﻿process-blocks and other illustrative figures. xv 



Fig. Page 



5. Bhyolitic breccia, Trecastell Mine 312 



6. Etching-figures on ' cubical ' galena 315 



7. Crystal of chalcopyrite enveloped by blende and galena, Nent- 



head Mine (Allendale) 316 



8. Crystal of chalcopyrite enveloped by galena, Leadhills Mine 



(Lanarkshire) 316 



9. Blende enclosed in galena, Halkyn Mine (Flintshire) 317 



10. Strings of native silver in galena, Nentsbury Mine (Alston) ... 318 



11. Strings of native silver in galena, Foxdale Mine (Isle of Man). 318 



1-3. [Figures illustrating an earthquake model] 348 



— Outcrop of Banded Ironstone in the bed of the Sebakwe Biver, 



near the Globe & Phcenix Mine 356 



1. Geological map of the Boss of Mull 378 



2. Folded Moine Schists, with granitic intrusions along the 



bedding 380 



3. Granitic intrusions along the bedding and along the strain- 



slips 381 



4. Specimen of the banded composite gneiss produced by in- 



jection 384 



5. Weathered surface of altered schist with knobs of sillimanite 



prisms 386 



6. Section of contact-altered pelitic gneiss 388 



7. Section of a weathered-out knob, showing cross-sections and 



long sections of sillimanite 388 



8. Section of a lenticle, showing mainly long sections of silli- 



manite 389 



9. [Crystallographic figure] 390 



10. Curved and fractured kyanite 393 



1. Vertical section of the Llansawel Group 406 



2. Section up the mountain road to Lampeter 410 



3. Section from near Maes y Cwarau to near Banc Goleugoed ... 414 



4. Geological map of Pen y Ddinas 415 



1. Sketch-map of Pulau Ubin and Changi (Singapore) 421 



2. North Quarry section, Pulau Ubin 423 



3. Angular masses of quartz-biotite gabbro in hornblende- 



granite 426 



— Diagrammatic section of the .Kinta Valley, looking north 437 



