878 REPORT— 1808. 



These couglomerates, for certain reasons urged, uudoubtedly belong to the 

 Upper Culm, and seem to rest unconformably on the lower members, or even on 

 the Devonian, thus marking a great interval. 



The Lower Culm during its deposition and elevation was accompanied with 

 igneous action, resulting in basic products which occupied a line running through 

 ■what is now the centre of Dartmoor. 



At the close of this interval great acid products rose up through this old line 

 of volcanic action, resulting in the great masses of granite. These granite masses, 

 especially that wh'ich forms Dartmoor in its upper and outer portions, may have 

 consisted of products of a trachytic nature, and formed like the Domite Puys 

 of Central France. 



Tlie Lower Culm rocks show the effects of great movements, cleavage 

 structure, &c. 



The conglomerates are but little disturbed, showing no signs of the previous 

 great movements which affected the Lower Culm. 



The interval between both is considered sufficient for the formation of the 



granite. 



The Devonian and Lower Culm strata had been folded and the strike determined 

 before the protrusion of the granite, as is clearly shown by the disposition and 

 relations of these strata to the granite. 



The alleged fragments of granite in the Permian breccias accord better with 

 the inter-Culm than with the post-Culm or pre-Triassic age of the granite. 



The conglomerates contain much arkose matter, quartz, felspar, mica, &c., in 

 abundance, which would be diiBcult to account for if derived from the ordinary 

 Devonian and Lower Culm strata of the adjoining area. 



12. Report on Fossil Phyllopoda. — See Reports, p. 519. 



1.3. Report on Life-zones in the British Carboniferous Rocks. 

 See Reports, p. 529. 



SATURDAY, SEPTEMBER 10. 

 The Section did not meet. 



MONDAY, SEPTEMBER 12. 

 The following Papers and Report were read: — 



1. On the Relation and Extension of the Franco- Belgian Coal-field 

 to that of Kent and Somerset. By R. Etueridge, F.R.S. 



2. The Laws of Climatic Evolution. By Marsden Manson, 



C.E., Ph.D. 



The prime object of this paper is to formulate the laws of climatic evolution. 

 In its entirety this problem ia one of the most far-reaching and grandest in 

 geological physics, embracing principles and laws applicable to other planets. 

 After presenting these laws, the author pointed out that in consequence of them a 

 hot spheroid rotating in space and revolving about a central sun, and holding 

 fluids of similar properties to water and air within the sphere of its control, must 



