Methodology:

TEM data were acquired with a Geonics PROTEM47 system consisting of a three-channel digital time-domain receiver unit, a three component multi-turn receiver coil (area 31.4 m2), and a TEM47 battery-powered transmitter. A 4x100 m square transmitter loop was laid out and the receiver coil was placed in the center of the square. Twenty-one TEM soundings were acquired every 500 m along a 10 km long profile. At each location the transmitter module was used to power 2 A of current around the 4x100 m square transmitter loop. A base frequency of 25 Hz was acquired with 30 measurement time gates, 30 second integration time, and seven stacks.

Furthermore, at each location the background noise was measured with the transmitter turned off.

For all soundings above the background noise level the raw data was converted from the raw field measurements (in Volts) to received voltages in Volts per amp meter squared (V/Am2). The error was calculated as one standard deviation from all seven stacks.

Sounding numbers 1,2,4,6,9,12,18, and 20 did not measure any data above the background noise level and therefore no data was processed to received voltages for these soundings.

Data collection:

The data were acquired using a Geonics PROTEM47 system consisting of a three-channel digital time-domain receiver unit, a three component multi-turn receiver coil (area 31.4 m2), and a TEM47 battery-powered transmitter.

Data quality:

Each sounding was recorded with an integration time of 30 second.

Sounding numbers 1,2,4,6,9,12,18, and 20 did not measure any data above the background noise level and therefore no data was processed to received voltages for these soundings.