Sir H. Hoivorth — Surface Contour of Scandinavia 8^ Finland. 397 



fan, slopinoj at a small angle, it may be, for miles down the valley, 

 and choking it to depths of hundreds of feet in some instances. 

 Temporary advances of the ice may crush this rough gravel up into 

 great ridges of water-worn rock, such as those, remnants of which 

 are to be seen above Cardiff, Swansea, etc. 



During the cold periods which caused the glaciers of Switzerland 

 to stretch out beyond the hills, erode many of the lake basins, 

 and give the valleys their characteristic outlines, the coarse gravel 

 thrown out from the ice caves choked the valleys of the Rhine, 

 Elione, and other rivers, to great depths. However, during warmer 

 periods, the modern valleys have been excavated through them, 

 and glacial gravel now forms extensive terraces overlooking the 

 newer deposits. 



III. — The Geologioallv Recent Origin of the Surface 



Contour of Scandinavia and Finland, and its Lessons. 



By Sir Henry H. Howorth, K.C.I.E., M.P., F.R.S., F.G.S. 



{Concluded from the August Number, p. 361.) 



LET us now turn to the angular gravel itself, the so-called 

 Krosstensgrus of the Swedes, which is formed in the main from 

 crystalline rocks, from granite, and gneiss, halleflinta or petrosilex, 

 crystalline limestones, mica-schists, quartzite diorites, diabases, 

 porphyries, etc. This angular gravel Erdmann not only pronounces 

 to be moraine material, but the only moraine material in the 

 country. How it is possible to correlate this angular di-ift with 

 any kind of moraine material, or to explain the angular gravel of 

 Sweden by the intervention of ice, I cannot understand, any more 

 than I can understand the application of the same cause to the 

 angular gravels of Southern England and Northern France. That 

 a jointed rock when soaked with water in summer will split into 

 fragments along its joints or cracks when that water is frozen in 

 winter, is true enough, but these variations of temperature are 

 quite impossible under a glacier, and if they were possible they would 

 not cause the splitting of flints, of granite and gneiss and porphyry, 

 into splinters. Nowhere do we find work of this kind being per- 

 formed in the homeland of glaciers at the present time, nor can 

 I conceive its possibility. 



It seems to me as plain as possible that these angular gravels 

 of Sweden, which occur at all levels among the surface beds, have 

 nothing to do in any way with ice. The angular gravel is clearly 

 connected with the angular erratics ; they form a continuous series 

 marked by the same features, and they seem to me explainable 

 by one cause only, that which I have already invoked to 

 account for the broken and angular rubble in the Chalky Clay of 

 England, namely, a violent breaking up of the solid matrix of the 

 rocky beds in situ by some subterranean force. Have we any 

 evidence of spasmodic changes of the surface involving the breakage 

 of the strata in situ in the area we are discussing ? 



One of the most curious facts in recent Glacial literature has been 



