Rapid cold water formation and recrystallization of relict bryophyte tufa at the Fall Creek cold springs, Alberta, Canada
Bibliographic record
Abstract
The Fall Creek Tufa is a relict, mid- to late-Holocene freshwater carbonate spring deposit that is formed almost entirely of calcite-encased Cratoneuron commutatum gametophytes. The spring is presently active, emitting 13 °C meteorically derived waters, but it is not precipitating calcite. Wood embedded in the youngest part of the tufa yielded a radiocarbon (14C) date of 310 ± 50 years BP. The oldest parts of the deposit could not be dated by radiocarbon methods because of a lack of embedded organics. The Fall Creek Tufa, however, probably began forming ~5000 years BP in response to the same wet climatic conditions that initiated calcite precipitation at Miette Hot Springs in Jasper National Park and the Cave and Basin Hot Springs in Banff National Park. The relict deposit is composed largely of calcite cements that were precipitated around the bryophytes, with lesser amounts of internal sediments. The tufa formed through a repeated four-stage developmental process that involved (I) encrustation, (II) encapsulation, (III) cavity occlusion, and (IV) diagenetic alteration. These stages were temporally and spatially variable. Although a young deposit, much of it has undergone extensive aggrading recrystallization, whereby crystal size has increased as adjacent calcite crystals were sutured together. Epifluorescence micro s copy shows that primary depositional fabrics were masked, but not destroyed, during recrystallization. Narrow ranges of δ18O (VPDB, Vienna Pee-Dee Belemnite standard) values (–18.4 to –17.7) and δ13C (VPDB) values (–1.2 to 0.5) indicate that the calcite was in isotopic equilibrium with the water that it precipitated from, and that diagenesis did not reset the stable oxygen and carbon isotopic compositions.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.003 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
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.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".