b'Minerals geophysics Minerals geophysicsAspects of innovation II for use in a wide range of resistivity environments, and a past user of the technique in ground surveys, continued In this issue of Preview, we have anotherdevelopment of an airborne version is in the series by geophysical contractorsdefinitely of interest. I invite you to read and consultants who are innovators inAndrews contribution below.their field. Andrew Carpenter from Expert Geophysics describes aspects of theAnd, as I wrote in the last issue of Preview, development of the MobileMT system,if you or your organisation have a story an advance in airborne magneto-telluricsof innovation in mineral exploration (MT) surveying. As a proponent of MTgeophysics youd like to tell, please get in touch. Wed love to hear it.Terry Harvey Associate Editorfor Minerals geophysicsterry.v.harvey@glencore.com.auExpert Geophysics driving ground-breaking new developments in airborne AFMAG technologyAndrew Carpenter Expert Geophysicsandrew@expertgeophysics.comAustralia is an ancient continent, and much of its undiscovered mineral wealth is masked by a thick cover of weathered rock, regolith, sediment, and soil, posing formidable exploration challenges.MobileMT in the Patterson Ranges.Mineral explorers lack the technological tools to discover new resources buriedharmonic magnetic field source, werepersist that restrict the use of the time-beneath the cover. Expert Geophysics,under constant development and activedomain AEM principle, including:a Canadian company with offices inuse during the last century. After many Toronto, Perth, and Johannesburg, isdecades of service, the frequency-domainThe depth of investigation only leading the development of the latestmethod remains limited in its depth ofsometimes meets exploration Airborne EM technologies capable ofinvestigation despite being sensitive torequirements, especially in conductive penetrating Australias deep and highlya broader range of resistivities. Time- environments and areas with conductive cover. domain systems (TDEM) excited by a stepconductive overburden.pulse have replaced frequency-domainThe measured signal and depth of Historically, airborne electromagneticsystems for most exploration applicationsinvestigation are highly dependent on induction methods (AEM) with controlleddue to a greater depth of investigation.the transmitter height, tilt, and geometry.primary field sources have been givenMany improvements to airborne time- This dependence creates difficulties attention by many specialists. Frequency- domain systems were achieved during theand restrictions for surveys in rugged domain systems (FDEM), which use alast 20 years. However, several limitationsterrain.33 PREVIEW AUGUST 2023'