The use of a geophysical method in mineral prospecting dates back to the beginning of the seventeenth century. The primitive but adequate magnetic method then used in search of the highly magnetic iron ores was perhaps as important to the general economy of the seventeenth and eighteenth centuries as are the modern methods to the economy of the present day. Despite considerable experimentation with the magnetic and other principles the present extensive development of physical methods in geological exploration was delayed until it came almost explosively in the 5 years, 1925-1929.
Neither the history of geophysics nor even of its methods is covered by this paper. The term “Geophysics” generally includes the application of physical principles to problems of the earth; hydrology, meteorology, geodesy, seismology, terrestrial magnetism, and vulcanology all have a common bond in their interest in some special phase of the physics of the earth. The history traced herein is concerned only with those methods which are used in mineral prospecting.
Figures & Tables
Published in celebration of the Geological Society of America’s 50th anniversary, this 578-page volume presents the progress in geology from 1888 to 1938. Written to serve as a comprehensive summary, both for the generalist and the specialist, it explores the fundamental fields of geology, including physiography, glacial geology, oceanography, invertebrate paleontology, vertebrate paleontology, prehistoric archeology, paleobotany, stratigraphy, sedimentation, structural geology, pre-Cambrian, mineralogy, petrology, volcanology, geochemistry, general geophysics, seismology, ore deposits, petroleum geology, exploratory geophysics, and engineering geology.