Lithology

The fixing process can be refined through the use of rock codes. In this way the intercepts that will be used to form the product of the horizon have to match both the seam code and the lithology wanted (rock codes). Intercepts that only match the seam will still form part of the structural thickness of the horizon, and may even indicate the top or bottom of the horizon, but do not contribute to the product thickness.

To use rock codes there must be lithology data present on the intercept records and the 'RockType' database synonym must be defined to point to that field. Also, the system must have been informed of the valid rock codes. Where continuation records have been used in the lithology to allow more than one rock type to be logged for each intercept, a percentage of a wanted rock type can also be defined if required. In this situation a field containing percentage data, with the 'Percentage' synonym, needs to have been defined. The use of both rock codes and percentage is only activated when both the synonym for percentage and one of the synonyms for continuation ('Continuation' or 'NextModifier') are specified for the current database.

Note: Intercepts that match the horizon name but do not meet the lithology requirements may occur at the top and/or bottom of the horizon, where they will define the horizon extents. This behaviour is different from the standard mapfile generation where they are ignored unless they are in the horizon as defined by product - so standard mapfiles may have these horizons with smaller structural thickness (but the same product thickness).

Refine product by lithology

Select this check box rock codes to be used to determine the product/waste intercepts.

Rock codes

Select this check box to use rock codes without percentage qualification. You will be required to specify a list of allowable rock codes (comma or whitespace separated), for example, CO,CL,CD,CS.

Alternatively, the rock codes can be specified in the form of a text file, which must be formatted as one code per line (whitespace separated). The text file can either be selected from the drop-down list, or chosen through using the Browse button.

Example - Text File Format

CO CL CD CS

Rock codes and percentages

Select this check box to use rock codes with percentage qualification. You will be required to specify a list of allowable rock codes (comma or whitespace separated), as well as the percentage value, for example, CO,75.5,CL,25.

Alternatively, the rock codes and percentage values can be specified in the form of a text file, which must be formatted as one code and percentage per line (whitespace separated). Select the text file from the drop-down list, or use Browse to select the file from a different location.

Example - Text File Format

CO 75.5 CL 25

Enable the Ignore percentage values check box to ignore the percentage values contained in the nominated text file.

Note: The same file may be used both for codes alone or for codes and percentages. Percentage values will be ignored if they are present when used for codes alone. Missing percentage values will be treated as 100% when used for codes and percentages. In all cases, the rock codes provided may contain wildcards (for example, C* will match all occurrences of CO, CD, or CL on an intercept record).

Intercepts with no rock data count as acceptable

By default when assessing lithology, intercepts that do not have rock code data are considered not to match the required lithology and are treated as waste material for parting. Select this check box to reverse this behaviour.

Intercepts with no percentage data (but matching rock) count as acceptable