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Record W6987240826

Spatial and temporal variability in the geochemistry of the sediments at the Main Endeavour Field, Juan de Fuca Ridge

2023· dissertation· en· W6987240826 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

VenueUVic’s Research and Learning Repository (University of Victoria) · 2023
Typedissertation
Languageen
FieldSocial Sciences
TopicEducational Methods and Outcomes
Canadian institutionsnot available
Fundersnot available
KeywordsHydrothermal circulationHydrothermal ventSeawaterSedimentPlumeTransectSettlingRidge
DOInot available

Abstract

fetched live from OpenAlex

Sediments near hydrothermal vents are enriched in metals derived directly from hydrothermal fluids (e.g., Fe, Cu, Zn, Mn) and those associated with scavenging and co-precipitation from seawater with hydrothermally derived Fe-sulfides and Fe-oxyhydroxide minerals (e.g., P, V, Co, Mo, As, REEs). The sediments surrounding active venting have high concentrations of these elements which decrease with distance from the vents due to both hydrothermal plume dilution with seawater and sedimentation of hydrothermal particles. The composition of hydrothermal sediments from the Main Endeavour Field on the Juan de Fuca Ridge, approximately 300 km off the coast of Vancouver Island, was determined using samples collected in sediment traps at three locations along a transect below the hydrothermal plume. These traps were deployed on-axis, 3 km, and 9 km off-axis allowing the spatial variability of the hydrothermal component of the sediments to be assessed. The chemical composition and mass accumulation rates of the hydrothermal component is governed by particle formation in the near vent region and is controlled by particle settling rates with distance from active venting. The concentration and mass accumulation rate of the hydrothermal component of the sediment decreases rapidly with distance, with an order of magnitude decrease between the on-axis and 3 km off axis sediment trap samples, and a further 1-2 orders of magnitude decrease from 3 km off axis to 9 km off axis. 
\nSediment trap samples are also used to create a high-resolution time series of hydrothermal sedimentation over the course of the approximately year sampling period, with each on-axis sample collecting 21 days of sediment and each off-axis sample collecting 12 days of sediment. These samples allowed for an initial assessment of the temporal variation in the chemical composition and mass accumulation rate of the hydrothermal sediment. The variability observed in the hydrothermal component mass accumulation rate suggests that physical oceanographic processes (e.g., flow reversal) impacts the rate of sedimentation. 
\nThe base of a 50 cm sediment core, collected 2.6 km northwest of the Main Endeavour Field, was dated at ~6,000 years and a high-resolution geochemical reconstruction is used to determine how the hydrothermal component has changed on a 100–1000 year time scale. The comparison of the sediment core to fresh sediment collected by the sediment traps is used to understand how post-depositional changes affect the composition of the hydrothermal component preserved in sediment, as well as the utility of some elements, such as Mn, in reconstructing paleo-hydrothermal sedimentation.

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)0.006
metaresearch head score (Gemma)0.002
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesScience and technology studies
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: Observational
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.031
Threshold uncertainty score1.000

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0060.002
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0020.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.001
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 head0.034
GPT teacher head0.351
Teacher spread0.317 · 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