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We have a set of old sections with drill data that I would like to extract and model. I can add sections just fine in Leapfrog, but I have issues with the drill holes, especially connecting the drill holes from the sections with the planar/top view of the section which is found directly under the section. How can I connect the drill hole with the planar view so I can get the dip and azimuth calculated automatically?

The software we use includes QGIS, ArcGIS Pro, Global Mapper, and Leapfrog, but for this, we are ready to learn something new if needed.


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  • $\begingroup$ Normally, data relating to drill holes: dip, down hole lengths and dip directions, as well as geological logging & assay would be kept in a drill hole database & drill hole trace information would be extracted from that to plot onto sections & plans, or in three dimensional viewing software. $\endgroup$
    – Fred
    Commented Oct 12, 2023 at 0:41
  • $\begingroup$ Every paper section has a data capture zone. Drill holes are never exactly drilled on section. There is always a margin of "error". Some holes may be some meters forward of the section, while others may be some meters behind the section. This is one reason while having access to the drill hole database is important for three dimension viewing. $\endgroup$
    – Fred
    Commented Oct 12, 2023 at 0:48
  • $\begingroup$ I understand this is common practice, but these are old drill holes, done in the '70 in the soviet union, and, as you can imagine, all those details are lost to time. We are aware that errors will be present, and are willing to accept that, as long as we are able to plot these drillholes and use the information presented. $\endgroup$
    – alecsx
    Commented Oct 12, 2023 at 6:50

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Digitizing paper based information, and more specifically the voids of underground mines, was not unusual from the mid 1980s until the mid to late 1990s. Then, large format digitizers were readily available.

Digitizing paper based drill hole information might have been done, but I'm not aware of anyone who did it the way you are trying to do it. If it needed to be done people tried to obtain the written geological logs of the holes and manually enter that data, with the collar survey data and the down hole survey data, if it existed, into a newly created digital database. It was tedious and what you will need to do will be equally tedious.

I'm unaware of any software that can do what you need. That doesn't mean it doesn't exist, I'm just unaware of it because I've never needed to do it.

What you need to do is direct mapping between the sectional data and the data in plan. I'm assuming the section data is on specific northings. Unless the northing has been written next to the collar of the hole in the plan view you will have to take the northing from the section northing and assign it to the collar of the drill hole. Sections typically have an easting and elevation grid. From this you will be able to get the easting and elevation of points down each hole. This will give you the three points you need to define the trace of the drill holes in three dimensions. I am also assuming the scale for northings is the same as the scale for eastings (or westings).

From the picture in the question, the lateral length of the holes is not long compare to the down hole length.

Initially for each hole, on the plan view, you will need to draw a faint horizontal line from the collar to the left. This will represent your section line.

For each drill hole, you will need to mark the collar and toe in the plan diagram. You then draw a faint vertical line from each point on the plan diagram until it intersects the drill hole in the vertical (cross) section. The intersection point at the drill hole trace in sectional view will give you the easting and elevation of the point. To obtain the northing from the point you need to add or subtract the distance the drill hole trace, in plan, is from the northing line that was drawn for the hole. If the drill hole trace is to the north of the line the difference is added to the section northing. If it is south of the line it is subtracted.

You will then have to do likewise for points in between the collar and the toe. To reduce the workload don't bother about taking points along straight portions of each hole. Mark the start and end of curved parts of the hole in plan view and get the data for those points. Then do the same for points along the curved parts. If you want reasonable accuracy have the points spaced at one meter intervals.

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