Virtual Silurian Reef -- Geological Field Work

MEASUREMENT OF A STRATIGRAPHIC SECTION

Once a geologist determines the location of a site in space and time, descriptive features of the site, such as rock type, etc., may be recorded as simple field notes. For detailed work on the geology of a site, however, the geologist records data in the form of a measured section. In a measured section, observations of the rocks are made in order from oldest to youngest beds, and the thickness of each bed (or set of beds) is measured with a tape. Photos of the entire section and individual beds are also commonly taken for additional documentation.

Although measured sections can be described as written notes, they are often recorded as a graphic plot. The beds are drawn to scale, and alongside each bed, information on features such as rock type, color, sedimentary structures, and fossil content is noted. This is an example of the field data collected as a measured section at point C in the study quarry at Lime Kiln Park.