GEOLOGY 



which are formed of alternate bands of limestone and shale extending 

 from the foreshore to the top of the cliff for a distance of 350 yards. 

 The limestone bands vary from 2 inches to 2 feet thick, weather a 

 yellowish grey, and form a marked contrast with the dark shale ; there 

 are from sixty to seventy distinct beds of each dipping at a low angle under 

 the greenstone. The blue and grey slates on both the north and south 

 banks of the Camel yield fossils of small interest, and amid these slates 

 are other beds 2 miles in extent of purple and green variegated slates 

 with a general southerly dip which have hitherto yielded no fossil of 

 any kind. North of these occasional fossiliferous beds of slate occur ; the 

 most interesting of which is in Epphaven Cove in Port Quin Bay. This 

 has recently yielded a small starfish, Opbiurina (?), besides some tiny 

 pyritized thorn-like organisms at present undetermined. 



Mr. S. R. Pattison, 1 writing on the geology of the Tintagel district 

 in 1847, says that fossils between Boscastle and Port Isaac were found in 

 and near the good slate and in an earthy bed among the slates. He 

 records Fenestella at Bossiney, Spirlfera gigantea and S. disjuncta and 

 crinoids at Tintagel, Delabole, Lesnewth and Trevivian, and Terebratula 

 and Ortboceras at Tintagel. He adds : ' Fragments of Spiriferce may be 

 seen in the roofing and flooring slates of all the quarries from Grower to 

 Delabole.' Good specimens of much flattened Spirifers are still con- 

 stantly found in the Delabole quarries. 



Sir Henry De la Beche in his Report gives a sketch of the junction 

 of the Devonian and Carboniferous rocks as seen from a boat outside 

 the harbour of Boscastle. He writes thus : 'Proceeding now to the 

 southern boundary line of this (Carboniferous) system ... we find that 

 the upper series rests upon the lower near Boscastle, in a bay between 

 the Meachard Rock and Short Island. Here though the one rests con- 

 formably upon the other, as represented (plate 4, fig. i), there is no 

 passage of the one system into the other. On the contrary, there is a 

 marked line between the carbonaceous slates and arenaceous rocks above 

 and the clay slates passing into roofing-slate beneath.' 



About a mile north of this junction line, the crest of Fire Beacon 

 Point, a very conspicuous landmark 469 feet above sea level, is composed 

 of a cherty rock showing casts of radiolaria. The foldings of the in- 

 tervening beds of grit and shale are numerous, but cannot be on a large 

 scale, as the chert appears nowhere else on the north coast. As we 

 follow the coast northwards the foldings and contortions increase in size 

 and complexity till we reach the extraordinary sections for which the 

 ' Northern Door ' and ' Millook ' are so notable. Further north General 

 McMahon in writing of Bude says that in some places the contortions 

 and convolutions are too complicated for verbal description . . . Beds 

 are not only doubled up and folded on themselves, but they are crushed, 

 ruptured and severed from each other in a way that has, in places, 

 reduced them to the condition of a Chinese puzzle. The conclusion he 

 arrived at after a microscopical examination of the rocks, was that the 



1 Trans. R. Geol. Soc. Com. vii. 3-12. 

 I 41 6 



