Underground mining of the Kiirunavaara iron mineralization is causing large-scale deformation of the hangingwall of the orebody. To understand and possibly predict future deformation, a structural model of the hanging wall and a good understanding of the petrophysical and mechanical properties of the constituent rocks is necessary. This thesis presents results from the study of Anisotropy of Magnetic Susceptibility (AMS), magneto-mineralogy, fracture frequency (F/m), rock quality (RQD), rock strength (Point Load) and P-wave velocity and anisotropy of the rocks from the hanging wall, as well as seismic reflection surveying and gravity modelling. The results are combined into a structural model of the hanging wall and further used for analysis of the correlation between petrophysical and rock mechanical parameters.In total, 76 samples from 12 outcrops and 295 samples from three drillcores in the hanging wall have been included in the AMS study. Axial and diametrical P-wave velocity was measured on 25 water-saturated samples and 156 samples were used for the Point Load tests. F/m and RQD data for the drillcores already existed. The drillcores are located along the eastern end of the seismic profiles and consist of both crystalline and sedimentary rocks.A high degree of magnetic anisotropy observed in the crystalline rocks indicates a low degree of metamorphism. AMS data also indicates the presence of a magnetic foliation in the rocks. The dip of the magnetic foliation plane (F) and the degree of magnetic anisotropy (Pj) measured in samples from outcrops was plotted as iso-maps and shows that both F and Pj decreases towards the east, which was confirmed by data from the drillcores. The decrease in both parameters is primarily a reflection of a change in rock type, but is also changing within the crystalline rock sequence.A good correlation (r > 0.6) between Pj, and F and RQD, and F and F/m was observed in one drillcore for both crystalline and sedimentary rocks; and between the shape parameter (T) and F/m in crystalline rock in another drillcore. This suggests the AMS parameter may be used as an indicator of rock mechanical properties. AMS data was also correlated to joint strike orientations and it was concluded that AMS can also be used to predict joint orientation.Two parallel reflection seismic profiles were shot within the town of Kiruna i order to locate deformation zones and lithological boundaries in the hangingwall. No deformation zones were found, but five seismic reflectors corresponding to five lithological boundaries were located, and their strike and dip calculated. The result of the seismic survey was used to constrain the gravity model, as was density measurements of 230 samples from the drillcores. The gravity model has a depth of three km, and indicates that the crystalline rock in the hanging wall can be separated into two parallel N-S trending blocks. / Godkänd; 2011; 20111021 (maimos); DISPUTATION Ämnesområde: Tillämpad geofysik/Applied Geophysics Opponent: PhD Satu Mertanen, Geological Survey of Finland, Åbo Ordförande: Professor Sten-Åke Elming, Institutionen för samhällsbyggnad och naturresurser, Luleå tekniska universitet Tid: Måndag den 19 december 2011, kl 10.00 Plats: F531, Luleå tekniska universitet

The Bergslagen region has three base-metal mines operating today, and one of them is the Lovisa mine, which host a Zn-Pb-Ag deposit. The Lovisa mine is located in the Guldsmedshyttan area north of Lindesberg. The mine is part of in the X-Mine H2020 project that includes four different mines with the aim of an improved environmental resource management. The project aims at reducing the environmental impact from transport, ore processing and chemical handling as well as result in lowering the costs per produced amount of metal. The purpose for this thesis is to determine the petrophysical characteristics of the host rocks to the thin tabular mineralised units in the Lovisa mine with petrophysics. Petrophysics is used to obtain information about the physical properties of rocks, which is then is integrated with geophysics and the geology, to obtain an improved understanding about the different geophysical anomalies. The petrophysic methods used here, reviled three different physical properties of the rocks: density, magnetic volume susceptibility and natural remanent magnetization. These properties were measured on five different drill cores and correlated with the literature data and lithologies of the core. The lithologies close to the ore correspond to literature data for volcanic siltstone, volcanic sandstone, massive rhyolite, skarn (calc-silicates) and dolomite. Dolomite is not present in the cores and corresponds to breccia, volcanic sandstone and skarn. My conclusion for this method, is that in order to do a lithological interpretation based on the measured petrophysical properties, is that a good knowledge of the lithologies as well as a good understanding of the geological processes that have affected the rocks in the investigated area are required. / I Bergslagen finns det idag tre aktiva gruvor som bryter sulfidmalm, och en av dem är Lovisagruva som är en malmkropp Zn-Pb-(Ag)-malm. Lovisagruvan ligger i Guldsmedshytteområdet, norr om Lindesberg. Gruvan är en del av X-Mine-projektet som bl.a. undersöker små, komplexa malmkroppar i syfte att reducera miljöpåverkan och effektivisera produktionen. Syftet med detta kandidatarbete är att bestämma petrofysiska egenskaper hos lithologin i det malmnära sidoberget vid Lovisagruva. Petrofysik används för att ta reda på bergets fysikaliska egenskaper, och dessa egenskaper används sedan inom geofysik, för att få en förståelse för de olika avvikelser som visas i andra geofysiska mätningar. De petrofysiska mätningarna som utfördes, gav tre fysikaliska egenskaper hos varje prov, densitet, magnetisk susceptibilitet och den naturliga magnetiska remanensen. Resultaten från varje prov korrelerades sedan med litteraturdata och jämfördes med borrkärneloggar från Lovisa. De petrofysiska mätningarna utfördes på prover från fem olika borrhål. Resultatet visar att det malmnära sidoberget korrelerar med litteraturdata på vulkanisk siltsten, vulkanisk sandsten, kalksilikat, ryolit, skarn och dolomit. Dolomit finns inte i kärnorna utan representeras av bl.a. breccia, vulkanisk sandsten och skarn. Min slutsats är att det går att bestämma lithologin med dessa fysikaliska egenskaper, men man måste ha en god kännedom om vilka bergarter som förväntas att förekomma i området samt vilka geologiska processer som påverkat dem. / H2020 X-mine