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Record W7007319796

カナダラブラドル地方、ネーン岩体の地質:最古の海洋地殻の発見に向け

2013· article· en· W7007319796 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

VenueTokyo Tech Research Repository (Tokyo Institute of Technology) · 2013
Typearticle
Languageen
FieldEarth and Planetary Sciences
TopicGeological and Geochemical Analysis
Canadian institutionsnot available
Fundersnot available
KeywordsHadeanZirconMetamorphismUltramafic rockFelsicVolcanic rockPeriod (music)
DOInot available

Abstract

fetched live from OpenAlex

The Hadean is the most mysterious period because no rocks and geologic bodies are preserved except for only the zircons in\nWestern Australia, Canada, China and Greenland (Froude et al., 1983, Nature; Nelson et al., 2000, EPSL; Mojzsis & Harrison,\n2002 EPSL; Iizuka et al., 2006, Geology;Wang et al., 2007, CSB). But, it is the most important period because the early evolution\npossibly clinched the history of the earth. We try to find the earliest supracrustal rocks in the world to investigate the Hadean\ntectonics and decode surface environments. As far, the oldest supracrustal rocks are found in Akilia association in West Greenland,\nNuvvuagittuq in Quebec, and Nain Complex in Labrador (Nutman et al., 1996, Precamb. Res.; O’Neil et al., 2008, Science;\nSchiotte et al., 1989, Can Jour Earth Sci.). Because the Akilia association suffers from severe metamorphism and alteration, the\nprecursors are highly in debate (e.g. Fedo & Whitehouse, 2002, Science). Recent geological works in the Nuvvuagittuq, Quebec\nshowed the sequence contains amphibolite with a pyroclastic rocks affinity, ultramafic sills, felsic sediment, BIF and conglomerate.\nAlthough a pseudoisochron age of 147Sm/144Nd-142Nd/144Nd implies the Hadean age (O’Neil et al., 2008, Science), the\nsupracrustal belt possesses 3811 Ma by conventional U-Pb zircon ages (David et al., 2009, GSAB).\nWe made geological survey in the Nain Complex, and reinvestigated the occurrence of the supracrustal rocks and their relationship\nwith the ambient orthogneisses. Previous works focused on distribution of the supracrustal belts within the orthogneisses\n(e.g. Bridgwater et al., 1974 Geol Surv Canada, Paper), but the detailed field occurrence of the supracrustal rocks within the belts\nis still ambiguous. Therefore, we focus on their internal structures.\nThe supracrustal belts are repeatedly intruded by granitic intrusions with some ages and their original structures are obscured,\nbut their lithostratigraphies are relatively well preserved in Nulliak, Big and Shuldham islands and St Jones Harbor.\nThe supracrustal belts in Nulliak and Big islands comprise ultramafic rocks, mafic rocks and mafic sediments intercalated with\nfeldspathic sediments and banded iron formations in ascending order. In the St Jones Harbor, it is composed of ultramafic rocks,\nmafic rocks, banded iron formation, and clastic sediments, intercalated with chert in the middle and with bedded carbonate rocks\nin the upper part, respectively, in ascending order. In the Shuldham Island, it consists of ultramafic rocks, layered gabbro with\nprecursors of plagioclase and pyroxene accumulation layers, mafic rocks and terrigenous sediments in ascending order. The\nlithostratigraphies are very similar to oceanic plate stratigraphy. The fact that some supracrustal belts are intruded by Uivak I\northogneisses, and presence of >3.86 Ga zircons in the supracrustal rocks suggest that the supracrustal belts have early Archean\nages. In addition, despite of the still ambiguous relationship between Nanok Gneiss and supracrustal rocks, presence of Nanok\nGneiss (3.85 to 3.91 Ga) in this area (Collerson, 1983 in Abstracts for Early Crustal Genesis Field Workshop, LPI, Technical\nReport 83-03; Shimojo et al., 2012, Goldschmidt Conf.) implies that the supracrustal belts date back to the earliest Archean.

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)0.001
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesScience and technology studies, Insufficient payload (model declined to judge)
Consensus categoriesInsufficient payload (model declined to judge)
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Bench or experimental · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.351
Threshold uncertainty score1.000

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0010.001
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0010.000
Bibliometrics0.0010.003
Science and technology studies0.0010.003
Scholarly communication0.0000.001
Open science0.0020.000
Research integrity0.0010.001
Insufficient payload (model declined to judge)0.0030.002

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 head0.028
GPT teacher head0.261
Teacher spread0.233 · 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