Computing Grade x Thickness Statistics for I-Data Grade Values

( I-Data / Analyze / GT (Grade x Thickness) Compositing )
 

This RockWorks Borehole manager program reads a column of I-Data that represents grade values (e.g. eUranium) and computes a variety of GT (grade x thickness) statistical information based on user-defined minimum grade and maximum waste-thickness cutoff values.

The output from this program may be stored within an Excel-compatible CSV file, I-Data columns, or a special XYZ file that may be used for subsequent point-mapping and/or contouring.

Menu Options

• Input (Grade) Track: Click here to select the I-Data track that contains the grade data. For example, this might represent %eU3O8 (Uranium Grade Equivalent), ounces per ton Gold, etc.
• Output: Expand this heading to define how the data are to be output.  The output from this program may be saved within a CSV file, tracks (columns) within the I-Data table, and/or an ASCII (American Standard Code for Information Interchange) text file with xyz-style data for subsequent mapping.
  • CSV File (Excel Report): If checked, the output from this program will be saved within a Excel-compatible CSV (Comma Separated Values) file as shown by the following example.

  

  Because CSV files are "generic" (readable by a wide variety of programs - including RockWorks), there is no formatting. As a consequence, any special formatting such as column title centering, font sizes, etc, must be performed by the user after the CSV file has been auto-loaded into Excel.

  • File Name: Click on this item to enter the name for the CSV file that will be created by the program and automatically loaded into Microsoft Excel (or whatever program has been associated, via your Windows settings, with the CSV file extension).
  • Report Title: This is the title that will appear within the first row of the CSV file.

  • I-Data Tracks: Check this item if you want to export the output from this program into tracks (columns) within the I-Data table as shown by the following example.

    

    ! Please note that the I-Data output columns must be defined within the I-Data table before this program is used.

    • Thickness: Check this box if you want to store the intercept thicknesses. 
      (The intercept is a zone of contiguous material that meets the criteria defined by the minimum acceptable grade and the maximum acceptable waste thickness, defined below.)
      • Track: Click to select the I-Data column in which the Thickness computations should be stored.
    • Sum of Grade x Thickness: Check this box if you want to store the sum of all grades multiplied by the thicknesses for each sample interval within the associated intercept.
      • Track: Click to select the I-Data column in which the Sum of Grade x Thickness computations should be stored.
    • Average Grade: Check this box if you want to store the average grade for all sample intervals within the associated intercept.
      • Track: Click to select the I-Data column in which the Average Grade computation should be stored.
    • Maximum Original Grade: Check this box if you want to store the maximum grade value for all of the sample intervals within the associated intercept. 
      • Track: Click to select the I-Data column in which the Maximum Original Grade values should be stored.
    • Minimum Original Grade: Check this box if you want to store the minimum grade value for all of the sample intervals within the associated intercept.
      • Track: I-Data column in which the Minimum Original Grade values are to be stored.
         
  • XYZ File: If checked, the program will save an XYZ point within the designated file for each borehole. The x-coordinate will contain the easting for the borehole collar, the y-coordinate will contain the northing for the borehole collar, and the z-value will represent the total for all "sum of grade x thickness" values for that particular borehole.
    • This data is intended for plotting borehole location maps in which the point label represents a summary to the borehole's economic value. These values may also be contoured, but (and this is important), inclined boreholes will produce misleading contour maps since the xy location for each point always corresponds with collar location. Please note that creating an XYZ file only makes sense if you're processing all of the borehole (see "Apply to" option below).
    • File Name: This is the name for the ASCII file in which the tab-delimited xyz data will be stored.
    • Z-Decimals: Number of decimal places to use when saving the z-value (sum of GT values). This setting is useful if the XYZ file is to be used for creating a two-dimensional map as shown below.

    
     

• Cutoffs: This are the primary filtering values that are used to determine the extents of the ore intercepts. 
  • Minimum Acceptable Grade: Click here to enter the minimum value in the Input track to be considered.  This value determines what is considered "acceptable" ore.
  • Maximum Acceptable Waste Thickness: This value defines the amount of waste, or "interburden" that is acceptable for zones that are bounded, above and below, by intervals that contain material that have "acceptable" grade values.
     
• Filtering: These options allow you to force the program to consider only input data within a specified depth and/or elevation range.
  • Depth Filtering: If checked, this setting will cause the program to only process data that is between the specified minimum depth and the specified maximum depth. We specifically avoid the terms "above" or "below" because the borehole may be inclined upwards (e.g. an underground exploration hole drilled upwards).
    • Minimum Depth: Sample intervals between the collar and this depth will be ignored.
    • Maximum Depth: Sample intervals between this depth and the total depth (TD) of the hole (TD) will be ignored.
  • Elevation Filter: If checked, the program will ignore all sample intervals above the maximum elevation or below the minimum elevation.
    • Minimum Elevation: Sample intervals below this elevation will be ignored by the program.
    • Maximum Elevation: Sample intervals above this elevation will be ignored by the program.
       
• Apply to: This program may be used to compute GT-related values for just the currently-highlighted borehole or all of the boreholes.
  • All Enabled Boreholes: Compute GT-related values for all of the enabled boreholes (boreholes with a checked-box next to their names within the Borehole Manager).
  • Currently Highlighted Borehole: Compute GT-related values only for the currently "active" borehole as defined by an arrow adjacent to the borehole name within the Borehole Manager.

Step-by-Step Summary

1. Access the Borehole Manager.
2. Select the I-Data / Analyze / GT (Grade x Thickness) Compositing menu option.
3. Establish the desired menu options, as discussed above.
4. Click the Process button to proceed with the computations.

The program will read the contents of the input I-Data track, determine for each borehole the areas where the minimum grade and maximum waste parameters are met, and determine the thickness of those zones or intercepts. 

The program will record the computations in the requested output reports: Excel CSV and/or I-Data columns and/or XYZ file (you can choose as many of the output options as you like).

Here is an example of how the Sum GT, Average Grade, and Maximum Original Grade computations recorded in the I-Data table could be plotted with the original grade data in a striplog.

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