Growth and demise of continental arcs and orogenic plateaux in the North American Cordillera: from Baja to British Columbia
Bibliographic record
Abstract
Abstract In the North American Cordillera, crustal thickening, magmatism and flow of deep crust created an orogenic plateau, or series of related plateaux, in the Late Mesozoic-Early Cenozoic. From west to east, the plateaux extended from the continental arcs to the inboard crystalline belts of the Omineca-Sevier belt. From north to south, the plateaux ranged from British Columbia/SE Alaska to Baja California, Mexico. Although a vast region of western North America was characterized by thickened crust (60–70 km), unroofing of deep crust from >30 km was largely confined to the edges of the plateaux: the arcs and the eastern margins. Comparison of the unroofing histories of the Cordilleran arcs reveals that they differed dramatically from each other in the amount and style, but not timing, of exhumation. The northern Cordilleran arc and northern interior (Omineca) belt were exhumed from deep mid-crustal levels, with regional-scale Eocene extension accompanied by magmatism. In contrast, the central (Sierra Nevada) and southern (Peninsular Ranges) arcs were unroofed to much shallower levels (typically <15 km), primarily by erosion and local deformation. North to south differences in exhumation style and magnitude in the Cordilleran arcs may reflect differences in the degree of coupling between the subducting plate and the thickened continental lithosphere in the north v. south. In the northern Cordillera, relationships between Pacific-region plate activity and Tertiary continental extension/magmatism and deep exhumation suggest continued geodynamic coupling between subducting plates and orogenic crust following crustal thickening and plateau formation. In contrast, the central and southern Cordilleran arcs do not contain evidence for mechanical links with the subducting plate after the Late Cretaceous.
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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".