drill core, representing depths from 55.5 m to 2503.9 m. The determined parameters were density and porosity, magnetic susceptibility and the intensity of remanent magnetization, electrical properties (resistivity and chargeability), P-wave velocity and thermal conductivity. The samples represented different rock types, and their petrophysical parameters showed typical values reflecting the mineralogical variation in the rocks. Generally weak magnetic properties characterize both the drill core samples and the outcropping bedrock (magnetic susceptibilities mainly ≤ 1000 × 10-6 SI). The only magnetically anomalous rocks are serpentinites and other altered ophiolitederived rocks of the Outokumpu assemblage, with susceptibilities of the order of ≥ 10 000 × 10-6 SI. No clear systematic effect of depth along the drill core on density or susceptibility can be observed. P-wave velocity and specific resistivity tend to decrease with depth. The porosity of mica schists increases with depth, but the drill core bulk densities do not change. Microfracturing due to pressure release possibly explains part of this effect. However, the grain densities of mica schists tend to increase with depth. Compared with surface densities, the densities of different rock types in the core are ca. 40 kg/m3 higher than the densities of corresponding rock types exposed around the drilling site (< 100 km). The magnetic properties of different rock types are of about the same intensity. Only black schists on the surface are more highly magnetic than those from the core, suggesting differences in monoclinic / hexagonal pyrrhotite contents. Article 2011 English 978-952217152-8 07828535 Special Paper of the Geological Survey of Finland 2011 Kukkonen I.T. 63 – 82 51 Finland; Ita Suomen; Outokumpu; bedrock; deep drilling; density; electrical property; magnetic susceptibility; metamorphic rock; mica; outcrop; physical property; porosity; remanent magnetization https://www.scopus.com/inward/record.uri?eid=2-s2.0-80051881757&partnerID=40&md5=ba03b74e950d423732997ac2c129a3b7 Cited by: 8 Meri-Liisa Airo Heikki Säävuori Satu Vuoriainen article Västi201117 Deep reflection seismic measurements in 2002 across the Outokumpu region revealed numerous reflectors, some of which related to mafic rock assemblages or to rocks that otherwise showed impedance contrasts with their surroundings. Two shallow reflective zones were later targeted for drilling in order to test interpretations of the seismic data. The immediate proximity of the famous Outokumpu ore belt naturally provided an additional incentive for drilling, which was undertaken by NEDRA, a state owned Russian drilling contractor. The Outokumpu region is located within the Paleoproterozoic Karelian schist belt close to the boundary between the Neoarchaean craton in the east and the Paleoproterozoic Svecofennian island arc complex in the west. The Karelian schist belt is divided into the lower Sariolan and Jatulian (2.5-2.1 Ga, mainly autochthonous), and the upper Kalevian (2.1-1.9 Ga) units. The deep drill hole R2500 is located in the allochthonous upper part of the latter unit. The uppermost 2 km of the drill hole consists mainly of mica schist with minor biotite gneiss, chlorite-sericite schist, black schist and hornblende-epidote schist intercalations. Within the interval ca. 1300-1500 m, the mica schist formation encloses a previously unknown assemblage of Outokumpu-type rocks. From ca. 1650 m downwards mica schist is intruded by pegmatitic granitoids, which in turn dominate from ca. 2000 m downwards. The chemical index of alteration (CIA) of the mica schists and biotite gneisses (50.3-65.2) indicates weak to moderate weathering of their source rocks. The lower CIA values of the mica schists probably reflect rapid and subsequent erosion, transportation and re-deposition from large deltas. On the other hand the higher CIA value of the biotite gneisses is a consequence of mineralogy, because it was originally fine-grained shale rich in clay minerals. Chlorite-sericite schist closely resembles mica schist chemically, while the hornblende-epidote schist differs in containing distinctly more CaO and less Na2O and K2O. Black schists are divided into two main types: "ordinary" black schist and calcareous black schist. The latter type is rich in tremolite and differs chemically mainly in containing less SiO2 and more CaO and MgO. Rocks of the Outokumpu assemblage consist of lithologically diverse rock types ranging from monomineralic serpentinites to various diopside- and/or tremolite-bearing skarns and quartz rocks. A few narrow and strongly schistose mafic dykes, which have been altered to chlorite schists, crosscut skarn. Primarily the Outokumpu-type rock assemblages represent fragments of mantle peridotites affected by hydrothermal and metasomatic alteration. For this reason serpentinites, skarns and quartz rocks usually have trace element concentrations very similar to pyrolite. Although pegmatitic granitoids show significant variations in the modal composition, they are always very leucocratic (M=0.2-4). Chemically all pegmatite types display peraluminous affinities (A/CNK = 1.02-2.08). On A/CNK versus SiO2 and Na 2O versus K2O diagrams pegmatites fall into