Tectonic and petrogenetic settings of the Eocene Challis-Kamloops volcanic belt of western Canada and the northwestern United States
Bibliographic record
Abstract
The Eocene Challis-Kamloops volcanic belt, which runs through the interior of British Columbia and northwest United States for >2, 000 km, developed within a short time interval from ~55 to ~45 Ma. Volcanic rocks of the belt are discontinuously distributed in a series of grabens, half-grabens and calderas. Although predominantly composed of high- to medium-K calc-alkaline rocks that are typical of continental arcs, they were extruded during a time of regional transtensional tectonics in the Cordilleran orogen, which also led to the contemporaneous emplacement of Precambrian metamorphic core complexes near the belt. Their relative contents in Y, Nb, La, Sm, Gd, Yb and Ta suggest that the magmas were formed in relation to slab-failure (slab break-off). Initial Sr and Nd isotopic ratios and neodymium depleted mantle model ages indicate that the northern and southern parts of the belt had isotopically distinct lithospheric mantle sources with, respectively, Palaeozoic to Mesozoic and Precambrian model ages. As all rocks of the belt share common tectonic and petrogenetic settings, greater contents in incompatible trace elements in rocks from the southern part of the belt suggest that the Precambrian sources were more metasomatically enriched in these elements than the Phanerozoic sources.
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 | 0.003 | 0.003 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.005 | 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".