GEOLOGY. 245 



chan;5es in the geographical flistnl)ution of plant?:, under nearly 

 equal lines of temperature, are not due to the mechanical texture 

 of composition of the soil, but to the variable supplies of moist- 

 ure ; that in the winds, as the agents in the distrilnition of that 

 moisture, we have an adequate cause to explain the phenomena 

 of forest, prairie, and desert. 



EAST ANGLIAN GEOLOGY. 



At the 1868 meeting of the British Association, the President of 

 the Geological section, Mr, Godwin Austen, opened the proceed- 

 ings with an address, in which he said Suffolk and Norfolk, which, 

 geologically as well as ethnologically, formed one region, were part 

 of the slope of the North Sea basin, for the North Sea valley was a 

 true physical depression compared with its breadth, and the depth 

 of the North Sea was exceedingly small. The channel running 

 parallel with the coasts of Essex, Suffolk, and Norfolk had a maxi- 

 mum depth of only 180 feet, so that a change to that amount of 

 depression of sea-level would lay bare the whole of the sea-bed 

 from the coast of Northumberland across to Jutland. A depres- 

 sion of 120 feet would extend the great Germanic plain nearly to 

 our area. A deep submarine trough had been traced at a mean 

 distance of about 50 miles from the coast-line of Norway. Across 

 the line of greatest depth the change was abrupt. This curious 

 feature was just what would have been produced by the subsi- 

 dence of the whole of the southern portion of the Scandinavian 

 region, together with 50 miles of area around to a depth of 600 or 

 700 feet. There were good grounds for supposing that such had 

 been the process ; and the geological history of the basin seemed 

 to supply the precise date of the subsidence in question. It was 

 the depression of the Scandinavian mass along the line indicated 

 which produced the channels of the Skaggerach and the Cattegat, 

 and opened a communication from the North Sea into the Baltic 

 depression. 



Over the whole of the European area there is a region which 

 presents broad expanses of water-worn detritus, sands, and loams, 

 often placed at considerable elevations above present water-levels, 

 which, from their superficial extent, have caused them to be iden- 

 tified with the component members of another detrital group (the 

 glacial drift) peculiar to another area, from which they are dis- 

 tinct as to conditions and mode of accumulation. A line drawn 

 across the European area, occasionally on one side or other of that 

 of north lat. 51, defines the north limit of all this class of detrital 

 accumulations of the Kainozoic period. On the south of this, all 

 these accumulations have their limits. North of this line the de- 

 trital accumulations are neither local as to composition, nor have 

 they much reference to surface configuration, although such con- 

 figuration pre-existed. Over this area, too, are the indications 

 of low temperature and broad alluvia. The distribution of the 

 detritus over this area shows that the expanse of water was con- 

 tinuous, and was marine. Over the British and part of the Euro- 

 21* 



