The most basic step in fieldwork is locating a site of interest
on a map. In the United States, geologists and most other scientists who work in
the field use topographic maps published by the U.S. Geological Survey. These
maps show elevation as well as areal location. They also allow a point on the map
to be expressed as latitude and longitude, universal grid coordinates, or section,
township and range.
This example shows the location of the study quarry at Lime Kiln Park, Grafton, on a U.S. Geological Survey map named the Cedarburg 7.5 minute quadrangle. The map location can be specified in three ways: