TRANSACTIONS OF SECTION C. 577 



has teen accomplished hy sunple meohanioal disintegration smce the island was 

 raised above the 375 feet level. The joints are the most important factors in 

 denudation ; excepting movtonnee faces, the author considers most of the bare rock 

 faces which constitute the surface of Northern Norway as merely exposed joint 

 planes. He has seen joints in the same rock, and having the same direction, ex- 

 tending from a few feet to over a thousand, and surface features in parallelism with 

 them, from a facet not a yard across to precipices over a thousand feet high. 



8. On a Fragment of Mica Schist. 

 By Professor W. J. SohLks, M.A., F.B.8.E., F.G.S. 



The author called attention to some appearances presented by a fragment of 

 mica schist pointed out to him by Prof. Wm. Ramsay, Ph.D., while walking 

 on the beach at Bodo, Norway. It is a tabular fragment, showing fine foliation 

 laminae, and traversed by an undidating vein of quartz. The undulations are very 

 high and narrow, eight complete ones occurring along a distance of 10 inches in a 

 straight line. The planes of foliation correspond to the bedding in the rocks of the 

 neighbourhood (amongst which the same phenomenon was afterwards noticed). 

 The folded quartz vein was originally straight, and cut across the laminae at right 

 angles ; the folding must have been accomplished by compression of the schist at 

 right angles to its folise ; and by measuring the length of the quartz vein between 

 two points, along its undulations (26 inches), and directty along its path (10 

 inches), one finds the amoimt of compression which has taken place (13: 5). The 

 argument is the same as that used by Dr. Sorby for the bed of quartzite folded 

 in the slate of Devonshire. 



9. On the Geological Age and Itelations of the Siivalik and PiJcermi Ver- 

 tebrate and Invertebrate Faunas. By W. T. Blanfokd, F.B.8., F.G.S. 



There is much similarity between the two collections of organic remains found 

 in the Siwalik beds of Northern India and the strata of Pikermi in Attica. Both 

 consist chiefly of mammalian remains, and amongst the forms represented there is 

 an immense preponderance of large animals, that is, of mammals ranging from the 

 size of a sheep to that of a large elephant, and a great deficiency of smaller species, 

 the micro-mammalia (small rodents, bats, and insectivores) being almost imrepre- 

 sented. In both, some bones of birds and reptiles and a few mollusca accompany 

 the mammals. Finally, both have been generally referred to the Miocene epoch. 



The Siwalik rocks are the upper strata of the Tertiaiy fringe, extending almost 

 throiighout the western and northern margins of the great Indo-Gangetic plain 

 from Sind to Assam. The mass of the typical Siwalik fossils were found in the 

 north-eastern Punjab, in the country between the Sutlej and Jumna, not far from 

 Simla. The Tertiary beds here consist of — 



Upper. 

 Siwalik series ■[ Middle. 



Lower (Nahan). 

 Upper (Kasauli). 

 Sirmur series -{ Middle (Dagshai). 

 Lower (Subathu). 



These two series roughly correspond to Upper and Lower Tertiary, the best-defined 

 horizon being that of Subathu, which is Nummiditic (middle or upper Eocene). The 

 Siwalik fossils are from the upper and middle Siwaliks. None of the beds, except 

 the Nummulities of Subathu, contain marine fossils. 



The rocks of Sind have recently been examined in detail, and the nimiber of 

 well-marked fossiliferous marine beds is much greater than in the sub-Himalayan 

 region. The tertiary beds are thus sub-divided : — 



Manchhar \ ^P?^"" " ' J'liocene (?). 



Mancnnar . j ^ower . . Upper miocene. 



1880. p P 



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