Seismotectonic characteristics of the Lower St. Lawrence Seismic Zone, Quebec: insights from geology, magnetics, gravity, and seismics
Bibliographic record
Abstract
The estuary of the St. Lawrence River between Baie-Comeau and Sept-Îles is an area where 50 to 100 earthquakes are detected yearly. This study defines the major lineaments of the Precambrian basement and compares them with mapped faults where possible, and examines their possible correlation with the local earthquakes. Onshore, aerial photographs, remote sensing images, and field mapping are used to identify the geological structures of the Precambrian basement, while offshore, they are interpreted from potential field (magnetic, gravity) and a published synthesis of seismic reflection profiles. The Precambrian basement dips towards the southeast under the Appalachian nappes with normal faults with kilometre-scale throw and eastwest or ENEWSW strikes. Onshore, a system of normal brittle faults with a complex history of movements crosscuts both the Precambrian basement and the overlying Ordovician sedimentary cover. Most earthquakes occur beneath the St. Lawrence River at focal depths between about 7 and 25 km that place them well within the Precambrian Shield. In the Lower St. Lawrence Seismic Zone, the trend of the normal faults that changes from SWNE to mostly eastwest, and lateral density anomalies possibly enhance the local stress level. It is also suggested that local faults could be weak because of crustal fluids at depth, possibly under hydrostatic pressure, or to fault gouge, which leads to a lower coefficient of friction. It is possible that the region was intensely fractured by the emplacement of the Sept-Iles layered igneous complex.
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 | 0.002 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".