Norra Metals Corp. announced that it has completed ~327-line kilometers, or 59.3 Km2, helicopter airborne magnetic, electromagnetic and radiometric survey over the entire area of the Bleikvassli Project ("Bleikvassli" or the "Project") in northern Norway. The objective of the survey was to obtain a dense high resolution magnetic, electromagnetic and radiometric dataset over the Bleikvassli area merging the reprocessed 1993 data in conjunction with this new survey.

The final dataset results of a 100m line spacing that will aid in general understanding of the regional geology of the area as well as better definition of the previously selected targets and identify new ones. The survey was flown by NGU (Norwegian Geological Survey) with a 200m line spacing with 135º azimuth, with tie lines at 1000m distance from each other. The height clearance for the magnetometer and the electromagnetic probe was 49.5m and for the spectrometer was 79.5m.

NGU had flown over the same area in 1993 and the new flight was intended to intercalate the new flight lines with old ones in a way to increase data density and resolution (Figure 1). The magnetic and radiometric data from 2021/22 were merged with the data from 1993, with exception for the electromagnetic survey due to the different type of instruments and transmission frequencies. NGU used a modified Hummingbird electromagnetic and magnetic system installed in a Eurocopter AS350-B3 (LN-OSD) helicopter designed to obtain low level, low speed detailed airborne magnetic and electromagnetic data.

The system was supplemented by 1024 channel gamma ray spectrometer to acquire radiometric data. The magnetic data were recorded at 0.2 second intervals resulting in approximately 6m average point spacing. The data was visually inspected and spikes were removed and after several corrections were applied before gridding.

The electromagnetic data were recorded at 0.1 second intervals resulting in data with a sample increment of 3m along the ground on average. The electromagnetic system transmits five fixed frequencies and records an in-phase and a quadrature response for each of the four coil sets of the system. The received signals were processed and used for computation of an apparent resistivity.

The radiometric data were recorded every 1 second intervals giving a point spacing of approximately 29.8m. The radiometric data were processed using standard procedures recommended by International Atomic Energy Association (IAEA). For quality control, the surveys, altitude and navigation data were monitored on four separate windows in the operator's display during the flight while they were recorded in three streams to the PC hard drive.