42 



DR. J. W. EVAN'S ON A MONCHIQUITE FROM [Feb. I9OI, 



group of Girnar.^ I took specimens, but have only recently had 

 leisure to study them in the laboratory. ^ 



The rock, which is the subject of the present paper, is closely 

 associated with the nepheline-syenite, and is met with on the north- 

 western shoulder of the central ridge of Girnar (which runs east and 

 west). It is easily accessible from the small steps on the compara- 

 tively little-used route up the mountain which, starting like the 

 main ascent, at the end of the carriage-road from the city of 

 Junagarh, turns off at once to the left, and passes round to the 

 north of the rock known as the Ehairava Jap. 



Sketc7i-map of the central ridge of Mount Girnai 



M = Monchiquite. ----- — Footpaths. 



N = Nepheline-syenite, containing isotropic material in the interstices 



of the other minerals. 

 Note. — ' Kbund ' means a spring or pool ; ' nes,' a forest-hamlet. 



The central mountain consists of a mica-auglte-diorite, passing 

 peripherally into an olivine-gabbro which occupies the lower 

 ground. These rocks are at many points penetrated, and some- 

 times broken up, by dj^kes rich in alkalies, apparently of nearly the 



^ This lies immediately east of the city of Junagarh, and must not be 

 confounded with the bills of the Gir Forest, which extend over a wide area in 

 the east of the State. 



'^ 1 have to acknowledge the facilities afforded to me by Prof. Judd at the 

 Eoyal College of Science, and the kindness of Prof. Bonuey in arranging for 

 the chemical analysis of rock-specimens. 



