Composite Strata by Interval

The purpose of compositing strata is to create regularized samples and control bias for geostatistical modeling.  For example, one drilling campaign may have sampled strata on a 10' interval, while another drilling campaign sampled on a 3' interval. Using a mix of the two in modeling would lead to distinct zones of higher and lower grade variability purely due to the measurement length.  Compositing the 3’ to 10’ would remove this measurement bias. 

It is important to note that this command will create new drillhole entities rather than modifying the original drillholes. This allows you to run other commands with either the original drillholes or the composited drillholes to compare results.

When the command is first executed, you will be prompted to select the drillholes to modify. The below dialog will then appear.

Drillhole Prefix/Suffix: These settings will apply a prefix/suffix to the names of the composited drillholes.
Drillhole Type: This setting controls the Drillhole Type of the composited drillholes. It is important to note that this option will not allow you to select a Drillhole Type in use by the selected drillholes - you must select a new drillhole type. Drillhole Types may be modified by clicking the ellipsis button. More information regarding Drillhole Types is found in the Drillhole Lookup Database documentation.

Interval Length: This value sets the sample length for the new composites. If the Method is set to Fixed Length, the program will start at the top of the drillhole and create composites of this exact length moving dowward. Any remaining length will be retained as a shorter sample. If the Method is set to Best Fit, the program will divide the drillhole into equal lengths that are as close to the specified Interval Length as possible.
Strata to Include: This option controls which Strata will be considered for compositing. When using the Selected option, you will be prompted to select the strata in a separate dialog.

Allow Mixed Strata and Bed Types: This option determines if compositing will occur across strata/bed boundaries. When enabled, other settings related to mixing strata/bed types will be made active.
Density Attribute: This option sets the density attribute used for attribute weighting. This option is only required when samples are attributes are weighted by Sample Weight (as opposed to Sample Length)
Strata or Bed Naming Method: This option determines the resulting strata/bed name when composites cross strata/bed boundaries.
The Use Dominant option will retain the name of the longest/heaviest sample contributing to the composite. For example if a 10' composite is created from 7' of Strata A and 3' of Strata B, the resulting composite strata name will be A.
The Concatenate option will concatenate the strata names contributing to composite. For example, if a 10' composite is created from 3' of Strata A, 3' of Strata B, and 4' of Strata C, the resulting composite strata name will be A_B_C.
The Label Mixed option will not retain any of the original strata names when more than one strata contributes to the composite, but will instead label the resulting strata according to the name entered for the Mixed Strata or Bed Label.
It is important to note that the Strata Names and Bed Names are considered separately. If a composite is created from 3 samples of Strata A with varying Bed Names, only the Bed Name will be subject to change. Alternatively, if a composite is created from 3 samples with 3 different Strata names but the same Bed Name, only the Strata Name will be subject to change.

Key Status of Mixed Composite: This option controls the key status of the resulting composite strata.
The Use Dominant option will retain the key status of the longest/heaviest strata contributing to the composite.
The Key if Mixed Status will set all Mixed composites as key.
The Non-Key if Mixed Status will set all Mixed composites as non-key.

Include Original Parent Sample Summary: When enabled, the composited strata will contain additional strata attributes indicating the strata attribute values from the contributing strata.

Numeric Attributes: This spreadsheet will list all numeric strata attributes found in the selected drillholes. Strata attributes may be averaged by the Weighting column (Sample Length or Sample Weight). If the strata attributes contain a specific value for null values, this value may be specified in the Null Value column when the Has Null Value column is set to Yes.

Text Attributes: This spreadsheet will list all text strata attributes found in the selected drillholes. If the Naming Method is set to Dominant, only the value of the longest/heaviest contributing strata will be retained in the composite, based on the option selected in the Weighting column. If the Naming Method is set to Concatenate, the resulting text value will be a concatenation of the contributing text values. If the Naming Method is set to Label Mixed, the resulting text value will be set according to the Mixed Label column.

An example drillhole before and after compositing on a 5' Fixed Length is shown below.

Pulldown Menu Location: Drillhole > Strata/Bed Utilities
Keyboard Command: compdownhole