Download Drillhole Histograms

MineMap IMS 2.0
Intelligent Mining Software “Solutions”
MineMap IMS - Drillhole Histograms
Produced by W.S. Mart and G. Markey
For MineMap Pty Ltd
Intelligent Mining Software “Solutions”
MineMap IMS - Drillhole Histograms
Copyright © 2014 by William Seldon Mart and Geoff Markey. All rights reserved.
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Intelligent Mining Software “Solutions”
MineMap IMS - Drillhole Histograms
Table of Contents
INTRODUCTION.................................................................................................................... 3
RUNNING THE HISTOGRAM MODULE .......................................................................... 4
The Parameters Page ................................................................................................................. 6
The Axes Page ............................................................................................................................... 8
The Data Page ............................................................................................................................. 10
The Fonts Page ........................................................................................................................... 11
The Report File Page ................................................................................................................ 12
STATISTICS REPORTED ................................................................................................... 13
Histograms and Cumulative Plots ....................................................................................... 13
APPENDIX: USING HISTOGRAMS FOR QUICK TONNAGE CALCULATIONS ... 14
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Intelligent Mining Software “Solutions”
MineMap IMS - Drillhole Histograms
INTRODUCTION
The Histogram module performs statistical analysis on drillhole data. It provides the distribution of
the value of the parameter, considered with respect to the total drillhole area or a portion of the
drillhole area or a specified plan file. Any stratigraphic type (i.e. stratigraphic units present in the
drillhole data) may be used with or without weighting for thickness.
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MineMap IMS - Drillhole Histograms
RUNNING THE HISTOGRAM MODULE
To create a histogram for the drillholes:
1. Drag the required MineMap IMS drillhole file from File Explorer Pane to either the 3D Pane
or the Loaded File Pane.
2. Select the <Drillholes><Histograms...> menu item (Figure 1) to display the first page of the
Histogram parameters wizard (Figure 2).
Figure 1: Selecting the Histogram menu item
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MineMap IMS - Drillhole Histograms
Figure 2: Selecting stratigraphic units from drill data
3. Select either Select All Stratigraphic Units or Individual Stratigraphic Units.
4. If you select the second option then select the check boxes next to the required stratigraphic
units.
5. Select the <Next> button to display the Select Stratigraphic Units From Drillhole Data page
if your loaded drillhole data contains seam names or the Parameters page if there are no seam
names.
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MineMap IMS - Drillhole Histograms
The Parameters Page
Figure 3: The parameters page
1. Enter the name of the plot file or leave it blank if a plot file is not required. Plot files are
standard EMF (Enhanced Meta Files) that can be viewed in any image viewer.
2. Select the plot type. There are five plot types available:
 Histogram
 Histogram (Log Scale)
 Cumulative
 Cumulative (Log Scale)
 Scatter
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MineMap IMS - Drillhole Histograms
3. Enter the width and height of the plot. The plot will be scaled to fit the sizes specified here.
The sizes refer to the actual graph only and do not include the axis labels, titles, etc. A
practical minimum x-axis size is about 200mm.
4. Select the title box option if required. If you choose not to include the title box then the plot
will be produced without the title box border.
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MineMap IMS - Drillhole Histograms
The Axes Page
Figure 4: Axis parameters
1. Select the quality required to calculate the statistics. The qualities are shown in Table 1.
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Table 1: Available qualities.
Data Type
Roof
Floor
Thickness
Depth
Qualities (Assays)
Use On
Laminar Models
Laminar Models
Laminar Models
Laminar Models
Drill Data
1. Enter the minimum and maximum values for the x-axis.
2. Enter the increment for the x-axis. This determines the interval between tick marks. Up to a
maximum
of
three
hundred
intervals
can
be
used
on
each
axis,
(i.e.
).
3. Enter the minimum and maximum accepted values. Only data that falls between (and
including) these values are considered in the calculations.
4. Enter the upper-cut. Data values larger than the upper-cut are reassigned the upper-cut value.
5. If you selected a scatter plot type then the y-axis parameters are enabled.
a.
b.
c.
d.
Select the quality for the y-axis.
Enter the minimum and maximum values for the y-axis.
Enter the increment for the y-axis. This determines the interval between tick marks.
If you require a regression line then select the Show regression check box.
6. If you require grid lines on the plot then select the Show x-grid and/or the Show y-grid check
boxes.
7. If you require a line representing the median on the histogram plot then select the Show
histogram median line check box.
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The Data Page
Figure 5: Restricting the data.
1. Select the subset of data required for the plot.
2. If you select Use data inside polygons then a file selection dialog box is displayed. Enter the
name of a plan file in this dialog box. The plan file must contain at least one closed polygon
to define the region of interest.
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MineMap IMS - Drillhole Histograms
The Fonts Page
Figure 6: Fonts for graph elements
Select the fonts for the various graph elements. Only the font name, colour and size (in points) are
currently available.
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MineMap IMS - Drillhole Histograms
The Report File Page
Figure 7: Reporting the statistics
1. Enter the name of the report file or leave blank if a report file is not required.
2. Enter the header line text if required.
3. Press <Finish> to start the calculations.
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MineMap IMS - Drillhole Histograms
STATISTICS REPORTED
The Histogram module displays the required graph on screen and saves it to the plot file if one was
specified. The statistics displayed on the graph are a subset of those used in the calculations. Consult
the report file for the extra statistics (e.g. standard deviation, the number of observations and the
median).
NOTE: If the number of observations is less than thirty then a simple standard deviation is used.
Otherwise, the Histogram module uses a population standard deviation.
Histograms and Cumulative Plots
Standard deviations are calculated as grouped data points, i.e. the midpoint of each class interval is
taken to be the datum for the calculations. However, the value added to that class interval is the
thickness for the selected drillhole divided by the total average thickness of all drillholes.
Since the calculations are performed on grouped data, the reported standard deviation will be
marginally different to that of the raw data. If a calculation of the raw data statistics is required, it is
necessary to reduce the class intervals to the minimum possible.
NOTE: The maximum number of class intervals is three hundred. This procedure will still not
produce completely comparable results but will reduce any possible errors to an absolute
minimum.
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MineMap IMS - Drillhole Histograms
APPENDIX: USING HISTOGRAMS FOR QUICK TONNAGE CALCULATIONS
The Histogram module provides the following benefits:
 It presents the results of the analysis in a compact and easily readable form.
 The shape of the distribution is immediately apparent.
 The output is suitable for inclusion in reports without further processing.
If the analysis is weighted by thickness then the results can be used to derive the ore tonnages for each
nominated step in the parameter value(s) by applying the percentage derived for that step to the total
tonnage for the stratigraphic unit. This is achieved as follows:
1. Graph the thickness of the stratigraphic unit and the qualities (weighted by stratigraphic unit
thickness) of interest.
2. Determine the mean of each of these parameters and multiply the average thickness of the
seam by the mean quality derived.
3. Multiply the result gained by the area of interest.
This procedure supplies tonnages provided the relative density of the quality being considered is
corrected by using Equation 1.
Equation 1: Quick tonnage calculations
Example
Average thickness of strat unit = 1.5m (from the Histogram module)
Average grade of product
= 10.0% (from the Histogram module)
Area of interest
= 1,000,000m2
Relative density of product
= 2 tonnes / m3
Therefore the total tonnage is
product.
tonnes of
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