Ice-rafted dropstones at midlatitudes in the Cretaceous of continental Iberia
Bibliographic record
Abstract
Abstract The Cretaceous is widely considered to have been a period subjected to super-greenhouse conditions. Here, we provide multiscale sedimentologic evidence of glaciers developing at mid-paleolatitudes (~45°N) in continental Iberia during the Hauterivian cold snap. Striated and faceted ice-rafted glacial dropstones (cobble to boulder size) and striated and grooved silt- to sand-sized grains (ice-rafted debris [IRD]) occur in a lacustrine sequence of the Enciso Group in the eastern Cameros Basin, Spain. The ice-rafted materials constitute the first evidence reported for a Cretaceous continental cryospheric record in Europe, and they are attributed to calving of glacier snouts, releasing icebergs into an ice-contact lake. The sedimentary succession resembles glacial-deglacial records in lakes overridden by the late Pleistocene Laurentide Ice Sheet in eastern Arctic Canada. The Iberian glacial succession was coeval with plateau permafrost in Asia and IRD records in the Arctic and Australia, revealing a stronger than previously thought cryosphere during the global Hauterivian cold snap.
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 | 0.001 | 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 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 0.002 |
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; both teacher heads agree on what is shown here.
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".