The following is a selection of structural geology software packages developed by Rod Holcombe and available at:



Windows-based (premium) software for structural calculations including both oriented and partially oriented core calculations. Handles batch processing of data by either pasting directly into the application (from any spreadsheet or database table) or by input from text files (e.g. csv files). Software can be downloaded on a trial basis prior to purchase.


Windows-based (premium) software for plotting and analyzing structural data from any source, including oriented core) in stereographic and other projections, and in rose diagrams. Includes several new types of stereographic Classification Plot© not previously published. Combined with drillhole data, classified plots can be used to link parameters such as grade or vein width, with structural data.

Strain Calculator©

Strain Calculator is a tool (free) for calculating and plotting 3D strain from various 2D measurements. It was originally designed as a teaching aid but it contains a graphical shear calculator that is very useful for analysing the amount of shear deformation (and perhaps displacement) from shape fabrics or fabric orienation core or outcrop.


The image shows the tool being used to determine the shear strain in core in a 25m-wide gold-bearing shear zone in the DRC. In this instance the 10:1 aspect ratio of the fabric constrains the shear strain to being 2.85, which indicates a displacment of about 70 metres is required to produce the fabric.


Free Mapinfo tool (.mbx file) to plot geological structural symbols in a MapInfo mapper as vectors (fixed size) rather than as fonts. Contains about 50 predefined structural symbols but these can be modified, or added to, as User-Defined symbols.


Free Mapinfo tool (.mbx file) to extract orientations from lines and polylines in mapper windows. Orientations can be extracted as either trends or as strikes or dips (assuming Right Hand Rule). Useful for digitising structural symbols from map images, or for analysing fracture or fault data.


I have use this tool in a Russian project to analyse the distribution of map faults relative to linears interpreted from magnetic imagery. It is very easy to run the tool on both data sets in a mapper window, then copy the resultant column of trend orientations and paste them into a rose diagram plot using GEOrient.


Free Mapinfo tool (.mbx file) to extract the X & Y locations of all the nodes from any Table of polylines. Optionally, an additional attributes of each polyline in the parent table can be associated with each node orienation. This is a very useful tool for extracting point X,Y,Z data from contour polylines for producing DEM models in other software.