Stratigraphy, Sedimentology, and Diagenesis of Ordovician Outliers, Northern Ottawa–Bonnechere Graben, Central Ontario
Bibliographic record
Abstract
Several Ordovician outliers along or near the northern Ottawa-Bonnechere graben are bounded by Precambrian rocks of the Canadian Shield.Correlation of outlier stratigraphy reveals that these remnant bodies form part of a once expansive Late Ordovician phase of the St. Lawrence Platform extending into the craton interior from the Laurentian margin.Integrating litho-, bio-, and chemostratigraphic data sets, four outliers (Deux Rivières, Brent Crater, Cedar Lake, and Manitou Islands) preserve Turinian strata, whereas a fifth (Owen Quarry outlier) illustrates how local downfaulting has preserved lower Chatfieldian strata.Each outlier documents a unique depositional succession but, in common, record shallow-water depositional environments during net transgression.Local diagenetic records reveal the roles of surface marine, shallow-burial, and deep-burial alteration of limestone.Several dolomite types are present: fabric-selective, pervasive replacement, and local fracture/paleovoid-fill.Isotope (C, O, Sr) signatures identify interaction of dolomitizing fluids with a 87 Sr-enriched reservoir, and very negative δ 18 O values of dolomite suggest either elevated temperature or meteoric influence.Dolomite shows basement-related, stratabound, and fault/fracture-related spatial distributions.Early-stage dolomitization may be related to Mg derived from marine or meteoric waters whereas late-stage dolomitization, including hydrothermal saddle dolomite, likely involves brines that migrated along Paleozoic-Precambrian boundary, then refocused along vertical faults and fractures.In general, this study demonstrates stratigraphic and sedimentary connectivity in the Laurentia craton interior during the early Late Ordovician, and dolomitization that may be related to local and regional fluid migration.
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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 | 0.002 | 0.003 |
| Science and technology studies | 0.002 | 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) | 0.004 | 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".