TWENTY-FOURTH ORDINARY MEETING. 301 
form may have been imparted to them, either during or subsequent 
to their formation. 
The structure I have attempted to describe is best seen where the 
phosphate-producing rock is least disturbed and where the joint-fissures 
are moderately small and close together, but the same arrangement 
obtains among the larger deposits. The principal mass in a working 
sometimes passes from a vertical joint to one in another set, or from 
one of the latter to a horizontal joint, thus giving the mass the form 
of the letter |_ as seen in plan in the first instance or in vertical sec- 
tion in the second. An example of the first of these forms on a 
large scale is described by Mr. Torrance as occurring at Major Chap 
leau’s Mine on lot 17, range VI, of Portland, East—(Geol. Survey 
Report of Progress, 1882-84, page 16 J.) 
Along the intersections of any two of the planes of the joints, an 
more especially at the points where all three intersect one another, 
the apatite is accumulated in the largest quantity. The angles of 
adjacent blocks are frequently rounded off and thus larger spaces are 
found for the deposition of the mineral. Sometimes the apatite 
follows only one set of vertical joints, when it appears as parallel 
veins ; at others it is nearly confined to the horizontal ones, when it 
forms a succession of “ floors,” and again it may follow both of the 
vertical sets or even all three, in which cases it appears in a reticu- 
lating form, which is of very common occurrence. 
If the above view of the nature of the majority of our phosphate 
deposits in the pyroxenite be correct, we should naturally expect to 
find the mineral most freely exposed where upward movements of 
the apatite-bearing rocks had occurred, and that the deposits of the 
mineral between the blocks of the country-rock would be widest 
above, and further, that in going downward they would become 
pinched towards the ‘next leading horizontal joint below, where they 
would open out again ; also that the successive bunches of the mineral 
would become smaller and smaller in descending. These conditions 
appear to correspond with the experience of mining so far. 
The great numbers of small “shows” which are found on the sur- 
face among the apatite-bearing rocks appear to afford additional proof 
of the correctness of the view | have put forth. Many of these have 
been worked to a small extent on the surface by farmers and others, 
but the great majority of them show a tendency to pinch out at a 
limited depth, when they are usually abandoned. As many as 300 
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