The Snow Lake Deposits in Manitoba, Canada: Formation of Metamorphosed Amphibolite Facies Orogenic Gold Deposits During a Progressive and Prograde Orogenic Event
Bibliographic record
Abstract
Abstract The Snow Lake camp is located in the ca. 1.89 Ga Flin Flon-Glennie Complex in the Paleoproterozoic Trans-Hudson orogen, Manitoba, Canada. The Flin Flon-Glennie Complex is bordered by the ca. 1.855 to 1.84 Ga metasedimentary Kisseynew domain to the north and by the Archean Superior craton to the east and is underlain by the Archean Sask microcraton. It hosts several orogenic gold deposits, including the No. 3 zone, Boundary zone, and New Britannia deposit (Toots, Dick, Hogg, Ruttan, and Mine East zones), which formed during thrusting of the Flin Flon-Glennie Complex and Kisseynew domain over the Sask microcraton. The New Britannia deposit produced 1.6 Moz Au and is the largest orogenic gold deposit in the Trans-Hudson orogen in Manitoba. The deposits consist of quartz ± carbonate veins surrounded by alteration zones of biotite, hornblende, plagioclase ± carbonate, diopside, orthoclase, and garnet. The veins and ore zones are folded within the hinge of the synthrusting Nor-Acme anticline, which has an axial plane cleavage defined by biotite and hornblende, but they also cut across the hinge of the anticline and contain foliated fragments of the wall rocks. These mutually overprinting relationships suggest that the veins and ore zones are synfolding. Garnet, diopside, and amphibole porphyroblasts grew during folding because they overgrow the foliation, which also wraps around them. Inclusions of gold and sulfide minerals within the porphyroblasts indicate that mineralization was emplaced early during folding at greenschist or lower amphibolite metamorphic conditions prior to the growth of the porphyroblasts at peak middle amphibolite metamorphic conditions. These observations are corroborated by laser ablation-inductively coupled plasma-mass spectrometry element maps of arsenopyrite grains. These maps reveal a primary internal enrichment of gold in arsenopyrite grains from the Toots, No. 3, and Boundary zones and a lack of primary lattice-bound gold in arsenopyrite grains of the Dick, Ruttan, and Mine East zones. The latter results from the deposition or remobilization of gold during a second hydrothermal event that occurred during shearing of these ore zones along a structure, the Howe Sound fault, which acted as a detachment surface during folding. The Snow Lake deposits are examples of orogenic gold deposits that formed early during a major thrusting and folding event and were later modified and metamorphosed at middle amphibolite facies conditions during the same progressive orogenic event.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 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) | 0.000 | 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 teacher head, 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".