U-Pb Ages, Hafnium Isotope Ratios, and Trace Element Concentrations by Laser-ablation Split Stream (LASS) Analysis of Igneous and Metamorphic Zircons from the Yukon-Tanana Upland, Eastern Alaska
Bibliographic record
Abstract
This dataset contains U-Pb isotopic data and ages, Hf isotope data, and trace element concentrations of zircon from igneous rocks collected from the Yukon-Tanana Upland, eastern Alaska. The sample suite was collected as part of geological mapping and supporting geochemical and geochronological analysis conducted from 2013 to 2019. Zircon was obtained from these igneous rocks to determine the crystallization age for the bedrock samples. The data tables accompanying this data release report the composition of uranium (U) and thorium (Th) measured in each grain, ratios of three isotopes of lead (206Pb, 207Pb, 208Pb), two isotopes of uranium (235U and 238U), and one isotope of thorium (232Th), as well as the age of each grain, plus trace element abundances from the same ablated aliquot, including P, V, Sr, high field strength elements (HFSE), and rare earth elements (REE). Reported Hf (and Lu) isotope data includes 176Hf/177Hf, 176Lu/177Hf, and 178Hf/177Hf ratios, calculated epsilon Hf values, and age-corrected isotope ratios and epsilon values.
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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) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.005 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.016 | 0.012 |
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".