FOUND IN CANADIAN ROCKS—WESTON. 3 
similar coneretions in a Cretaceous rock of Grand Rapids, Atha- 
basea River*, as follows :— 
“Tt is remarkable for the large number of spheroidal siliceous 
concretions which it contains, and which range in size up to ten 
feet or more in diameter. No fossils were found in the conere- 
tions or in the rocks which hold them.” 
The same ageney which produced these great concretions no 
doubt formed the smaller pipe-stem concretions, so numerous 
in the Miocene rocks at the head waters of Swift Current, N. 
W. T., and which are now being formed on the shores of Lake 
Champlain. 
4, Another interesting concretion locality hes half a mile west 
of White Mud River, near the Fort Walsh trail, in the Assini- 
boine district, N. W. T., the rocks belonging to the Laramie 
formation, Here a small butte was pointed out to me by my 
half-breed Indian guide, who called the place gun-shot butte, 
and said a few years ago when he, with others, hunted buttalo 
in that locality, they sometimes, when ammunition was scarce, 
used these “ balls” in their guns and rifles. I found the hill, or 
butte, to consist largely of calcareous sand, which contained 
enormous quantities of spheroidal concretions, varying in size 
from that of buck-shot to an inch in diameter; the ordinary 
size being that of rifle balls. A great number of these are 
compound forms representing two halves of a sphere coalescing 
together, sometimes a number of these marbles (as the Indians 
call them), are clustered together into pieces as large as one’s 
head. They are all more or less covered with nodes. About 
one-third of each is carbonate of lime, which dissolves out with 
muriatic acid, leaving a residue (as seen under the microscope), 
of grains of pure silex, with a few of feldspar, magnetite, and 
mica. There are no concentrie layers and no nuclei. 
5. The Animikie argentiferous rocks of the Thunder Bay dis- 
trict are remarkable for “ bombs,” so called by the miners. At the 
Beaver silver mine, a few miles from Port Arthur, many concre- 
tions resembling cannon balls may be seen in the black 
carbonaceous slates which are largely developed at this locality. 
* Geological Survey Report for 1889-90-91. 
