Details of the abstract
Title of paper | The use of the ‘’floating’’ S-plane for effective interpretation of airborne TEM data |
List of authors | Author Hallbauer-Zadorozhnaya, Co-author Stettler E. |
Affiliation(s) |
AeroPhysX (pty) Ltd, South Africa University of Witwatersrand, South Africa |
Summary |
B-field TEM data due to a pulsing ground loop and collected with a DJI 600Pro hexacopter with MagArrow magnetometer as well as helicopter borne VTEM dB/dt data was modelled with the ‘floating’ S-Plane interpretation technique. The former stems from the Flat Mine North copper deposit and the later was recorded at the Hondekloof nickel occurrence, both in South Africa. Since interpretation routines for B-Field recordings are not well known the main objective of our research was to develop a single procedure for the interpretation of B- and dB/dt airborne TEM data. For the drone survey a transmitter (Tx) loop 1000x800 m2 in size, on the ground and a MagArrow magnetometer below the drone was used as receiver to record both the magnetic and TEM variations. Soundings were recorded both inside and outside the Tx loop (up to ~500 m from all sides) and are 15m apart resulting in a total of about 1000 TEM soundings. After digital separation of the magnetic and electromagnetic field components a modified method for calculating the apparent longitudinal conductivity S (Stau) was applied. Firstly, the parameters of an equivalent conducting S-plane with longitudinal conductivity at a fixed depth, are determined. Then the theoretical emf curve was calculated for known parameters of the “floating” plane. To comply with the conditions of the near zone, the calculation of theoretical curves was carried out for the in-loop configuration but simulated by using Tx loops with smaller dimensions. Then Sas a function of depth H was calculated according to the well-known usual technique and converted into a resistivity voxel showing possible deeper ore bodies. For the VTEM data at Hondekloof the classical method of calculation SH)was used, taking into account the excess of the transmitter-receiver configuration above the ground. At the site, exposed ore bodies are reflected in zones of increased longitudinal conductivity. Numerous anomalies have been identified, possibly associated with unexplored reserves of nickel ores. |
Session Keyword | 3.0 Exploration, Monitoring and Hazards |
File upload |
3.0_the_use_of_the_______floa_hallbauer-zadorohnaya_08.pdf
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