Thermodynamic constraints on the mineralogical and fluid composition evolution in a clastic sedimentary basin: the Athabasca Basin (Saskatchewan, Canada)
Bibliographic record
Abstract
To evaluate the critical parameters controlling the mineralogical evolution of a dominantly clastic sedimentary basin, the Athabasca Basin (Saskatchewan, Canada), activity diagrams have been constructed with respect to the mineralogy, thermo-barometry, and fluid composition documented from previous studies. Relative to standard diagrams, which exist for ideal clay minerals, the present diagrams are the first to include all of the significant minerals present in the sediments, accounting specifically for the occurrence of dravite, sudoite, and two types of illite having identical chemical compositions, but different crystal morphologies and structures. The occurrence of the different mineralogical assemblages is mainly controlled by the K + /H + and Mg 2+ /(H + ) 2 activity ratios, and the silica and B(OH) 3 activities in addition to temperature and pressure. Variations in the activities of the major brine components (Cl - , Na + , Ca 2+ ) and the oxygen fugacity (above the hematite-magnetite buffer) have little effect on the mineral stabilities. The mineralogical evolution of the Athabasca Group sandstone results from mass transport processes involving a basement-derived fluid, richer in K, Mg, B, and/or pH, and possibly undersaturated in silica. The zoned distribution of the minerals in the uranium-mineralized Shea Creek area can be explained by a progressive interaction of the basement-derived fluid with the diagenetic brine and minerals of the Athabasca Group sandstone. During peak diagenesis, the brine in the basal Athabasca Group was buffered by the assemblage I Mc illite-kaolinite. During the syn-ore stage, the estimated values of log(K + /H + ), log(Mg 2+ /(H + ) 2 ) and B(OH) 3 activity decrease from 3.9, 6.4, and 0.005 in breccia zones immediately above the orebody, down to 2.7-3.6, 4.7-6. 1, and 0.004 in the inner alteration halo, and down to 2.7, 4.9, and 0.003 in the outer alteration halo, respectively.
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 | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".