both S-type or I-type categories. Article 2011 English 978-952217152-8 07828535 Special Paper of the Geological Survey of Finland 2011 Kukkonen I.T. 17 – 46 51 Finland; Ita Suomen; Outokumpu; Archean; biotite; craton; deep drilling; gneiss; granitoid; metasedimentary rock; mica; mineralogy; pegmatite; petrology; Proterozoic; schist; seismic data; seismic reflection; serpentinite; skarn https://www.scopus.com/inward/record.uri?eid=2-s2.0-80051871690&partnerID=40&md5=89c43fa5c805254bfe8f7ca60aeddbcc Cited by: 11 Kaj Västi article Elbra201195 Longitudinal (VP) and shear wave (Vs) velocities of the upper 1.5 km of the Outokumpu Deep Drill Core were measured using a novel ultrasonic instrument. The aim of the laboratory tests was to determine the seismic velocities of rocks as a function of pressure and temperature and to identify parameters that influence these velocities. The velocities differed significantly throughout the core due to variations in mineralogical composition, lithology, fracturing and anisotropy. Notably, even a minor increase in pressure dramatically increased the VP and VS due to microcrack closure. When the pores and microcracks were closed by pressurization, the highest velocities in the upper schist series (33-1314 m) and the ophiolitic series (1314-1515 m) were met within chlorite-sericite schists (VP 5704 m/s, VS 3495 at 30 MPa) and diopside-tremolite skarns (VP 6572 m/s, VS 3752 m/s at 30 MPa), respectively. This new velocity data could improve the interpretation of crustal models by providing constraints on seismic velocities as well as estimates of the seismic impedances and Poisson's ratios in various rock types in the area of the Outokumpu Deep Drill Core. Article 2011 English 978-952217152-8 07828535 Special Paper of the Geological Survey of Finland 2011 Kukkonen I.T. 95 – 104 51 Finland; Ita Suomen; Outokumpu; crustal structure; deep drilling; metasedimentary rock; P-wave; Proterozoic; S-wave; seismic velocity; seismic wave; wave velocity https://www.scopus.com/inward/record.uri?eid=2-s2.0-80051860763&partnerID=40&md5=c9bc180a991c106742433f339f8ae9e4 Cited by: 2 Tiiu Elbra Ronnie Karlqvist Ilkka Lassila Edward Hæggström Lauri J. Pesonen article Kern201183 Laboratory measurements as well as modelling of the physical properties of rock materials are important for the understanding and interpretation of both downhole (logging) and geophysical (surface) observations. On 29 core samples of the Outokumpu scientific drill hole, covering the depth range of 198-2491 m, we calculated the average (isotropic) intrinsic P- and S-wave velocities (V p,Vs) and densities from their modal composition, based on bulk rock (XRF) and mineral chemistry (microprobe), using least squares fitting. For 13 cube-shaped samples representing the main lithologies, we measured P- and S-wave velocities in 3 orthogonal directions at pressures of up to 600 MPa in order to determine their directional dependence and crack sensitivity. Comparison of the calculated velocities with the experimentally derived in situ velocities gave evidence for microcracks that are not completely closed. Microcracks may have an important bearing on the in situ velocities, in addition to the lithological control. Velocity measurements as well as 3D velocity calculations based on neutron diffraction texture measurements revealed that velocity anisotropy and shear wave splitting are important properties of the biotite gneisses that dominate about 70% of the drilled crustal section. Reflection coefficients (Rc) for the various lithological contacts based on modelled and measured velocities provide evidence that the different lithologies of the ophiolite-related assemblage have the potential to cause the marked reflections at 1300-1500 m depth, as revealed by the high-resolution seismic reflection line (OKU-1). Article 2011 English 978-952217152-8 07828535 Special Paper of the Geological Survey of Finland 2011 Kukkonen I.T. 83 – 94 51 Finland; Ita Suomen; Outokumpu; crustal structure; deep drilling; microcrack; ophiolite; P-wave; Proterozoic; S-wave; seismic anisotropy; seismic reflection; seismic wave; wave velocity https://www.scopus.com/inward/record.uri?eid=2-s2.0-80051915214&partnerID=40&md5=570ee1f7d46f5ed2daa5fb8ea09ddc3a Cited by: 6 Hartmut Kern Kurt Mengel book kukkonen2011outokumpu 2011 9789522171511 Geological Survey of Finland Geological Survey of Finland https://books.google.de/books?id=gCN6ygAACAAJ I. Kukkonen article Dietze2011133 This study examined the rock magnetic properties and magnetic mineralogy of serpentinite, skarn, black schist and mica schist of the Outokumpu (OKU) rock type assemblage, which occur between 1314 and 1515 m in the Outokumpu Deep Drill Hole in Eastern Finland. This depth interval is related to pronounced magnetic anomalies. A banded magnetic anomaly pattern, similar to the one observed in the OKU drill cores, is seen in aeromagnetic surveys for the surface in the vicinity of the OKU borehole. Magnetic logging has revealed that the magnetic anomalies are mostly related to the ferrimagnetic serpentinite units in the OKU assemblage. The serpentinite units show a significant scattering of magnetic susceptibility (κ) from 0.04 to 192.7*10-3 SI and natural remanent