Impact of Seasonal Changes on the Formation and Accumulation of Soft Siliceous Sediments on the Discharge Apron of Geysir, Iceland
Bibliographic record
Abstract
Abstract Unconsolidated, highly porous, permeable siliceous sediments found in shallow-water pools on the middle and distal parts of Geysir's discharge apron are formed of cryogenic opal-A (COA), opal-A spheres, opal-A cement, silicified microbes, and detrital lithic grains. Silicified leaves and silica-coated grass stems and twigs are locally present with these pool sediments, and microbial mats commonly cover the sediment surface. Partially consolidated layers (< 0.5 cm thick) form when the constituent grains are bound together by filamentous microbes, exopolysaccharides, and/or opal-A cement. Most components of the sediment can be related to processes that are controlled largely by seasonal variations. Low temperatures in winter promote freezing of the medial to distal discharge waters and lead to formation of COA in ice. When the ice melts, the released COA grains become part of the pool sediments. Microbial mats trap and bind sediment and provide templates for silica precipitation during spring and summer, but become (semi-)dormant during the constant darkness that Iceland experiences during winter. When the waters are sufficiently supersaturated, opal-A precipitates as spheres in the water column and cement in pool deposits. In some pools, seasonal changes are evident from the alternation of “soft” and “hard” (partly cemented) laminae. Elsewhere, however, the distinction between the different time-dependent components is lost because they become superimposed on each other or as aperiodic changes in flow patterns affect different pools.
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.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot 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.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.004 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 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 teacher head, 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".