The Duke of Argyll on the Geological Structure of Argyllshire. 315 



After adducing evidence, both stratigraphical and palseontological, 

 to prove that no portion of the Speeton clay is of Gault age, the 

 author showed that this great series of clays (probably over 1000 

 feet thick) belongs to no less than seven formations, viz. Upper, 

 Middle, and Lower Neocomian, Portlandian, and Upper, Middle, 

 and Lower Kimmeridge. These formations, as displayed in Filey 

 Bay, were described in detail ; lists of the fossils from each (drawn 

 up with the assistance of Mr. Etheridge) were given, and their 

 equivalents, both in this country and on the continent, pointed out ; 

 and the author concluded his paper with appendices on the fossils 

 and the economic products of the Speeton clay. 



2. " Notice of the Hessle Drift as it appeared in Sections more 

 than forty years since." By Professor John Phillips, D.C.L.,F.R.S., 

 F.G.S. 



Referring first to the difficulties formerly experienced in attempt- 

 ing to explain the origin of the Boulder-clays and Northern drifts 

 more than forty years ago, without the aid of glaciers and icebergs, 

 the author expressed his belief that the lowest gravels, resting on 

 the chalk at Hessle, are of Prseglacial date. He stated his opinion 

 that there is no evidence of the beds in question being marine ; 

 while the abundance of mammalian remains offers a strong pre- 

 sumption against this interpretation. Beds of this order, composed 

 of chalk and flint fragments, not only are unknown to occur in the 

 midst of the Boulder-clay, but can hardly be imagined to exist there. 

 Further, the Boulder-clay rests on them without conformity. Pro- 

 fessor Phillips also observed that if the Hessle clay be the upper 

 part of the great Holderness deposit, and not met with beyond the 

 outcrop of the chalk, it must be designated a third Boulder-clay; and 

 he concluded his paper by a detailed description of his original ob- 

 servations of the Hessle cliff more than forty years ago. 



February 5th, 1868.— Warington W. Smyth, Esq., M.A., F.R.S., 

 President, in the Chair. 



The following communication was read: — 



1. "On the Geological Structure of Argyllshire." By His Grace 

 the Duke of Argyll, K.T., D.C.L., F.R.S., F.G.S., &c. 



The object of the paper was to set forth some of the author's 

 reasons for not accepting the views propounded by Mr. Geikie in his 

 • Scenery of Scotland viewed in connexion with Physical Geology.' 

 His Grace believes that, although the atmospheric agencies of waste 

 have produced great modifications of the surface, the form of the 

 hills and valleys has in the main been determined by the action of 

 subterranean forces. 



In illustration of his opposition to Mr. Geikie's theory, he de- 

 scribed a supposed case of the formation of a valley by atmospheric 

 agencies, observing that, if the crumplings of the strata have not 

 affected the present surface, a subsequent submergence and a fresh 

 unconformable deposition filling in all the inequalities must have 

 ensued, and that these new deposits must have been again raised 



