PROCESS-BLOCKS AND OTHER ILLUSTRATIVE FIGURES 

 BESIDES THOSE IN THE PLATES, 



Fig. Page 

 1 & 2. Plan and section of wells at Cay thorpe 30 



1, 2, & 3. The ' Filon Licone [near Cogne, Graian Alps] 56, 57, 58 



1. Rough sketch of the Semna barrier on the Nile, as seen from 



the western bank 68 



2. Sketch showing potholing of the gneiss-barrier in the Nile, 



Semna Cataract 70 



1. Geological map of a portion of Tiree . ., 92 



2. Enlargement of a portion of the preceding map 93 



3 & 4. Limestone from fields south-east of Balephetrish Hill 94,95 



5. Crush-conglomerate on the shore west of Port Abhuinn 99 



1. Map of the district round Victory Quarry 106 



2. Horizontal section through the district mapped in the fore- 



going figure 108 



3 & 4. Section and plan of the Pliocene cavern at Dove Holes 110 



5. Section of passage in the same cavern Ill 



6 & 7. Diagrams of Helm Pot and the Long Churn Cavern 112 



8. Section of Windy Knoll 123 



9. Photograph of clay with blocks of limestone at the northern 



end of the cave at Dove Holes 124 



10. Map of the British Isles in the Upper Pliocene Age 127 



1. Geological Map of Oligga Head and Perranporth 144 



2. View of Cligga Head 146 



3. Greisen-bands in the cliff at Cligga Head 147 



