Digital geologic mapping

Digital geologic mapping is the process by which geological features are observed, analyzed, and recorded in the field and displayed in real-time on a computer or personal digital assistant (PDA). The primary function of this emerging technology is to produce spatially referenced geologic maps that can be utilized and updated while conducting field work. Geologic mapping is an interpretive process involving multiple types of information, from analytical data to personal observation, all synthesized and recorded by the geologist. Geologic observations have traditionally been recorded on paper, whether on standardized note cards, in a notebook, or on a map. In the 21st century, computer technology and software are becoming portable and powerful enough to take on some of the more mundane tasks a geologist must perform in the field, such as precisely locating oneself with a GPS unit, displaying multiple images (maps, , aerial photography, etc.), plotting strike and dip symbols, and color-coding different physical characteristics of a lithology or contact type (e.g., unconformity) between rock strata. Additionally, computers can now perform some tasks that were difficult to accomplish in the field, for example, handwriting or voice recognition and annotating photographs on the spot. Digital mapping has positive and negative effects on the mapping process; only an assessment of its impact on a geological mapping project as a whole shows whether it provides a net benefit. With the use of computers in the field, the recording of observations and basic data management changes dramatically. The use of digital mapping also affects when data analysis occurs in the mapping process, but does not greatly affect the process itself. Data entered by a geologist may have fewer errors than data transcribed by a data entry clerk. Data entry by geologists in the field may take less total time than subsequent data entry in the office, potentially reducing the overall time needed to complete a project.