24-MMP-A1 General Geology and Exploration · December 2015
Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
EGBC National Exam — Mining and Mineral Processing Engineering, 09-Mmp-A1 General Geology and Exploration, 2015-Dec. Closed book; only a Casio or Sharp approved calculator permitted. Questions 1–4 are compulsory; a candidate then completes ONE more question chosen from Questions 5, 6 or 7.
Reference texts: Guilbert & Park, The Geology of Ore Deposits (genetic classification, deposit-type descriptions throughout); Evans, Ore Geology and Industrial Minerals, 3rd ed. (deposit classification, ore-body morphology); Klein & Dutrow, Manual of Mineral Science, 23rd ed. (crystal systems, diagnostic physical properties, hand-specimen identification); Telford, Geldart & Sheriff, Applied Geophysics, 2nd ed. (gravity, magnetic, electrical, EM and radiometric methods); Kearey, Brooks & Hill, An Introduction to Geophysical Exploration, 3rd ed. (survey design and method selection); Rose, Hawkes & Webb, Geochemistry in Mineral Exploration, 2nd ed. (stream-sediment/soil survey design); Peters, Exploration and Mining Geology, 2nd ed. (sampling methods, drilling programs).
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.
| Method | Description and use |
|---|---|
| (i) Hand sampling | Manual collection of representative rock chip or grab samples directly from an outcrop or showing; used at the earliest reconnaissance stage to obtain a first, cheap geochemical/assay indication of whether mineralization is present before committing to more expensive methods. |
| (ii) Float mapping | Systematically locating and recording mineralized rock fragments (float) that have been physically transported away from their bedrock source by glacial or fluvial action; used to trace the float train back up-ice (or upstream) to pinpoint the bedrock source area, especially valuable in glaciated, outcrop-poor terrain like the Canadian Shield. |
| (iii) Trenching | Mechanically stripping the thin overburden along a line to expose fresh bedrock for direct mapping and channel sampling; used to test near-surface geochemical/geophysical anomalies cheaply, establishing structure, width and continuity of mineralization before committing to a drill program. |
| (iv) Stream sediment sampling | Collecting the fine active-sediment fraction from a drainage; used at the regional reconnaissance stage to identify anomalous catchments (a metal dispersion train) that point back toward an upstream mineralized source, at very low cost per unit area covered. |
| (v) Drilling | Diamond (core) or reverse-circulation (cuttings) drilling recovers a physical subsurface sample; used to test and confirm the presence, grade, geometry and continuity of mineralization at depth, and is the only method that provides the data needed for a compliant mineral resource estimate. |
| # | Reason | Explanation |
|---|---|---|
| 1 | Budget exhausted | Exploration programs operate under a fixed budget; once allocated drilling funds are spent, the program stops regardless of remaining geological targets, pending a new financing round. |
| 2 | Target condemned by consistently negative results | When a sufficient, statistically representative number of holes returns results below cutoff grade or shows the target geometry does not continue as modelled, the target is considered tested and uneconomic, and further drilling would not change the conclusion. |
| 3 | Geological/technical objective achieved | Once enough holes at the required density have been completed to support the intended resource-classification category (e.g. Indicated or Measured under NI 43-101/CIM guidelines) or to answer the specific engineering question the program was designed for, additional holes add cost without adding decision-useful information. |
| 4 | Technical/safety drilling problems | Unstable ground, excessive water inflow, hole collapse, equipment failure or other unsafe subsurface conditions can force abandonment of a hole or suspension of the program on safety grounds. |
| 5 | Access, permitting or seasonal constraints | Expiry of a drilling permit or land-access agreement, unresolved land-claim/consultation requirements, or the end of an accessible drilling season (e.g. spring breakup restricting access to a remote Shield or northern site) can force a program to stop independent of the geological results. |
