| Summary: | Abstract. Kuusivaara in Sodankylä, Finland, is the planned site for mining infrastructure for the Sakatti Cu-Ni-PGE mine project by Anglo American plc, and knowledge of the Quaternary sediments in Kuusivaara is needed for the design and planning of the infrastructure. The aim of this thesis was to construct a 3D model of the Quaternary sediments in the Kuusivaara area to define the spatial distribution of the different sediment units within the area. The geochemical and hydrogeological properties of the sediments were also studied. The sedimentological data used in this study was obtained from test pits, soil drilling and peat coring logs, and ground penetrating radar profiles. A 3D model was created in the Leapfrog Geo software using the sedimentological data. The geochemistry of the sediments was studied with element analyses using aqua regia solution performed on recent sediment samples and archived till samples from 1973 and 1975. The solubility of metals and other substances was tested on a small number of samples using the two-step batch leaching test. The water permeability of the sediments was determined by slug tests in groundwater wells and by using empirical equations to estimate the water permeability based on the grain-size distributions of the sediment samples. The created 3D model consists of a framework stratigraphy with nine units developed for the study area based on the in situ sedimentological data. The units in the stratigraphy are, listed from the top: peat, surface sand, upper sandy till, gravel, inter-till sand, lower sandy till, silty till, weathered bedrock, and bedrock. In the 3D model, the upper sandy till is widely the only sediment unit overlying the weathered bedrock and bedrock in Kuusivaara. The surface sand is present on the ground surface in limited areas and widely present below the peat on the mire areas south of the Kuusivaara hill. The gravel and inter-till sand are found below the upper sandy till in limited areas, and the lower sandy till is found in most of those areas ...
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