﻿42 



IGNEOUS BOCKS OF THE BRISTOL DISTRICT. 



[vol. lxxii r 



about Woodspring Cove some rock-specimens for which he was in 

 fact indebted to the Author, as they had been obtained during the 

 visit of the Geologists' Association to Bristol in 1907. The slides 

 from these specimens showed forms the organic origin of which 

 could scarcely be doubted, recalling radiolaria and other organisms, 

 but too imperfect for determination. These bodies were embedded 

 in the ground-mass of the lava, in such a- way as to suggest that 

 they had been taken up by a subaqueous lava-flow from sediments 

 still in the state of mud. 



It was believed that the exceptional microscopic occurrences, 

 and the general relations of lava to sediments, could be best 

 explained on the hypothesis of a subaqueous eruption over a floor of 

 imperfectly-consolidated sediment. 



The Authoe, in reply to Dr. Strahan, said that the information 

 leading him to map the igneous rocks at Goblin Combe as 

 two separate crescentic masses could have been obtained only by 

 digging many trial-holes. To Prof. Sibly he said that at Worle 

 Hill his attention had been confined to the igneous rocks, and that 

 he had not attempted to study the general structure of the hill ; 

 he had, however, little doubt that the failure to find any trace of 

 igneous material east of Florence Cottage and between Spring 

 Cove and Furze Close indicated that the volcanic rocks of the 

 Milton-Hill neighbourhood were cut off at both ends of their 

 outcrop by cross-faults. 



