Assessing Event Sedimentation in the Bluesky Formation of the Peace River Oil Sands using the Ichnogenus Rosselia
Bibliographic record
Abstract
Summary Spectacular examples of well-preserved, stacked Rosselia Dahmer, 1937 have been observed in Cretaceous Bluesky Formation core from Alberta’s Peace River oil sands deposit. Stacked Rosselia segments reflect burrow re-adjustments of a single tracemaker following sedimentation. These traces can be used as a ‘measuring stick’ for determining the magnitude and frequency of sedimentation events (MacEachern and Pemberton 1992; Nara, 1995, 1997). In this study, two cores with Rosselia were logged, sedimentological and ichnological characteristics were scrutinized and the length and number of stacked segments were measured. These cores are interpreted to represent shoreface deposition in a wave-influenced bay. Rosselia burrows record one to two post-depositional re-establishments per tracemaker, where each re-adjustment represents an average 3.6 cm to 5.6 cm of sediment deposition. In extreme cases, up to four re-adjustments totaling nearly 30 cm were observed, reflecting multiple depositional events in a relatively short time frame--months to perhaps two years depending on the lifespan/growth rate of the organism (Seitz and Schaffner, 1995). The use of Rosselia in this study provides high-resolution analysis of modal sedimentation in the Bluesky Formation, a depositional parameter rarely measurable in the rock record but fundamental to understanding sedimentary processes.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| 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 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".