Protracted (>100 m.y.) deep crustal orogenesis revealed by in situ monazite petrochronology in the Shuswap Metamorphic Complex, British Columbia, Canada
Bibliographic record
Abstract
Abstract The Shuswap Metamorphic Complex in southeastern British Columbia, Canada, exposes penetratively deformed rocks exhumed from deep crustal levels (~25–30 km depth) of the Canadian Cordillera. Existing models describing its tectonometamorphic evolution are not directly linked to absolute age constraints acquired through modern petrochronological methods and, therefore, remain ambiguous. To differentiate between proposed models, here we apply U-Th-Pb monazite petrochronology, petrological modeling, and microstructural analysis to quantify conditions and timing of deformation across a transect of the Shuswap Metamorphic Complex. Our results demonstrate that metamorphism decreases in age with increased structural depth associated with progressive localization of NE-directed shearing toward the base of the Shuswap Metamorphic Complex. Monazite U-Th-Pb age data from the structural level exposed in the study area are consistent with protracted northeast-directed compression from ca. 167 Ma to ca. 59 Ma, after which west-directed ductile extension continued until at least ca. 49 Ma and was progressively localized along the Okanagan Valley fault system. New data presented are consistent with a model of basal accretion in front of a foreland-propagating ductile thrust system, followed by exhumation of the Shuswap Metamorphic Complex facilitated in large part by crustal-scale extension.
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 | 0.002 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".