By Sam Bain
The “Interval Selection” tool in Leapfrog combines most of the abilities of Grouping and Splitting (as discussed in previous blogs) with fewer restrictions. The Grouping and Splitting tools provide workflows for combining or splitting existing lithologies exclusively. The intervals selection is ideal when elements of both the grouping and splitting workflows need to be combined. For example, perhaps assay data indicates some intervals have been incorrectly logged and need to be assigned to a new lithology. If these intervals have been logged as several different lithologies then they need to be split from their old lithologies and then grouped to a single new lithology. The interval selection tool allows you to do this.
The “Interval Selection” tool is found by right clicking on an interval table under the “New Column” sub-menu (Figure 1). In this case I have chosen to make an interval selection based on the “Geology” interval table. An interval selection can be made on any interval table, such as of assay data, or on a merged table. The first dialog lets you choose the base column for the interval selection (Figure 2).
If a base column is selected then the intervals from that base column will be automatically duplicated in the new interval selection column. I have created an interval selection called “DemoInterval” using the “Lithology” column as the base column (Figure 3). By opening the “Geology” interval table we can see that for now the new “DemoInterval” column has the same intervals as the original “Lithology” column.
You may choose to have no base column. Essentially, this will mean starting with a blank canvas. However, you can still show other interval columns on the boreholes in the scene and make selections based on these. No base column simply means there will be no automatic assigning of intervals. An example of an interval selection with no base column is shown below (Figure 4).
The interval selection tool uses many of the controls as encountered in the split lithologies tool. These controls are highlighted below (Figure 5).
These tools are as follows:
- A – The “Select Intervals” icon changes the mouse function to allow selection of intervals in the scene.
- B – The “Change Selection Line Width” icon allows the user to alter the width of the select intervals envelope.
- C & D – “Add To” or “Remove From” option buttons change what happens when intervals are selected. The current function of the mouse (“Add To” or “Remove From”) can be temporarily inverted by holding down the “CTRL” button.
- E – The “All Visible” button selects all intervals visible in the scene. This tool can be quite powerful as the visibility of intervals in the scene can be controlled in a number of ways (toggling visibility from legends, query filters, and value filters).
- F – The “Deselect All” button clears the current selection.
- G – Then “Invert Selection” button inverts the current selection of intervals (selected intervals become deselected, and all other intervals are selected).
There are no limitations to the intervals that can be selected and assigned to a new lithology. I have selected intervals from several lithologies from a range of boreholes and will assign these to a new lithology (Figure 6).
A name and colour are chosen for the new lithology – I will call this new interval selection “Vein” (Figure 7).
Once the name and colour have been chosen, the selected intervals are now assigned to the new lithology and are coloured appropriately on the boreholes (Figure 8).
Opening up the “Geology” interval table, we can see that selected intervals have now been assigned to the new “Vein” lithology in the “DemoInterval” column (Figure 9).
The “Interval Selection” tool is very powerful as it allows you the freedom to define new lithologies based on selections from any of the interval columns in an interval table. This means a new lithology can be defined based on a combination of lithological logging and assay results if they are present in the same interval table. However, we have only scratched the surface of this tool with this introductory example so I encourage you to try it out yourself.