Petrophysic of the Host-rock to the Ore in the Lovisa Mine, Bergslagen

Sammanfattning: 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.