Tin enrichment in a highly fractionated A-type granite: Origin and mineralization potential of the Dayishan granite batholith in the Shi–Hang magmatic zone, South China
Bibliographic record
Abstract
A-type granite intrusions in the southern Shi–Hang magmatic zone, South China, contain several world-class W–Sn deposits. The Dayishan granite batholith is located in the north of the southern Shi–Hang magmatic zone, and contains potential Sn mineralization. The batholith contains three intrusive phases, which are the Guankou, Tangshipu, and Nibantian phases. The Guankou phase consists mainly of biotite–K-feldspar granite (G1). The Tangshipu phase consists of three secondary units, which are coarse-grained biotite monzogranite (G2) that cut monzogranite (G3) and fine-grained two-mica monzogranite (G4). The Nibantian phase consists of coarse-grained two-mica monzogranite (G5). Zircon U–Pb dating indicates that the G1 to G4 granites were emplaced at ca. 160 Ma and the G5 granites formed at ca. 144 Ma. All the granites are silica-rich (SiO2 = 69.24–77.02 wt%) A2 sub-type granites, among which G1 granites are metaluminous and G2 to G5 granites are peraluminous. High εNd(t) (−6.9 to − 5.2) and zircon εHf(t) (−6.2 to − 1.9) values suggest that the parental magma was probably derived by partial melting of lower crust, which was induced by input of mantle-derived basaltic magmas. Oxygen fugacity determinations show that the G2 to G5 granitic magmas were reduced, but the G1 granitic magmas were relatively oxidized. From the G1 to G4 granites, Ba, Th, Nd, Zr, Hf, and rare earth element contents decrease, while Rb and Ta contents increase, indicative of extensive fractional crystallization of K-feldspar, plagioclase, and accessory minerals. This suggests that the G1 granites represent the least fractionated magmas, while the G2 to G4 granites are the highly fractionated products of the G1 granitic magma, with the G4 granites being the most fractionated. The G5 granites were formed during a later magmatic activity, though they show similar geochemical features with the G2 and G3 granites. Due to this continuous fractionation process, Sn was efficiently and progressively enriched in the G2 to G4 granites, as indicated by the good correlations between Sn contents and TiO2 contents, Eu/Eu*, Rb/Sr, Rb/Ba, K/Rb, Zr/Hf, Nb/Ta, and Y/Ho ratios, and TE1,3 values. Furthermore, the G2 to G4 granites crystallized at the magmatic–hydrothermal transition. These data indicate that the G2 to G4 granites underwent Sn mineralization, but the G4 granites are the best target for exploration. The G5 granites might also have Sn mineralization potential considering the similar geochemical features with G2 and G3 granites. Given the reduced nature of the magmas, the potential economic mineralization types are greisen and skarn.
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 | 0.001 |
| Science and technology studies | 0.000 | 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 teacher head, 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".