184 PETROGRAPHICAL ABSTRACTS AND REVIEWS 



Hogbom, A. G. "Ueber einen Eisenmeteorit von Muonionalusta 

 im nordlichsten Schweden," Bull. Geol. Inst. Univ. Upsala, 

 IX (iqio), 229-38. PI. 1. 

 This is a description of the first iron meteorite found in Sweden. The 



essential constituents are the iron-nickel kamazite, taenite, and plessite- 



Troilite and daubreelite form a minor part. Chemically, the meteorite 



contains 91 per cent Fe and 8 per cent Ni. 



W. T. SCHALLER 



De Lapparent, Jacques. "Les gabbros et diorites de Saint- 

 Quay-Portrieux et leur liaison avec les pegmatites qui les 

 traversent," Bull, de laSoc. Francaise de Mineralogie, XXXIII 

 (1910), 254-70. 



Near Saint-Quay-Portrieux on the coast of Brittany, intrusive in 

 mica schists, there is a mass of rather coarse hypersthene-gabbro with a 

 periphery of dioritic facies. Both gabbro and diorite contain inclusions 

 of a finer-grained hypersthene-bearing rock with the structure of beer- 

 bachite. These rocks are cut by dikes of aplite essentially composed 

 of labradorite and quartz. The diorite and the marginal, but not the 

 central, part of the gabbro are cut also by small dikes of pegmatite com- 

 posed essentially of microcline, albite, quartz, and a little biotite, with 

 local muscovite and tourmaline. The albite has crystallized before the 

 microcline. 



The principal types are represented by five analyses. 



The microscope shows the hypersthene of the gabbro in process of 

 replacement by a mixture of biotite and quartz, and the augite more 

 or less uralitized. In the peripheral " diorite " both alterations are much 

 more advanced; the augite is almost completely uralitized, and the 

 hypersthene wholly replaced by biotite and quartz. The author ascribes 

 these changes to the agency of the pegmatite and believes them to have 

 been effected before the gabbro was fully consolidated. He considers 

 for reasons not fully stated that the first phase was the production of 

 soda-lime feldspar by the reaction with the femic magma of siliceous 

 alkaline vapors, rich at first in soda. He supposes the vapors subse- 

 quently to have become more abundant and richer in potash, water, and 

 boric acid. The quartz and biotite, it is pointed out, would be formed 

 by combination of the constituents of hypersthene with those of potash- 

 feldspar; there is evidence that this reaction took place in the central 

 gabbro before the hypersthene was completely crystallized, and in the 



