With demand for lithium predicted to continue increasing in the coming years, lithium exploration and the development of recovery techniques to extract it will become increasingly important. Lithium is particularly important for the energy transition due to its use in lithium-ion batteries. A major source of lithium are Lithium-Caesium-Tantalum (LCT) pegmatites. Lithium is contained within spodumene crystals and these are therefore the focus of most extraction techniques. The main objective of this study was to create an overview of the lithium distribution in lithium pegmatites based on textural and mineralogical information, combined with elemental analysis using Laser Induced Breakdown Spectroscopy (LIBS). The purpose was to improve the understanding of spodumene characteristics in lithium pegmatites which could affect lithium exploration and recovery.
Six samples from two different lithium pegmatite fields were analysed. Four samples were from the Bergby pegmatite field in Sweden and two samples were from the Bougouni pegmatite field in Mali. Petrographic descriptions were made to understand the mineralogy and textures of spodumene and LIBS analysis was used to measure lithium concentrations across profiles on a micrometre scale. Notable features in the Bergby (Sweden) samples included recrystallised, fine grained spodumene in uneven rims around the primary spodumene crystals as well as in the finer grained groundmass. The average lithium content measured for spodumene from the block samples was between 1.4 to 2.1 wt % Li, which is lower than the commonly measured range for spodumene of 2.8 to 3.5 wt % Li (Aylmore et al., 2018). LIBS analysis on the thin sections was attempted and showed higher average lithium content in the micrometre-scale fractures in the spodumene than in the surrounding spodumene crystal. The results of this thesis show that the majority of the lithium remains contained within primary spodumene crystals in lithium pegmatites but lower concentrations are also present in certain locations in the surrounding rock. Additionally, it indicates that the Keyence EA-300 may not be suitable for Li detection in spodumene crystals due to the significant differences in lithium concentration between thin section and block sample measurements. In future it would be critical to consider factors such as matrix effects, sample preparation and calibration of the Keyence EA-300 for true quantitative analysis of lithium content in spodumene.

Measuring and analyzing the tunnel deformation through convergence measurements and cross-correlation with geological mapping is essential for understanding and controlling tunnel stability, worker safety and predicting failure zones. In order to achieve this, a new device, the so-called GroundProbe GML is tested and analyzed in this study. Currently, the deformation in the Kristineberg mine is measured through conventional techniques, such as the tape extensometer, that are labor intensive and time-consuming. On top of that, the geological mapping is done by visual inspection by experienced geologists. There is no system in place that correlates the geological setting to the deformation of the tunnels. This research aims to explore the possibility to quantify tunnel wall convergence and correlate the movement to geological circumstances. An accuracy analysis is performed, to identify the accuracy of the Light Detection and Ranging (LiDAR) technology in comparison to conventional techniques. This analysis is conducted in both a controlled (above-ground) and an uncontrolled (underground) environment and focuses on the use of different targets, i.e. prisms or reflectors, and the difference between continuous and periodic measurements. The fresh rock surfaces are also mapped by means of geological LiDAR data as well as Red-Green-Blue (RGB) image analysis and this is correlated with tunnel wall convergence. This is done to increase the understanding of the impact of the geological setting on the tunnel wall convergence.
The accuracy presented by GroundProbe of _3 mm for periodic measurements is difficult to achieve in an underground environment with mining activity. Especially the deformation of measurement points that are at a more oblique angle to the scanner prove to be difficult to assess. The geological LiDAR data can be used to distinguish different rock types and geological features with limited subjectivity. The transition zones from one rock type to the other become clearly visible from the geological LiDAR data. Additionally, geological features such as joints can be identified when combining LiDAR data with RGB image analysis. The primary promotor of tunnel wall convergence is the hanging wall that pushes down on the foot wall in combination with non-uniform waste rock areas, that are for example split into two sections by a joint. In a tunneling environment where mining activities are conducted, such as the application of shotcrete, scaling, blasting and leveling of the floor, periodic measurements with a LiDAR set-up on a tripod are difficult. One of the main limitations is the absence of stable reference points that the LiDAR scanner uses to determine its XYZ-position. The oblique angle can also be a limiting factor, measurement points closer to the LiDAR scanner provide more reliable results. For continuous measurements however, this proves to be less relevant because the repositioning error can be omitted. The LiDAR scanning technology has the potential to be used as geological mapping tool based on the varying reflectivities of different rock types. By combining LiDAR technology with RGB image analysis, a more thorough understanding of the geological setting can be obtained. By relating this understanding to the quantification of the tunnel wall convergence, this technique can be used to correlate the geology to the movement of the rock mass.