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Record W1656067241

PALEOENVIRONMENTAL CHARTS FOR TERRESTRIAL IMPACT STRUCTURES - A SIMPLE TOOL TO TEST IMPACT AGES AND MARINE/CONTINENTAL IMPACT CONDITIONS.

2008· article· en· W1656067241 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

VenueLPICo · 2008
Typearticle
Languageen
FieldEarth and Planetary Sciences
TopicMarine and environmental studies
Canadian institutionsnot available
Fundersnot available
KeywordsGeologyImpact structureImpact craterPaleontologyArchaeologyBrecciaEarth sciencePhysical geographyGeography
DOInot available

Abstract

fetched live from OpenAlex

Introduction and Background: Most of the ~175 impact structures currently known on Earth are still insufficiently dated [1-2]. At buried or deeply eroded impact structures that lack material suitable for isotopic dating, stratigraphic methods provide the only con-straints for the timing of crater formation; in many cases, only the maximum age (the actual age of the shocked target rock) is given in the literature and in terrestrial impact crater listings [3]. In addition to isotopic and stratigraphic dating, paleogeographic considerations may help to test and refine poor and/or equivocal impact ages as recently done for PuchezhKatunki (Russia) and Obolon (Ukraine) [4]. Paleogeographic studies are, furthermore, an essential tool to discriminate between impact structures that formed in continental or marine environments. Only a small number (~25) of marine terrestrial impact structures have been reported so far [5]. Structural and sedimentological investigations (e.g., the recognition of submarine resurge breccia deposits) helped to reveal some additional marine impact structures, such as Obolon (Ukraine) [6]. However, further efforts need to focus on the recognition of marine impact structures on Earth. Data: Combining recent paleogeographic maps of North America (provided by Ron Blakey, Northern Arizona University [7]) with impact ages available in the literature [3; 8-14], we present a preliminary set of paleoenvironmental charts for some selected North American impact structures (USA: Ames, Oklahoma; Avak, Alaska; Crooked Creek, Missouri; Newporte, North Dakota; Sierra Madera, Texas; Upheaval Dome, Utah; Wells Creek, Tennessee; Canada: Carswell, Saskatchewan; Charlevoix, Quebec; Pilot, Northwest Territories; Steen River, Alberta; Fig. 1). Interpretation and Results: In accordance with [7], given that both the paleogeographic maps and impact ages can include uncertainties, the paleoenvironmental charts suggest that Newporte (~500 Ma [8]) and Steen River (91 ± 7 Ma [9]) formed under marine conditions and that Ames (>470 Ma [10]), Avak (~93-88 Ma [11]), Charlevoix (~450-480 Ma [12]), and Carswell (115±10 Ma [13]) are probably marine impact structures. The Pilot (445±2 Ma [13]) event was obviously a continental impact scenario, as most likely was the Wells Creek (200±100 Ma [14]) impact. Charts exhibit transitions in environmental conditions for Crooked Creek (320±80 Ma [14]), Upheaval Dome (<170 Ma [3]), and Sierra Madera (<100 Ma [14]). New field studies and the detection of structural and sedimentological features diagnostic for marine or continental impact, respectively, might strongly narrow the age windows for these structures.

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)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesInsufficient payload (model declined to judge)
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: Observational
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.014
Threshold uncertainty score0.998

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0070.000

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 head0.013
GPT teacher head0.242
Teacher spread0.229 · 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