Geology, Alteration, and Geochronology of the Cerro Vetas Porphyry Gold-Copper Deposit, Middle Cauca Belt, Colombia
Bibliographic record
Abstract
Abstract The Cerro Vetas porphyry deposit is part of the Titiribi district of the Middle Cauca porphyry-epithermal belt of western Colombia. The Cerro Vetas porphyry stock consists of a premineral diorite intruded by a late-mineral quartz monzonite, with intrusion and contact breccias. These units intrude pre-Cenozoic basement metabasalts and schists, Oligocene-Miocene Amagá Formation sedimentary rocks with intercalated andesite flows. Two phases of potassic alteration are recognized, a biotite-dominant phase in the diorite, and secondary K-feldspar in the quartz-monzonite intrusion. An overprinting and grade destructive, calcic-sodic alteration (actinolite + albite ± magnetite) affects both porphyries. Biotite alteration is overprinted by weak-moderate phyllic alteration in the upper 100 m in the deposit. Below 100 m, phyllic alteration assemblages are constrained to structural zones. Mineralization is dominated by a chalcopyrite-gold-pyrite assemblage associated with biotite that is hosted in a truncated stockwork in the apical portion of the deposit with metal ratios typical of a gold-rich copper-gold porphyry. The intrusions were dated, using U-Pb in zircon laser ablation inductively coupled plasma-mass spectroscopy, to between 7.65 to 7.24 Ma, consistent with other deposits in the Middle Cauca belt. Lithologic, alteration, and stratigraphic relationships at the deposit suggest that the Cerro Vetas porphyry was emplaced at shallow depths and that the upper portion of the deposit has been eroded.
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 | 0.001 | 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".