Geology and thermotectonic evolution of the western margin of the Trans-Hudson Orogen: evidence from the eastern sub-Athabasca basement, Saskatchewan
Bibliographic record
Abstract
In the Cree Lake Zone of northern Saskatchewan, reworked Archean orthogneisses are overlain by a highly deformed supracrustal sequence, the Paleoproterozoic Wollaston Group. This package of rocks was deformed and metamorphosed during the ca. 1.8 Ga continentcontinent collision of the Trans-Hudson Orogen (THO), forming the Wollaston foldthrust belt that underlies the eastern Athabasca Basin. The Hudsonian structural, metamorphic, and magmatic evolution of the Wollaston fold-thrust belt in the eastern Athabasca area involved six major stages. (1) Early collisional stage, D P1 at 18601835 Ma, involved burial of Wollaston Group metasediments from surface to depths equivalent to 35vkbar (1 kbar = 100 MPa) by thrust-pile stacking or imbrication tectonics, prograde metamorphism with garnet growth and development of early leucosomes, and emplacement of ca. 1840 Ma grey granite suite. (2) Collisional stage, D P2a at 18351820 Ma, involved continued deeper burial of Wollaston Group metasediments along a prograde PTt (pressuretemperaturetime) path at depths equivalent to peak pressures of 69 kbar and approaching peak temperatures (750825 °C), mafic magma underplating in the lower crust, initiation of large-scale crustal melting, emplacement of 18351820 Ma tholeiitic to calc-alkaline intrusions, and initiation of strike-slip tectonics. (3) Oblique collisional stage, D P2b at 18201805 Ma, involved strong transpressional tectonics with NESW shearing and NWSE shortening, partitioned high-strain ductile flow, kilometre-scale fold development, initiation of exhumation, attainment of peak temperatures (750825 °C), and essentially isothermal decompression with decompressional melting and intrusion of the main pulse of leucogranites and granitic pegmatites. (4) Late oblique collisional stage, D P3 at 18051775 Ma, caused development of amphibolite-facies dextral strike-slip shear zones and retrograde movement of older shear zones. It included apparent rotation of the main shortening axis and development of accommodation features due to vertical uplift (i.e., extension). (5) Post-collisional stage, D P4 at 17751760 Ma, involved continued localized adjustments along an essentially isobaric cooling path and produced NNE-trending, sinistral, oblique-slip reverse faults with reactivation of older shear zones. (6) Late post-collisional stage, D P5, produced north- to northwest-trending sinistral faults, including the Tabbernor fault system. Extension and tectonic extrusion during D P4 and D P5 were significant and resulted in orogenic collapse and formation of the Athabasca Basin at ca. 17501680 Ma.
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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 | 0.001 | 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 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 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 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".