An enigmatic profile from a 3440 m deep drill hole in the southern Canadian Shield: results from apatite fission track and (U -Th)/H e thermochronometry
Bibliographic record
Abstract
A 3440 m deep borehole at Sudbwy, in the southern Canadian Shield has been investigated using a combination ofapatite fission track (AFT) and (U-Th)/He thermochronometry as part of a major regional thermochronological study of the Canadian Shield. 19 samples were collected downhole at ~200 m intervals. Apparent AFT ages range from -360 Ma at the surface to -140 Ma at the base. Chemical composition of apatite ranges from 0.1 to 2 wt% Cl. Preliminaiy apatite (U-Th) He results yield ages o f-250 Ma at the surface and decrease towards 0 Ma at -3000 m, at a present day bottom hole temperature o f -65 °C. The age-depth projile reveals a sinuous form with an amplitude of-W 0 m.y. for the AFT ages. The projile form is also independently rejlected in the (U-Th) He data. A preliminary interpretation o f the projile pattern indicates that it did not result J'rom tectonic offsets, but is possibly related to hot Jluidjlow or chemical composition affects or a combination of both.
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 | 0.002 | 0.002 |
| 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) | 0.001 | 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".