Penological Abstracts and Reviews 



ALBERT JOHANNSEN 



Bowen, N. L. "The Crystallization of Haplobasaltic, Haplodi- 

 oritic and Related Magmas," Amer. Jour. Sci., XL (1915), 

 161-85. 

 The terms haplobasaltic, haplodioritic, and so on, are applied by 

 the writer to simple (pure) artificial mixtures of feldspars of various 

 compositions, and diopside. He uses the rock names according to the 

 best and most recent practice. Various mixtures of these substances 

 were studied by the quenching method of thermal analysis, that is, by 

 sudden chilling at known temperatures, and the material was studied 

 microscopically. No attempts were made to study the optical proper- 

 ties of the minerals formed, it being necessary only to distinguish diopside 

 from plagioclase in these experiments, the results of which are plotted 

 in numerous diagrams. From his results the writer concluded that 

 crystallization controls differentiation in the subalkaline igneous rocks. 



Bowen, N. L., and Andersen, Olaf. "The Binary System MgO- 

 Si0 2 ," Amer. Jour. Sci., XXXVII (1914), 487-500. 

 A study of equilibrium in the binary system MgO-Si0 2 by the method 

 of quenching. Forsterite (Mg 2 Si0 4 ) and clinoenstatite (MgSi0 3 ) were 

 found capable of existing in contact with liquid in the binary system. 

 Clinoenstatite was the only stable form of MgSi0 3 found. It has no 

 true melting-point, but at 1,557° breaks up into forsterite and liquid. 

 At 1,577° the forsterite dissolves. There is no eutectic between these 

 two compounds. 



Bowen, N. L. "The Ternary System Diopside-Forsterite-Silica," 

 Amer. Jour. Sci., XXXVIII (1914), 207-64. 

 An investigation of various mixtures of silica, calcium carbonate, 

 and magnesia. It was found that the systems diopside-silica and diop- 

 side-forsterite show the simple eutectic relations; forsterite-silica shows 

 one intermediate compound (clinoenstatite) unstable at its melting- 

 point; and clinoenstatite-diopside forms an unbroken series of solid 



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