Cyclostratigraphy of the Ediacaran Nama Group in Namibia based on photogrammetry
Bibliographic record
Abstract
The middle Nama Group, deposited during the late Ediacaran in southern Namibia, is a 1 km-thick mixed carbonate-siliciclastic shallow-marine succession that displays observable regularity in its weathering profile. However, the possible role of astronomical climate forcing in this succession remains poorly understood. As a first step to understand the origin of the regularity, an initial cyclostratigraphic framework was developed using Google Earth satellite images and published U-Pb zircon ages of volcanic ash beds. Although the estimated average periodicity of 120-180 k.y. for the dominant scale of variation falls within the frequency band of astronomical forcing, it is not yet possible to discriminate between an origin related to short (~100 k.y.) eccentricity or 173 k.y. obliquity amplitude modulation. In order to refine the framework, we generated high-resolution quantitative records of the weathering profile based on drone photogrammetry. Spectral analysis on the depth series of slope steepness reveals significant spectral power related to the dominant variation at a scale of tens of meters. Additionally, it captures spectral power related to smaller-scale variations at less than 10 m. For age control, the depth series are linked to published U-Pb ages as well as to newly collected volcanic ash samples more closely tied to the analyzed sections. New high-precision dates will be crucial to determine the astronomical origin of these cycles.
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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 | 0.000 | 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".