RELATIVE AND ABSOLUTE TIMING OF GOLD MINERALIZATION ALONG THE MELIADINETREND, NUNAVUT, CANADA: EVIDENCE FOR PALEOPROTEROZOIC GOLD HOSTED IN AN ARCHEANGREENSTONE BELT
Bibliographic record
Abstract
The Meliadine area of the Neoarchean Rankin Inlet greenstone belt is located on the western shore of Hudson Bay, Canada, and is host to several important orogenic or mesothermal gold deposits. Supracrustal rocks comprise alternating southeast-striking panels of mafic volcanic and clastic sedimentary rocks, both of which are host to banded iron formation. The dominant structural element is the Pyke Break, a several-kilometer-wide, high-strain zone characterized by multiple foliations and regionally important shear zones. Gold mineralization is spatially associated with these shear zones. The maximum age of mineralization is constrained by the observation that auriferous veins crosscut ca. 2450 Ma mafic dikes, and a minimum age is constrained by undeformed, postore lamprophyre dikes emplaced at ca. 1830 Ma. Highly concordant SHRIMP-determined ages on hydrothermal monazite indicate auriferous veining occurred at ca. 1850 Ma. These relative and absolute timing constraints suggest gold was concentrated in Neoarchean supracrustal rocks during Paleoproterozoic tectonothermal activity that was widespread in the western Churchill province at ca. 1850 Ma. These observations do not preclude the presence of Archean gold occurrences in the Rankin Inlet greenstone belt, but no early deformed ores can be linked to auriferous veins introduced at ca. 1850 Ma, suggesting remobilization from earlier formed deposits was not a factor in concentrating gold at Meliadine.
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 | 0.001 |
| 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 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".