Assign Lithologies to Drillhole Data

Interactively apply lithological values held within a drillhole object to displayed sample intervals. This command is commonly used in conjunction with define-lithology.

Lithologies can either be unique lithological values or grouped values. An existing drillholes object must be loaded, from which a lithological attribute is used to provide a selection of lithological values. These values can be applied to drillhole sample intervals.

Interval lengths and positions (FROM, TO, LENGTH) are not defined with this tool and cannot be altered; intervals are set according to raw survey infromation, the respective desurveying method and/or by other pre-processing of the drillholes data table.

Drillhole data should be displayed to use this command. You can display your data using the default legend for the selected Lithology Field, or you can use any other legend (and potentially edit it).

The basic procedure for using this tool is: Select your intervals first, then apply the lithology or lithological group.

Command settings will persist between dialog sessions; previous values will automatically be restored (within the same project session).

Note: Assignments made with this tool can be undone using <CTRL> and <Z> and re-done using <CTRL> and <Y>

Assign Lithology Legends

When a new Lithology Field is chosen, a check is made to see if a default legend already exists for the selected attribute. If it does, it is automatically selected and appears in the Legend field. The list of field values will update to show, where possible, the appropriate colour for each legend item.

If you are using a default legend to colour your display, you can edit any of the lithology values and add or remove values which will automatically update the default legend as changes are made.

In this situation, there will always be a 'match' between Lithology Field values and Legend items.

Using Non-default legends

If you select a legend that is not the default legend (i.e. one that has been created by a separate process), you can choose whether you can edit that legend using the Assign Lithology task. You may, for example, wish to use a standard (corporate) legend to colour your display of ROCK values, where you do not wish to edit the legend inadvertently.

To protect your selected legend, disable Allow Changes to Legend. This will prevent you from editing the colours displayed below and any additions to or removal from the list of values will not update the legend. Where a match cannot be made between a Lithology Field value and a Legend 'bin', the current fixed colour for the current overlay is used (as defined using the Drillhole Properties dialog).

For example, the ROCK attribute is selected, which contains 17 unique values. These, plus an absent data item indicator are listed when the Lithology Field is set. In this example, Allow Changes to Legend is enabled, meaning edits to the legend will be made automatically.

A corporate legend is selected, but it only contains three of the values found in the selected field, e.g.:

Once the legend is selected, the list displays the 17 values, with four of them coloured using the legend:

All unmatched values are shown in the current fixed colour for the overlay (in this case, red), with a cross indicating a match can't be found.

Editing [AW] (double-clicking the colour chip and changing it to orange) results in:

The legend is automatically updated, e.g.:

If Allow Changes to Legend is unchecked, you can't edit the colours of the displayed items (whether there is a legend category match or otherwise).

You can reinstate the default legend at any time using the button to the right of the Lithology Field drop-down list:

To assign a lithology to a loaded drillhole object

  1. Open the Assign LIthology managed task:

  2. Select a Drillhole Table. All loaded drillhole objects are listed.
  3. Select a Lithology Field. This can be any field, but will commonly be either an attribute representing a lithology or rock type, or a grouping attribute.

    Unique attribute values are listed below. If you selected a group field, this list can include lithologies that have not been assigned to a group and group names in combination, for example:



    In the above example, there is an absent (-) value indicator (always present), two group values representing confidence and a set of four distinct lithological values which have no grouping.

    Double-click a label to edit the name of a listed lithology item or group

    Warning: Avoid using yellow to format lithologies as it is the selected 3D item colour in Studio and things could get confusing!

  4. Choose how you want the view of 3D window data to be updated using Auto Look at the bottom of the task:

    • If checked, the view of the active 3D window will automatically scale and orient so that it is looking directly at the enabled attribute values. The view will be oriented to be orthogonal to a mean plane of the displayed samples.

    • If unchecked, no view adjustment will be performed when changes are made in the attribute values table.

  5. Choose how you want data to be applied after task changes using Auto Apply:

    • If checked, 3D window data will be automatically filtered to show only enabled attribute values. Non-active attribute values will be hidden.

