Review pf Recent Geological Literature . 151 
articles included in the first issue is one entitled “Ueber die eruptive 
Hatur gewisser Gneissesowie des Granulitsim sachsischen Mitteigebirge/’ 
by E. Danzig, of Rochiitz, Saxony. After referring to the different opin¬ 
ions which have been held by geologists concerning the nature of the 
Saxony Mittelgebirge (Naumann, Steizner, Credner, Bathe and Lehmann) 
he gives his own observations on the granite dykes of different kinds in 
the granulyte, and on the gneiss-granite in the granulyte and gneiss-mica 
schist. Many of these observations* as well as the figures to illustrate 
them, are strikingly similar to observations made by Mr. A. C. Lawson in 
the region of the Lake of the Woods and by the Minnesota geological 
survey, illustrated in the fifteenth report of that survey. Following is a 
brief statement of his conclusions: 
1. The granites of our mountains belong, as was first proved by J» Leh¬ 
mann, to a single geological formation, though perhaps they originated 
periodically. The separation of bedded granite (granite gneiss) and se¬ 
cretion granite (believed to have been formed by lateral secretion) from 
the granites in the granulyte, which former had already been recognized 
as indubitably eruptive, is not justified by the knowledge obtained. 
2. As far as the observations extend the gne'ssoid rocks of the granu¬ 
lyte mountains of Saxony, wherever they cannot be designated simply as 
gneiss, must be considered in the main as mixtures of granite material 
with that which was originally sedimentary; but also partly as schistose 
beds produced through metamorphism due to dislocations in the granu¬ 
lyte. 
3. In spite of the bedded structure displayed in members of the granu¬ 
lyte formation, and notwithstanding its differentiation into beds which are 
variously composed, chemically and mineralogically, which are appar¬ 
ently stratigraphically equivalent, it cannot be considered as a sedimentary 
formation, nor one which has resulted from metamorphism of such a 
formation. The light colored granulyte seems much more eruptive since 
it contains the characteristic inclusions, and sends out branches into the 
surrounding rock. The pyroxene granites are not genetically similar to 
the other kinds of granulyte, but probably represent altered inclusions in 
the granulyte magma. 
The author did not undertake the consideration of all the rocks of the 
granulyte mountains. The garnet-serpentines, whose close relation to the 
pyroxene granite has been recognized, will be the subject of a later paper. 
On the other hand the facts concerning the gabbros and the bronzite ser¬ 
pentine do not appear to furnish sufficient data to answer the question of 
the origin of this rock if we set aside the description by Dr. Lehmann of the 
metamorphism of the gabbros brought about by mechanical forces. The 
hornblende schists in the mica schists and phyllytes, as well as the green 
schists around Hainch, may perhaps, from the results obtained elsewhere, 
be considered properly to be -diabase or dioryte metamorphosed, which 
were erupted before the granitic rocks (including the granulytes)—espec¬ 
ially since in the Hartz mountains a diabase belongs with the pre-granitic 
eruption. 
It is very remarkable that Naumann’s hypothesis of the origin of the 
