Nature and Origin of the Amphibolites in the Precambrian Basement Complex of Iseyin and Ilesha Schist Belts, Southwestern Nigeria
Bibliographic record
Abstract
Petrographic and geochemical studies of amphibolites from Wonu-Apomu area in Iseyin-Oyan schist belt and Ife-Ilesa area in Ilesha schist belt, southwestern Nigeria, were carried out with a view to unravel their nature and petrogenesis. The amphibolites in Wonu-Apomu are associated with quartzite, quartz schist, talc-schist, granite and pegmatites, while those of Ife-Ilesha area are associated with anthophyllite schist, talc tremolite and talc chlorite schists. Chemical data of the amphibolites showed high Al2O3 (>14%), Fe2O3 (>12.40%), CaO (>8.10), Na2O (>3.10%) and K2O (>5.0%) contents. Trace element data showed that the amphibolites are enriched in Ba (>137ppm), Sr (>122ppm), Rb (>33ppm), Zr (55pm) and Y (>37ppm), but impoverished in Cr (<62ppm), Ni (<57ppm) and Zn (<83ppm). Petrogenetic indices and discriminant plots of Na2O + K2O vs SiO2, Ga vs Y, Zr/Y vs Zr, Cr vs Ni, Fe2O3 –Na2O + K2O – MgO, indicated tholeiitic basalt affinity of the amphibolites and emplacements of the precursor basaltic rocks within continental crust.
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 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 | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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 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".