J. A. GRUTTERINK. „Examination of specimens of sand from borings done at the works 
of the outer harbour at Scheveningen.” 
Il 
aA 
EY: 
Pepe oe og 4e qe se os be be omm JO ir 10 te so set ae sten bo bp poor ™ 
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seen ere eee - quartz-grains 
heavy minerals 
so 35 40 us 50 sf bo bs Jong mn: 
Proceedings Royal Acad. Amsterdam. Vol. LV. 
