Analisi geochimiche (delta13Corg) attorno al limite Norico-Retico del Bacino Lombardo (Alpi Bergamasche)
Bibliographic record
Abstract
The stratigraphic successions of Brumano-Italcementi and Malanotte Formation (Bergamasc Alps, northern Italy) were investigated with the aid of chemostratigraphycal analyses of δ13Corg. The successions belong to the Lombard Basin with a time-scale ranging between the Norian-Rhaetian (NRB) and the Triassic-Jurassic boundaries (TJB). The outcoming isotopic curve of δ13Corg shows a prominent isotopic excursion around the Norian-Rhaetian boundary (at the base of the Zu2 Member, minimum of δ13Corg = -27,86‰). In the early Rhaetian the isotopic curve returns to background values (δ13Corg = ca. -25,75‰), but in the middle Rhaetian a strong negative shift within the Zu3a Member (minimum of δ13Corg = -28,13‰) can be noted. Eventually, around the TJB another drop is showed, reaching the minimum value at the Hettangian base (within the base of the Malanotte Formation, δ13Corg = -28,75‰). These three major δ13Corg shifts were correlated with those of other Tethyan sections (Pignola-Abriola section, Lagonegro Basin, southern Italy) and extra- Tethyan sections (Queen Charlotte Islands, Bristish Columbia, Canada). On the basis of these bio-chemostratigraphyc correlations, the global occurrence of the three major δ13Corg shifts was demonstrated, therefore a common global cause can be thought. Negative δ13Corg global excursions are caused by a 12C enrichment in the oceanatmosphere system, likely related to: primary productivity drops, decrease in organic carbon burial rate, gas hydrates dissociations from ocean bottoms, and volcanogenic CO2 giant ejections linked to the emplacement of magmatic provinces. We propose the probable emplacement of a huge magmatic province as the cause of these shifts, likely ascribed to the activity of the Central Atlantic Magmatic Province (CAMP).
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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 | 0.002 | 0.001 |
| Science and technology studies | 0.000 | 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) | 0.002 | 0.001 |
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".