Geochronology and Trace Element Characteristics of Pyrite from Selected Carbonate Hosted Pb-Zn Ore Deposits
Bibliographic record
Abstract
Carbonate-hosted ore deposits, such as Mississippi Valley-type (MVT), and Irish-type deposits, are a major class of Pb-Zn ores. Due to the mineralogy of these deposits, numerical constraints on the timing of mineralization are few. This thesis investigates pyrite Re-Os geochronology for dating of ore formation, supplemented by a study of trace elements in pyrite. The two major deposits studied are the Lisheen deposit from Ireland, and the Nanisivik deposit from Nunavut. At Lisheen, different models of formation have been proposed, based upon ore formation ages of either ~ 345 Ma or ~ 280 Ma. The new Re-Os data show that Lisheen formed between 340 - 355 Ma in a primarily syngenetic/syndiagenetic fashion, and discount the significant of a ~ 280 Ma paleomagnetic age as a primary ore-forming event. The Re-Os pyrite geochronology from Nanisivik confirms it is a rare example of a Precambrian MVT deposit, forming at approximately 1100 Ma.
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 | 0.001 | 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 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".