Map location literacy—How well does Johnny Geologist read?

The geographic information published in the geologic literature of the United Stales is inadequate to locate many, perhaps most, described localities. Precise location information can most easily and accurately be determined and conveyed by use of the Universal Transverse Mercator (UTM) grid. This grid can be read to 10 m × 10 m from standard modern maps. Geographic coordinates are an adequate and acceptable substitute of slightly lower precision when read to 1″ × 1″ of latitude and longitude. This paper evaluates and describes the use of both location systems to these precisions and includes suggestions for their use. Other systems are imprecise or inadequate (or both) for modern scientific work and should be avoided.