Penrose I APATITES OF CANADA. 37 
formation of cavities seems especially apt to take place at the point of 
junction of the limestone and a harder mineral in the vein. Thus in the 
township of Loughboro', Frontenac County, Ontario, was seen the cavity 
represented in Fig. 13, where a mass of limestone in a vein came in con- 
tact with a mass of apatite-bearing pyroxenite. From this opening sev- 
eral hundred pounds of loose apatite crystals were taken. Though it 
will thus be seen that the apatite of Canada often occurs in well defined 
veins, yet the largest deposits yet discovered occur in irregular masses in 
the pyroxenic and feldspathic rocks (see Figs. 2, 14, 15, 16, 17, 18, and 
21). They seem to occur at some places in fissures and at others as simple 
segregations. As a general rule it may be said that the vein character 
is best developed in the Ontario district, while the segregation and 
pocket formations are more common in the Quebec district. A very 
characteristic section, showing the occurrence of pockets of apatite is 
given in Fig. 18. It is a figure from the side of McLaurin's mine in 
Templeton, Ottawa County, Quebec. The mineral seems to lie in no 
definite vein, but to have been formed by the segregation of apatite 
from the including rocks. This seems especially probable, as the sur- 
rounding pyroxene often contains 10 to 15 per cent, of apatite and 
seems to increase in richness as the pocket is approached. It is also well 
known that phosphate of lime has, more than any other mineral, the 
property of forming into concretionary and segregated masses. Thus 
Professor Eogers found, in the materials dredged in the Challenger ex- 
pedition, numerous phosphatic concretions scattered over many parts 
of the sea bottoms. Again, in the phosphorite deposits of southwestern 
France and of Estremadura, in Spain, the concretionary form is one of 
the most common conditions of the phosphate, while in the phosphate 
region of South Carolina the nodular phosphates, especially those from 
Bull River, show sometimes a distinctly concretionary structure. At 
Crown Point, N. Y., phosphate of lime occurs in radiating and botry- 
oidal masses forming the eupyrchroite of Emmons, and even in the 
guano beds of Peru concretionary nodules of phosphate of lime have 
been found. 1 
The pockets and fissures of apatite are of variable size (see Figs. 2, 
14, 15, 16, 17, 18, and 21), sometimes being only a fraction of an inch in 
diameter and sometimes consisting of immense bodies of massive or 
crystalline apatite, measuring many feet in thickness. Such pockets 
are to be seen at the Emerald, Battle Lake, North Star, High Rock, 
Union, and other mines on the Du Lievre River. The apatite is, gen- 
erally, not sharply divided from the pyroxenite, but gradually blends 
with it. The pockets show sometimes a banded structure, such as that 
of a cavity lined with pyroxene and the central part occupied by apatite. 
Occasional large bowlders of country rock are found embedded in the 
1 In the introduction to this report yet other instances of concretionary forms are 
noted, as well as the fact that many are probably at present forming in the muds be- 
neath certain swamps. — N. S. S. 
(511) 
