150 



QUATERNARY PERIOD. 



flint and sandstone, and may have originated from the conglo- 

 merate of the surrounding mountains. .In one spot, where the 

 lignite was of great thickness, it was traversed in the middle by 

 a deposit of clay which thinned out in the form of a wedge. In 

 another place this clay -bed was divided into several bands, di- 

 stinguished by their light colour and greater thickness from the 

 dark-coloured loam-bands of the coal already mentioned (which 

 the workmen call ' ' silver ") . The deposit here, probably after 

 its formation, had been ruptured by a slip and separated into 

 very irregular and variously bent layers by the intercalations of 

 clays. In one place a portion of the lignite-deposit is placed 

 almost perpendicularly, and only covered by a thin layer of 

 arable soil, while elsewhere the deposit is 'generally in a hori- 

 zontal position and covered by a bed of stratified sand and 

 pebbles. 



At the spot where the lignite-deposit was of great thickness 

 the following section (fig. 328) was to be seen. It contained in 



Fig. 328. 



Section of the paper-coal or lignite deposit, and pebble-beds, at Diirnten : 

 a, loam (lake-chalk) ; &, lignite, or paper coal ; c, pebbles and sand ; 

 d,/, loam ; e t upper thin band of paper coal or lignite ; g, layers of 

 pobbles and sand j h, erratic blocks. 



ascending order : 



