Till and bedrock heavy mineral signatures of the Kiggavik uranium deposits, Nunavut
Bibliographic record
Abstract
In 2010, a drift prospecting study was initiated over the Kiggavik uranium (U) deposit under the Geomapping for Energy and Minerals (GEM) Program. The objective of this study was to document the till geochemical and heavy mineral signatures of the Kiggavik U deposit and to identify potential applications of those characteristics in future exploration for drift-covered, basement-hosted, unconformity-related U deposits. The study area is within the zone affected by the migration of the Keewatin Ice Divide of the Laurentide Ice Sheet. Mineralized and non-mineralized bedrock and near-surface till samples (n = 71) were collected directly overlying, up-ice, and at various distances (50 m, 100 m, 200 m, 500 m, 1 km, 2 km, 3 km, 5 km, and 10 km) in a fan-shaped pattern down-ice from the deposit with respect to the dominant north-northwest, northwest, and west ice-flow directions. Detailed microscopy and microprobe analysis of ore samples from drill core reaffirmed uraninite and coffinite as the dominant ore minerals at the Kiggavik U deposit, with accessory galena, pyrite and very minor native gold associations. These minerals are predominantly very fine-grained and rarely exceed 100 ?m in diameter, with the exception of rare massive crystalline uraninite. Examination of the sand-size heavy mineral concentrate (HMC) from till yielded no U-rich or directly associated accessory ore minerals, reflecting the overall fine-grained nature and instability of these minerals in oxidizing conditions such as those found in near-surface till. This ultimately limits the utility of these minerals as empirical indicators of U deposits. Native gold grains in till samples collected in this study are, however, more abundant than those in regional background samples. Elevated counts were found up to 3 km down-ice of the Kiggavik Main Zone (KMZ) in a west-northwest direction. The sample containing the highest gold grain count in till was collected directly overlying the KMZ, suggesting local provenance and the applicability of native gold as an indicator mineral for Kiggavik-style unconformity-type U deposits. Moreover, Pb-rich fluorapatite grains (up to 8% PbO), from the alteration zone around the KMZ U deposit, are of particular interest due to their uniqueness, stability under near-surface weathering conditions, and thus their potential to be an indicator mineral for such deposits. However the fluorapatite grains are very finely crystalline, as are the main Ubearing phases observed in ore samples, therefore a new technique to separate, collect, and identify the finer fraction of the HMC needs to be developed.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 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 teacher head, 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".