PETROLOGICAL ABSTRACTS AND REVIEWS 477 



DuPARC, Louis. "Recherches Geologiques et Petrographiques sur 

 rOural du Nord," Pt. Ill: Le bassin de la Haute- Wichera, 

 Memoires de la Societe de Physique et d'Histoire NatureUe de 

 Genbve, 1909, XXXVI, fasc. i. 



Pp. 53-114 are devoted to the petrography of diabases and pre-Devonian 

 metamorphic rocks. 



The diabases are of ordinary types, essentially composed of plagioclase 

 and augite. The optical properties of the pyroxene and its alterations are 

 fully described. 



The metamorphic rocks comprise quartzites, amphibolites with albite 

 and epidote, albite-chlorite schists, glaucophanites with albite and epidote, 

 sericitic albite gneiss, quartz-sericite schist, and quartzitic schist. Numer- 

 ous rock analyses are given and the amphibolites are said to be derived from 

 diabases. The optical properties of the amphiboles are described with 

 much detail. Ahiphiboles related to glaucophane occur in many of the 

 schistose rocks. 



F. C. Calkins 



FiNLAYSON, A. M. "Petrology and Structure of the Pyritic Field 



of Huelva, Spain," Geol. Mag., 1109, VII, 220-29. Figs. 3, 



pl.L 



The pre-Cambrian rocks which occur in this area consist of gneisses, 



hornblende schists, crystalline and metamorphic limestones, succeeded by 



less altered schists and phyllites. Cambrian schists with quartzites and 



greywackes are conformable with the upper members of the crystalline 



series. Granites of varying composition occur as a series of intrusive 



bosses. Rhyolite, trachyte, syenite, and monzonite porphyries occur 



and are thought to be intrusive in agreement with Vogt and opposed to 



Klockman. Basic intrusions, consisting of diabases, augite porphyrites, 



dolerites, and augite diorites are mentioned. 



Albert D. Brokaw 



GoLFiER, J. "Recherche des parametres qui caracterisent les 

 types classiques de roches eruptives," Bull. Soc. Geol. Fr., 4th 

 ser., 1908, VIII, 55-64. 

 The author attempts to define chemically the divisions of the current 

 classification developed by Rosenbusch and others. 



The "parameters" used for the purpose are certain especially character- 



