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Record W2977399579 · doi:10.2138/am-2019-6890

Discrete Zr and REE mineralization of the Baerzhe rare-metal deposit, China

2019· article· en· W2977399579 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.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.

Bibliographic record

VenueAmerican Mineralogist · 2019
Typearticle
Languageen
FieldEarth and Planetary Sciences
TopicGeological and Geochemical Analysis
Canadian institutionsUniversity of Windsor
Fundersnot available
KeywordsZirconGeologyGeochemistryMonaziteMineralization (soil science)SilicatePlutonMineralogyChemistryTectonics

Abstract

fetched live from OpenAlex

Abstract Although REE (lanthanides + Sc + Y) mineralization in alkaline silicate systems is commonly accompanied with Zr mineralization worldwide, our understanding of the relationship between Zr and REE mineralization is still incomplete. The Baerzhe deposit in Northeastern China is a reservoir of REE, Nb, Zr, and Be linked to the formation of an Early Cretaceous, silica-saturated, alkaline intrusive complex. In this study, we use in situ laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) analyses of zircon and monazite crystals to constrain the relationship between Zr and REE mineralization at Baerzhe. Three groups of zircon are identified and are differentiated based upon textural observations and compositional characteristics. Type Ia zircons display well-developed oscillatory zoning. Type Ib zircons are darker in cathodoluminescence images and have more irregular zoning and resorption features than type Ia zircons. In addition, type Ib zircons can locally occur as overgrowths on type Ia zircons. Type II zircons contain irregular but translucent cores and rims with oscillatory zoning that are murky brown in color and occur in aggregates. Textural features and compositional data suggest that types Ia and Ib zircon crystallized at the magmatic stage, with type Ia being least-altered and type Ib being strongly altered. Type II zircons, on the other hand, precipitated during the magmatic to magmatichydrothermal transition. Whereas the magnitude of the Eu anomaly is moderate in the barren alkaline granite, both magmatic and deuteric zircon exhibit pronounced negative anomalies. Such features are difficult to explain exclusively by feldspar fractionation and could indicate the presence of fluid induced modification of the rocks. Monazite crystals occur mostly through replacement of zircon and sodic amphibole; monazite clusters are also present. Textural and compositional evidence suggests that monazite at Baerzhe is hydrothermal. Types Ia and Ib magmatic zircon yield 207Pb-corrected 206Pb/238U ages of 127.2 ± 1.3 and 125.4 ± 0.7 Ma, respectively. Type II deuteric zircon precipitated at 124.9 ± 0.6 Ma. The chronological data suggest that the magmatic stage of the highly evolved Baerzhe alkaline granite lasted less than two million years. Hydrothermal monazite records a REE mineralization event at 122.8 ± 0.6 Ma, approximately 1 or 2 million years after Zr mineralization. We therefore propose a model in which parental magmas of the Baerzhe pluton underwent extensive magmatic differentiation while residual melts interacted with aqueous hydrothermal fluids. Deuteric zircon precipitated from a hydrosilicate liquid, and subsequent REE mineralization, exemplified by hydrothermal monazite, correlates with hydrothermal metasomatic alteration that postdated the hydrosilicate liquid event. Such interplay between magmatic and hydrothermal processes resulted in the formation of discrete Zr and REE mineralization at Baerzhe.

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 score0.041
Threshold uncertainty score1.000

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 studies0.0000.001
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0010.000

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 head0.004
GPT teacher head0.177
Teacher spread0.173 · 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