Petrology of kimberlite debris from the GSC showing, Amaruk Kimberlite Field (NTS 57A/03), Kitikmeot region, Nunavut, Canada
Bibliographic record
Abstract
Kimberlite debris was discovered on a regional geological traverse in 2005 by geologists of the Geological Survey of Canada's Boothia Integrated Geoscience Project. Petrographic and mineral chemical data indicate that the debris comprises an 'archetypal', Group I, segregation textured serpentine-calcite kimberlite. Heavy mineral separates and petrographic studies indicate that the kimberlite contains common ilmenite nacrocrysts, and peridotite paragenesis garnets of both lherzolitic G9 and sheared high-TiO2 G11 types. Chrome spinels are not common and have MgO and Cr2O3 contents less than those from other known diamond intergrowths and diamond inclusions. Ilmenites form rounded macrocrysts and anhedral groundmass grains and exhibit complex compositional variations. Ilmenite macrocryst compositions mimic those of Mitchell (1986) although trending to slightly higher Fe2O3. Ilmenite mantles on the macrocrysts are MgO-rich and Cr2O3-poor, whereas groundmass ilmenites are MgO and Cr2O3 rich. These observations suggest a three phase evolution for the kimberlite: 1) entrapment and disaggregation of ilmenite macro/megacrystic-bearing lherzolitic lithospheric mantle in a kimberlitic magma; 2) reequilibration of these mantle xenocrysts during magmatic ascent through the lithosphere and; 3) crystallization of small groundmass ilmenite during final emplacement and cooling of the kimberlite.
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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 | 0.004 | 0.002 |
| Science and technology studies | 0.002 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 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".