C..A; Vanhise— Enlargements of Feldspar. 399 
Art. XLVIL—On Secondary enlargements of Feldspar frag- 
by C. A. VANHISE 
ments in certain Keweenawan sandstones ; by C. A. V 
Spar (not perhaps always of the same species) may have been 
enlargements of feldspar fragments. In the slate conglomerates 
of the north shore of Lake Huron, I have found what seem to 
be enlarged feldspar grains, but the evidence that any of the 
material is of secondary origin is not sufficiently satisfactory, the 
ines of separation between the supposed new material and the 
nuclei being ill marked. However, I have found what seem 
certainly to be additions to grains of that mineral, in certain of 
the Keweenawan feldspathic sandstones. The specimens in 
which these supposed enlargements were first found are taken 
t On the N ature of the Induration in the St, Peters and Potsdam Sandstones, 
1883; Philips and Bonney, 8 : : 
Q Same Occurrence was noted in the quarizites of Eureka, abel ne 
dings and Arnoi ague as long ago as the summer of 1881, although these ob- 
a 
