Phanerozoic Record of Northern Ellesmere Island, Canadian High Arctic, Resolved Through <sup>40</sup>Ar/<sup>39</sup>Ar and (U‐Th)/He Geochronology
Bibliographic record
Abstract
Abstract The northern margin of Ellesmere Island, Canada, has experienced a complex geological history throughout the Phanerozoic, including multiple episodes of orogenesis and first‐order depositional cycles related to Circum‐Arctic evolution. Whereas previous studies have documented the structural and stratigraphic record of these events, supporting geochronological data are sparse. To constrain the age of these tectonic episodes, we apply 40Ar/39Ar geochronology and (U‐Th)/He low‐temperature thermochronology methods to polydeformed fault zones that bisect the Pearya terrane and Franklinian Basin of northern Ellesmere Island. Multiple single crystal 40Ar/39Ar dating of micas resulted in sample‐dependent date dispersion, with some samples exhibiting robust Paleozoic ages corresponding to the assembly and accretion of the Pearya terrane. Other samples yielded intra‐sample date dispersion that spanned the Late Paleozoic and Mesozoic, suggestive of a previously unreported post‐Ellesmerian and pre‐Eurekan history. Zircon and apatite (U‐Th)/He dates are largely Eocene in age, with dominant populations of c. 48 and c. 41 Ma, respectively. Inverse thermal history modeling of (U‐Th)/He data indicates episodic Mesozoic burial and unroofing coinciding with changes in the regional stress regime, and rapid cooling during nascent (>53 Ma) and initial (53–47 Ma) phases of Eurekan deformation. When integrated, our data provide temporal constraints on the timing of deformation, structural reactivation, and the Phanerozoic burial and erosive history of northern Ellesmere Island.
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 | 0.003 |
| 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) | 0.001 | 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".