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Record W2336768714

An Early/Middle Devonian 40Ar/39Ar Age for the Charlevoix Impact Structure (Quebec, Canada) - An Approach Closer to Reality

2012· article· en· W2336768714 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

aboutThe title or abstract carries a Canadian signal from the geographic lexicon.
no affNo Canadian affiliation: this work is invisible to an affiliation-only frame.
No Canadian affiliation. An affiliation-only frame, the usual design, would never have seen this work. It is one of the works that make the case for inverting the frame.

Bibliographic record

VenueMeteoritics and Planetary Science Supplement · 2012
Typearticle
Languageen
FieldPhysics and Astronomy
TopicPlanetary Science and Exploration
Canadian institutionsnot available
Fundersnot available
KeywordsImpact structureGeologyDevonianImpact craterOrdovicianBrecciaDikeBasementOrogenyCarboniferousPaleontologyPaleozoicBaltic ShieldClastic rockGeochemistrySedimentary rockPrecambrianArchaeologyTectonicsGeographyStructural basin
DOInot available

Abstract

fetched live from OpenAlex

Introduction: The ~54 km Charlevoix impact structure is hosted in ~0.9 Ga crystalline rocks of the Grenville Province of the Canadian Shield that are overlain by Middle Ordovician sedimentary rocks. Impactites mainly comprise impact melt rocks of variable appearance and textures, as well as pseudotachylitic breccia dikes in the shocked crater basement. Although the Charlevoix impact structure has been studied for a long time, no precise data for the age of the impact event exist. The maximum impact age is defined by the occurrence of shatter-coned Middle Ordovician limestones (~460-450 Ma) in downfaulted parts of the impact structure [1]. The southeastern part of the impact structure is overthrusted by the northern Appalachian front along the Logan’s Line. The Late Devonian terminal Acadian orogeny (~377 Ma [2]), thus, marks the minimum impact age [1]. Existing Age Constraints: The first K-Ar ages for impact melt rocks obtained by [3] yielded (recalculated) Carboniferous ages between 321 and 356 Ma for the Charlevoix impact structure. 40 Ar/ 39 Ar laser spot total fusion analyses of impact melt

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.

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.001
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: Observational
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.133
Threshold uncertainty score0.670

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0010.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0010.000
Scholarly communication0.0000.001
Open science0.0010.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

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.

Opus teacher head0.029
GPT teacher head0.270
Teacher spread0.241 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it