Stable isotope evidence of late MIS 3 to middle Holocene palaeoenvironments from Sehonghong Rockshelter, eastern Lesotho
Bibliographic record
Abstract
ABSTRACT Evidence for human occupation of southern Africa's high‐altitude Maloti–Drakensberg Mountains is surprisingly common in the last glacial, yet the attraction of this relatively severe, cold region for hunter‐foragers remains unclear. Sehonghong Rockshelter (1870 m asl), in the eastern Lesotho Highlands, provides evidence for human occupation spanning Marine Isotope Stage 3 through the late Holocene. Excellent organic preservation provides opportunities for establishing multiple palaeoenvironmental proxy records to address this conundrum. In high‐altitude zones, the proportions of C3 and C4 plants archived in soil organic matter and faunal enamel provide sensitive indicators of past temperature shifts. We first extended the radiocarbon chronology to ca. 35 ka using ABOx‐SC radiocarbon dates of charcoals. Next we analysed stable isotopes in soil organic matter from the sedimentary sequence, and in faunal tooth enamel from the newly dated lower strata. The results suggest, predictably, that C3 vegetation and low temperatures prevailed until early warming at ca. 15 ka, with a series of sharp shifts thereafter. Low values for δ13C and δ18O in faunal enamel ca. 33 ka suggest a negative temperature excursion at this time, and potentially greater precipitation as snowfall in the highlands compared with lower altitudes.
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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 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".