ae 
166 The American Naturalist. [February, 
MINERALOGY AND PETROGRAPHY.' 
Globular Granite in Finland.—An occurrence of spherical gran- 
ite is reported by Frosterus? from the southern and eastern portions of 
Borga in South Finland. In the midst of a number of knolls of red 
or gray microcline granite, is one in which spherical nodules are plen- 
tiful. Of the rock forming this knoll there are two varieties distin- 
guished by the difference in size of their nodules. In one the nodules 
are small and consist of a light covered zone surrounded by a dark 
periphery composed of two or three concentric biotite shells. The ker- 
nel is a granular aggregate of oligoclase, some microcline, a little 
quartz, and considerable biotite toward the center. The rock enclos- 
ing the nodules is a dark gray granite in which quartz and microcline 
are more abundant than in the nodules. In the second variety of rock 
the nodules are large. Their kernels are like the small nodules 
described. Around these is usually a narrow band of feldspar and 
around this a zone of mica. The rock in which the spherules lie is & 
grayish red granitite. i 
After investigating carefully the relations of the minerals in the 
nodules to each other and the relations existing bétween the nodules 
themselves, the author concludes that the spherules existed as plaste 
bodies in the rock magma while this was still liquid. When in con 
tact with each other the nodules are often distorted, whereas at other 
times they are broken across. Itis believed that the mica and other 
more basic components first separated in the form of a shell enclosing 
some of the rock’s magma, that afterward gave rise to the grani 
nucleus upon cooling. The nodules are thus looked upon as basic cor- 
eretions, and since they are distributed through a few restricted ae 
only, they are thought to form basic “ Schlieren.” The author’s ar 
is well illustrated by several handsome plates. 
The Inclusions in the Basalts of the Oberlausitz.—4 
further study of the granite inclusions in the basalts of Oberlausitz by 
Beck’ adds a few items of information concerning the ae ee 
between volcanic rocks and their included fragments. 
have had pre 
Hirschberg the granite inclusions in nepheline-basalt 
1 Edited by Dr. W. S. Bayley, Colby University, Waterville, Me 
* Minn! u. Petrog. Mitth., XIII, p. 177. 
* Minn. u. Petrog. Mitth., XIII, p. 231. 
