The geology of the northern part of the Aurora district

Abstract

An advance, blue-line topographic map of the Aurora quadrangle was available from the US Geological Survey, and, in addition, a planimetric map of the same quadrangle was available from the U. £. Forest Service, along with the aerial photographs from which the planimetric map was constructed. The necessary parts of these naps were enlarged to a scale of 1:24,000. The geology was plotted on the aerial photographs in the field and later transferred to the enlarged maps by means of a Kail radial planimetric plotter. Cross-sections and formation thicknesses were obtained from this final map.