As an innovation in the EU-funded H-2020 GREENPEG project (GA 869274), the Geological Survey of Norway (NGU) has developed a state-of-the-art piezoelectric seismograph (PES) as a valuable contribution to pegmatite exploration. The instrument utilizes the piezoelectric effect which describes the conversion of mechanical pressure into electrical energy, or vice versa. This technology has been leveraged to detect quartz, for gold exploration since the 1970s. NGU applied newest electrotechnology and data processing to customize it for granitic pegmatite exploration. The pilot was deployed in different settings e.g. at the GREENPEG demonstration sites in Tysfjord/Drag pegmatite field, Norway, where the pegmatite occurs in the Tysfjord granitic gneiss intrusion as lens-shaped bodies. The pegmatite mainly consists of feldspar, plagioclase, biotite, and a quartz core with dominant accessory minerals of Niobium, Yttrium and Fluorine (NYF). The survey detected buried quartz deposits at a depth of 5–10 m, using 100g minimal invasive explosive charges. The results were confirmed by drill cores. At another site in Tysfjord/Håkonhals the quartz was found at even 15–25 m depth embedded in the host rocks amphibolite and gneiss, using an 80 kg drop-weight with minimal environmental impact.
Since this novel piezoelectric seismograph is exclusively sensitive to the presence of quartz, it has a lower ambiguity compared to other geophysical methods applied in pegmatite exploration and is a sustainable and cost-efficient method for pegmatite exploration, both as a stand-alone method and in combination with other methods on brownfields and greenfields.