GEOD is a computer-assisted drawing tool for geological cross-sections. It allows users to produce accurate cross-sections, saved as vector PDF files, which can then be printed at high quality on any PostScript-compatible printer.
GEOD provides features specifically designed for geological cross-section drawing. In particular, lithological patterns are drawn so that they always follow the layer boundaries, whether the beds are horizontal, vertical, or dipping at any angle, and whether their thickness is constant or variable.
Layer boundaries, faults, and the topographic surface are described using polygonal lines or, more efficiently, Bézier curves. These parametric curves, widely used in computer graphics and CAD, make it possible to represent almost any geometric shape.
GEOD does not work like a conventional drawing program. Instead of tracing Bézier curves directly with the mouse, as in Illustrator with the pen tool, the user enters text commands and numerical values in the integrated editor of GEOD.
The information is therefore stored in textual form, as a script written in a language specific to GEOD.
This approach offers several important advantages:
GEOD still provides a limited degree of mouse interaction. For example, the coordinates of a point can be entered quickly by clicking on the cross-section, but this remains a secondary feature of the software.
The GEOD language is deliberately simple and is based on a small set of main commands:
These commands are used to define:
Other commands such as input, output, scale, and origin are used to specify the units as well as the display scale on screen and the output scale for printing.
Most commands include a substantial set of subcommands. In this respect, the pattern and fill commands are the richest. To make navigation easier, the Commands menu provides a complete list of all commands and their subcommands.
The integrated editor in GEOD highlights commands, subcommands, parameters, and comments using different colors, which greatly improves script readability.
The effect of an instruction can be visualized immediately by pressing F8 or Return. In this sense, GEOD behaves almost like a WYSIWYG system (*what you see is what you get*).
GEOD is not only a drawing program. It is also a 2D modeling tool capable of constructing a layer of constant thickness from either its upper or lower boundary, that is, from the roof or the base of the unit.
The calculation algorithm automatically removes intersections that inevitably appear in areas of strong curvature.
To reconstruct a complete geological cross-section, GEOD requires only a limited amount of information:
By changing just one parameter, for example the dip at a given point or the thickness of a formation, the entire cross-section can be modified quickly. The full geometry is then recalculated automatically.
GEOD is therefore particularly well suited to the production of serial cross-sections. By simply copying and pasting a script and adjusting the relevant parameters, several variants can be generated very rapidly from the same initial structural model.
Required hardware configuration: