DIGITAL MAPPING AND RECORDING OF GEOLOGIC FIELD DATA IN A COMBINED SED/STRAT AND STRUCTURE COURSE

At Lafayette we have we have moved to digital collection, interpretation and presentation of all of structural and stratigraphic data in both Sedimentology/Stratigraphy and Structural Geology. Because analysis and interpretation of geologic data is commonly done using digital methodologies (GIS, Google Earth, Stereonet, spreadsheet and drawing programs), we have developed two iPad applications (apps) to digitally record and display structural (GeoFieldBook) and stratigraphic (StratLogger) field data. The apps are not geologic mapping programs, but rather ways of acquiring digital data directly so that it can then be used in display and analysis programs.

GeoFieldBook, using the onboard gps and image base, records observations and then displays them on the map base with strike/dip, fault or joint symbols correctly oriented. The app allows the user to select from five different structural data situations: contact, bedding, fault, joints and “other”. Observations are stored as individual records within a user defined project folder. The exact information gathered depends on the nature of the observation, but common to all pages is the ability to log date/time, lat/lon and pictures directly from the tablet. Map images are easily captured for use in other programs.

In StratLogger, the user records bed thickness, lithofacies, biofacies, and contact data in preset and modifiable fields. Each bed/unit record may also be photographed and location referenced by the iPad. As each record is collected, a column diagram of the stratigraphic sequence builds in the app, complete with color, lithology, and fossil symbols. The recorded data from any measured stratigraphic sequence can be exported as the live app-drawn column image.

The collection of the data in digital form allows for a much easier transition to digital interpretation and display once the students have returned from the field, since all data can be easily exported to a .csv file. The students' field reports (a substantive analysis of the depositional and deformational history of the mapped area) are also completed digitally. This includes the stratigraphic column, geologic and structural maps, cross-sections and stereoplots. Without the tedium of analog to digital transfers the student more quickly transitions from observation to interpretation.