Upper crustal investigation of the Gulf of Saint Lawrence region, eastern Canada using ambient noise tomography
Bibliographic record
Abstract
Abstract We studied the 3‐D shear wave velocity (Vs) structure in the Gulf of St. Lawrence (GSL) and adjacent onshore areas to 20 km depth by inverting Rayleigh wave dispersion extracted from the vertical components of continuous ambient seismic noise waveforms. The region is divided into three broad zones based on their Vs characteristics. In the northwest, the Grenville Province (i.e., the exposed edge of predominantly Middle‐Proterozoic Laurentian crust) is dominated by high Vs, except for well‐known anorthosite sites, which are characterized by relatively lower Vs. In contrast, the central segment of the GSL region corresponds to a belt with generally low Vs at upper crustal levels. In the southeastern part of the GSL, prominent low Vs in the uppermost crust are found to coincide with locations of subsidiary basins of the Canadian Maritime Basin, while higher Vs characterize the accreted Appalachian terranes where they are exposed on land. The Grenville Province is wedged out at depth by the Red Indian Line, which is the suture between composite Laurentia and peri‐Godwanan Ganderia in the Canadian Appalachians. The geometry and Vs characteristics of the south‐easternmost peri‐Gondwanan terranes of Avalonia and Meguma suggest that they may be fully or partially structurally overlying a basement with distinct seismic characteristics, which could be a vestige of the West African craton that was underthrust beneath composite Laurentia during the terminal Alleghenian continent‐continent collision. In the middle of the GSL, the 3‐D geometry of the Canadian Maritimes sedimentary basins overlying the Appalachian terranes shows that the depth to the top of basement is in excess of 8 km.
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 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 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 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".