QUARTZ REPLACEMENT BY "KEROLITE" IN GRAPHIC QUARTZ-FELDSPAR INTERGROWTHS FROM THE VEZNA I PEGMATITE, CZECH REPUBLIC: A COMPLEX DESILICATION PROCESS RELATED TO EPISYENITIZATION
Bibliographic record
Abstract
Quartz replacement by kerolite (variety of talc) was examined in coarse- to medium-grained graphic intergrowths of quartz + feldspars (oligoclase An13-15Or3/orthoclase Or95-99Ab5-1) from the desilicated granitic pegmatite hosted in serpentinized apoharzburgite, at the locality Věžna I, western Moravia, Czech Republic. Pale brownish to white kerolite (Mg2.77-2.79Al0.09-010 Fe0.04 Si 4.05-4.08O10(OH)2.1.98H2O) forms aggregates, up to 2 cm in size, varying from massive fine-grained (1-10 m) to radial (needles up to ~1 mm long). Diffraction patterns exhibit a very broad peak at ~ 10 A (001) and a sharp peak at ~ 1.52 A (060). Kerolite does not swell at ethylenglycol atmosphere; cation exchange capacity (CEC) was 31+2.3 meq/100 g. Kerolite is a product of interaction between quartz and Mg-rich fluids originating from the host rock by the simplified reaction: 4SiO2 + 3MgCl2 + 6H2O = Mg3Si4O10(OH)2.2H2O + 6HCl. The process of kerolitization was evidently associated with albitization of oligoclase producing minor to trace amounts of Ba-rich K-feldspar, pectolite, analcime, natrolite, celadonite, monazite-(Ce) and niobian titanite, and possibly with vermiculitization of phlogopite. The simplified reaction including oligoclase, SiO2 released during kerolitization, and assuming immobility of Al was calculated as: 20(Na0.85Ca0.10K 0.05)Al1.15Si2.85O8 + 14SiO2 + 4.5H2O + 6NaCl = 21NaAlSi3O8 + 1KAlSi3O8 + 1NaCa2Si3O8 (OH) + 1NaAlSi2O6.H2O + 6HCl. This process likely proceeded at T ~ 100-300 C and P lt; ~ 0.5-1 kbar, under high activity of alkalis and low tectonic stress. Pseudomorphs of kerolite locally with rare relics of quartz were later almost completely removed because of surface weathering, which produced empty cavities in the graphic unit. Similar processes such as kerolitization of quartz at Věžna occur not only in granitic pegmatites but may operate in episyenites, where a direct dissolution of quartz and consequential formation of open vugs typically occurs.
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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 | 0.001 | 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 | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 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".