Origins of Mineral Deposits, Belt-Purcell Basin, United States and Canada: An Introduction
Bibliographic record
Abstract
The fill of the Mesoproterozoic Belt-Purcell Basin, which straddles the United States-Canada border within the Rocky Mountains of western North America (Fig. 1), consists of marine and nonmarine clastic and carbonate strata 15 to 20 km thick. Three giant metal-producing ore deposits or districts account for the bulk of the known metal endowment within the bounds of the Belt-Purcell Basin: (1) the syndepositional Sullivan Pb-Zn-Ag deposit in southern British Columbia (total production: Pb, 8.4 million tonnes [Mt]; Zn, 7.9 Mt; Ag, 0.0093 Mt; Lydon, 2000), (2) the mesothermal Pb-Zn-Ag veins of the Coeur d’Alene district in northern Idaho (total production: Pb, 7.5 Mt; Zn, 3.0 Mt; Ag, 0.052 Mt; Long, 1998; post-1997 data from USGS Annual Minerals Yearbooks), and (3) the Cretaceous porphyry copper deposit and associated polymetallic veins in the Butte district in Montana (total resource: Cu, 35 Mt; Zn, 4.6 Mt; Ag, 0.044 Mt; Long et al., 1998). The Sullivan Mine closed in 2001 after more than 92 years of production. Mining of 26 major vein deposits in the Coeur d’Alene district began in the 1880s and peaked about 1950. Production in the Coeur d’Alene district continues today from the Galena and Lucky Friday Mines (the latter closed for 2012 to refurbish the mile-deep vertical access shaft). Mining at Butte began in 1875, with copper production peaking in 1917. Mining continues today in the eastern upfaulted portion of the Butte porphyry copper deposit at the Continental Mine. Fig. 1 Locations of major ore deposits within the Belt-Purcell Basin area, along with other ore deposits and mineralized trends that are discussed in this issue. Deposit locations are plotted on a geologic map showing the distribution of five stratigraphic units within the Belt-Purcell Basin in the United States and Canada. Lower Belt formations include the Prichard, Altyn, Appekunny, Chamberlain, Newland, LaHood, …
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.004 | 0.009 |
| Science and technology studies | 0.004 | 0.001 |
| Scholarly communication | 0.003 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.010 | 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".