i64 ALBERT JOHANNSEN 



deep-seated rock consisting of two- thirds melilite and one-third 

 dark constituents (magnetite and pyroxene) with some accessory 

 perofskite and apatite. The extrusive equivalent is melihte- 

 basalt Stelzner^ (Syn. MeHhthit Loewinson-Lessing^) . 



CLASS 2, OEDER 2 



(222) Quartz-granite. Since the term granite in itself carries 

 the idea of a quartz-bearing rock, the term quartz-granite will 

 indicate a granite that is rich in quartz. All other rocks which, 

 by definition, carry quartz may be similarly qualified, namely, 

 adamellite, granodiorite, tonalite, etc. 



(223) Quartz-adamellite. See note under (222). Here 

 belongs, though far from the center point, the Hauksuo, Kisko, 

 apUte, described by Eskola,^ which consists of quartz 48 . 9 per cent, 

 plagioclase (average AbssAuij) 22.9 per cent, microcline 20.4 per 

 cent, biotite 4 . 4 per cent, magnetite i . 9 per cent, and epidote i . 5 

 per cent. 



(224) Quartz-granodiorite. See note under (222). 



(225) Quartz- tonalite. See note under (222). For the use 

 of tonalite for quartz-diorite see (2210). 



(227) Granite. This term is of very old date. It is not found 



in Pliny. Breislak says it was first used by Caesalpinus'* in 1596. 

 The name may be derived from the Italian granito, "grained" 

 (Lat. granum), but its origin is uncertain. The word is similar 

 in sound in many languages, for example, gwenith faen ("wheat 

 stone") in Welsh, and it is possible that the name was brought from 

 Wales by the Romans who built roads and worked the mines there 

 about 78 A.D. 



Family (227) is that of the normal granites. These rocks consist 

 of quartz, orthoclase, less oligoclase or andesine, and a moderate 



'Alfred Stelzner, " Mittheilungen an den Redaction," Neues Jakrb., I (1882), 

 230-31; also "tJber Melilith und Melilithbasalte," Neues Jahrh., B.B., II (1882), 

 364-440. 



^ F. Loewinson-Lessing, "Kritische Beitrage zur Systematik der Eruptivgesteine, 

 IV," T.M.P.M., XX (1901), 114- 



sPentti Eskola, "On the Petrology of the Orijarvi Region in Southwestern 

 Finland," Bull. d. I. com. geol. d. Finlande, No. 40 (1914), P- 83- 



4 Andreas Caesalpinus (Cesalpino), De Metallicis (1596), II, cap. 11. 



