
Phillip Hallof earned his status as one of the “fathers of modern geophysics” for his pioneering and innovative work in the field of frequency domain induced polarization (IP), which grew from an obscure research effort into an essential exploration tool. He contributed in many ways to the research and development of geophysical equipment, techniques and interpretation, and also provided technical expertise to the mineral exploration industry through his leadership of McPhar Geophysics Inc. and later Phoenix Geophysics. Another legacy of his 35-year career was aiding the discovery of mineral wealth for the benefit of Canada and the global economy.
Hallof was born in St. Louis, Missouri, and educated at the prestigious Massachusetts Institute of Technology (MIT), where he earned a bachelor’s degree in geology (geophysics option) in 1952. While still a graduate student, he undertook research into the then-novel, variable frequency IP method being developed by Newmont Exploration and demonstrated that it gave measurable responses over certain known sulphide deposits. The technology was further refined and successfully field tested, resulting in a valuable new tool to help identify buried mineral deposits that were not conductive and which conventional electromagnetic (EM) surveys could not detect. He also created a new and useful mode ofdisplaying multi-spaced IP and resistivity data in the now standard pseudosection format.