OF ARKANSAS. 



27 



Chemical analysis of shell-marl, from T. P. Harris' well, Greene covnfij, 



Arkansas. 



Water 1 .3 



Insoluble silicates 



Carbonic acid 2.7 



Peroxide of iron 3.C 



Alumina 2.0 



Lime 2.9 



Magnesia 1.2 



Phosphoric acid .45 



Potash .5 



Loss .45 



TSilicf 

 f Aluir 



umina tinned with iron 



84.9 <( Lime 



72.8 



6.8 

 .8 

 .3 

 .9 



3.2 

 .Manganese trace 



Magnesia 

 Potash- • • 

 Soda 



84.8 



100.00 



For comparison, is subjoined the chemical analysis of the corresponding 



shell-marl of Hickman county, Kentucky: 



Water 1.35 f Silica- • ■ 



.30 | Alumina 

 73.30<( Lime 



Organic matter sol. in water 



Insoluble silicates 



Carbonic acid 10.00 



6.8 



3.78 

 2.8 

 .12 



1.55 



Lime 



Magne-da 



Alumina and peroxide of iron 

 Chlorine 



Loss, alkalies and phospho-) 

 ric acid, not determined •) 



Magnesia 



60.6 



7.4 

 1.1 

 .4 



Loss, alk, and a trace of i 

 oxide of iron not esti-V 

 mated ) 



3.8 



. .3 



"arse 



100.00 

 From the best information obtained, the materials passed through in 

 digging this well, were: 



Soil and sub-soil 3 h 



Dark-red under-clay 14 



Shell-marl ■ • > 29 



Gravel and white coarse sand, mixed- 2 



The water was obtained in the last member, viz: the white 

 gravel and sand. 



At James Lamb's, three quarters of a mile east ot Harris', th< 

 marl was struck in sinking his well at 54 feet; at Henry Cook's, 

 and at Daniel Martins' (where Lindley now lives), water was obi ji 

 18 feet in the shell-marl. 



Thus I have, even to the depth of 54 feet beneath the surface 

 able to obtain the least evidence of the existence of any of the members 

 of the cretaceous formation, as far north in the north-eastern part of 

 Arkansas, as they have been laid down by some geological map <ts; 



•11- 

 ( et; 



at 



ueen 



