MétaCan
Menu
Back to cohort
Record W2887824659

The oxidative weathering of organic matter and its carbon dioxide emissions: Insight from the trace elements rhenium and molybdenum

2018· dissertation· en· W2887824659 on OpenAlex
Kate Horan

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

VenueDurham e-Theses (Durham University) · 2018
Typedissertation
Languageen
FieldEarth and Planetary Sciences
TopicGeochemistry and Elemental Analysis
Canadian institutionsnot available
Fundersnot available
KeywordsWeatheringEarth scienceSedimentary rockGeologyGeochemistryEnvironmental chemistryTrace elementCarbon dioxideCarbon dioxide in Earth's atmosphereCarbon cycleTrace metalTotal organic carbonEnvironmental scienceClimate changeChemistryOceanographyEcosystemMetalEcology
DOInot available

Abstract

fetched live from OpenAlex

Throughout geological history, the exposure of sedimentary rocks to chemical weathering at Earth’s surface has profoundly affected the geochemistry of the atmosphere, rivers and oceans. Oxidative weathering reactions can release redox-sensitive trace elements, and the concentration and isotope composition of these elements in geological materials may provide an insight into the environmental conditions and processes occurring both today and over Earth’s history. To constrain how Earth’s geological carbon cycle operates, and the influence it has on global climate change, a better understanding of the controls on oxidative weathering is required. The oxidation of organic carbon in sedimentary rocks (petrogenic organic carbon, OCpetro) releases carbon dioxide (CO2) from long-term storage in the lithosphere, and consumes atmospheric O2. Alongside volcanism, the oxidative weathering of OCpetro is the main source of CO2 to the atmosphere over millions of years. However, OCpetro oxidation is poorly understood, both in terms of the rate at which it releases CO2 and the factors that interact to drive the reaction. Trace metals associated with organic matter in rocks, such as rhenium (Re) and molybdenum (Mo), can be released to the dissolved load of rivers during oxidative weathering. Quantifying these element fluxes has the potential, therefore, to provide insight into the oxidative weathering processes involved. Here, rates of OCpetro oxidation rates are quantified in rapidly eroding mountain river catchments in the western Southern Alps, New Zealand, and the Mackenzie River Basin, north west Canada. Physical erosion is found to be a first order control on the oxidative weathering fluxes, but catchments dominated by valley glaciers and exposed to frost-shattering processes experience a further two to three times elevation in CO2 emissions relative to catchments with less glacial cover. The oxidative weathering processes are also found to fractionate metal isotopes (e.g. Mo) in the Critical Zone, which places an important control on the Mo isotope composition of both continental runoff and the World’s oceans.

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 score0.257
Threshold uncertainty score0.999

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 studies0.0010.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0020.000

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 head0.007
GPT teacher head0.181
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