Tectonostratigraphy of the Chazyan (Late Middle–Early Late Ordovician) Mixed Siliciclastic–Carbonate Platform, Quebec Embayment
Bibliographic record
Abstract
Abstract: The Middle to lower Upper Ordovician (Chazyan) platform succession of eastern North America extends landward of the ancient Quebec Embayment along the Laurentian margin, part of a foreland basin peripheral to an arc-collisional plate boundary. The platform grades from seaward reefal carbonate (Chazy Group, Champlain Valley) into platform- and foreland-interior tide- and wave-dominated siliciclastics (Rockcliffe Formation) and restricted peritidal muddy carbonate (Hog's Back Formation). The latter two formations occur in the sedimentary Ottawa Embayment, which overlies the trace of a Neoproterozoic rift. Prominent tectonostratigraphic surfaces bound and subdivide the Chazyan platform-interior succession, and are characterized by abrupt marine transgressions, local synsedimentary faults, and seismogenic beds. The depositional history includes: (1) accumulation of shallow-marine siliciclastics (Rockcliffe Fm) across a differentially faulted paleoplatform; (2) abrupt regional retrogradation (∼ 100 km) of this siliciclastic system, replaced by an intraplatform shale basin (lower Hog's Back Formation); (3) basin fill and development of a low-energy muddy carbonate platform interior (upper Hog's Back Formation) coincident with regional fall in sea level and change in subsidence along the Laurentian margin; and (4) abrupt high-frequency base-level changes preceding regional onlap of Mohawkian (Turinian) shale contemporary with local synsedimentary deformation and rapid subsidence along the distal arc-collisional plate boundary. Structurally controlled sedimentation patterns in the platform (and foreland) interior document episodic tectonism coincident with relatively sustained deposition along the outer platform (the Chazy Group). This difference is interpreted to be a response to foreland-interior flexuring, modified by local reactivation of the Precambrian rift, that was coincident with preferential subsidence at seaward sites more proximal to structural loading along the arc-collision plate boundary.
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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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".