Rank 1 vs Rank 4 Resolution Data

Comparison of rank 1 and rank 4 aeromagnetic surveys for geologic mapping of the Albuquerque Basin near Albuquerque, N.M. In this area, the shallowest magnetic sources (magnetic sediments and volcanic rocks) are at the ground surface, so the shallowest source depth is the same as the terrain clearance. The rank 4 survey is from a 1974 digitized contour map with line spacing of 1,609 meters (m) and average terrain clearance of 621 m (ratio of 2.6). The rank 1 survey is from 1996–1997 data, taken with real-time GPS navigation. Line spacing and terrain clearance are 100–150 m (ratio of 1.0). Color scale is magnetic field strength in nanoteslas. QT is Quaternary-Tertiary; s is alluvium and basin-fill sediments; v is intrabasin volcanic rocks; Mz is Mesozoic sedimentary rocks on the basin flanks; thick black lines represent major basin faults. See Grauch and Hudson [2007] for more details.