magnetization (NRM) from 0.06 to 45.1 A/m, indicating a heterogeneous distribution of ferrimagnetic minerals in the ultramafic rocks. The main magnetic minerals are magnetite and pyrrhotite. Furthermore, variation in the Königsberger ratio (Q) from below 1 up to 16 indicates that some ultramafic rocks in the OKU assemblage are able to carry a remanent magnetization (Q-ratio > 1). The strong scattering of rock magnetic properties is interpreted to reflect a complex geological history of the studied rocks. Magnetite is known to form during the serpentinization of ultramafic rocks on the sea floor or during subduction-related processes. In the OKU assemblage it was partially decomposed during early deformation stages by listwaenite-birbirite-type carbonatequartz alteration. During subsequent events of regional deformation, the magnetic minerals were deformed or some new formation of magnetic minerals occurred. Article 2011 English 978-952217152-8 07828535 Special Paper of the Geological Survey of Finland 2011 Kukkonen I.T. 133 – 150 51 Finland; Ita Suomen; Outokumpu; borehole logging; deep drilling; magnetic anomaly; magnetic property; magnetic survey; magnetic susceptibility; magnetite; mineralogy; remanent magnetization; rock property; serpentinite; skarn https://www.scopus.com/inward/record.uri?eid=2-s2.0-80051905179&partnerID=40&md5=d67c6be1dbacbc3bfde402dc2973546d Cited by: 5 Frank Dietze Agnes Kontny article Hölttä201147 Metamorphic mineral assemblages and mineral compositions were investigated in metasediments of the Outokumpu drill hole from the surface to 2.5 km depth in order to determine the Proterozoic geothermal gradient. The common mineral assemblage of the mica gneisses is biotite-plagioclase-quartz±muscovite. Finegrained garnet and Al silicates (sillimanite, kyanite, andalusite) are locally found, whereas staurolite is rare. Small abundances of leucosome indicating the onset of partial melting are present, especially in the lower parts of the hole, which also show some grain-size coarsening. The Fe and Mg distribution coefficient (KD) between coexisting garnet and biotite increases slightly from the surface to the deeper levels, indicating increasing temperature. The garnet-biotite thermometer shows a slight increase in temperatures from c. 605-610 °C near the surface to c. 620-630 °C at 1200-1500 m depth, indicating an average gradient of 19 °C/km, but the result is within the error limits of the thermometer (±15 °C). Temperatures calculated using Thermocalc software are several tens of degrees higher. Metamorphic pressures calculated using the garnet-biotite-plagioclase- quartz and garnet-muscoviteplagioclase- quartz barometers and the Thermocalc average PT method are in the range from c. 4-9 kbars. Pressures given by fluid inclusion barometry are 2-5 kbars. Geobarometry does not indicate systematic changes as a function of the depth. A clockwise PT path, where pressure increased to 8-9 kbars and was followed by decompression down to the andalusite field, explains the observed mineral assemblages and thermobarometric results. Article 2011 English 978-952217152-8 07828535 Special Paper of the Geological Survey of Finland 2011 Kukkonen I.T. 47 – 62 51 Finland; Ita Suomen; Outokumpu; biotite; fluid inclusion; garnet; gneiss; grain size; iron; magnesium; metamorphism; metasediment; mica; mineralogy; P-T conditions; P-T-t path; partial melting; Proterozoic https://www.scopus.com/inward/record.uri?eid=2-s2.0-80051908795&partnerID=40&md5=061749191ad12bc9f8f7f333c9994ef8 Cited by: 4 Pentti Hölttä Petriikka Karttunen article Elbra2011405 Petrophysical, in particular seismic velocity, measurements of the Outokumpu deep drill core (depth 2.5 km) have been carried out to characterize the geophysical nature of the Paleoproterozoic crustal section of eastern Finland and to find lithological and geophysical interpretations to the distinct crustal reflectors as observed in seismic surveys. The results show that different lithological units can be identified based on the petrophysical data. The density of the samples remained nearly constant throughout the drilled section. Only diopside-tremolite skarns and black schists exhibit higher densities. The samples are dominated by the paramagnetic behaviour with occasional ferromagnetic signature caused by serpentinitic rocks. Large variations in seismic velocities, both at ambient pressure and under in situ crustal conditions are observed. The porosity of the samples, which is extremely low, is either intrinsic by nature or caused by decompaction related to fracturing during the core retrieval. It is noteworthy that these microfractures have dramatically lowered the VP and VS values. From the measured velocities and density data we have calculated the seismic impedances, Young's modulus and Poisson's ratios for the lithological units of the Outokumpu section and from these data the reflection coefficients for the major lithological boundaries, evident in the surveyed section, were determined. The data show that the strong and distinct reflections visible in wide-angle seismic surveys are caused by interfaces between diopside-tremolite skarn and either serpentinites, mica schist or black schist. © 2010 The Authors