    • If unchecked, no 3D window changes will be performed automatically after task edits.

  6. Choose if you wish to display samples of multiple attribute values in the 3D window during task usage, using Unique:

    1. If checked, only a single attribute value at a time can be selected.

    2. If unchecked, any number of attribute values can be selected.

  7. Select a Legend to colour the display of the drillholes, or accept the default legend that is specified.
  8. Use Allow Changes to Legend to determine if a non-default legend can be edited using the Assign Lithology tool:
    • If checked, you can choose a colour for a value that doesn't yet exist in the selected legend, then add it to the legend automatically.
    • If unchecked, legend items will not be editable. This can be useful if the legend is shared with others.
  9. Ensure Select Mode is enabled to allow independent drillhole samples to be selected.
  10. Select one or more sample intervals in the 3D window.

    Tip: Use box/rectangle selection to select intervals. Hold <CTRL> to append the selection group. You can also use a combination of box/swipe selection and left-click picking.

    Intervals containing absent lithological data can be selected and assigned in the same way as any other listed value


  11. Optionally, choose Select All to automatically select intervals of all currently selected items in the values table. This can be useful if you wish to select independent (ungrouped) lithologies and apply them to an existing group.
  12. Select (only) one lithology or group lithology item in the values list.
  13. Click Assign.

    The selected lithology is applied to the selected interval(s).

  14. If Auto Apply is unchecked, click Apply Now to update your 3D view with the latest changes.

  15. To update the physical file associated with the Drillhole table, click Save File. This operation cannot be undone automatically.

To add a new lithological value:

You can add a new lithological value to the list at any time by clicking New.

New items will be assigned a unique name, which can be edited. For alphanumerics, this will be "New " followed by an index number, for numeric lithology field values, it will be the next available number in sequence (starting from zero).

  • If you create a new lithology item and a default legend is in used, a new legend category will be added to the default legend automatically.
  • If a non-default legend is used and Allow Changes to Legend is checked, a new legend category will be added to the non-default legend automatically.
  • If a non-default legend is used and the Allow Changes to Legend is unchecked, a new value will appear in the list, but will be displayed with the current drillhole overlay's fixed colour (as defined using the Drillhole Properties dialog). You will not be able to edit this colour.

To unassign a lithological value:

Any selected interval can be unassigned, meaning it will be given an absent lithology value.

  1. Enable Select Mode.

  2. Select drillhole data in a 3D view.

  3. Click Unassign.

    Currently selected drillhole samples will be assigned an absent ("-") lithological value.

  4. If Auto Apply is unchecked, click Apply Now to update your 3D view with the latest changes.

To delete a lithological value:

You can remove lithologies and groups from the displayed list.

  1. Select a value to remove from the list of available lithological values.

    Note: The absent item cannot be deleted.

  2. Click Delete.

    The lithology will be removed from the list and an absent value will be assigned to all drillhole intervals with the deleted value.

    Tip: If you delete a lithology by mistake, you can reinstate it using <CTRL> and <Z>.

  3. If Auto Apply is unchecked, click Apply Now to update your 3D view with the latest changes.

To rename a lithology or group:

  1. Double click a lithological value in the list.

  2. Type in either a numeric or alphanumeric value and press <ENTER>.

    The value will be updated, as will all values in the drillhole data object.

  3. If you wish to make your drillhole data changes permanent, Save your drillhole object.

You can rename any item in the displayed list providing:

  • If the selected field is numeric, the description of either the grouped or ungrouped is item is also numeric (with the exception of setting a name to "absent" or "-", both of which assign the absent data symbol.

  • The name is unique, otherwise the previous value will be reinstated.

  • For alphanumeric data, the data definition of a saved samples file will be automatically adjusted to ensure the longest description is accommodated.

To merge existing groups and ungrouped items

The group-lithology command contains tools for grouping lithological values. However, you can also merge groups and ungrouped items interactively using the assign-lithology task:

  1. Select an attribute value to merge.

  2. Click Select All.

  3. Select the target attribute value to receive the new intervals.

  4. Click Assign

Related Information and Activities