100 rUCK. K. HULL, I.L.n., F.K.S., K.G.S., ON THK SUB-OCEANIC 



reo-avdiii"' tlio pariicipation of the Apennines in the latest sub- 

 mergence which took plncc, unless they were subjected to a sub- 

 sequent eniei-sion, basin j^- my argument upon the great geological 

 differences between them and the Alps with the two N.W.-S.E. 

 chains of mountains fo their south. Professor Sacco alludes to 

 Pliocene clay rising to the height of 500 metres (1,640 feet), at 

 Pianfei (Cuneo). Strata of the same age, abounding with marine 

 mollusca, largely of species still living in the Mediterranean, 

 are among tlie commonest along the lower skirts of the Apennines, 

 from one extremity to the other, often overlaid to considerable 

 elevations by Pleistocene clays, sands, etc. Balducci found 

 Pliocene strata in Sicily at the height of nearly 1,000 metres 

 (3,200 feet). On the southern slope of the Western Alps, Pliocene 

 strata are by no means common, and these towards their base, an 

 apparent indication that subsidence occurred differently in the 

 Apennines to what it did in the Alps.* 



If this view be correct it may be inquired whether certain 

 fractures may not have resulted from the greater subsidence of 

 the Alps in which the Apennines participated to a far lesser 

 extent. At their base, approximately parallel to their axis we 

 find intrusive rocks of various periods, such as granite at Cavour 

 and Traversella (Turin) ; syenite at Qnittengo, and granite at 

 Biella, Pella, and Baveno (Novara), basalt (Vicenzci) ; trachyte in 

 the Euo-anean hills (Padua). It is a question which remains to 

 be investigated. 



[The Rev. Professor Blake, F.G.S., took part in the discussion, 

 and expressed the view that the sides of the submarine channels 

 consisted of mud brought down by the rivers and deposited on 

 either hand of the current.] 



Mr. Henry BiiNiosr. — It has afforded me much pleasure to be 

 present this afternoon, as the subject of Professor Hull's paper 

 is one in which I take more than a passing interest. Last year 

 I was favoured by the Seci'etary of the Geographical Society with 

 an invitation to an afternoon lecture by Professor Hull, and found 

 that his views coincided in some I'espects with those that I 

 entertain myself, and, in fact, I had a paper before the Geographical 

 Society at that time, which subsequently appeared in the Journal ; 

 from observations of the sea bottom, which have come within my 



'- There are nouu. It was the period of " tlie great elevation." — E. H. 



