Bibliographic record
Abstract
Abstract The 23-year evaluation history of the Diavik kimberlites (1994–2017) commenced with elevated microdiamond stone counts from small samples of drill core. These stone counts equated with high sample grades, grades that were higher than anyone had expected (2–5 carats per tonne [ct/t]), and caused many experienced explorers to change their opinions on the prospectivity of small kimberlites (1–2 ha in surface area). The diamond size-frequency distributions were coarser trending, and the diamond quality was “mixed,” resulting in >1-mm diamond prices of about US$100 per ct, slightly better than the world average. This grade and price combination gave ore values ranging from US$200 to US$500 per tonne and, with four kimberlites, the Diavik joint venture partners estimated that there would be sufficient ore to underpin a 20-year mine life at a treatment rate of 2.2 million tonnes per annum. Primary diamond deposits are usually sampled on 50- or 100-m grids. Grade drilling at Diavik was conducted on 25-m centers, allowing for 12- × 6-in holes in each kimberlite. The kimberlites are located beneath Lac de Gras and had to be bulk sampled underground to generate diamond parcels (approximately 12,000 and 8,000 ct) for sorting and valuation. Three of the kimberlites transitioned from open-pit to underground mines (two sublevel retreats and one cut and fill). The fourth kimberlite narrows at depth and is unlikely to be mined from underground. Grade reconciliation has presented challenges; each kimberlite comprises three to four geologic units and plant feed can comprise ore from three kimberlites concurrently. Careful ore management and tracking has overcome these difficulties, meaning that grade, size-frequency, and size-quality reconciliations have been meaningful and, for the most part, have varied less than ±5% on an annual basis. The Diavik mine is neither the largest nor the smallest deposit in the world. However, by the end of its life it will have produced about 7 million carats of diamonds per annum for 22 years at an average grade of 3.4 ct/t. It represents an exceptional diamond resource for kimberlites ~100 m in diameter, considering that it is also located in one of the coldest and remotest locations on Earth.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.005 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".