GeoFieldBook vs StraboTools

GeoFieldBook is designed for use in structural geology field mapping projects as a complement or replacement for the traditional paper field notebook and maps. The App integrates the iPad's GPS, camera, data management and mapping capabilities to allow geologists to record structural and formation information, automatically log geo-located data, link images to each record and input pre-defined formation names for different mapping areas. The records are then displayed in real-time on an image base (Apple) with strikes and dips displayed in the correct orientation and color-coded to the formation list. Field measurements and notes can be exported in csv format for integration into analysis software. Existing data sets (records and formation lists) can also be imported into the App. Record types currently supported (more are coming): - Bedding - Contacts - Faults - Joints - Other (generic entries) - Up to five additional user-defined record types with five additional fields per record. Depending upon the record type selected, inputs include: - Name (your entry) - Location (auto recorded) - Time/date (auto recorded) - Dip amount and direction (from your measurements) - Formations (scroll wheel entry) - Notes (your entry) - Five additional user-defined input fields

StraboTools is designed to aid geologic field work by providing quantitative data that are otherwise difficult to estimate in the field. The app was developed for work in plutonic rocks such as granite, but it can be useful in field work in any type of rock and for study of thin sections as well. The app analyzes a photograph taken within the app or imported into it. •The Edge Fabric tool plots an ellipse that summarizes the orientations of image brightness gradients. In rocks with a fabric produced by deformation, this ellipse provides the orientation of the fabric and an axial ratio, which correlates with bulk deformation. The tool also reports the orientation in space of the line defined by the long axis of the ellipse. If, for example, the fabric being measured is planar, then these intersection lineations will lie on a great circle. Edge fabric diagrams are useful both in the field and for analysis of photomicrographs. •The Color Index tool allows quantitative determination of the color index (CI; area percent dark minerals) from a photograph. The user takes a photograph and then moves a slider to highlight those pixels darker than a certain threshold. The resulting area percent is displayed. Both adaptive and full-image thresholding are available. •Edge Detect applies an edge detection filter to the image. This can be useful in highlighting subtle features in an outcrop and in interpreting edge fabric ellipses.