Deep drill hole in the Devonian South Mountain batholith, Nova Scotia: a potential for hidden mineral deposits within the batholith
Bibliographic record
Abstract
The drill hole near Digby in southwestern Nova Scotia is the deepest on-shore hole in the Canadian Appalachians, and penetrated to a depth of about 1.5 km. The site of the drill was selected at the periphery of the Devonian South Mountain batholith, which contains important mineralization of tin and uranium. The drill hole intersected texturally uniform megacrystic biotite granodiorite, which does not display any pronounced primary vertical zonation. At depth, the drill core contains zones of alteration, fracturing, and brecciation. The alteration is mainly due to fluid flow along the fractures. Some fractures are mineralized and contain galena, sphalerite, pyrrhotite, chalcopyrite, pyrite, hematite, quartz, and carbonate minerals. Common occurrence of alteration zones in the hole suggests that such zones are widespread in the batholith and point to abundant hydrothermal activity deep within the massif. It is inferred that the potential for hidden economic mineral deposits within the batholith is much greater than is suggested by surface features. The association of mineralization as seen in the drill core with the most primitive rocks of the batholith further indicates that mineral deposits in granitoid rocks are not always hosted by the most evolved and fractionated rocks. Extensive fracturing demonstrates that the batholith is not a suitable candidate for the storage of radioactive waste material. High temperature measured in the drill hole (~68°C at a depth of about 1,450 m) suggests that the pluton has promise as a source of geothermal energy. RESUMÉ Le puits de forage creusé#xE9; prè#xE8;s de Digby dans le Sud-Ouest de la Nouvelle-É#xC9;cosse constitue le puits sur rivage le plus profond dans les Appalaches canadiennes; il s’enfonce à#xE0; une profondeur d’environ 1,5 kilomè#xE8;tre. L’emplacement du trou de forage a é#xE9;té#xE9; choisi à#xE0; la pé#xE9;riphé#xE9;rie du batholite dé#xE9;vonien du mont South, qui abrite une miné#xE9;ralisation importante d’é#xE9;tain et d’uranium. Le trou de forage a entrecoupé#xE9; de la granodiorite à#xE0; biotite phé#xE9;nocristalline à#xE0; texture uniforme qui n’affiche aucun rubanement vertical primaire prononcé#xE9;. En profondeur, la carotte de forage pré#xE9;sente des zones d’alté#xE9;ration, de fissuration et de bré#xE9;chification. L’alté#xE9;ration est principalement due à#xE0; un é#xE9;coulement de fluides le long des fissures. Certaines fissures sont miné#xE9;ralisé#xE9;es et renferment de la galè#xE8;ne, de la sphalé#xE9;rite, de la pyrrhotine, de la chalcopyrite, de la pyrite, de l’hé#xE9;matite, du quartz et des carbonates. La pré#xE9;sence fré#xE9;quente de zones d’alté#xE9;ration dans le trou permet de supposer que ces zones sont ré#xE9;pandues dans le batholite et elle signale une activité#xE9; hydrothermale abondante en profondeur à#xE0; l’inté#xE9;rieur du massif. On en dé#xE9;duit que le potentiel de gî#xEE;tes miné#xE9;raux rentables caché#xE9;s à#xE0; l’inté#xE9;rieur du batholite est beaucoup plus vaste que ce que laissent supposer les caracté#xE9;ristiques à#xE0; la surface. L’association de la miné#xE9;ralisation avec les roches les plus primitives du batholite dont té#xE9;moigne la carotte ré#xE9;vè#xE8;le par ailleurs que les gî#xEE;tes miné#xE9;raux dans des roches granitiques ne sont pas toujours inclus dans les roches les plus é#xE9;volué#xE9;es et les plus fractionné#xE9;es. Le degré#xE9; de fissuration prononcé#xE9; ré#xE9;vè#xE8;le que le batholite ne constitue pas un candidat convenable pour le stockage des dé#xE9;chets radioactifs. La tempé#xE9;rature é#xE9;levé#xE9;e relevé#xE9;e dans le trou de forage (~68°#xB0;C à#xE0; une profondeur de 1 450 m) laisse supposer que le pluton repré#xE9;sente une source prometteuse d’é#xE9;nergie gé#xE9;othermique.
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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 | 0.000 |
| Science and technology studies | 0.000 | 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".