326 report— 1879. 



Section C— GEOLOGY. 



PRESIDENTJ3F THE SECTION — Professor P. MARTIN DUNCAN, F.R.S.£Vice- 



President of the Geological Society. 



THURSDAY, AUGUST 21, 1879. 



The President delivered the following Address: — 



Everyone who is interested in the science which is especially considered in this 

 section of the British Association for the Advancement of Science must be impressed 

 with the importance of the geological construction of this district in determining 

 its physical geography, in producing the features of its landscapes, and in originating 

 and developing many of the industries of the busy town of Sheffield. 



It was inevitable that you should be addressed, at the commencement of your 

 labours, upon the subject of the Carboniferous formation, especially as the intention 

 of this peripatetic congress is to advance science amongst those who require it. 

 It will therefore be my privilege to bring before you some of the more important 

 generalisations of the day, and some other considerations, regarding the great 

 formation which is so fully developed in this part of England ; trusting that 

 whilst many of you will submit to be reminded of the results of the labours of 

 the men who have established our science and of those of yourselves, some who 

 desire further information than they have hitherto obtained may be advanced in 

 knowledge. 



Of all geological formations, the Carboniferous is the most important to 

 mankind at the present time, and the most interesting to the student. It gives the 

 earliest clear and definite idea of a land surface on the earth, or rather of the 

 existence of many lands ; for they are to be traced here and there from high up in 

 Arctic latitudes to Australia, and from the West of America to Eastern Asia. 

 It offers evidence of the existence, even in those remote days as in the much 

 later Miocene age, of astronomical conditions which do not now prevail. It yields 

 proofs of the persistence of a vast lowland flora during extraordinary vicissitudes 

 of the relative level of land and sea, and of the existence of a fauna remarkable 

 for its great fish and amphibia, and whose air-breathing mollusca and insecta are 

 of surpassing interest, foreshadowing as they do many recent forms. And its study 

 indicates that the movements of the crusts of the earth, which occurred during 

 and terminated the age, were of the grandest kind, and have been of the greatest 

 importance to mankind, destroying, it is true, all the vestiges of a large part of a 

 volume of the earth's history, but bringing coal within the reach of the explorer and 

 miner. 



This world-wide formation, usually very thick everywhere, has all the evidences 

 of having lasted during a vast age, and there are present in it the relics of sea 

 flows, of shallow seas and estuaries, of land surfaces, rivers and marshes. The 

 volcanic activity of the age was great, and is capable of demonstration. 



So deep are some of the sediments composing the Carboniferous formation in 

 different parts of the world that the idea of exact contemporaneity is not neces- 

 sarily much modified. It was in all probability coal time universally, and for a 

 long duration. But the beginning of the period was not synchronous in different 

 parts of the earth, neither was the ending. The Devonian age lasted longer in 



