Ben Snook

Ben Snook, BSc (Hons), MSc, MCSM

Department: Camborne School of Mines
Research Centre/Unit: Geology

Project Summary

Developing exploration tools for high purity quartz and rare metals in the south Norwegian Bamble-Evje pegmatite cluster

Project rationale: The pegmatites of the south Norwegian Bamble-Evje Pegmatite Belt (BEPB) are a potential source of high-purity (including solar-grade) quartz, ceramic feldspar, beryl and a wide range of rare metals. Exploration for high-purity quartz is driven by its increasing monetary and strategic value in the production of high-tech components such as solar cells and computer chips. As the purity of quartz cannot be determined in the field, its identification relies on sampling and laboratory analysis, which is expensive and has little value in determining the 3-D nature of potential deposits. Predictive exploration tools are therefore needed to target and assess pegmatites carrying high purity quartz and other potential commodities. To develop these requires a better understanding of the processes of pegmatite formation, including the origin of pegmatite melts, their evolution, emplacement mechanisms and interaction with host rocks. The proposed research complements existing studies on granite petrogenesis at the CSM and will form an important component of an established research programme at the NGU.

Key project objectives and methodologies: Exploration tools will be developed by testing the following hypotheses: 1) The pegmatites represent the final, most evolved volatile-rich melts from the emplacement of the Høvringsvatnet granites in southern Norway, rather than granite-unrelated melt batches mobilised during Sveconorwegian thrusting; 2) The purity of quartz is controlled by its temperature of crystallisation, linked to the extent of undercooling and by the alkalinity of the pegmatite melts; 3) Rare metals such as Be, Nb, Y, Ta, U, Th and Sc are enriched in certain pegmatites due to local undercooling and more extensive fractionation. The hypotheses will be tested by carrying out: 1) Geological mapping of representative pegmatites during a one month field campaign from mid September 2010 and two months in the summer of 2011; 2) Sampling and analysis (including dating) of pegmatite bulk samples, pegmatite-forming minerals (quartz, feldspar, mica) and accessory rare metal minerals (columbite, gadolinite, etc.) using electron microprobe, ICP-MS, XRF, XRD, cathodoluminescence and QEMSCAN; 3) Geophysical studies and 3D-modelling of pegmatites to determine the nature of the pegmatite bodies and relationships with local granites and structures; 4) U/Pb age determinations of zircons from representative pegmatites and local granites by laser ablation ICP-MS at NGU in Trondheim and SIMS at Nordsim in Stockholm; 5) Oxygen isotope studies on quartz and K-feldspar at Nordsim.

Supervisory Team

Dr. Ben Williamson, Prof. Frances Wall (University of Exeter - Camborne School of Mines - CSM) and Dr. Axel Müller (Geological Survey of Norway - NGU).

Wider Research Interests

Nickel Laterites; formation, mineralisation, analysis and extraction