Mr. H. B. Medlicott on the Alps and Himalayas. 397 



the sections exposed on the south flank of the Himalayas, and sug- 

 gested a parallelism between them and those exhibited in the Alps. 

 The clays, sands, and conglomerates of the Sivaliks are very like 

 those of the Molasse ; and in both regions the coarser deposits pre- 

 vail towards the top. In the Himalayas also the younger Tertiary 

 deposits almost invariably dip towards the mountain-range which 

 they fringe, the plane of contact inclining in the same direction, 

 and thus producing actual, though not parallel, superposition of the 

 older rocks. All the arguments which have been used to prove 

 prodigious faulting in the case of the Alps would therefore, the 

 author stated, be quite as applicable to that of the Himalayas. But, 

 as regards the latter range, Mr. Medlicott brought forward evidence 

 which appeared to him sufficient to prove that the present contact 

 of the Sivalik formation with the mountains is the original one, 

 modified only by pressure, without relative vertical displacement, 

 and that the sinking of the mountain-mass is the proximate cause 

 of the contortions of the Tertiary strata. He then endeavoured to 

 show that this explanation is equally applicable to the Alps, espe- 

 cially as it seems also to account for collateral phenomena which 

 appear difficult of explanation consistently with the ordinary hypo- 

 thesis ; and he concluded by discussing the current theories of the 

 formation of lake-basins, in relation to the more immediate subject 

 of his paper. 



2. " On some striking Instances of the Terminal Curvature of 

 Slaty Laminae in West Somerset." By D. Mackintosh, Esq., F.G.S. 



Whilst engaged in investigating the nature and extent of oceanic 

 and atmospheric denudation, and the origin of superficial accumula- 

 tions in the West of England, the author observed, on the nearly 

 level floor of one of the valleys which indent the Quantock hills, the 

 laminae of Devonian (Carboniferous ?) Slate, very regularly and 

 distinctly bent backwards towards the south. 



Sections near W 7 iveliscombe exhibited some interesting instances 

 of the curvature of the laminae, the line of demarcation between the 

 commencement of the curving back and the undisturbed mass of 

 slate below being remarkably distinct and straight along the strike 

 of the cleavage ; but at right angles to the strike, the surface formed 

 by the edges of the laminae beneath, though as distinctly marked, is 

 very uneven. 



At Raleigh's Cross other instances of the curvature are seen. 

 The most important fact in connexion with the sections was thus 

 stated : — the bending and curving back over extensive areas has 

 taken place on perfectly level ground, with a declivity instead of an 

 elevation on the side whence the movement must have come. 



An exaggerated continuation of the general curving back is seen at 

 Gupworthy, which at first sight appeared to be part of a denuded 

 anticlinal fold. Instances have also been exposed in a cutting of 

 the Exeter and South Devon Railway near Plymouth. 



In all parts of Devon, West Somerset, and Cornwall, if not in all 

 districts, where the slates are flexible, and where the cleavage-laminae 



