478 



PREHISTORIC EUROPE. 



Similar appearances are shown in the following record of a 

 boring pnt down near Emden : — 



Alluvium (marine) 

 Darg (peat) 

 Soil-bed . 

 Alluvium (marine) 

 Darg (peat) 

 Soil-bed 



Alluvium (marine) 

 Darg (peat) 

 Alluvium (marine) 

 Darg (peat) 



13 feet. 

 4 

 1 

 1 

 2 

 1 

 1 

 1 

 2 

 3 



The Darg-j)e&t in East Friesland varies, according to Professor 

 Grisebach, from 1 to 15 feet — 2 to 4 feet being a medium 

 or average thickness. Near Brockdorf in Holstein, however, 

 its thickness is as much as 20 feet. 1 It is generally of a 

 yellowish -brown colour, and of a consistency between that 

 of heather-peat and ordinary moss-peat. The plants of which 

 it is composed betray its land-origin. Grisebach says it contains 

 many stalks, one to two inches thick, of reeds and rushes similar 

 to those which are common upon the margins of such rivers as 

 the Ehine and the Maas, and he has no doubt that it has been 

 formed in the same way as meadow-peat, which grows upon low 

 marshy ground. Ehrenberg, he says, got microscopic marine or- 

 ganisms (Polythalamice) in the Darg, and the alluvia with which 

 it is interbedded are clearly of marine origin, but the peat 

 itself is composed wholly of land- and freshwater-plants. After 

 a careful examination under the microscope, Grisebach did not 

 succeed in detecting a single trace of any marine algse. The 

 mere occurrence of intercalations of marine alluvia does not 

 therefore prove the marine origin of this bottom-peat, as some 

 writers have supposed. The peat which occurs above the Darg and 

 its associated marine beds attains a thickness in Holland and 



"which form the "high and dry ground," and which have been proved to extend 

 underneath the peat, blown sand, and recent marine clays of those countries, as 

 at Eotterdam, Antwerp, and many other places. Carl Vogt : Lehrbuch der 

 Geologic und Petrefaktenkunde, Bd. ii. p. 125. 



1 Kuss : Naturbeschreibung der Herzogthumcr Schlemoig und Holstein, p. 36. 



