PENROSE.] 
PHOSPHATES OF NORTHERN FRANCE. 
[III. Craie Brune (Nivoit, ibid.)l 
107 
Constituents. 
Organic matter 
Lime 
Magnesia 
Alumina and oxide of iron 
Potash and soda. 
Carbonic acid 
Sulphuric acid 
Phosphoric acid 
Silica and sand 
Chlorine and fluorine 
f£ 
a> 
ari 
p 
X 
T3 
O 
® a 
a 
^.y 
% 
>a *2 
A 
« 3 
<r! 
fc d 
£ 
2.83 
4.40 
53.24 
52.00 
0.12 
Trace 
1.01 
1.29 
0.19 
0.28 
28.10 
24.32 
0.89 
0.92 
11.66 
15.19 
1.96 
1.60 
Trace 
Trace 
100. 00 
100. 00 
fIV. Craie Brune (Petermann, Bull. Acad. Sci. roy. Belgique, vol. 39, p. 34).] 
Phosphoric acid. 
(a) Mass poor in phosphate grains.. 10.00 
( b) Mass poor in phosphate grains , 9. 27 
(c) Mass rich in phosphate grains 13.90 
(d) Incoherent fragments _ 10.87 
(e) Incoherent fragments 11.62 
(/) Incoherent fragments 10.87 
[V. Craie grise ou brune (Nivoit, Assoc, francaise avanc. sci., 1875).] 
Loss by calcination 31. 00 
Sand and clay 2.10 
Phosphoric acid 11. 13 
Lime 54.00 
Oxide of iron 1. 10 
Loss and undetermined matter 0. 67 
100. 00 
PHOSPHATES OF NORTHERN FRANCE. 
The phosphates of northern France occur mostly in the provinces of 
Ardennes and Meuse, though they are also found in smaller quantities 
in other northern provinces. They are in the Cretaceous, and, like 
the phosphates of the English Cretaceous, appear both at the summit 
and base of the Gault (Gault Argileux). But there is also a third bed, 
which is not found in England, and which occurs immediately under 
the Craie Blanche, a calcareous bed corresponding to the Upper Chalk 
of England. The following section will show the relative positions of 
these beds, in descending order: 
(1) Craie Blanche (" Upper Chalk"). 
(2) Marnes Crayeuses (" Chalk Marl"). 
(581) 
