| Abstract |
We introduce the 3DGEm method for creating 3D geological maps using electromagnetics. The 3DGEm method captures ambient electric and magnetic data to create high-definition 3D geological maps to present subsurface models in two modes: Mode A features regions of inductance indices that chart lithological units, hydrogeological features or alteration zones; Mode B displays impedance coefficients that uniformly increment with depth, but readily disrupted by faults, sedimentary structures and lithological or geochemical boundaries. Unlike traditional geophysics which defines quantitative physical anomalies, 3DGEm data reveals qualitative geological models of the subsurface. Mode A images reveal patterns in geological materials that, in geothermal areas, may serve as fluid migration channels. Mode B create detailed images of faults and lithostratigraphic boundaries, unmasking interesting and unexpected structural features of geothermal significance, including mofette structures and Schli |