Geophysical Journal International © 2010 RAS. Article 2011 English 1365246X 10.1111/j.1365-246X.2010.04845.x Geophysical Journal International 184 405 – 415 1 Finland; Ita Suomen; Outokumpu; Acoustic impedance; Core drilling; Core samples; Drills; Geological surveys; Lithology; Mica; Paramagnetism; Reflection; Seismic waves; Seismology; Silicate minerals; Structural geology; Velocity; Ambient pressures; Black schist; Body waves; Crustal structure; Density data; Drill core; Eastern Finland; In-situ; Laboratory measurements; Mica schists; Microfractures; Paleoproterozoic; Petrophysical; Petrophysical properties; Poisson's ratio; Reflection coefficients; Seismic impedance; Seismic surveys; Seismic velocities; Young's Modulus; acoustic property; body wave; crustal structure; geophysics; lithology; Poisson ratio; porosity; schist; seismic survey; seismic velocity; skarn; wave propagation; Young modulus; Acoustic wave propagation https://www.scopus.com/inward/record.uri?eid=2-s2.0-78650121773&doi=10.1111%2fj.1365-246X.2010.04845.x&partnerID=40&md5=9a4625b5c5d0d270f89d2fb2201682ff Cited by: 22; All Open Access, Bronze Open Access, Green Open Access Tiiu Elbra Ronnie Karlqvist Ilkka Lassila Edward Hæggström Lauri J. Pesonen article Ahonen2011151 Extensive hydrogeological studies on the Outokumpu Deep Drill Hole R2500, drilled in 2004-2005, have been carried out during both the drilling phase as well as the post-drilling period. The present paper introduces the main results and characteristics of deep fluids and gases in the 2516 m deep hole drilled into a Paleoproterozoic formation of metasediments, ophiolite-derived altered ultrabasic rocks and pegmatitic granite. The main hydrogeological experiments during drilling were the daily monitoring of drilling fluid electrical conductivity, pH, composition and consumption (loss) of drilling fluid, as well as targeted fluid sampling and hydraulic testing during drilling breaks with the drill stem method. Hydrogeological sampling of the drill hole water with a tube method has been carried out three times to up to 1500-2350 m depths in the post-drilling period, and undisturbed formation fluid was pumped for several weeks from a packer-isolated fracture system at 967 m. The loss of drilling water during drilling was very heavy in the uppermost 1000 m of the hole (1-4 m3 of water per 1 m of drilling), but it decreased to a low level (<1 m3/m) at lower depths, indicating that hydraulically conductive fractures are more frequent in the first kilometre of bedrock than beneath. The hydraulic testing carried out at approximately 500-m depth intervals in 40-70 m thick sections indicated a similar pattern of hydraulic conductivity decreasing with depth: about 7.5 · 10-6 m/s at 500 m, 5.3 · 10-7 m/s at 1000 m, and practically impermeable rock at deeper levels. The electrical conductivity of the drill hole fluid rapidly increased in the post-drilling period due to the discharge of saline water from several fracture systems, and was monitored with repeated down-hole logs. In the uppermost 1000 m, fluid salinity has been in a semi-stable condition since about 2006, but in the deeper parts of the hole electrical conductivity continued to gradually increase in 2008 and 2009, when the most recent downhole logs and fluid sample profiles were obtained. The fluids are Ca-Na-Cl fluids with elevated Mg concentrations at the depths of the ophiolite-derived rocks of the Outokumpu assemblage. The fluids contain abundant gases, with methane and nitrogen being the main components. The stable isotope compositions (δ2H, δ18O) of the saline fluids indicate that they are not meteoric fluids but probably result from long-term water-rock interaction. The results indicate distinct water bodies isolated in fracture zones with minimal hydraulic connections. Article 2011 English 978-952217152-8 07828535 Special Paper of the Geological Survey of Finland 2011 Kukkonen I.T. 151 – 168 51 Finland; Ita Suomen; Outokumpu; bedrock; borehole; deep drilling; electrical conductivity; groundwater; hydraulic conductivity; hydraulic fracture; hydrochemistry; hydrogeology; isotopic composition; magnesium; salt water; stable isotope https://www.scopus.com/inward/record.uri?eid=2-s2.0-80051901472&partnerID=40&md5=5cc788f3a2d251190d1a54d67196ae39 Cited by: 25 Lasse Ahonen Riikka Kietäväinen Nina Kortelainen Ilmo T. Kukkonen Arto Pullinen Taru Toppi Malin Bomberg Merja Itävaara Aura Nousiainen Mari Nyyssönen Marjo Öster article Heinonen2011105 The Outokumpu area, located in eastern Finland, is well known for its Precambrian Cu-Zn-Co-Ni-Ag-Au sulphide deposits hosted by ophiolite-derived altered ultramafic rocks. In 2004-2005, a 2.5 km deep research borehole was drilled on the south-east side of the main ore belt. The ophiolite-related Outokumpu-assemblage rocks were penetrated at depths of 1.3-1.5 km. The other main lithologies observed in the Outokumpu Deep Drill Hole were mica schist with biotite-gneiss layers (upper 2 km) underlain by pegmatitic granite. In May 2006, high resolution reflection seismic data with 4 m receiver spacing were acquired at the drilling site along two crooked lines to further refine the geological model of the area. The Outokumpu Deep Drilling Project provided