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
|
|
9
|
0.2
|
|
10
|
3
|
15. What is meant by:
- The lag
- The geostatistical variance
- The semi-variance
- The semi-variogram
- The sill
- 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 data
|
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
|
|
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 JORC.
20. Detail any special requirements for reporting nuggetty gold deposits within the JORC Code?
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 to 3%?
|
Drill hole id number
|
Collar elevation (m)
|
Easting coordinate (m)
|
Northing coordinate (m)
|
Depth to mineralised zone
(m)
|
|
1
|
1000
|
1000
|
1000
|
100
|
|
2
|
1050
|
1500
|
1000
|
150
|
|
3
|
1060
|
2000
|
1000
|
160
|
|
4
|
1010
|
2500
|
1000
|
110
|
|
5
|
1020
|
1000
|
1500
|
120
|
|
6
|
1070
|
1500
|
1500
|
170
|
|
7
|
1050
|
2000
|
1500
|
150
|
|
8
|
1000
|
2500
|
1500
|
100
|
|
9
|
1040
|
1000
|
2000
|
140
|
|
10
|
1020
|
1500
|
2000
|
120
|
|
11
|
1000
|
2000
|
2000
|
100
|
|
12
|
1070
|
2500
|
2000
|
170
|
|
13
|
1040
|
1000
|
2500
|
140
|
|
14
|
1010
|
1500
|
2500
|
110
|
|
15
|
1020
|
2000
|
2500
|
120
|
|
16
|
1000
|
2500
|
2500
|
100
|
|
|
|
Incremental sequence of samples taken from the mineralised zone
|
|
|
Hole id #
|
10m
|
15m
|
20m
|
10m
|
5m
|
10m
|
5m
|
20m
|
|
Sample
Grades
In %
|
1
|
3
|
2
|
2.5
|
3.5
|
3.8
|
3
|
1.7
|
1.6
|
|
2
|
3.5
|
3
|
2.5
|
2
|
2.5
|
3
|
2
|
1.5
|
|
3
|
4
|
4.2
|
4.4
|
4.5
|
4
|
3.5
|
2
|
1.6
|
|
4
|
3.2
|
2.7
|
2.5
|
3.2
|
3
|
2.5
|
1.5
|
1.4
|
|
5
|
4
|
3.5
|
2
|
2.2
|
2
|
1.7
|
1.6
|
1.5
|
|
6
|
3.2
|
2.8
|
3
|
3
|
2.5
|
2
|
2.2
|
1.4
|
|
7
|
4
|
3.5
|
2.2
|
2
|
2
|
1.6
|
1.5
|
1.2
|
|
8
|
3.5
|
3
|
2.5
|
2
|
2.5
|
3
|
2
|
1.5
|
|
9
|
4
|
3.6
|
3.2
|
3.4
|
3.1
|
2.6
|
1.6
|
1.2
|
|
10
|
3.7
|
3.8
|
3.5
|
3.4
|
2.7
|
2.3
|
1.7
|
1.4
|
|
11
|
3.2
|
3
|
2.8
|
2.6
|
2.4
|
2
|
1.9
|
1.5
|
|
12
|
3.8
|
3.9
|
4.2
|
4.1
|
3.4
|
2.7
|
1.5
|
1.2
|
|
13
|
3.8
|
3.2
|
3
|
3.4
|
2.4
|
1.7
|
1.5
|
1.5
|
|
14
|
4.3
|
4
|
4.1
|
3.4
|
2.7
|
2.4
|
2
|
1.2
|
|
15
|
4
|
3.8
|
2.7
|
3.2
|
2.6
|
1.6
|
1.4
|
1.1
|
|
16
|
3.6
|
3
|
3.1
|
3.1
|
2.2
|
2
|
1.7
|
1.4
|
North Boundary of the property 2500mN
South Bindery of the property 1000mN
East Boundary of the property 2500mE
West Boundary of the property1000mE School of Engineering and Information Technology
27.
1. The table below shows the Copper ore grade results from a core drilling program undertaken on a regular 100m x 100m grid.
|
|
|
|
Copper ore % Cu at coordinate values
|
|
|
|
|
|
|
|
Easting Coordinate (m)
|
|
|
|
|
|
|
0
|
100
|
200
|
300
|
400
|
500
|
600
|
700
|
800
|
900
|
|
 
|
0
|
0.50
|
0.55
|
0.60
|
0.70
|
0.73
|
0.83
|
0.74
|
0.52
|
0.5
|
0.5
|
|
100
|
0.72
|
0.74
|
0.75
|
0.73
|
0.72
|
0.83
|
0.79
|
0.72
|
0.70
|
0.70
|
|
200
|
0.72
|
0.82
|
0.83
|
0.82
|
0.81
|
0.83
|
0.75
|
0.71
|
0.71
|
0
|
|
300
|
0.71
|
0.71
|
0.69
|
0.90
|
0.91
|
0.81
|
0.82
|
0.83
|
0.81
|
0.71
|
|
400
|
0.82
|
0.84
|
0.81
|
0.83
|
0.83
|
0.82
|
0.82
|
0.81
|
0.81
|
0.71
|
|
500
|
0.82
|
0.91
|
0.82
|
0.83
|
0.82
|
0.82
|
0.81
|
0.81
|
0.71
|
0.71
|
|
600
|
0.54
|
0.64
|
0.65
|
0.72
|
0.69
|
0.63
|
0.71
|
0.72
|
0.75
|
0.80
|
|
700
|
0.70
|
0.71
|
0.78
|
0.79
|
0.65
|
0.66
|
0.67
|
0.65
|
0.71
|
0.71
|
|
800
|
0.71
|
0.72
|
0.68
|
0.85
|
0.84
|
0.80
|
0.81
|
0.80
|
0.81
|
0.80
|
|
900
|
0.70
|
0.81
|
0.84
|
0.78
|
0.80
|
0.81
|
0.81
|
0.81
|
0.70
|
0.70
|
Undertake classical statistics on this data set, calculating the mean, variance and standard deviation.
2. Using the data from question 21, determine experimental variograms in the west to east and north to south directions.
3. Use ordinary kriging to estimate the grade at the location 475m East, 350m North.