Petrological Abstracts and Reviews 



ALBERT JOHANNSEN 



ScHLOSSMACHER, K. "Die Sericitgneise des rechtsrheinischen 



Taunus," Jahrh. d. Preuss. Geol. Landesanst., f. igi'j, XXXVIII 



(1919), Th. I, 374-433, Pl- I, figs. 2. 



The sericite-gneisses of the Taunus are dynamo-metamorphosed quartz- 



keratophyres and felso-keratophyres. Ten chemical analyses are given, of 



which four are new. A general description and a discussion of the chemical 



relationships are followed by descriptions of the various localities. 



ScHLOSSMACHER, K. "Ein Verfahren zur Herrichtung von schie- 

 frigen und lockeren Gesteinen zum Diinnschleifen," Centralhl. 

 /. Min. Geol., etc., 1919. Pp. 190-92, fig. i. 



The usual method of boiling porous and schistose rock fragments in Canada 

 balsam is not efficient. Here is described an apparatus by means of which the 

 pore spaces in the rock may be filled with balsam. A tube with a stoppered 

 side opening is partially filled with balsam, placed in a water bath, and the air 

 exhausted. Any time thereafter chips to be sectioned are placed in the side 

 tube, the air is exhausted, the tube is tilted so that the chip falls into the 

 balsam where it is left until the bubbles cease. 



ScHLOSSMACHER, K. ''Keratophyre und ihre dynamometamor- 

 phen Aquivalente aus der Umgegend von Bad Homburg itn 

 Taunus," Jahrh. d. Preuss. Geol. Landesanst. f. igig, XL (1920), 

 Th. I, 460-505. 



The metamorphic rocks of the Taunus are keratophyres and soda-kerato- 

 phyres; tuffs were nowhere found. Detailed petrographic descriptions and 

 two new chemical analyses are given. 



ScHLOSSMACHER, K. " Emigc nichtmetamorphe palaovulkanische 

 Eruptivgesteine aus dem Vordertaunus," Zeitschr. d. Deutsch. 

 Geol. GeselL, LXXII (1920), 25-27. 

 Unmetamorphosed paleovolcanic albite-trachytes and trachy-andesites, 



that is, keratophyres and keratophjre-porphyrites, are described from eight 



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