Geoconsult Global Ltd. Services

Exploration and Mining Consultants

Thiel Surface Impedance Method

The Thiel Surface Impedance Method (TSIM) enables low cost, minimal impact appraisal of subsurface geology and structure. This technique allows the interpreter to accurately delineate known geological features and identify previously unrecognised discontinuities. This has the potential to enable a considerable time and cost saving to be made when planning and implementing drilling programs to define the orebody.

The TSIM Tool is a passive surface electromagnetic device that uses VLF radio waves at a single frequency to measure apparent resistivity changes in the subsurface, thus enabling impedance measurements to be made. One person can easily manage field operation of the lightweight battery-powered equipment, making it a very cost-effective method for surface exploration work.

The light weight and passive nature of the tool also makes it a very safe device to operate.

The technique has proven particularly successful in locating the line of oxidation (LOX) at various sites in the central Queensland coalfields. This has resulted in a significant reduction of LOX drilling and considerable cost saving.

TSIM has proven useful in the identification of geological structures such as dykes and faults.

The TSIM Tool has also demonstrated success in mineral exploration and mining, including the determination of the extent of mineralisation boundaries in sulphide deposits.

The instrument has considerable hydrogeological applications. It can be used to provide details on the water table, including the presence of palaeochannels and perched aquifers.

TSIM is a powerful, cost effective tool. It is versatile, safe and has the potential to provide invaluable data in many diverse environments.

Measurements of the magnetic field, electric field and phase are used to calculate the apparent resistivity and phase angle at each point on the traverse. The lateral conductivity changes as present at the line of oxidation, faulting or intrusions provide strong geophysical anomalies that can be mapped by TSIM.

GeoConsult Global Ltd provides a complete service from survey planning and design, access to the TSIM equipment, data acquisition, interpretation and professional reporting. GeoConsult Global Ltd welcomes any inquiries regarding TSIM data interpretation.