214 ALBERT JOHANNSEN 



by Rose.^ The name was too suggestive of a rock entirely com- 

 posed of h5rpersthene ; therefore Tornebohm^ gave to them the 

 name hyperite, although this term had previously been used 

 by Senft^ for his group composed of eclogites, gabbros, and 

 hj^ersthenites. 



Syn.: Hypersthene-syenit, Hj^ersthenite Rose, 

 Hypersthene-gabbro, Augite-norite, etc. 



Basalt. The derivation of the term is unknown. It 

 may be derived from the Ethiopian bsalt, "cooked," suggesting a 

 baked rock, or from barzalten, barzel, the Hebrew for "iron." 

 Pliny'' speaks of "basalten" found in Ethiopia, a rock which "in 

 color and hardness resembles iron, and is used in making statuary." 

 Agricola^ thought that certain rocks in Saxony were identical with 

 the basalt of the older writers, and applied this term to them, and 

 Werner^ used it for the same rocks, which he considered sedi- 

 mentary. Basalt is the extrusive equivalent of gabbro, and in 

 general the term is applied to rocks with basic plagioclase and 

 augite, with or without oKvine. Some writers apply the term to 

 plagioclase-augite rocks with olivine, irrespective of the kind of 

 plagioclase, though in general, at the present time, this is not the 

 basis of separation from the andesites. On the basis of the feldspar, 

 therefore, there would be 



f Hornblende-andesite 

 With acid plagioclase ^ Augite-andesite 



[ Olivine-augite-andesite, etc. 



' Hornblende-basalt 

 Basalt (with pyroxene) = Auganite 



WiNCHELL 



, Olivine-basalt, etc. 



With basic plagioclase < 



^G. Rose, "tjber Hypersthenit," Fogg. Ann., XXXIV (1835), 10. 



*A. E. Tornebohm, "tJber die wichtigeren Diabas- u. Gabbro-Gesteine 

 Schwedens," Neues Jahrb. (1877), P- 379- 



3 Ferdinand Senft, Classification und Beschreihung der Felsarten (Breslau, 1857), 

 P- 59- 



^ C. Plinii Secundi Naturalis Historiae xxxvi. cap. vii. Ed. Lugd. Batav. Rotero- 

 dami, Ao. 1668, p. 645. 



5 Georg Agricola (Georg Bauer), De re metallica, 1556. 



^ A. G.Werner, "Bekanntmachungeiner .... iiber die Entstehung des Basaltes 

 gemachten Entdeckung ....," Bergmdnn. Journ., Pt. II (1788), p. 845. 



