at Dinas Read, North Gornwall 



15 



be determined. The brown rusty spots are sometimes irregular and 

 sometimes of such forms as would be yielded by rhombs. There 

 can be no doubt that they are pseudoraorphs after a ferriferous 

 carbonate." 



Proceeding westward we find near the highest point of the head- 

 land some slate surrounded by the soda rock at " &." The soda rock 

 is here mostly compact, dark bluish-gray in colour, and weathers 

 white. A knife will not scratch the dark rock but will scratch 



Greenstone |+ -t-| 

 Sioda jeLspar |:-...::.| 



SLate |i|li!| 



Lttnestone (>ands 1 1 i i | 



SpKeruUUc f fe;{|/| 



Diagrammatic map of Dinas Head, 208 feet to the inch. 



the white crust. One specimen from this spot shows the ferruginous 

 material in closely set parallel bands, or in curved sutures, or massed 

 together somewhat in circular form on one side, whilst the other 

 side of the specimen is uniform in colour with several minute holes 

 from ^ to 1 mm. in diameter. 



Descending the cliff due south from this point we pass over 

 alternate exposures of greenstone and soda rock. The latter near 

 the bottom of the descent is at "c" thinly bedded, dipping in a 

 northerly direction at an angle of about 35°. It is studded with 



