GEOTEM

GEOTEM is a proven time-domain EM system with a long record of discoveries and successes in base metals, diamonds, uranium, coal, oil and gas, water mapping and geological mapping. GEOTEM systems have successfully flown over 2 million line kilometers of survey worldwide.

The GEOTEM system is installed on a Casa 212 aircraft which has been modified to carry a 6-turn transmitter loop, high resolution magnetometer and gamma-ray spectrometer. This aircraft configuration is best suited for survey operations up to 3,000 meters above sea level. 

The GEOTEM system has continuously been enhanced with the leading edge technology developed for the MEGATEM system. The difference between the two systems is the smaller diameter transmitter loop, hence a smaller dipole moment. The advantages of the GEOTEM system are:

860,000 Am² dipole moment

GEOTEM offers excellent depth penetration as demonstrated on surveys and tests carried out over the Caber deposit, Nighthawk and other deposits around the world.

Multiple receiver coils to measure X, Y & Z axis response

The additional data from the 3-axis receiver coils improves the interpretation of conductor location and orientation yielding more definitive information about conductor depth, shape, strike, dip, and lateral offset from the flight line.

25 / 30 / 75 / 90 Hz Transmitter frequency

The low frequency options are used to increase the depth of penetration in low resistivity environments. The higher frequencies provide better signal-to-noise ratios which improve depth penetration in high resistivity environments.

B-field, dB/dt, on-time, and off-time measurements

Expand the sensitivity range to weak conductors and very good conductors; e.g. nickel sulphides.

Early time measurements (broadband)

Broadband receivers allow collection of early time windows, improving sensitivity to weak conductors with rapid decay, such as alteration halos and zinc sulphides and increasing depth of penetration in resistive environments.

Large separation between transmitter and receiver coils

The combined effect of the GEOTEM geometry and dipole moment result in a large exploration footprint with good depth penetration.

GEOTEM is ideal for exploration and mapping surveys requiring good depth penetration and excellent data interpretation characteristics.

GEOTEM System Specifications

GEOTEM Waveform

With the flexibility of both selecting the base frequency of the transmitter to suit ground conditions and arranging the 30 receiving windows during the on-time and off-time, the GEOTEM system can be tuned to the most diagnostic response characteristics of the target being sought. For example, these settings may be different on a ground water exploration survey compared to a VMS survey.  

 

Nominal System Geometry