THE GEOLOGICAL AGE OF CENTRAL AND WEST CORNWALL. 165 



Kecently my friend Mr. Howard Fox has been working' out 

 the conglomerates and breccias of this neighbourhood, and liero 

 — as in the case of the rocks examined by Mr. Phillips from the 

 Truro and Perran districts — he finds numerous fragments of 

 older rocks, many being of igneous origin. 



The country hereabouts is very difficult to make out, the 

 surface being mostly cultivated, the clifl's much broken up by 

 faults and falls of rock, and the foreshores either covered by 

 djbris, or very difficult of access. We have, nevertheless, 

 endeavoured to illustrate what we believe to be the main 

 feature of its stratigraphy on tho accompanying enlarged map. 

 Of course it is to a considerable extent hypothetical, but it will, 

 at least, serve as a basis for and to give definiteness to future 

 observations — by ourselves or others.* 



Comments have been made upon the non-existence of fossils 

 in the rocks now under consideration. As to the cause of this 

 absence we may choose between the following conclusions : — 



1. — The fossils are there hit have not yet been found. We are 

 not bold enough to say that no fossils will ever be found in the 

 Ladock beds, but a great deal of labour has already been spent 

 in searching for them during many years and by many workers, 

 and so far quite fruitlessly. 



2. — The fossils ivere there hit have been removed by chemical 

 agencies. This supposition is, we think, negatived by tho absence 

 of the casts of fossils. 



3. — Very few or no fossils -were ever present. We must confess 

 that we believe this last to be the true explanation. If so, we 

 have still to ask what was the cause of such a local dearth of 

 organic remains. Two reasons may perhaps bo assigned. 



a. — The deposits were accumulated so tumtcltuously that life teas 

 impossible. In tho former paper it was mentioned that many 

 signs of rapid deposition ai-e visible — cross-bedding and tho 

 like. But this cause alone would not suffice, as we ought to have 

 indications of organisms brought in from more tranquil regions. 



* The dyke of mica-trap wbicli cuts through the conglomerate in the little 

 cove below Peuare Farm has not hitherto l)eeu noticed — at least by any author 

 known to us. We first observed it when in company with Mr. Clark, in 1879. It 

 is in all i-espects like the dykes in the Truro river, to which the attention of 

 geologists was first called by Mr. A. K. Barnett, F.G.S., of Penzance, and will 

 be aguin referred to in another part of the present japer. 



