Nature and origin of dolomite-hosted Th-U-HREE mineralization in the Tethyan Metallogenic Belt, Biga Peninsula, Northwestern Türkiye
Bibliographic record
Abstract
The Biga Peninsula in northwestern Türkiye, a metallogenic province in the Tethyan Metallogenic Belt, hosts economically significant gold-copper deposits and thorium-uranium-rare earth elements (Th-U-REE) occurrences, including both light REE (LREE) and heavy REE (HREE) styles of mineralization. This contribution focuses on the nature and origins of Th-U-REE mineralization in the Arıklı district, Biga Peninsula, where three zones of Th-U-REE mineralization (A, B, and C) each extends only a few meters along faults in Cenozoic volcanic rocks. Zones A and C of U-Th-LREE mineralization are hosted by fluorapatite-sulfide-hematite and dolomite-fluorapatite assemblages and have U-Th-REE concentrations up to 1,152 ppm and 2,221 ppm, respectively, with fluorapatite as the principal U-Th-REE-bearing mineral. In contrast, Zone B of Th-U-HREE mineralization is hosted by a dolomite-dominant assemblage, with Th, U, and total HREE + Y concentrations up to 25,600 ppm, 4,100 ppm, and 3,535 ppm, respectively, with cheralite (CaTh(PO 4 ) 2 ) as the principal ore mineral. Four stages of dolomite have been identified in the main mineralization Zone B: fine to medium-crystalline dolomite (D1; anhedral), pervasive medium-grained dolomite (D2; subhedral to anhedral), dolomite rhombs (D3), and void-/vein-filling coarse-crystalline dolomite (D4). Two stages of void-/vein-filling cheralite coincide with dolomite D3 and D4. The first stage cheralite shows intense hydrothermal modification, resulting in a disturbed U-Th-Pb isotopic system. Secondary cheralite of minimal hydrothermal disturbance yielded 206 Pb- 238 U age of 18.8 ± 1.6 Ma (2σ, MSWD = 1.3) and 208 Pb- 232 Th age of 18.15 ± 0.08 Ma (2σ, MSWD = 2.3). Carbon and oxygen isotope compositions differ significantly from those of primary igneous carbonatites but are close to sedimentary rocks, indicating that all dolomites have a hydrothermal origin with sedimentary sources. These results collectively suggest that Early Miocene hydrothermal fluids most likely originated from mantle-derived alkaline magmatism and interacted with carbonate sedimentary rocks, facilitating the mobilization, enrichment, and precipitation of dolomite-hosted Th, U, and HREE mineralization in fault zones.
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) | 0.001 | 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".