an excellent opportunity to correlate high resolution seismic data with drilling results. The main emphasis in the processing of the reflection seismic data was put on static corrections. Substantial topographic variation and a significant velocity contrast between the glacially deposited overburden and the bedrock caused severe travel time variations in the near surface. Results achieved using static corrections carried out with the standard refraction method and using a tomographic approach were compared. Sonic velocity and density logs were used to calculate acoustic impedances and a synthetic seismogram, and theoretical calculations were compared with reflectivity observed in the seismic section. The results indicate that the host rocks of the Outokumpu type deposits are bright reflector packages that can be observed with reflection seismic techniques. The pegmatitic granite shows only weak reflection contrast with the mica schist, but it can be delineated as homogeneous, transparent domains, whereas the mica schist is internally more heterogeneous. A fracture zone at the depth of 967 m can be observed as a sharp sub-horizontal reflector. Article 2011 English 978-952217152-8 07828535 Special Paper of the Geological Survey of Finland 2011 Kukkonen I.T. 105 – 118 51 Finland; Ita Suomen; Outokumpu; borehole; data processing; deep drilling; granite; host rock; lithology; metamorphic rock; ore deposit; pegmatite; seismic data; seismic reflection; seismogram; well logging https://www.scopus.com/inward/record.uri?eid=2-s2.0-80051865405&partnerID=40&md5=801e0d4202718f04cf8833dde9ca17ce Cited by: 17 Suvi Heinonen Ilmo T. Kukkonen Pekka J. Heikkinen Douglas R. Schmitt article Kukkonen20119 Detailed geothermal studies of deep drill holes provide insights to heat transfer processes in the crust, and allow separation of different factors involved, such as palaeoclimatic and structural conductive effects as well as advective fluid flow effects. We present high resolution geothermal results of the 2516m deep Outokumpu Deep Drill Hole in eastern Finland drilled in 2004-2005 into a Palaeoproterozoic formation with metasedimentary rocks, ophiolite-derived altered ultramafic rocks and pegmatitic granite. The down-hole temperatures have been logged five times after end of drilling and extend to day 948 after drilling. The hole is completely cored (79% core coverage) and thermal conductivity measurements were done at 1m intervals. The geothermal results on temperature gradient, thermal conductivity and heat flow density yield an exceptionally detailed data set and indicate a significant vertical variation in gradient and heat flow density. Heat flow density increases from about 28 - 32mWm-2 in the uppermost 1000m to 40-45mWm-2 at depths exceeding 2000m. The estimated undisturbed surface heat flow value is 42mWm-2. We present results on forward and inverse transient conductive models which suggest that the vertical variation in heat flow can mostly be attributed to a palaeoclimatic effect due to ground surface temperature (GST) variations during the last 100,000years. The modeling suggests that the average GST was about -3 to -4°C during the Weichselian glaciation. Holocene GST values are within ±2° from the present average GST in Outokumpu (5°C). The topographic hydraulic heads and hydraulic conductivity of crystalline rocks are low which suggests that advective heat transfer in the formation is not significant. The slow replacement of fresh flushing water by saline formation fluids is observed in the hole, but it does not generate significant thermal disturbances in the logs. On the other hand, free sluggish thermal convection is present in the large diameter (22cm) borehole, and temperature variations in the range of few mK to 0.01K occur over times of minutes to tens of minutes. Theory suggests that convection cells are about as tall as the drill hole diameter, and thus the free convection is expected to generate only local thermal 'noise' not affecting the general geothermal results. © 2011 Elsevier B.V. Article 2011 English 00319201 10.1016/j.pepi.2011.06.002 Physics of the Earth and Planetary Interiors 188 9 – 25 1-2 Baltic Shield; Finland; Calluna vulgaris; Boreholes; Climatology; Crystalline rocks; Flow of fluids; Glacial geology; Heat transfer; Hydraulics; Rock drills; Saline water; Thermal conductivity; Thermal logging; Conductive effects; Conductive model; Convection cell; Data sets; Drill hole; Eastern Finland; Fennoscandian Shields; Finland; Fluid flow effect; Geothermal gradients; Ground surface temperature; Heat flow density; Heat flows; Heat transfer process; High resolution; Holocenes; Hydraulic heads; Inverse transient; Large diameter; Metasedimentary rocks; Paleoclimatology; Saline formation; Surface heat flow; Temperature gradient; Temperature variation; Thermal conductivity measurements; Thermal convections; Thermal disturbance; Ultramafic rocks; Vertical variation; drilling; geothermal gradient; granite; heat flow; heat transfer; hydraulic conductivity; hydraulic head; paleoclimate; Proterozoic; thermal conductivity; thermal convection; ultramafic rock; Geothermal energy https://www.scopus.com/inward/record.uri?eid=2-s2.0-80053316188&doi=10.1016%2fj.pepi.2011.06.002&partnerID=40&md5=83142dafe7f07718ebf3116dd0346bb7 