Preliminary paleoenvironmental analysis and luminescence dating of upper Middle Pleistocene permafrost deposits of the Ulakhan Sular Formation, Adycha River, east Siberia
Bibliographic record
Abstract
Abstract Ulakhan Sular provides one of the largest natural stratigraphic sections through ancient permafrost deposits in the Batagay–Betenkes region of the Yana Uplands of western Beringia, but their depositional environment, age, and paleoenvironmental significance are uncertain. To address these uncertainties, we report the results of reconnaissance observations of the stratigraphy, sedimentology, paleosols and soil-like bodies, plant and insect macrofossils, and geochronology of the permafrost deposits at the stratotype section of the Ulakhan Sular Formation. Sedimentologically, this formation is dominated by well-sorted, fine to very fine sand that contains fluvial, aeolian, and permafrost sedimentary structures consistent with deposition near the paleo-Adycha River. The fluvio-aeolian deposits have similarities and differences to periglacial fluvio-aeolian and aeolian deposits in modern arctic regions of Canada and Greenland, and Pleistocene deposits in Alaska, China, and northwest Europe. The remarkable thickness of aeolian deposits (~50 m) at Ulakhan Sular is attributed to abundant local sand sources, ample accommodation space, and intensive aeolian transport and deposition. Optically stimulated luminescence dating of quartz sand and post-infrared–infrared dating of K-feldspar sand suggests deposition of the Ulakhan Sular Formation during late Marine Oxygen Isotope Stage (MIS) 6 or MIS 5. The aeolian sand-sheet deposits are correlated with other cold-climate aeolian sand and silt (loess) deposits in Beringia and southern Siberia, indicating a regional episode of aeolian sand transport and deposition at a similar time to glaciation by the Eastern Siberian Ice Sheet.
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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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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".