QGIS Geoscience Plugin

Geoscience has the following tools available from the Geoscience menu or accessible from the Geoscience toolbar.

• Drill Hole Display: Desurvey holes, project drill hole traces to surface and create surface projects of down hole data.
• Reverse Line Direction: Reverse the direction of lines. This is needed when using non-symmetric line symbology (eg normal faults).
• Transparent Rasters: Transparent black or white pixels for all selected images (great for EM channels, remote sensing channels etc).
• Change Drive Letter: Search and replace drive letter in a Project (for when you move to another hard disk).

Contents

• Drill Hole Tools
• Drill Setup
• Desurvey Data
• Display Traces
• Create Section
• Vector Tools
• Reverse Line Direction
• Raster Tools
• Make White Transparent
• Make Black Transparent
• Project Tools
• Change Drive Letters
• What's Next?

Drill Tools

Tools to display drill holes and down hole data in QGIS. This includes de-surveying the holes using collar azimuth and dip or a survey table if available. Prior to using Drill Tools you need to open the collar, survey (optional) and down hole data (optional) tables in QGIS. You can use any format supported by QGIS including shapefiles, MapInfo Tab files or CSV files. To open data using CSV, use the existing Delimited Text tool . Drill Tools will only work with projected coordinate systems (ie not latitude and longitude)

The workflow to display the surface projection of drill traces is:

1. Open the Collar layer. If using the Delimited Text tool in QGIS, select Point Geometry and the appropriate columns for Easting and Northing, followed by the Coordinate Reference System.
2. (Optional) Open the Survey layer. If using the Delimited Text tool in QGIS, select No Geometry to just import the data columns.
3. (Optional) Open the Down hole data layers. You can use multiple layers (eg. lithology and assay) and if you are using the Delimited Text tool in QGIS, select No Geometry to just import the data columns.
4. Choose Geoscience -> Drilling -> Drill Setup. Fill in the dialog with the Collar and Survey (if available) layers, then choose the appropriate attribute fields. All will be guessed by Geoscience if sensible names have been used.
5. Choose the Desurvey Length. Drill holes will be reconstructed using straight line segments of this length.
6. Choose Geoscience -> Drilling -> Desurvey Data. A new layer is created and loaded in QGIS. You can now see the surface projection of drill holes.
7. Choose Geoscience -> Drilling -> Display Traces. Choose the source Downhole Data layer and the appropriate attribute fields. Again, these are chosen automatically if sensible names are used. Check all the attribute fields that you want to include in the downhole data layer to be created. You also need to provide a brief descriptive name to be appended to the layer name.
8. The downhole trace layer is created and loaded into QGIS with each row containing one line segment for each interval from the source. You then need to Symbolise the new layer to display the attributes as you desire.

Vector Tools

• Reverses the order of all the nodes in the selected line features, in effect reversing the direction of the line. This is necessary when using asymmetric line styles such as reverse and normal fault symbols. Note that the layer must be editable before using the tool.

Raster Tools

• Sets the transparent colour to white for all the raster images selected in the project tree. To use, first select all the rasters you wish to process using control and shift left clicks, then choose this menu entry or toolbar button. Ideal for image sets such as EM channels or hyperspectral images.
• Sets the transparent colour to black for all the raster images selected in the project tree. To use, first select all the rasters you wish to process using control and shift left clicks, then choose this menu entry or toolbar button. Ideal for image sets such as EM channels or hyperspectral images.

Project Tools

This tool does a simple string search and replace in the project file to change the disk drive letter (Windows Only). You would mainly use this when copying you project to another computer or portable drive. Note that the drive letter string is internally expanded to include "file:///" and therefore reduce false matches with other project settings.

What's Next?

• Better bad data handling & reporting
• Drill sections
• Downhole graphs
• Downhole labels
• Easy dip symbol display

Released under GPL license.