12 



To arrive at an appreciation of the quantity of sea water, which 

 thus could possibly be contained in sedimentary strata, we have 

 first to examine what tiie pore space in sedimentary strata can 

 amount to. 



If the constituting elements were perfectly spherical, the amount 

 of pore space would depend only on the way of their being piled 

 up, and would vary between the values of 25,95 to 47,64 volume 

 percentage (5) (6) (7). 



As the constituting elements are not perfectly spherical however, 

 the pore space of sediments has to be determined empirically; it 

 was found to vary between the values of 16 to 70 volume per- 

 centages'). And it is a remarkable fact that pore space-capacity of 

 sedimentary strata increases with the diminution of their constituting 

 elements. 



The above holds for deposits situated relatively near to the surface; 

 the question is now whether we may accept a similar conclusion 

 for deposits situated at very great depllis beneath the surface? 



The overwhelming amounts of oil, water and gas met with in 

 sedimentary strata at depths of 1000 meters and more, already seem 

 to point towards such conclusion not being unlikely. 



But we have more direct indications to go by in the ascertained 

 pore space of Dakota sandstone (Cenomanian) and the Potsdam 

 sandstone (Paleozoic). 



The researches of F. H. King showed that, under their hydro- 

 static levels, the Dakota sandstone 15 to 38 and the considerably 

 older Potsdam-sandstone contains 10 to 38 volume percentages of 

 water =) (5). 



The first mentioned deposit extends over an area of over 900,000 

 km'., the latter over an area of more than 350,000 km^. both 

 with an average thickness of about 300 meters. 



The former is covered in the Denver District by more recent 

 deposits having a total thickness of 2000 m., the latter by a series 



great depths, is left undiscussed here; should we accept llie possibility of it, tiic 

 proportion of occluded water might be greater still. 



1) loc. cit. (7) p. 127 and (5). 



") it is true that Newell found that a marble only contained 0,62''/u of water. 

 But as a marble is not a sedimentary deposit but a modification of it, this per- 

 centage (as little as that of eruptive rocks) may not be taken as a basis tor an 

 appreciation of the amount of water which can be stored up in the pore-space of 

 sedimentary strata, laid down in the G.S. The only conclusion we might perhaps 

 be allowed to draw from it is, that as the percentage is yet considerable relatively, 

 in spite of the intense metamorphism the deposit underwent since its deposition 

 the original contents must have been much greater. 