Cited by: 39 Ilmo T. Kukkonen Volker Rath Liisa Kivekäs Jan Šafanda Vladimir Čermak article Kukkonen2011181 We present high resolution geothermal results from the 2516 m deep Outokumpu Deep Drill Hole in eastern Finland drilled in 2004-2005 into a Palaeoproterozoic formation with metasedimentary rocks, ophiolite-derived altered ultramafic rocks and pegmatitic granite. Detailed geothermal studies of deep drill holes provide insights into heat transfer processes in the crust, and allow the separation of different factors involved, such as palaeoclimatic and structural conductive effects as well as advective fluid flow effects. The down-hole temperatures of the Outokumpu hole have been logged five times following the end of drilling and extend to day 948 after drilling. The hole was continuously cored (79% core coverage) and thermal conductivity was measured at 1-m intervals. The temperature gradient, thermal conductivity and heat flow density results yield an exceptionally detailed geothermal data set and indicate significant vertical variation in the gradient and heat flow density. This result has important implications for correcting shallow (<1 km) heat flow data in the Fennoscandian Shield. The heat flow density was determined to increase from about 28-32 mW m-2 in the uppermost 1000 m to 40-45 mW m-2 at depths exceeding 2000 m. The estimated undisturbed surface heat flow value was 42 mWm-2. We present results based on inverse transient conductive models that suggest that the vertical variation in heat flow can mostly be attributed to a palaeoclimatic effect due to ground surface temperature (GST) variations during the last 100,000 years. The modelling suggests that the average GST was about -3...- 4 °C during the Weichselian glaciation. Holocene GST values are within ±2 degrees of the present average GST in Outokumpu (5 °C). The topographic hydraulic heads and hydraulic conductivity of crystalline rocks are low, which suggests that advective heat transfer in the formation is not significant. The slow replacement of fresh flushing water by saline formation fluids is observed in the hole, but it does not generate significant thermal disturbances in the logs. On the other hand, free sluggish thermal convection is present in the large diameter (22 cm) borehole, but it generates only local thermal 'noise' in the range of 0.001-0.01 K not affecting the general geothermal results. Article 2011 English 978-952217152-8 07828535 Special Paper of the Geological Survey of Finland 2011 Kukkonen I.T. 181 – 198 51 Baltic Shield; Finland; Ita Suomen; Outokumpu; Calluna vulgaris; borehole; crystalline rock; geothermal gradient; granite; heat flow; heat transfer; hydraulic conductivity; hydraulic head; metasedimentary rock; paleoclimate; surface temperature; temperature gradient; thermal conductivity; thermal convection; ultramafic rock https://www.scopus.com/inward/record.uri?eid=2-s2.0-80051915212&partnerID=40&md5=5b3bc4b199c1677a83b2af74165a2ae4 Cited by: 5 Ilmo T. Kukkonen Volker Rath Liisa Kivekäs Jan Šafanda Vladimir Čermak article Piribauer2011169 Fluid inclusions in quartz veins in the Outokumpu Deep Drill Core are characterised by high salinities and high homogenisation temperatures in excess of 330 °C. In addition to an aqueous phase, fluid inclusions also contain gaseous phases such as CO2 and CH4. The cation ratios of the dissolved salts are higher than seawater, with Li/Na ratios indicating the influence of magmatic water in deeper parts of the drill hole. Stable isotope (δD, δ18O) signatures point to a metamorphic origin of the palaeofluids. Deep groundwaters in the Outokumpu crystalline basement deviate significantly from fluid inclusions in their stable isotope ratios, which plot to the right of the global meteoric water line in a δD, δ18O diagram. This suggests that they may have formed as a mixture of meteoric and saline waters. In addition, Cl/Br and Na/Br ratios point to chemical exchange with the host rocks. Many models have been proposed to account for the enhanced salinity of deep groundwaters and the shift in the stable isotopes, but our data indicate that the saline fluids are primarily derived through water-rock interaction. The role of fluid inclusions as important contributors to the saline fluids is not supported. Article 2011 English 978-952217152-8 07828535 Special Paper of the Geological Survey of Finland 2011 Kukkonen I.T. 169 – 180 51 Finland; Ita Suomen; Outokumpu; fluid inclusion; groundwater; host rock; isotopic ratio; meteoric water; oxygen isotope; quartz vein; salinity; stable isotope; water-rock interaction https://www.scopus.com/inward/record.uri?eid=2-s2.0-80051878476&partnerID=40&md5=d8edb04984bcbe0c06590a774b3ef3f0 Cited by: 6 Christoph J. Piribauer Sven Sindern F. Michael Meyer Torsten W. Vennemann Walter Prochaska article Itävaara2011295 This paper demonstrates the first microbiological sampling of the Outokumpu deep borehole (2516m deep) aiming at characterizing the bacterial community composition and diversity of sulphate-reducing bacteria (SRB) in Finnish crystalline bedrock aquifers. Sampling was performed using a 1500-m-long pressure-tight tube that provided 15 subsamples, each