Knowledge / Mining & Geoscience / Drilling & Sampling
Drilling & Sampling
How the subsurface is actually sampled, and what has to be recorded for a sample to mean anything: hole geometry, intervals, recovery, logging and the quality control that lets a laboratory number be believed.
All 7 articles are published. Each one states what it needs, what can be concluded with it, and what cannot — and every one stays marked DRAFT until it has had independent geological review.
- 1. Anatomy of a drillhole publishedCollar, azimuth, dip, measured depth and true vertical depth — and why depth is not position.
- 2. Bulk density publishedBulk, particle and specific gravity; what moves density; and why volume alone yields no tonnage.
- 3. Sampling and representativity publishedWhere a sample boundary belongs, what a badly placed one hides, and why sample mass is not arbitrary.
- 4. QA/QC: duplicates, blanks and standards publishedHow a laboratory result earns the right to be believed.
- 5. Core recovery and RQD publishedHow much rock came back, how broken it was, and why a missing metre is not a zero grade.
- 6. Drilling methods: rotary, RC and diamond publishedWhat each method returns, what it costs, and what it destroys.
- 7. Logging: what a drill log records publishedTurning a length of rock into a defensible table of observations.