1897.] Petrography. 327 
formed feldspar. The schistose porphyries differ from the more mas- 
sive ones in the greater degree of their alteration. Analyses of the 
two types follow : 
SiO, Al,0, Fe,O, FeO CaO MgO K,O Na,O H,O Total 
Massive 76.50 15.68 78 1.10 4.92 .88 — 99.76 
Schistose 72.08 16.15 2.21 18 .68 949 ZL 2.40 — 99.14 
The porphyry breccias consist of fragments of porphyry and of 
schists in a foliated matrix composed largely of porphyry and schist 
débris. In origin they are believed to be reibung’s-breccias formed at 
the juncture of schist and porphyry. The paper is handsomely illus- 
trated with photo-lithographs of thin sections. 
The Eclogite of the Fichtelgebirge.—Newland® gives a few 
notes on the eclogites comprising a portion of the central gneissic cone 
of the Bavarian Fichtelgebirge. Mineralogically, the eclogite is so 
varied in composition that the rock is very difficult to define. Its 
most characteristic component is garnet, but, in addition to this, it con- 
tains also omphacite, hornblende, cyanite, zoisite, sphene, andesine, 
muscovite, zircon, pyrites, magnetite, rutile, quartz, and a few other 
minerals. No olivine could be found in any of the sections, although 
it was searched for. The pyroxene, hornblende and feldspar are often 
arranged in intergrowths resembling granophyre, and the pyroxene or 
garnet is surrounded by a radial aggregate of feldspar, hornblende 
and omphacite, which, under low powers, looks like a reaction rim. 
Analyses of the rock indicate that it is nearly allied to certain types 
of eruptives. (1) represents the composition of the eclogite from 
Markt Schorgast, and (II) that of a diabase from Fichtelberg : 
SiOa ALO; Fe,0; FeO MnO CaO MgO KO NaO H,O CO, Total 
L 48.81 16.25 6.00 7.48 43 9.72 7.12 .« 64 ü — 99.03 
Tl. 47.60 15.29 7.09 687 12 841 648 1.40 3.62 214 16 = 99.18 
Nodular Granite from Finland.—Frosterus® describes a new 
nodular granite from Kangasnierni Parish in Finland. The rock was 
found as boulders in morainal deposits. It is a biotite-granite in which 
the nodules are thickly strewn. Each nodule is composed of three 
quite distinct parts—an inner nucleus of biotite, sometimes with a frag- 
mental outline, surrounded by a zone of coarse granite and an outer 
zone of fine-grained granite. Outside of these are several distinct en- 
velopes, the inner of which consists principally of feldspar and the 
outer of biotite and feldspar. In the envelopes the feldspar is radially 
* Trans. N. Y. Ac. Sciences, Oct., 1896, p. 24. 
* Bull. Com. Geol. d. la Finlande, No. 4, p. 1. 
