Assignment title: Information
NB: List and justify all your choices and assumptions.
1. Describe the process of exploration project to mining operation with reference to the ore
resource/reserve estimation process.
2. What is meant by ore? What is meant by the term waste? What is proto ore?
3. What is meant by core logging? Typically what parameters would typically be recorded
when undertaking core logging?
4. What is meant by the popularly-used word transparency?
5. Describe in detail an electrical exploration technique.
6. What is reverse cycle drilling? How does it differ from normal drilling?
7. What is meant by the following terms:
• Range
• Variance
• Standard deviation
• Kurtosis
• Skewness
8. Illustrate and discuss the effect of support on grade-tonnage relationships used to assess
selective mining units.
9. What are the rules regarding the reporting of exploration results?
10. Give three likely examples of support that might be used in a mining estimation, and
explain how you would change from one to another.
11. Describe a polygonal estimation technique.
12. Give an explanation of why kriging techniques are preferable to other estimation methods.
13. Explain what a "competent" person means in the JORC. What qualifications do competent
persons require?
14. Determine the variance for the grade data set in the following table
Sample Number Grade Au g/tonne
1 4.6
2 7
3 2
4 1
5 5.3
6 6.5
7 8
8 21
1
9 0.2
10 3
15. What is meant by:
• The geostatistical variance
• The semi-variance
• The semi-variogram
• The Nugget effect
• The range
16. Using the method of polygons, determine the average seam thickness and tonnage
represented by the following information if coal weighs 0.9 tonne/m3. Note surface is flat
and top of coal seam for all boreholes is intersected at the same depth.
Property Coordinates
East North
1000 1000
7000 1000
1000 7000
7000 7000
Drill hole Seam thickness (m) East Coordinate North Coordinate
1 5 2000 1000
2 4.5 4000 1000
3 3.5 6000 1000
4 4 1000 3000
5 5 3000 3000
6 3.9 5000 3000
7 3.7 7000 3000
8 4.5 2000 5000
9 4.6 4000 5000
10 4.8 6000 5000
11 3.9 1000 7000
12 5.6 3000 7000
13 2.9 5000 7000
2
14 2.8 7000 7000
17. What characteristics of an ore body, besides grade, could or should be treated using
geostatistical methods?
18. Give definitions for the following:
− Break-even cut-off grade
− Geological cut-off grade
− Incremental cut-off grade
− Marginal cut-off grade
− Optimal cut-off grade
− Resource/reserve cut-off grade
− Run of mine cut-off grade
19. Define the various categories of reserves and resources that can be employed under
20. Detail any special requirements for reporting nuggetty gold deposits within the JORC
21. How does the JORC code deal with stockpiles, low grade mineralisation and tailings?
22. Why do you need a mathematical expression to represent the experimental variogram?
23. What is meant by covariance?
24. What type of information concerning the deposit is provided by a variogram?
25. Use the method of polygons to determine the average ore grade and tonnage
represented by the information on the next page if the cut-off grade is 2.5% and the ore
has a density of 2.5 tonnes/m3.
26. What would be the impact on the answer to question 25 if the cut=off grade is increased