Clay mineral authigenesis along a mid-continental scale fluid conduit in Palaeozoic sedimentary rocks from southern Ontario, Canada
Bibliographic record
Abstract
Abstract Rocks above and below the Precambrian-Palaeozoic unconformity at the base of many Palaeozoic sedimentary basins of mid-continental North America are distinguished by secondary K-feldspar, chlorite and illite. Thrusting of the Appalachian foreland is generally considered responsible for the fluid migrations which caused this alteration. We have examined secondary chlorite and illite from Cambro-Ordovician rocks which overlie the unconformity in southern Ontario, Canada. This area is situated along the interface between the Michigan and Appalachian basins. Water involved in chloritic alteration at ~150°C has an O isotope composition compatible with a basinal brine evolved from seawater. Brine migration was probably triggered by the Taconic Orogeny to the east. In comparison, the secondary illite (365–321 Ma) largely postdates the Acadian Orogeny, and the illite-forming fluids have stable isotopic compositions typical of tepid (~40–55°C) meteoric water. We suggest that basement arches beneath southern Ontario were reactivated by this orogeny, which facilitated introduction of meteoric water. Similar alteration in underlying Precambrian rocks shows that fluid flow was focused along the unconformity during the regional Ordovician brine migration, as well as during the localized Mississippian introduction of fresh water.
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 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) | 0.062 | 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".