Soil geochemical survey over concealed kimberlites in the Attawapiskat area in northern Canada
Bibliographic record
Abstract
ABSTRACT: A soil geochemical survey was conducted over kimberlites in a discontinuous permafrost zone in the James Bay Lowlands, southeastern Hudson Bay Lowlands. The kimberlites are concealed by 10 to 30 m of tills and Tyrell Sea clay sediments. Samples of humus and B-horizon soil were collected at 25–50-m intervals over traverses with the total lengths of 562 m over the Whiskey kimberlite and 740 m over the Yankee kimberlite pipe. B-horizon soil samples, sieved to <80 mesh and dried at 60C, have high carbonate contents above the margins of the kimberlite pipes. Ammonium acetate leach at pH 5 (AA5) dissolves most of these carbonates, and shows anomalies of REE, Y and Ni above the margins instead of the centres of kimberlites. Since the leach dissolves not only carbonates but also amorphous Al-O-OH originating from the clastic component, the ratios of metals to Al are effective to display geochemical anomalies associated with kimberlites. The concentrations of high field strength elements, such as Nb and Ta, are low in AA5 relative to their detection limits, whereas these elements show anomalies in the Enzyme leach. The ratios of these metals to Mn in the Enzyme leach are useful to display the anomalies associated with kimberlites because soil samples over kimber-lites contain high contents of these metals and low contents of Mn. Our data suggest that a soil geochemical survey may be used to assist in discriminating kimberlites from other targets during diamond exploration in sub-Arctic settings.
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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
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".