Constraining the age and depositional framework of the late Paleoproterozoic to early Mesoproterozoic Muskwa Assemblage, northern British Columbia
Bibliographic record
Abstract
The Muskwa Assemblage is one of several Proterozoic successions that developed as part of an extensive passive margin succession along the present-day western margin of Laurentia between 1.74 and 1.45 Ga in a back-arc setting facing Bonnetia and northeastern Australia. The >7 km of exposed strata have an almost identical detrital zircon age distribution to that of the Athabasca Basin. The maximum depositional age of 1.766 ± 0.014 Ga is based on a zircon from the Tuchodi Formation. The upper age is constrained by cross-cutting 0.777.3 ± 0.003 Ga Gunbarrel dikes. Direct U/Pb dating of mudstone indicates deposition of the Aida Formation at around 1.571 ± 0.02 Ga, roughly overlapping with sedimentation of the Douglas Formation in the Athabasca Basin. Strata of the Chischa Formation at the base of the assemblage include carbonate, sandstone, and minor mudstone deposited largely above storm wave base in an inner- to mid-shelf setting. The low-angle unconformity at the base of the Tetsa Formation indicates minor tectonic flexure. The carbonaceous mudstone and minor sandstone in the Tetsa Formation were deposited in a distal ramp setting, prior to progradation of shallow-water carbonate of the George Formation. Mixed dolostone, sandstone, and mudstone in the overlying Henry Creek Formation indicate renewed deepening on the ramp. Sandstone and minor mudstone in the overlying Tuchodi Formation were deposited on a wave-, storm-, and tide-influenced shelf. Mudstone and minor carbonate in the overlying Aida and Gataga formations accumulated in progressively deeper water on the outer-shelf and slope.
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 | 0.003 | 0.003 |
| Science and technology studies | 0.003 | 0.000 |
| Scholarly communication | 0.002 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 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".