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Geology. - "Considerations on the Staringian "Zanddiluvium"". 

 By P. Tesch. Communicated by Prof. 1\. Martin). 



The sandy areas form a great pari of the Dutch land. When from 

 tlic so-called diluvial half of our country the gravelous diluvium 

 with the boulder-clay, the alluvial moors and river deposits and the 

 regions where the wind has influenced the bottom, are subtracted, 

 the districts are resting where the surface consists of sand without 

 or with little gravel and which are gathered by Staring under the 

 collective name of "zanddiluvium". These districts have in the different 

 parts of our country a different appearance and a different fertility. 

 Therefore the neutral name of "zanddiluvium" has been chosen by 

 Staring for a very good reason, in which name the origin rests' 

 undecided by this name. Yet he speaks on the pages 114 to 121 

 of the second volume of his "Bodem van Nederland" about the 

 origin of these sand deposits as follows: 



"Evidently it has been formed in the last part of the diluvial 

 period or in the very first part of the alluvial period; for everywhere 

 where it is found, it rests upon the gravelous diluvium and is covered 

 by the alluvial beds." 



'This form (tin 1 horizontal position of the composing strata) 

 connected with its position upon the gravelous diluvium and at the 

 foot of the hills formed by this, permits to decide, with great 

 probability, about the presumptive origin of the "zanddiluvium". The 

 sand with boulders and gravel being transported to the places where 

 it is found now and having 'taken its present form, still a long time 

 must have passed, before the -surface was fastened by the vegetation 

 and the currents were streaming in their present beds. During this 

 period frost and rain will have had a stronger influence on these 

 accumulations of sand and boulders than afterwards when their 

 surface was protected by a thick crust of humus. The rocks which 

 are capable ol' disintegration, many granites, mica slates, sand-stones 

 and grits, have been converted into gravel, sand and (day, and the 

 rain water has transported it for a great pari to the valleys. These 

 valleys were tilled up and at the same time the hills became lower 

 and took a more rounded form than was originally the case. That 

 this sand represents the detritus of the gravelous diluvium and has 

 been formed during tin' transition-lime to the alluvial period, is also 

 to be concluded from the reflection thai such a formation must exist 

 and that this formation cannot be pointed out in another than in 

 this sand." 



