24-MMP-A4 Mine Valuation and Mineral Resource Estimation · December 2014
Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
EGBC National Exam — Mining and Mineral Processing Engineering, 09-Mmp-A4 Mine Valuation and Mineral Resource Estimation, 2014-Dec. 3 hours duration; one handwritten 8.5×11 in reference sheet permitted (not an open-book exam); only approved Sharp or Casio calculators allowed. Question 1 is compulsory (40 marks, parts 1.1–1.7); candidates then select FOUR of the six optional Questions 2–7 (15 marks each) to complete the paper.
Reference texts: Isaaks & Srivastava, An Introduction to Applied Geostatistics (variogram modelling, kriging estimators, volume–variance relations); Hustrulid, Kuchta & Martin, Open Pit Mine Planning and Design (mine valuation, NPV and cut-off grade methodology, mineable reserves); Gentry & O'Neil, Mine Investment Analysis (Canadian mining taxation, smelter/refining contract terms, net smelter return); SME Mining Engineering Handbook, 3rd ed. (mineral exploration/evaluation stages, ore reserve classification); CIM Best Practice Guidelines and NI 43-101 (Canadian Securities Administrators).
Question text not reproduced: the examination questions are © Engineers and Geoscientists BC. Open the official past paper (linked at the top of this page) to read the question, then follow the worked solution below.
The nugget (C0) is the value the model jumps to as h→0 — the discontinuity at the origin caused by micro-scale variability, sampling/assay error, and any spatial structure shorter than the closest sample spacing; by definition γ(0)=0 exactly, but any non-zero lag shows this jump. The sill (C0+C) is the plateau value the curve flattens to once samples are far enough apart to be statistically independent; it equals the total (a priori) variance of the population, sometimes called C(0), the point/dispersion variance. The range (a) is the lag distance at which the curve first reaches the sill — beyond this distance samples carry no more information about one another (zero spatial correlation), so it defines the practical search radius for interpolation (kriging, inverse distance) and the natural scale of geological continuity in the deposit.
