M. Bolitlink on the Moun fains in Scandinavia. 253 



coloured marls of the Jura. The greater degree of interest attaches to 

 Uiese singular rocks, from their forming the basis of the country in almost all 

 the parts of Russia visited by M. Robert. The certainty of their exist- 

 ence will contribute to put geologists more and more on their guard against 

 the notion which ascribed to the rocks forming the secondary envelope 

 of the globe, a greater degree of hardness, and a more compact and mas- 

 sive structure, in proportion as they happen to be more ancient. 



The rocks of Nova Zembla, which M. Robert procured at Archangel, 

 shew us that the south-west coast of this polar land contains deposits of 

 blackish clay-slates and limestones with orthoceratites andgoniatites, which 

 is assuredly very remarkable. 



Finally, the drawings and specimens which he likewise obtained at 

 Archangel, establish the important fact, that the argillaceous and marly 

 deposits of the medium oolitic stage extend from the interior of European 

 Russia, namely, on one side in Russian Lapland, and on the other to the 

 embouchure of the Pechora, near the strait of Vaigatch.* 



Notice of the Principal Traces left hy the last great Bevolution 

 which took place in the Mountainous Countries of Scandi- 

 navia, By M. W. Bohtlink. 



In the mountainous parts of Scandinavia, in Norway, Sweden, Fin- 

 land, and Lapland, we find in all the districts hitherto examined, without 

 exception (provided only that the rock be sufficiently compact to resist at- 

 mospheric influences), rocks which on one side are abraded or smoothed, 

 often even polished to such a degree as to reflect the rays of the sun, 

 also striated or scratched, and furrowed or grooved. The side, against 

 which the bodies causing the friction have been pressed, has been named 

 by M. Sefstrom the opposing or polished side {^Stos seite) ; he has named 

 the opposite one the sheltered side or lee-side (Lee seite). f 



We generally find that the polished or opposing side ( Stos seite) of the rocka 

 is turned towards the principal plateaux of these countries. It is from theso 

 plateaux that the impelling power seems to have originated which deter- 

 mined the direction of the bodies which scooped ou£ the grooves.| 



Insulated hills, even when they exceed an elevation of 1000 feet above 

 the plain, produce in the direction of the furrows a lateral deviation alto- 

 gether local, similar to that occasioned by small rocks a few feet ia 

 height. On the summits of these insulated hills the furrows grooved pre- 

 SCTit the general normal direction. 



The large valleys have exercised a marked influence on the direction 



♦ From the Institut, No. 384, 8th May 1841, p. 149. 



t Sir James Hall, one of the earliest observers of these appearances, 

 names the polished side a-ag, the lee-side tail. — Edit. 



I In explanation of the terms used in this and the preceding articles, th« 

 following may be noted ; moving sand polishes the surface, coarsegrayel scrathes 

 and furrows, and large stones scoop out grooves in it.— Edit. 



VOL. XXXI. NO. LXII.— OCTOBEIl 1841. E 