corresponding to a 100-m section down the borehole. Microbial density measurements, as well as community fingerprinting with 16S rRNA gene-based denaturing gradient gel electrophoresis, demonstrated that microbial communities in the borehole water varied as a function of sampling depth. In the upper part of the borehole, bacteria affiliated to the family Comamonadaceae dominated the bacterial community. Further down the borehole, bacteria affiliated to the class Firmicutes became more prominent and, according to 16S rRNA gene clone libraries, dominated the bacterial community at 1400-1500m. In addition, the largest number of bacterial classes was observed at 1400-1500m. The dsrB genes detected in the upper part of the borehole were more similar to the dsrB genes of cultured SRBs, such as the genus Desulfotomaculum, whereas in the deeper parts of the borehole, the dsrB genes were more closely related to the uncultured bacteria that have been detected earlier in deep earth crust aquifers. FEMS Microbiology Ecology © 2011 Federation of European Microbiological Societies. No claim to original Finnish government works. Article 2011 English 15746941 10.1111/j.1574-6941.2011.01111.x FEMS Microbiology Ecology 77 295 – 309 2 Bacteriological Techniques; Biodiversity; Colony Count, Microbial; DNA, Bacterial; Finland; Gene Library; Phylogeny; RNA, Ribosomal, 16S; Sulfur-Reducing Bacteria; Water; Water Microbiology; Baltic Shield; Finland; Ita Suomen; Outokumpu; Bacteria (microorganisms); Comamonadaceae; Desulfotomaculum; Firmicutes; uncultured bacterium; bacterial DNA; RNA 16S; water; aquifer; bacterium; bedrock; borehole; community composition; crystalline rock; dominance; electrokinesis; extremophile; groundwater; microbial community; sampling; species diversity; vertical distribution; article; bacterial count; biodiversity; chemistry; classification; Finland; gene library; genetics; Gram negative anaerobic bacteria; isolation and purification; microbiological examination; microbiology; phylogeny https://www.scopus.com/inward/record.uri?eid=2-s2.0-80955177493&doi=10.1111%2fj.1574-6941.2011.01111.x&partnerID=40&md5=6bba1ae811bc7c3425f6c995bc9940d5 Cited by: 101; All Open Access, Bronze Open Access Merja Itävaara Mari Nyyssönen Anu Kapanen Aura Nousiainen Lasse Ahonen Ilmo Kukkonen article Gorbatsevich2011207 We present the results of laboratory measurements of the elastic and nonelastic properties of drill core samples from depths of 94-2298 m in the Outokumpu Deep Drill Hole, eastern Finland. A total of 43 cubic rock samples were prepared (30-40 mm side length) and measured with the method of acoustopolariscopy under ambient conditions. In addition, the average velocities were calculated from the modal composition of the rocks. The measurement results provide the complete velocity matrices of the samples with the main components of P-waves as well as S-waves and their anisotropy factors. From the surface down to a depth of ∼1300 m (mostly metasediments), the Outokumpu rocks were found to be strongly anisotropic. The lowest measured anisotropy values were observed in the ∼1300-1600 m depth range (ophiolite-derived altered ultramafic rocks and metasediments). In the lower part of the hole from 1600 m to the hole bottom (metasediments and pegmatitic granite), the velocity anisotropy was variable. The effect of linear acoustic anisotropic absorption (LAAA) is exhibited in samples from the upper and lower sections of the drill hole. We attribute the variations in P- and S-wave velocities and their anisotropies to the variation in rock types and the drilling-induced relaxation of pressure (and to a minor degree temperature), which has resulted in decompaction and the formation of micro-cracks in the drill core. Therefore, a linear decrease in seismic velocities as a function of depth is observed in the laboratory measurements. Article 2011 English 978-952217152-8 07828535 Special Paper of the Geological Survey of Finland 2011 Kukkonen I.T. 207 – 218 51 Finland; Ita Suomen; Outokumpu; borehole; crystalline rock; elastic property; igneous rock; laboratory method; metamorphic rock; metasediment; microcrack; P-wave; S-wave; seismic anisotropy; seismic velocity; ultramafic rock https://www.scopus.com/inward/record.uri?eid=2-s2.0-80051883040&partnerID=40&md5=ed82bf2a730a5a391aaad1709b237d41 Cited by: 3 Felix F. Gorbatsevich Mikhail V. Kovalevsky Olga M. Trishina article Virgil201037 Article 2010 English 18163459 10.2204/iodp.sd.9.07.2010 Scientific Drilling 37 – 40 9 https://www.scopus.com/inward/record.uri?eid=2-s2.0-78651584355&doi=10.2204%2fiodp.sd.9.07.2010&partnerID=40&md5=4bd73f17271836f19ce00f01e8be243f Cited by: 8; All Open Access, Gold Open Access, Green Open Access Christopher Virgil Andreas Hördt Torsten Klein Jochem Kück Martin Leven Erich Steveling article Lassila2010178 P- and S-wave propagation velocities in dry mica schist samples obtained from the Outokumpu deep drill hole in Eastern Finland were measured under uniaxial compression in a custom built measurement device. At 300 MPa pressure the obtained velocities (5520 ± 130) m/s and (3270 ± 60) m/s, for P- and S-waves, respectively, agreed with those measured under triaxial compression, (5530 ± 200) m/s and (3300 ± 90) m/s. The increase in Vp with uniaxial pressure was steeper, whereas this was not the case with Vs. These results indicate that ultrasound velocity measurements can be performed under uniaxial compression without the need to alter the cylindrical geometry of a borehole sample. Results obtained with the device can improve the interpretation of seismic crustal structure maps by providing seismic velocity data of the Outokumpu drill core as well as seismic impedances and reflection coefficients measured under crustal conditions. © 2010 Elsevier B.V. Article 2010 English 09269851 10.1016/j.jappgeo.2010.09.001 Journal of Applied Geophysics 72 178 – 183 3 Finland; Ita Suomen; Outokumpu; Core drilling; Cylinders (shapes); Mica; Rock drills; Seismology; Shear waves; Silicate minerals; Ultrasonic velocity; Ultrasonic velocity measurement; Ultrasonics; Wave propagation; Crustal structure; Cylindrical geometry; Drill core; Drill hole; Eastern Finland; Fennoscandian Shields; Measurement device; Mica schists; P- and S-waves; Reflection coefficients; Seismic impedance; Seismic velocities; Triaxial compression; Triaxial loading; Ultrasound; Uni-axial compression; Uniaxial pressures; Wave propagation velocities; compression; crustal structure; data interpretation; geometry; P-wave; S-wave; seismic reflection; seismic velocity; uniaxial strength; wave propagation; Velocity https://www.scopus.com/inward/record.uri?eid=2-s2.0-78649477486&doi=10.1016%2fj.jappgeo.2010.09.001&partnerID=40&md5=c7f60e26e26acc303ce8e3a6a074c1d2 Cited by: 10 I. Lassila R. Karlqvist T. Elbra F.K. Gates L.J. Pesonen E. Hæggström article Kern2009151 The Outokumpu scientific deep drill hole intersects a 2500 m deep Precambrian crustal section comprising a 1300 m thick biotite-gneiss series (mica schists) at top, followed by a 200 m thick meta-ophiolite sequence, underlain again by biotite gneisses (mica schists) (500 m thick) with intercalations of amphibolite and meta-pegmatoids (pegmatitic granite). From 2000 m downward the dominating rock types are meta-pegmatoids (pegmatitic granite). Average isotropic intrinsic P- and S-wave velocities and densities of rocks were calculated on the basis of the volume fraction of the constituent minerals and their single crystal properties for 29 core samples covering the depth range 198-2491 m. The modal composition of the rocks is obtained from bulk rock (XRF) and mineral chemistry (microprobe), using least squares fitting. Laboratory seismic measurements on 13 selected samples representing the main lithologies revealed strong anisotropy of P- and S-wave velocities and shear wave splitting. Seismic anisotropy is strongly related to foliation and is, in particular, an important property of the biotite gneisses, which dominate the upper and lower gneiss series. At in situ conditions, velocity anisotropy is largely caused by oriented microcracks, which are not completely closed at the pressures corresponding to the relatively shallow depth drilled by the borehole, in addition to crystallographic preferred orientation (CPO) of the phyllosilicates. The contribution of CPO to bulk anisotropy is confirmed by 3D velocity calculations based on neutron diffraction texture measurements. For vertical incidence of the wave train, the in situ velocities derived from the lab measurements are significantly lower than the measured and calculated intrinsic velocities. The experimental results give evidence that the strong reflective nature of the ophiolite-derived rock assemblages is largely affected by oriented microcracks and preferred crystallographic orientation of major minerals, in addition to the lithologic control. © 2009 Elsevier B.V. All rights reserved. Article 2009 English 00319201 10.1016/j.pepi.2009.03.009 Physics of the Earth and Planetary Interiors 175 151 – 166 3-4 Anisotropy; Crystallography; Curve fitting; Elasticity; Fatigue of materials; Granite; Intercalation; Lithology; Mica; Mineralogy; Mining; Rock drills; Rocks; Seismic waves; Seismology; Shear waves; Silica; Silicate minerals; Single crystals; Three dimensional; Velocity; 3d velocities; Biotite gneiss; Bulk rocks; Crustal rocks; Crystallographic orientations; Crystallographic preferred orientations; Depth ranges; Elastic wave velocities; In-situ; Intrinsic velocities; Least squares fittings; Lithologic controls; Measured and calculated elastic properties; Mica schists; Micro probes; Mineral chemistries; Modal composition; Nature of seismic reflections; Outokumpu deep drill hole; Precambrian; Rock types; S-wave velocities; Seismic anisotropies; Seismic measurements; Shallow depths; Shear-wave splitting; Single-crystal properties; Strong anisotropies; Texture measurements; Velocity anisotropies; Wave trains; crustal structure; crystallography; drilling; elastic wave; granite; laboratory method; least squares method; mica; neutron diffraction; numerical model; P-wave; S-wave; schist; seismic anisotropy; seismic reflection; wave velocity; Minerals https://www.scopus.com/inward/record.uri?eid=2-s2.0-67349098374&doi=10.1016%2fj.pepi.2009.03.009&partnerID=40&md5=cf12770420787e4110327ad463a480d7 Cited by: 56; All Open Access, Green Open Access H. Kern K. Mengel K.W. Strauss T.I. Ivankina A.N. Nikitin I.T. Kukkonen