Barian Micas and Exotic Ba-Cr and Ba-V Micas Associated with Metamorphosed Sedimentary Exhalative Baryte Deposits near Aberfeldy, Scotland, UK
Bibliographic record
Abstract
Regionally metamorphosed, Neoproterozoic stratiform baryte deposits near Aberfeldy in the Grampian Highlands of Scotland, UK, contain barium-poor and barium-rich micas in the host rocks and mineralized strata, respectively. The barium-rich micas include muscovite, biotite, phlogopite, and chromium-bearing muscovite. They occur in schistose metasediments and metabasites, in barium-feldspar rocks, and in small amounts in baryte rock. An extensive study of micas in a range of lithologies using electron-probe micro-analysis found up to 10.86 wt% BaO in muscovite, 5.46 wt% in biotite, and 15.70 wt% in Ba-Cr muscovite, the latter containing up to 9.27 wt% Cr2O3. Compositions are comparable with Ba- and Ba-Cr-micas in other metamorphosed Sedimentary Exhalative deposits and barium-rich metasediments worldwide. In one baryte rock sample, disseminated crystals of an exotic Ba-V-Cr mica contain up to 12.33 wt% BaO and 10.82 wt% V2O3, compositionally similar to Ba-V micas in the Hemlo lode gold deposit, Ontario. Ba2+ incorporation is mainly by coupled substitution with Al3+ for K+ + Si4+ in the tetrahedral site. The extent of phengitic (Tschermakitic) substitution is typical of micas in amphibolite-facies metasediments. Similar Fe:Mg ratios in coexisting muscovite and biotite reflect partitioning of iron into sulphides and metamorphic equilibration, with rare exceptions in fine-grained rocks that exhibit millimetre-scale disequilibrium.
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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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| 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) | 0.000 | 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".