11 
The quereyite from British Columbia is certainly not pure francolite 
nor dahllite as the following ratios show: 
Molecular ratio 
(Quereyite) 
(Dahllite) 
(Francolite) 
1 
2 
3 
CaO 
100 
100 
100 
27 
29 
29 
F 
10 
18 
COi 
13 
12 
7 
H*0 
26 
10 
9 
Analysis 1. Quereyite, B.C. 
Analyses 2 and 3. Sehaller, W, T.: U.S. Geol. Surv., Bull. 509, Mineralogieal Notes, ser. 2, 
pp. 98 and 96 (1912). 
It appears to be typical quereyite which carries an appreciable amount 
of collophanite, but this contradicts the results furnished by microscopical 
examination, as these show the British Columbia quereyite to be composed 
of one definite mineral having characteristic indices of refraction, bire- 
fringence, and specific gravity. The simple formula 3CaO P 2 O 5 CaO COa 
H 2 0 ^CaF 2 derived from chemical analysis strongly suggests that 
quereyite may not only be one mineral but a new one. Further 
research on foreign quereyite should prove very interesting. 
ORIGIN OF PHOSPHORITE 
The phosphate deposit at Francois Lake has not been examined in 
detail, consequently it is not definitely known how the phosphates formed. 
The deposit in some respects is similar to a deposit of quereyite referred 
to by Professor Lacroix 1 , which is found at Bozouls in the department of 
Aveyron, France, and which unlike other French quereyite deposits does 
not occur in limestone but in basaltic tuffs. The quereyite occurs as con- 
cretions here and there in the eruptive rocks. Professor Lacroix does not 
attempt to describe the origin of this particular deposit. It might be of 
interest, however, to give his views on the origin of the deposits which 
occur in the limestone. 
Following a long period of marine invasion in the beginning of Tertiary time, caverns 
and fissures were made in the limestone. These were later on (in Eocene and Oligoeene 
time) filled with debris from running water in a fashion somewhat similar to the one seen 
today in action in caverns. Clays which were residual products of limestone were con- 
centrated in these caverns. The remains of animals who once lived in these caverns or 
were carried there by running water yielded phosphate to solutions which attacked the 
limestone walls, and also added themselves to the lime phosphate already contained in the 
residual clays. Running water carrying carbonic acid remanipulated these phosphates 
and determined their crystallization as concretions in clay or on the walls of the caverns. 
The importance of the role played by carbonic acid is strongly put in evidence by the fact 
that it is an essential element of all the phosphate deposits. At Herault, where numerous 
interesting deposits of phosphate occur, a blue Oxfordien limestone is found containing 
large amounts of bats’ bones, and the brain is sometimes entirely transformed into phos- 
phate. 
Mr. G. Hanson believes that the phosphorite of lake Frangois is a 
filling between two flows of lava rather than the filling of a fracture. He 
also suggests that the material of the vein accumulated on the surface 
tLoe. cit. 
37233—2 
