M. J. Grolier, and J. M. Boyce, 19840101, Geologic map of the Borealis region Mercury: , https://doi.org/10.5066/P9Y1PE26.
Summary
Most of the photographs used for geologic mapping were acquired by the departing spacecraft during the first pass (Mercury I). The Mercury II encounter provided no usable images of the map area; two low-oblique photographs suitable for geologic mapping were acquired during the third flyby on March 17, 1975 (Davies and others, 1978, p. 31). No stereoscopic phtographic pairs are available for the Borealis region.
Summary
Most of the photographs used for geologic mapping were acquired by the departing spacecraft during the first pass (Mercury I). The Mercury II encounter provided no usable images of the map area; two low-oblique photographs suitable for geologic mapping were acquired during the third flyby on March 17, 1975 (Davies and others, 1978, p. 31). No stereoscopic phtographic pairs are available for the Borealis region.
Digitized 1:5,000,000-scale geologic map of the the Borealis quadrangle of Mercury. Originally mapped on Mariner 10 imagery the map was digitized as a GIS product in 1999. The polygon shapefile has been smoothed and transformed to align with the more current 2013 Messenger basemap. Then a polyline feature was created and attributed with contact type.