Potassium Metasomatism at the Polymetallic NICO Deposit, Northwest Territories, Canada
Bibliographic record
Abstract
High temperature K-metasomatism pervasively replaced Paleoproterozoic volcanic and metasedimentary rocks at Lou Lake NWT. This replacement developed primarily at the structural interface juxtaposing non-metamorphosed Lou Lake volcanic rocks over Treasure Lake Group metasedimentary rocks. This crustal-scale fault developed coeval with the emplacement of anorogenic magmatism within a post-collision extensional setting. Emplacement of porphyry dykes into the fault breccia coincided with K-metasomatism at peak upper-greenschist to amphibolite-facies thermal conditions.\nThe K-metasomatism resulted from co-mingling of descending crustal fluids and ascending potassic magmatic fluids along the decollement surface. Pervasive K-metasomatism resulted in complete replacement of precursor rocks by potassium feldspar. The pronounced element liberation and SiO2-Al2O3-K2O enrichment resulted in the homogenization of diverse rock types into brick-red potassium feldspar metasomatite characterized by high K2O/Na2O ratios and up to 13.4 wt%, K2O. The secondary microcline approaches end member orthoclase composition. Petrographic and isotopic evidence indicate associated iron oxide is an inherited component from precursor rocks. Oxidizing conditions were superimposed by continued flux of crustal fluids during a prolonged retrograde cooling history.
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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 | 0.001 | 0.001 |
| Science and technology studies | 0.003 | 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) | 0.006 | 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".